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S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
Cisco Nexus 7000 Series NX-OS Unicast
Routing Configuration Guide, Release 4.x
April 18, 2011
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Text Part Number: OL-20002-02

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Table of Contents

   Related Manuals for Cisco Nexus 7000 Series

   Summary of Contents for Cisco Nexus 7000 Series

  • Page 1 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 2 OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks.
  • Page 3: Table Of Contents

    Stub Routing Routing Algorithms Static Routes and Dynamic Routing Protocols Interior and Exterior Gateway Protocols Distance Vector Protocols Link-State Protocols Layer 3 Virtualization 1-10 Cisco NX-OS Fowarding Architecture 1-10 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 4 Static and Dynamic Entries in the ARP Cache Devices that do not use ARP Reverse ARP Proxy ARP Local Proxy ARP Gratuitous ARP ICMP Virtualization Support Licensing Requirements for IPv4 Prerequisites for IPv4 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 5 CDP IPv6 Address Support 3-12 ICMP for IPv6 3-12 IPv6 Neighbor Discovery 3-13 IPv6 Neighbor Solicitation Message 3-13 IPv6 Router Advertisement Message 3-15 IPv6 Neighbor Redirect Message 3-16 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 6 Configuring DNS Clients Configuring the DNS Client Configuring Virtualization Verifying the DNS Client Configuration DNS Client Example Configuration Default Settings Additional References Related Documents Standards Feature History for DNS Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 7 5-13 Standards 5-13 Feature History for WCCPv2 5-13 Routing Configuring OSPFv2 C H A P T E R Information About OSPFv2 Hello Packet Neighbors Adjacency Designated Routers Areas Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 8 Configuring Stub Areas 6-25 Configuring a Totally Stubby Area 6-26 Configuring NSSA 6-27 Configuring Virtual Links 6-29 Configuring Redistribution 6-31 Limiting the Number of Redistributed Routes 6-33 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x viii OL-20002-02...
  • Page 9 Address Family Support Advanced Features Stub Area Not-So-Stubby Area Virtual Links 7-10 Route Redistribution 7-10 Route Summarization 7-10 High Availability and Graceful Restart 7-11 Multiple OSPFv3 Instances 7-12 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 10 MIBs 7-43 Feature History for OSPFv3 7-43 Configuring EIGRP C H A P T E R Information About EIGRP EIGRP Components Reliable Transport Protocol Neighbor Discovery and Recovery Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 11 Adjusting the Interval Between Hello Packets and the Hold Time 8-25 Disabling Split Horizon 8-25 Tuning EIGRP 8-26 Configuring Virtualization for EIGRP 8-28 Verifying EIGRP Configuration 8-30 Displaying EIGRP Statistics 8-30 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 12 Configuring IS-IS Authentication in an Area 9-13 Configuring IS-IS Authentication on an Interface 9-14 Configuring a Mesh Group 9-16 Configuring a Designated Intermediate System 9-16 Configuring Dynamic Host Exchange 9-16 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 13 BGP and the Unicast RIB 10-7 BGP Virtualization 10-7 Licensing Requirements for Basic BGP 10-7 Prerequisites for BGP 10-7 Guidelines and Limitations for BGP 10-8 CLI Configuration Modes 10-8 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x xiii OL-20002-02...
  • Page 14 AS Confederations 11-4 Route Reflector 11-5 Capabilities Negotiation 11-6 Route Dampening 11-6 Load Sharing and Multipath 11-7 Route Aggregation 11-7 BGP Conditional Advertisement 11-8 BGP Next-Hop Address Tracking 11-8 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 15 Configuring Maximum Prefixes 11-29 Configuring Dynamic Capability 11-29 Configuring Aggregate Addresses 11-30 Configuring BGP Conditional Advertisement 11-30 Configuring Route Redistribution 11-32 Configuring Multiprotocol BGP 11-35 Tuning BGP 11-36 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 16 Configuring a Passive Interface 12-10 Configuring Split Horizon with Poison Reverse 12-11 Configuring Route Summarization 12-11 Configuring Route Redistribution 12-11 Configuring Virtualization 12-13 Tuning RIP 12-15 Verifying RIP Configuration 12-17 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 17 C H A P T E R Layer 3 Virtualization 14-1 Overview of Layer 3 Virtualization 14-1 VRF and Routing 14-2 VRF-Aware Services 14-3 Reachability 14-4 Filtering 14-4 Combining Reachability and Filtering 14-5 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x xvii OL-20002-02...
  • Page 18 Returning the TCAM to Default Settings 15-11 Estimating Memory Requirements for Routes 15-12 Clearing Routes in the Unicast RIB 15-13 Verifying the Unicast RIB and FIB 15-13 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x xviii OL-20002-02...
  • Page 19 Related Documents 16-19 Standards 16-19 Feature History for Route Policy Manager 16-19 Configuring Policy-Based Routing 17-1 C H A P T E R Information About Policy Based Routing 17-1 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 20 18-6 Guidelines and Limitations 18-7 Configuring GLBP 18-7 Enabling the GLBP Feature 18-7 Configuring GLBP Authentication 18-8 Configuring GLBP Load Balancing 18-10 Configuring GLBP Weighting and Tracking 18-10 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 21 Configuring HSRP Object Tracking 19-12 Configuring the HSRP Priority 19-14 Customizing HSRP 19-15 Configuring Extended Hold Timers for HSRP 19-16 Verifying HSRP Configuration 19-17 HSRP Example Configuration 19-17 Default Settings 19-18 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 22 Related Documents 20-22 Feature History for VRRP 20-22 Configuring Object Tracking 21-1 C H A P T E R Information About Object Tracking 21-1 Object Tracking Overview 21-2 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x xxii OL-20002-02...
  • Page 23 L O S S A R Y Configuration Limits for Cisco NX-OS Layer 3 Unicast Features, Release 4.x A P P E N D I X N D E X Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x xxiii OL-20002-02...
  • Page 24 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 25: New And Changed Information

    7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x. The latest version of this document is available at the following Cisco website: http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_2/nx-os/unicast/configuration/guide/l3_nx os-book.html To check for additional information about Cisco NX-OS Release 4.2 , see the Cisco NX-OS Release Notes available at the following Cisco website: http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_2/nx-os/release/notes/42_nx-os_release_n ote.html...
  • Page 26 Chapter 8, “Configuring EIGRP” VRF. EIGRP Added support for EIGRP4-MIB 4.0(3) Chapter 8, “Configuring EIGRP” EIGRP Modified the default EIGRP maximum paths to 8. 4.0(2) Chapter 8, “Configuring EIGRP” Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 27 IPv4 and IPv6 networks. Chapter 11, “Configuring Advanced BGP” Describes how to configure advanced features for the BGP routing protocol for IPv4 and IPv6 networks, including route redistribution and route aggregation. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 28: Document Conventions

    Optional alternative keywords are grouped in brackets and separated by vertical bars. string A nonquoted set of characters. Do not use quotation marks around the string or the string will include the quotation marks. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 29: Related Documentation

    Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide, Release 4.x Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 4.x Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 4.x Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide, Release 4.x Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 30: Obtaining Documentation And Submitting A Service Request

    Obtaining Documentation and Submitting a Service Request For information on obtaining documentation, submitting a service request, and gathering additional information, see the monthly What’s New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at: http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html...
  • Page 31: Overview

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . C H A P T E R Overview This chapter introduces the underlying concepts for Layer 3 unicast routing protocols in Cisco NX-OS. This chapter includes the following sections: Information About Layer 3 Unicast Routing, page 1-1 •...
  • Page 32: Routing Fundamentals

    The next hop might be the ultimate destination host or another router that executes the same switching decision process. As the packet moves through the internetwork, its physical address changes, but its protocol address remains constant (see Figure 1-1). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 33: Routing Metrics

    This section includes the following metrics: Path Length, page 1-4 • • Reliability, page 1-4 • Routing Delay, page 1-4 • Bandwidth, page 1-4 Load, page 1-4 • Communication Cost, page 1-4 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 34: Path Length

    For example, the line delay for a private line might be longer than a public line, but you can send packets over your private line rather than through the public lines that cost money for usage time. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 35: Router Ids

    ID. You can configure the router ID to any interface in the system. If you do not configure the router ID, Cisco NX-OS selects the router ID based on the following criteria: Cisco NX-OS prefers loopback0 over any other interface. If loopback0 does not exist, then Cisco •...
  • Page 36: Convergence

    The number of paths used is limited by the number of entries that the routing protocol puts in the routing table. Cisco NX-OS supports up to 16 paths to a destination.
  • Page 37: Administrative Distance

    In this network topology, the remote router does not need to receive routes that have been learned from other Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 38: Routing Algorithms

    BGP is an example of an exterior gateway protocol. Routing protocols used within an autonomous system are called interior gateway protocols or intradomain protocols. EIGRP and OSPF are examples of interior gateway protocols. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 39: Distance Vector Protocols

    However, link-state algorithms require more CPU power and memory than distance vector algorithms. Link-state algorithms can be more expensive to implement and support. Link-state protocols are generally more scalable than distance vector protocols. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 40: Layer 3 Virtualization

    VRF. A VRF belongs to one VDC. Each VDC can support multiple VRFs. For more information, Chapter 14, “Configuring Layer 3 Virtualization.” See to the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 4.x for details on VDCs.
  • Page 41: Unicast Rib

    • Hardware Forwarding, page 1-12 Software Forwarding, page 1-12 • Unicast RIB The Cisco NX-OS forwarding architecture consists of multiple components, as shown in Figure 1-4. Figure 1-4 Cisco NX-OS Forwarding Architecture The unicast RIB exists on the active supervisor. It maintains the routing table with directly connected routes, static routes, and routes learned from dynamic unicast routing protocols.
  • Page 42: Unicast Forwarding Distribution Module

    Software Forwarding The software forwarding path in Cisco NX-OS is used mainly to handle features that are not supported in hardware or to handle errors encountered during hardware processing. Typically, packets with IP options or packets that need fragmentation are passed to the CPU on the active supervisor. All packets that should be switched in software or terminated go to the supervisor.
  • Page 43: Summary Of Layer 3 Unicast Routing Features

    Link information consists of the link type, the link metric, and the neighbor router connected to the link. The advertisements that contain this link information are called link-state advertisements. For more information, see Chapter 6, “Configuring OSPFv2.” Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 1-13 OL-20002-02...
  • Page 44: Eigrp

    The EIGRP protocol is a unicast routing protocol that has the characteristics of both distance vector and link-state routing protocols. It is an improved version of IGRP, which is a Cisco proprietary routing protocol. EIGRP relies on its neighbors to provide the routes, typical to a distance vector routing protocol.
  • Page 45: Layer 3 Virtualization

    NX-OS supports Virtual Device Contexts (VDCs) which allow you to create separate virtual systems within a Cisco NX-OS system. Each VDC is isolated from the others, which means that a problem in one VDC does not affect any other VDCs. VDCs are also secure from the other. You can assign separate network operators to each VDC and these network operators cannot control or view the configuration of a different VDC.
  • Page 46 Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide, Release 4.x Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide • Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 4.x • Exploring Autonomous System Numbers: •...
  • Page 47 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . A R T...
  • Page 48 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
  • Page 49: Chapter 2 Configuring Ipv4

    Subnet masks are 32-bit values that allow the recipient of IP packets to distinguish the network ID portion of the IP address from the host ID portion of the IP address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 50: Multiple Ipv4 Addresses

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . The IP feature in the Cisco NX-OS system is responsible for handling IPv4 packets that terminate in the...
  • Page 51: Arp Caching

    ARP to obtain the MAC address of the destination device and delivers the packet. ARP is enabled by default. In Cisco NX-OS Release 4.1(4) and later, the default system-defined CoPP policy rate-limits ARP broadcast packets bound for the supervisor module. The default system-defined CoPP policy prevents an ARP broadcast storm from affecting the control plane traffic, but does not affect bridged packets.
  • Page 52: Devices That Do Not Use Arp

    Each server must be configured with a table of static mappings between the hardware addresses and • IP addresses. Maintenance of the IP addresses is difficult. RARP only provides IP addresses of the hosts and not subnet masks or default gateways. • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 53: Proxy Arp

    Gratuitous ARP Gratuitous ARP sends a request with identical source IP address and destination IP address to detect duplicate IP addresses. Cisco NX-OS Release 4.0(3) and later releases support enabling or disabling gratuitous ARP requests or ARP cache updates. ICMP You can use ICMP to provide message packets that report errors and other information that is relevant to IP processing.
  • Page 54: Virtualization Support

    License Requirement NX-OS IP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 55: Configuring Ipv4 Addressing

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 56: Configuring Multiple Ip Addresses

    Purpose Step 1 Enters configuration mode. config t Example: switch# config t switch(config)# Step 2 Enters interface configuration mode. interface ethernet number Example: switch(config)# interface ethernet 2/3 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 57: Configuring A Static Arp Entry

    DETAILED STEPS Command Purpose Step 1 Enters configuration mode. config t Step 2 Enters interface configuration mode. interface ethernet number Example: switch(config)# interface ethernet 2/3 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 58: Configuring Proxy Arp

    DETAILED STEPS Command Purpose Step 1 Enters configuration mode. config t Step 2 Enters interface configuration mode. interface ethernet number Example: switch(config)# interface ethernet 2/3 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-10 OL-20002-02...
  • Page 59: Configuring Local Proxy Arp

    DETAILED STEPS Command Purpose Step 1 Enters configuration mode. config t Step 2 Enters interface configuration mode. interface ethernet number Example: switch(config)# interface ethernet 2/3 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-11 OL-20002-02...
  • Page 60: Configuring Gratuitous Arp

    DETAILED STEPS Command Purpose Step 1 Enters configuration mode. config t Step 2 Enters interface configuration mode. interface ethernet number Example: switch(config)# interface ethernet 2/3 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-12 OL-20002-02...
  • Page 61: Configuring Ip Packet Verification

    Configuring IP Packet Verification Cisco NX-OS supports an Intrusion Detection System (IDS) that checks for IP packet verification. You can enable or disable these IDS checks. To enable IDS checks, use the following commands in global configuration mode:...
  • Page 62: Configuring Ip Directed Broadcasts

    To enable IP directed broadcasts, use the following command in interface configuration mode: Command Purpose ip directed-broadcast Enables the translation of a directed broadcast to physical broadcasts Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-14 OL-20002-02...
  • Page 63: Verifying The Ipv4 Configuration

    Parameters Default proxy ARP disabled Additional References For additional information related to implementing IP, see the following sections: • Related Documents, page 2-16 Standards, page 2-16 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-15 OL-20002-02...
  • Page 64: Related Documents

    Changed plaform ip verify command to hardware ip verify command. 4.0(3) Added support for gratuitous ARP. The following command was added: ip arp gratuitous {request | update} • 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 2-16 OL-20002-02...
  • Page 65: Chapter 3 Configuring Ipv6

    (RIP), Integrated Intermediate System-to-Intermediate System (IS-IS), Open Shortest Path First (OSPF) for IPv6, and multiprotocol Border Gateway Protocol (BGP). This section includes the following topics: IPv6 Address Formats, page 3-2 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 66: Ipv6 Address Formats

    The hexadecimal letters in IPv6 addresses are not case sensitive. Table 3-1 Compressed IPv6 Address Formats IPv6 Address Type Preferred Format Compressed Format Unicast 2001:0:0:0:0DB8:800:200C:417A 2001::0DB8:800:200C:417A Multicast FF01:0:0:0:0:0:0:101 FF01::101 Loopback 0:0:0:0:0:0:0:0:1 Unspecified 0:0:0:0:0:0:0:0:0 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 67: Ipv6 Unicast Addresses

    ID. The IPv6 global unicast address allocation uses the range of addresses that start with binary value 001 (2000::/3). Figure 3-1 shows the structure of an aggregatable global address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 68 (picked randomly and, if necessary, reconstructed) until both identifiers are unique. The first MAC address in the router is used as the identifier for interfaces using PPP. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 69: Link-local Addresses

    IPv4 and IPv6 protocol stacks and are used in automatic tunnels. Figure 3-3 shows the structure of an IPv4-compatible IPv6 address and a few acceptable formats for the address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 70: Unique Local Addresses

    Global ID — 41-bit global identifier used to create a globally unique prefix. • Subnet ID — 16-bit subnet ID is an identifier of a subnet within the site. • • Interface ID — 64-bit IID Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 71: Site-local Address

    1, 2, 5, 8, or E, respectively. For example, a multicast address with the prefix FF02::/16 is a permanent multicast address with a link scope. Figure 3-6 shows the format of the IPv6 multicast address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 72 Prefix Interface ID 24 bits Solicited-node multicast address FF02 Lower 24 128 bits Note IPv6 has no broadcast addresses. IPv6 multicast addresses are used instead of broadcast addresses. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 73: Ipv4 Packet Header

    Payload Length Similar to the Total Length field in the IPv4 packet header. The Payload Length field indicates the total length of the data portion of the packet. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 74 Typically, the final extension header has a Next Header field of a transport-layer protocol, such as TCP or UDP. Figure 3-10 shows the IPv6 extension header format. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-10 OL-20002-02...
  • Page 75 Upper-layer headers 6 (TCP) Headers that are used inside a packet to transport the data. The two main transport protocols are TCP and 17 (UDP) UDP. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-11 OL-20002-02...
  • Page 76: Dns For Ipv6

    IPv6 links. CDP IPv6 Address Support You can use the Cisco Discovery Protocol (CDP) IPv6 address support for neighbor information feature to transfer IPv6 addressing information between two Cisco devices. Cisco Discovery Protocol support for IPv6 addresses provides IPv6 information to network management products and troubleshooting tools.
  • Page 77: Ipv6 Neighbor Discovery

    The destination address is the solicited-node multicast address that corresponds to the IPv6 address of the destination node. The neighbor solicitation message also includes the link-layer address of the source node. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-13 OL-20002-02...
  • Page 78 1 are sent only in response to a neighbor solicitation message). Unsolicited messages confirm only the one-way path from the source to the destination node; solicited neighbor advertisement messages indicate that a path is working in both directions. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-14 OL-20002-02...
  • Page 79: Ipv6 Router Advertisement Message

    Additional information for hosts, such as the hop limit and MTU that a host should use in packets • that it originates Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-15 OL-20002-02...
  • Page 80: Ipv6 Neighbor Redirect Message

    Routers send neighbor redirect messages to inform hosts of better first-hop nodes on the path to a destination (see Figure 3-14). A value of 137 in the Type field of the ICMP packet header identifies an IPv6 neighbor redirect message. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-16 OL-20002-02...
  • Page 81: Configuring Ipv6

    IPv6 supports Virtual Routing and Forwarding instances (VRFs). VRFs exist within virtual device contexts (VDCs). By default, Cisco NX-OS places you in the default VDC and default VRF unless you specifically configure another VDC and VRF. For more information, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 4.x and see...
  • Page 82 • Configuring IPv6 Packet Verification, page 3-23 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 83: Configuring Ipv6 Addressing

    IPv6 is enabled on the interface. Enables IPv6 processing on an interface without configuring an IPv6 address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-19 OL-20002-02...
  • Page 84: Configuring Ipv6 Neighbor Discovery

    BEFORE YOU BEGIN Ensure that you are in the correct VDC (or use the switchto vdc command). You must first enable IPv6 on the interface. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-20 OL-20002-02...
  • Page 85 Last Neighbor-Solicitation sent: never Last Neighbor-Advertisement sent: never Last Router-Advertisement sent:never Next Router-Advertisement sent in: 0.000000 Router-Advertisement parameters: Periodic interval: 200 to 600 seconds Send "Managed Address Configuration" flag: false Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-21 OL-20002-02...
  • Page 86: Optional Ipv6 Neighbor Discovery

    Enables ICMPv6 redirect messages to be sent. ipv6 nd retrans-timer Configures the advertised time between neighbor solicitation messages in router advertisements. ipv6 nd suppress-ra Suppresses IPv6 router advertisement transmissions on a LAN interface. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-22 OL-20002-02...
  • Page 87: Configuring Ipv6 Packet Verification

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Configuring IPv6 Packet Verification Cisco NX-OS supports an Intrusion Detection System (IDS) that checks for IPv6 packet verification. You can enable or disable these IDS checks.
  • Page 88: Verifying The Ipv6 Configuration

    1000 milliseconds Additional References For additional information related to implementing IPv6, see the following sections: Related Documents, page 3-25 • Standards, page 3-25 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-24 OL-20002-02...
  • Page 89: Related Documents

    Changed plaform {ip | ipv6} verify command to hardware {ip | ipv6} verify command. IPv6 address 4.0(3) Added tag keyword to ipv6 address command. IPv6 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 3-25 OL-20002-02...
  • Page 90 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 91: Chapter 4 Configuring Dns

    This allows local control of the segments of the network through a client-server scheme. The DNS system can locate a network device by translating the host name of the device into its associated IP address. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 92: Name Servers

    For example, Cisco is a commercial organization that the Internet identifies by a com domain, so its domain name is cisco.com. A specific host name in this domain, the File Transfer Protocol (FTP) system, for example, is identified as ftp.cisco.com.
  • Page 93: Prerequisites For Dns Clients

    • Cisco NX-OS Virtual Device Context Configuration Guide). Configuration Guidelines and Limitations You configure the DNS client in a specific VRF. If you do not specify a VRF, Cisco NX-OS uses the default VRF. Configuring DNS Clients This section describes how to configure DNS clients and includes the following topics: Configuring the DNS Client, page 4-3 •...
  • Page 94 You can optionally define a VRF that Cisco NX-OS Example: uses to reach this name server if it cannot be reached switch(config)# ip name-server in the VRF that you configured this name server under. 192.0.2.22 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 95: Configuring Virtualization

    [ se-vrf vrf-name] ip domain-list name [use-vrf vrf-name] ip name-server server-address1 [server-address2... server-address6] [use-vrf vrf-name] ip domain lookup show hosts copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 96 VRF that you configured this name server under. 192.0.2.22 Step 5 (Optional) Enables DNS-based address translation for ip domain-lookup this VRF. Enabled by default. Example: switch(config-vrf)# ip domain-lookup Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 97: Verifying The Dns Client Configuration

    The example also configures the addresses of the name servers and the default domain name. ip domain lookup ip name-server 192.168.1.111 192.168.1.2 ip domain name cisco.com Default Settings Table 4-1 lists the default settings for DNS Client parameters. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 98: Additional References

    Feature History for DNS Table 4-2 lists the release history for this feature. Table 4-2 Feature History for DNS Feature Name Releases Feature Information 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 99: Information About Wccpv2

    • Information About WCCPv2 WCCPv2 specifies interactions between one or more Cisco NX-OS routers and one or more cache engines. WCCPv2 transparently redirects selected types of traffic through a group of routers. The selected traffic is redirected to a group of cache engines to optimize resource usage and lower response times.
  • Page 100: Wccpv2 Overview

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . WCCPv2 Overview WCCPv2 enables the Cisco NX-OS router to transparently redirect packets to cache engines. WCCPv2 does not interfere with normal router operations. Using WCCPv2, the router can redirect requests on configured interfaces to cache engines rather than to intended host sites.
  • Page 101 You configure each cache engine with a list of routers. Step 1 Each cache engine announces its presence and a list of all routers with which it has established Step 2 communications. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 102: Wccpv2 Designated Cache Engine

    Cisco NX-OS uses the mask method to assign traffic. The designated cache engine assigns the mask and value sets to the router in the WCCP Redirect Assignment message. The router matches these mask and value sets to the source IP address, destination IP address, source port, and destination port of each packet.
  • Page 103: Wccpv2 Authentication

    • example, when IP authentication has been turned on. WCCPv2 negotiates the packet return method between the router and the cache engine. Cisco NX-OS uses this traffic return method for all cache engines in a service group. WCCPv2 returns packets using the following forwarding method: Destination MAC rewrite—WCCPv2 replaces the destination MAC address of the packet with the...
  • Page 104: High Availability For Wccpv2

    • page 5-7). You can only configure WCCPv2 on Layer 3 or VLAN interfaces (see the Cisco Nexus 7000 Series • NX-OS Interfaces Configuration Guide, Release 4.x). If you configure VDCs, install the Advanced Services license and enter the desired VDC (see the •...
  • Page 105: Enabling The Wccpv2 Feature

    • Configuring WCCPv2 in a VRF, page 5-10 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 106: Configuring A Wccpv2 Service Group

    Ensure that you are in the correct VDC (or use the switchto vdc command). Enable the WCCPv2 feature (see the “Enabling the WCCPv2 Feature” section on page 5-7). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 107: Applying Wccpv2 Redirection To An Interface

    Applying WCCPv2 Redirection to an Interface To apply WCCPv2 redirection on an interface, use the following commands in interface configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 108: Configuring Wccpv2 In A Vrf

    {service-number | web-cache} [mode {open [redirect-list acl-name] | closed service-list acl-name}]] [password [0-7] pwstring] show ip wccp [vrf vrf-name] copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 5-10 OL-20002-02...
  • Page 109 Example: string up to 64 characters. switch(config-vrf)# show ip wccp vrf Red Step 5 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-vrf)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 5-11 OL-20002-02...
  • Page 110: Verifying Wccpv2 Configuration

    1/2 ip wccp web-cache redirect out no shutdown Note See the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x for information about IP access lists. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 5-12...
  • Page 111: Default Settings

    Feature History for WCCPv2 Table 5-2 lists the release history for this feature. Table 5-2 Feature History for WCCPv2 Feature Name Releases Feature Information WCCPv2 4.2(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 5-13 OL-20002-02...
  • Page 112: Feature History For Wccpv2

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 113: Routing

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . A R T Routing...
  • Page 114 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
  • Page 115: Configuring Ospfv2

    You can divide OSPFv2 networks into areas. Routers send most LSAs only within one area, which reduces the CPU and memory requirements for an OSPF-enabled router. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 116: Hello Packet

    The two OSPFv2 interfaces must match the following criteria: Hello interval • Dead interval • Area ID (see the “Areas” section on page 6-4) • Authentication • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 117: Adjacency

    The routers follow an election procedure based on which routers declare themselves in the DR and BDR fields and the priority field in the Hello packet. As a final tie breaker, OSPFv2 chooses the highest router IDs as the DR and BDR. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 118: Areas

    ID of 0. If you have more than one area, then one or more routers become area border routers (ABRs). An ABR connects to both the backbone area and at least one other defined area (see Figure 6-2). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 119: Link-state Advertisements

    Flooding and LSA Group Pacing, page 6-6 • Link-State Database, page 6-7 • Opaque LSAs, page 6-7 • LSA Types Table 6-1 shows the LSA types supported by Cisco NX-OS. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 120: Lsa Types

    By default, LSAs with link-state refresh times within four minutes of each other are grouped together. You should lower this value for large link-state databases or raise it for smaller databases to optimize the OSPFv2 load on your network. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 121: Link-state Database

    MaxAge. Routers flood a repeat of the LSA every 30 minutes to prevent accurate link-state information from being aged out. Cisco NX-OS supports the LSA grouping feature to prevent all LSAs from refreshing at the same time. For more information, see the “Flooding and LSA Group Pacing”...
  • Page 122: Simple Password Authentication

    You should use MD5 authentication to authenticate OSPFv2 messages. You configure a password that is shared at the local router and all remote OSPFv2 neighbors. For each OSPFv2 message, Cisco NX-OS creates an MD5 one-way message digest based on the message itself and the encrypted password. The interface sends this digest with the OSPFv2 message.
  • Page 123: Stub Area

    Virtual links allow you to connect an OSPFv2 area ABR to a backbone area ABR when a direct physical connection is not available. Figure 6-4 shows a virtual link that connects Area 3 to the backbone area through Area 5. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 124: Route Redistribution

    The two types of summarization are as follows: Inter-area route summarization • External route summarization • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-10 OL-20002-02...
  • Page 125: High Availability And Graceful Restart

    Summarizing overlapping ranges from two different routers could cause packets to be sent to the wrong destination. Configure external route summarization on ASBRs that are redistributing routes into OSPF. When you configure a summary address, Cisco NX-OS automatically configures a discard route for the summary address to prevent routing black holes and route loops.
  • Page 126: Ospfv2 Stub Router Advertisements

    OSPFv2 interface. All remote links are marked with the maximum cost (0xFFFF). Multiple OSPFv2 Instances Cisco NX-OS supports multiple instances of the OSPFv2 protocol that run on the same node. You cannot configure multiple instances over the same interface. By default, every instance uses the same system router ID.
  • Page 127: Prerequisites For Ospfv2

    Cisco NX-OS displays areas in dotted decimal notation regardless of whether you enter the area in • decimal or dotted decimal notation. If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 128: Configuring Basic Ospfv2

    (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Use the no feature ospf command to disable the OSPFv2 feature and remove all associated configuration. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-14 OL-20002-02...
  • Page 129: Creating An Ospfv2 Instance

    Example: switch# config t switch(config)# Step 2 Creates a new OSPFv2 instance with the configured router ospf instance-tag instance tag. Example: switch(config)# router ospf 201 switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-15 OL-20002-02...
  • Page 130: Configuring Optional Parameters On An Ospfv2 Instance

    OSPFv2 must be able to obtain a router identifier (for example, a configured loopback address) or you must configure the router ID option. Ensure that you are in the correct VDC (or use the switchto vdc command). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-16 OL-20002-02...
  • Page 131: Configuring Networks In Ospfv2

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port ip address ip-prefix/length ip router ospf instance-tag area area-id [secondaries none] Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-17 OL-20002-02...
  • Page 132 Configures the OSPFv2 dead interval, in seconds. ip ospf dead-interval seconds The range is from 1 to 65535. The default is four Example: times the hello interval, in seconds. switch(config-if)# ip ospf dead-interval Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-18 OL-20002-02...
  • Page 133: Configuring Authentication For An Area

    Ensure that all neighbors on an interface share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco NX-OS Security Configuration Guide. For OSPFv2, the key identifier in the key key-id command supports values from 0 to 255 only.
  • Page 134 1 to 255. The MD5 option 0 configures switch(config-if)# ip ospf the password in clear text and 3 configures the pass key message-digest-key 21 md5 0 mypass as 3DES encrypted. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-20 OL-20002-02...
  • Page 135: Configuring Authentication For An Interface

    Ensure that all neighbors on an interface share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco NX-OS Security Configuration Guide. For OSPFv2, the key identifier in the key key-id command supports values from 0 to 255 only.
  • Page 136 Example: switch(config-if)# show router ospf 201 interface ethernet 1/2 Step 8 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-22 OL-20002-02...
  • Page 137: Configuring Advanced Ospfv2

    Summarization” section on page 6-35. Filter list—Filters the Network Summary (type 3) LSAs on an ABR that are allowed in from an • external area. ASBRs also support filter lists. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-23 OL-20002-02...
  • Page 138 The following example shows how to configure a filter list in area 0.0.0.10: switch# config t switch(config)# router ospf 201 switch(config-router)# area 0.0.0.10 filter-list route-map FilterLSAs in switch(config-router)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-24 OL-20002-02...
  • Page 139: Configuring Stub Areas

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router ospf instance-tag area area-id stub area area-id default-cost cost show ip ospf instance-tag copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-25 OL-20002-02...
  • Page 140: Configuring A Totally Stubby Area

    You can create a totally stubby area and prevent all summary route updates from going into the stub area. To create a totally stubby area, use the following command in router configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-26...
  • Page 141: Configuring Nssa

    [no-redistribution] [default-information-originate [route-map map-name]] [no-summary] [translate type7 {always | never} [suppress-fa]] area area-id default-cost cost show ip ospf instance-tag copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-27 OL-20002-02...
  • Page 142 The following example shows how to create an NSSA that filters external routes and blocks all summary route updates: switch# config t switch(config)# router ospf 201 switch(config-router)# area 0.0.0.10 nssa route-map ExternalFilter no-summary switch(config-router)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-28 OL-20002-02...
  • Page 143: Configuring Virtual Links

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router ospf instance-tag area area-id virtual-link router-id show ip ospf virtual-link [brief] copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-29 OL-20002-02...
  • Page 144 50 (Optional) Configures the OSPFv2 hello interval, in hello-interval seconds seconds. The range is from 1 to 65535. The default is 10 Example: seconds. switch(config-router-vlink)# hello-interval 25 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-30 OL-20002-02...
  • Page 145: Configuring Redistribution

    Default information originate ignores match statements in the optional route map. Note Default metric—Sets all redistributed routes to the same cost metric. • If you redistribute static routes, Cisco NX-OS also redistributes the default static route. Note BEFORE YOU BEGIN Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv2 Feature”...
  • Page 146 0.0.0. even if the route does not exist in the RIB. DefaultRouteFilter route-map—Generate the default route if the • route map returns true. This command ignores match statements in Note the route map. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-32 OL-20002-02...
  • Page 147: Limiting The Number Of Redistributed Routes

    {bgp id | direct| eigrp id | isis id | ospf id | rip id | static} route-map map-name redistribute maximum-prefix max [threshold] [warning-only | withdraw [num-retries timeout]] show running-config ospf Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-33 OL-20002-02...
  • Page 148 The following example shows how to limit the number of redistributed routes into OSPF: switch# config t switch(config)# router ospf 201 switch(config-router)# redistribute bgp route-map FilterExternalBGP switch(config-router)# redistribute maximum-prefix 1000 75 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-34 OL-20002-02...
  • Page 149: Configuring Route Summarization

    [no-advertise | tag tag] addresses and optionally assigns a tag for this summary address that can be used for redistribution Example: with route maps. switch(config-router)# summary-address 10.5.0.0/16 tag 2 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-35 OL-20002-02...
  • Page 150: Configuring Stub Route Advertisements

    You should not save the running configuration of a router when it is configured for a graceful shutdown Note because the router will continue to advertise a maximum metric after it is reloaded. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-36 OL-20002-02...
  • Page 151: Modifying The Default Timers

    At the interface level, you can also control the following timers: Retransmit interval—Sets the estimated time between successive LSAs. • Transmit delay—Sets the estimated time to transmit an LSA to a neighbor. • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-37 OL-20002-02...
  • Page 152 Sets the LSA arrival time in milliseconds. The range is timers lsa-arrival msec from 10 to 600000. The default is 1000 milliseconds. Example: switch(config-router)# timers lsa-arrival 2000 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-38 OL-20002-02...
  • Page 153 (Optional) Displays information about OSPF. show ip ospf Example: switch(config-if)# show ip ospf Step 13 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-39 OL-20002-02...
  • Page 154: Configuring Graceful Restart

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router ospf instance-tag graceful-restart graceful-restart grace-period seconds graceful-restart helper-disable graceful-restart planned-only show ip ospf instance-tag copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-40 OL-20002-02...
  • Page 155: Restarting An Ospfv2 Instance

    120 switch(config-router)# copy running-config startup-config Restarting an OSPFv2 Instance You can restart an OSPv2 instance. This clears all neighbors for the instance. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-41 OL-20002-02...
  • Page 156: Configuring Ospfv2 With Virtualization

    <optional parameters configured> interface interface-type slot/port vrf member vrf-name ip-address ip-prefix/length router ospf instance-tag area area-id copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-42 OL-20002-02...
  • Page 157 Assigns this interface to the OSPFv2 instance and area configured. Example: switch(config-if)# ip router ospf 201 area 0 Step 10 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-43 OL-20002-02...
  • Page 158: Verifying The Ospfv2 Configuration

    {vrf-name | all | default | management}] addresses. show ip ospf virtual-links [brief] [vrf Displays information about OSPFv2 virtual links. {vrf-name | all | default | management}] Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-44 OL-20002-02...
  • Page 159: Displaying Ospfv2 Statistics

    0 mypass Default Settings Table 6-2 lists the default settings for OSPFv2 parameters. Table 6-2 Default OSPFv2 Parameters Parameters Default Hello interval 10 seconds Dead interval 40 seconds Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-45 OL-20002-02...
  • Page 160: Additional References

    SPF minimum hold time 1000 milliseconds Additional References For additional information related to implementing OSPF, see the following sections: Related Documents, page 6-47 • MIBs, page 6-47 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-46 OL-20002-02...
  • Page 161: Related Documents

    Feature History for OSPFv2 Table 6-3 lists the release history for this feature. Table 6-3 Feature History for IOSPFv2 Feature Name Releases Feature Information OSPFv2 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 6-47 OL-20002-02...
  • Page 162 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 163: Configuring Ospfv3

    Dijkstra’s Shortest Path First (SPF) algorithm to build its route table. You can divide OSPFv3 networks into areas. Routers send most LSAs only within one area, which reduces the CPU and memory requirements for an OSPF-enabled router. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 164: Comparison Of Ospfv3 And Ospfv2

    An OSPFv3 interface that receives these Hello packets determines if the settings are compatible with the receiving interface settings.Compatible interfaces are considered neighbors and are added to the neighbor table (see the “Neighbors” section on page 7-3). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 165: Neighbors

    (see the “Link-State Database” section on page 7-7). The local router compares these headers with its own link-state database and determines which LSAs are new or Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 166: Designated Routers

    Figure 7-1 DR in Multi-Access Network Router A Router B Router C Router D Router E or DR = Multi-access network = Logical connectivity to Designated Router for OSPF Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 167: Areas

    For more information, see “Advanced Features” section on page 7-8. Link-State Advertisement OSPFv3 uses link-state advertisements (LSAs) to build its routing table. This section includes the following topics: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 168: Lsa Types

    By default, the reference bandwidth is 40 Gb/s. The link cost is carried in the LSA updates for each link. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 169: Flooding And Lsa Group Pacing

    MaxAge. Routers flood a repeat of the LSA every 30 minutes to prevent accurate link-state information from being aged out. Cisco NX-OS supports the LSA grouping feature to prevent all LSAs from refreshing at the same time. For more information, see the “Flooding and LSA Group Pacing”...
  • Page 170: Ospfv3 And The Ipv6 Unicast Rib

    Use the address-family ipv6 unicast command to enter the IPv6 unicast address family configuration mode when configuring these features. Advanced Features Cisco NX-OS supports a number of advanced OSPFv3 features that enhance the usability and scalability of OSPFv3 in the network. This section includes the following topics: Stub Area, page 7-9 •...
  • Page 171: Stub Area

    With NSSA, you can extend OSPFv3 to cover the remote connection by defining the area between the corporate router and remote router as an NSSA (see the “Configuring NSSA” section on page 7-23). The backbone Area 0 cannot be an NSSA. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 172: Virtual Links

    Route summarization simplifies route tables by replacing more-specific addresses with an address that represents all the specific addresses. For example, you can replace 2010:11:22:0:1000::1 and 2010:11:22:0:2000:679:1 with one summary address, 2010:11:22::/32. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-10 OL-20002-02...
  • Page 173: High Availability And Graceful Restart

    Summarizing overlapping ranges from two different routers could cause packets to be sent to the wrong destination. Configure external route summarization on ASBRs that are redistributing routes into OSPF When you configure a summary address, Cisco NX-OS automatically configures a discard route for the summary address to prevent routing black holes and route loops.
  • Page 174: Multiple Ospfv3 Instances

    OSPFv3 supports Virtual Routing and Forwarding instances (VRFs). VRFs exist within virtual device contexts (VDCs). By default, Cisco NX-OS places you in the default VDC and default VRF unless you specifically configure another VDC and VRF. Each OSPFv3 instance can support multiple VRFs, up to the system limit.
  • Page 175: Configuration Guidelines And Limitations

    (config-router)# timers throttle spf 1 50 50 switch (config-router)# timers lsa-arrival 10 Note If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature might differ from the Cisco IOS commands that you would use. Configuring Basic OSPFv3 Configure OSPFv3 after you have designed your OSPFv3 network.
  • Page 176: Creating An Ospfv3 Instance

    Maximum paths—Sets the maximum number of equal paths that OSPFv3 installs in the route table for a particular destination. Use this parameter for load balancing between multiple paths. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-14...
  • Page 177 (Optional) Configures the OSPFv3 router ID. This ID router-id id uses the dotted decimal notation and identifies this Example: OSPFv3 instance and must exist on a configured switch(config-router)# router-id interface in the system. 192.0.2.1 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-15 OL-20002-02...
  • Page 178 The range Example: is from 1 to 16. The default is 8. Used for load switch(config-router-af)# maximum-paths 4 balancing. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-16 OL-20002-02...
  • Page 179: Configuring Networks In Ospfv3

    Step 1 Enters configuration mode. config t Example: switch# config t switch(config)# Step 2 Enters interface configuration mode. interface interface-type slot/port Example: switch(config)# interface ethernet 1/2 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-17 OL-20002-02...
  • Page 180 MTU does not match the local interface MTU. Sets the OSPFv3 network type. ospfv3 network {broadcast | point-point} Example: switch(config-if)# ospfv3 network broadcast Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-18 OL-20002-02...
  • Page 181: Configuring Advanced Ospfv3

    Modifying the Default Timers, page 7-34 • Configuring Graceful Restart, page 7-36 • Restarting an OSPFv3 Instance, page 7-37 • • Configuring OSPFv3 with Virtualization, page 7-38 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-19 OL-20002-02...
  • Page 182 Example: switch# config t switch(config)# Step 2 Creates a new OSPFv3 instance with the configured router ospfv3 instance-tag instance tag. Example: switch(config)# router ospfv3 201 switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-20 OL-20002-02...
  • Page 183: Configuring Stub Areas

    Ensure that there are no virtual links or ASBRs in the proposed stub area. Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router ospfv3 instance-tag Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-21 OL-20002-02...
  • Page 184: Configuring A Totally Stubby Area

    You can create a totally stubby area and prevent all summary route updates from going into the stub area. To create a totally stubby area, use the following command in router configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-22...
  • Page 185: Configuring Nssa

    [no-redistribution] [default-information-originate [route-map map-name]] [no-summary] [translate type7 {always | never} [suppress-fa]] address-family ipv6 unicast area area-id default-cost cost copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-23 OL-20002-02...
  • Page 186 The following example shows how to create an NSSA that generates a default route; switch# config t switch(config)# router ospfv3 201 switch(config-router)# area 0.0.0.10 nssa default-info-originate switch(config-router)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-24 OL-20002-02...
  • Page 187: Configuring Multi-area Adjacency

    OSPFv3” section on page 7-17 SUMMARY STEPS config t interface interface-type slot/port ipv6 router ospfv3 instance-tag multi-area area-id show ipv6 ospfv3 instance-tag interface interface-type slot/port copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-25 OL-20002-02...
  • Page 188: Configuring Virtual Links

    Hello interval—Sets the time between successive Hello packets. • Retransmit interval—Sets the estimated time between successive LSAs. • Transmit delay—Sets the estimated time to transmit an LSA to a neighbor. • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-26 OL-20002-02...
  • Page 189 Step 5 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-router)# copy running-config startup-config You can configure the following optional commands in virtual link configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-27 OL-20002-02...
  • Page 190: Configuring Redistribution

    Default information originate ignores match statements in the optional route map. • Default metric—Sets all redistributed routes to the same cost metric. If you redistribute static routes, Cisco NX-OS also redistributes the default static route. Note Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 191 | rip id | static} route-map map-name through the configured route map. Note If you redistribute static routes, Cisco NX-OS Example: switch(config-router-af)# redistribute also redistributes the default static route. bgp route-map FilterExternalBGP Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-29 OL-20002-02...
  • Page 192: Limiting The Number Of Redistributed Routes

    You can optionally configure the timeout period. BEFORE YOU BEGIN Ensure that you have enabled the OSPF feature (see the “Enabling the OSPFv3 Feature” section on page 7-13). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-30 OL-20002-02...
  • Page 193 Optionally tries to retrieve the redistributed routes. The num-retries range is from 1 to 12. The timeout range is from 60 to 600 seconds. The default is 300 seconds. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-31 OL-20002-02...
  • Page 194: Configuring Route Summarization

    SUMMARY STEPS config t router ospfv3 instance-tag address-family ipv6 unicast area area-id range ipv6-prefix/length [no-advertise] summary-address ipv6-prefix/length [no-advertise] [tag tag] show ipv6 ospfv3 summary-address copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-32 OL-20002-02...
  • Page 195 The following example shows how to create summary addresses on an ASBR: switch# config t switch(config)# router ospf 201 switch(config-router)# address-family ipv6 unicast switch(config-router)# summary-address 2001:0DB8::/48 switch(config-router)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-33 OL-20002-02...
  • Page 196: Modifying The Default Timers

    Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-34 OL-20002-02...
  • Page 197 Sets the estimated time in seconds between LSAs ospfv3 retransmit-interval seconds transmitted from this interface. The range is from 1 to Example: 65535. The default is 5. switch(config-if)# ospfv3 retransmit-interval 30 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-35 OL-20002-02...
  • Page 198: Configuring Graceful Restart

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router ospfv3 instance-tag graceful-restart graceful-restart grace-period seconds graceful-restart helper-disable graceful-restart planned-only show ipv6 ospfv3 instance-tag copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-36 OL-20002-02...
  • Page 199: Restarting An Ospfv3 Instance

    120 switch(config-router)# copy running-config startup-config Restarting an OSPFv3 Instance You can restart an OSPv3 instance. This clears all neighbors for the instance. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-37 OL-20002-02...
  • Page 200: Configuring Ospfv3 With Virtualization

    <optional parameters configured> interface type slot/port vrf member vrf-name ipv6 address ipv6-prefix/length ipv6 ospfv3 instance-tag area area-id copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-38 OL-20002-02...
  • Page 201 Example: switch(config-if)# ipv6 ospfv3 201 area Step 10 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-39 OL-20002-02...
  • Page 202: Verifying Ospfv3 Configuration

    OSPFv3 instance. show running-configuration ospfv3 Displays the current running OSPFv3 configuration. Displaying OSPFv3 Statistics To display OSPFv3 statistics, use the following commands: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-40 OL-20002-02...
  • Page 203: Ospfv3 Example Configuration

    OSPFv3 parameters. Table 7-2 Default OSPFv3 Parameters Parameters Default Hello interval 10 seconds Dead interval 40 seconds Graceful restart grace period 60 seconds Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-41 OL-20002-02...
  • Page 204: Additional References

    SPF calculation initial delay time 0 milliseconds Additional References For additional information related to implementing OSPF, see the following sections: Related Documents, page 7-43 • MIBs, page 7-43 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-42 OL-20002-02...
  • Page 205: Related Documents

    Feature History for OSPFv3 Table 7-3 lists the release history for this feature. Table 7-3 Feature History for IOSPFv3 Feature Name Releases Feature Information OSPFv3 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 7-43 OL-20002-02...
  • Page 206 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 207: Configuring Eigrp

    After this initial full route table update, EIGRP sends incremental updates to only those neighbors affected by the route change. This process speeds convergence and minimizes the bandwidth used by EIGRP. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 208: Eigrp Components

    EIGRP also uses the Hello messages as a keepalive to its neighbors. As long as Hello messages are received, Cisco NX-OS can determine that a neighbor is alive and functioning. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 209: Diffusing Update Algorithm

    Delay—The sum of the delays configured on the interfaces that make up the route to the destination network. Configured in tens of microseconds. • Bandwidth—The calculation from the lowest configured bandwidth on an interface that is part of the route to the destination. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 210: External Route Metrics

    Stub Routers, page 8-6 Route Summarization, page 8-6 • • Route Redistribution, page 8-6 Load Balancing, page 8-6 • Split Horizon, page 8-7 • Virtualization Support, page 8-7 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 211: Address Families

    Key-chain management allows you to control changes to the authentication keys used by MD5 authentication digest. See the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x, for more details about creating key-chains.
  • Page 212: Route Summarization

    Cisco NX-OS supports the Equal Cost Multiple Paths (ECMP) feature with up to 16 equal-cost paths in the EIGRP route table and the unicast RIB. You can configure EIGRP to load balance traffic across some or all of those paths.
  • Page 213: Split Horizon

    If a Cisco NX-OS system experiences a cold reboot, network does not forward traffic to the system and removes the system from the network topology. In this scenario, EIGRP experiences a stateless restart, and all neighbors are removed.
  • Page 214: Licensing Requirements For Eigrp

    Note You must enable graceful restart to support in-service software upgrades (ISSU) for EIGRP. If you disable graceful restart, Cisco NX-OS issues a warning that ISSU cannot be supported with this configuration. Licensing Requirements for EIGRP...
  • Page 215: Configuration Guidelines And Limitations

    Autosummarization is not enabled by default. Cisco NX-OS supports only IP. • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 216: Creating An Eigrp Instance

    1-5). Routes are not advertised or accepted from other autonomous systems unless you enable route redistribution. BEFORE YOU BEGIN Ensure that you have enabled the EIGRP feature (see the “Enabling the EIGRP Feature” section on page 8-9). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-10 OL-20002-02...
  • Page 217 You can configure the time Example: between warning messages, from 1 to 65535, in switch(config-router)# seconds. The default is 10 seconds. This command is log-neighbor-warnings enabled by default. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-11 OL-20002-02...
  • Page 218: Restarting An Eigrp Instance

    You can restart an EIGRP instance. This clears all neighbors for the instance. To restart an EIGRP instance and remove all associated neighbors, use the following commands: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-12 OL-20002-02...
  • Page 219: Shutting Down An Eigrp Instance

    {ip | ipv6} passive-interface eigrp instance-tag from forming and sending routing updates on an EIGRP interface. The instance tag can be any case-sensitive alphanumeric string up to 20 characters. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-13 OL-20002-02...
  • Page 220: Shutting Down Eigrp On An Interface

    Ensure that all neighbors for an EIGRP process share the same authentication configuration, including the shared authentication key. Create the key-chain for this authentication configuration. See the Cisco NX-OS Security Configuration Guide. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 221 20 characters. switch(config-router-af)# authentication key-chain routeKeys Step 5 Configures MD5 message digest authentication mode authentication mode md5 for this VRF. Example: switch(config-router-af)# authentication mode md5 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-15 OL-20002-02...
  • Page 222 1/2 switch(config-if)# ip router eigrp Test1 switch(config-if)# ip authentication key-chain eigrp Test1 routeKeys switch(config-if)# ip authentication mode eigrp Test1 md5 switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-16 OL-20002-02...
  • Page 223: Configuring Eigrp Stub Routing

    EIGRP will advertise the summary address out the interface with a metric equal to the minimum of all more specific routes. See the “Route Summarization” section on page 8-6. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-17 OL-20002-02...
  • Page 224: Redistributing Routes Into Eigrp

    {bgp as | {eigrp | isis | ospf | ospfv3 | rip} instance-tag | direct | static} route-map name default-metric bandwidth delay reliability loading mtu show {ip | ipv6} eigrp route-map statistics redistribute copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-18 OL-20002-02...
  • Page 225 {ip | ipv6} eigrp route-map statistics redistribute statistics. Example: switch(config-router-af)# show ip eigrp route-map statistics redistribute bgp Step 7 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-19 OL-20002-02...
  • Page 226: Limiting The Number Of Redistributed Routes

    {bgp id | direct | eigrp id | isis id | ospf id | rip id | static} route-map map-name redistribute maximum-prefix max [threshold] [warning-only | withdraw [num-retries timeout]] show running-config eigrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-20 OL-20002-02...
  • Page 227 The following example shows how to limit the number of redistributed routes into EIGRP: switch# config t switch(config)# router eigrp Test1 switch(config-router)# redistribute bgp route-map FilterExternalBGP switch(config-router)# redistribute maximum-prefix 1000 75 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-21 OL-20002-02...
  • Page 228: Configuring Load Balancing In Eigrp

    Step 3 Enters the address-family configuration mode. address-family {ipv4 | ipv6} unicast This command is optional for IPv4. Example: switch(config-router)# address-family ipv4 unicast switch(config-router-af)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-22 OL-20002-02...
  • Page 229: Configuring Graceful Restart For Eigrp

    SUMMARY STEPS config t router eigrp instance-tag address-family {ipv4 | ipv6} unicast graceful-restart timers nsf converge seconds timers nsf route-hold seconds timers nsf signal seconds copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-23 OL-20002-02...
  • Page 230 The following example shows how to configure graceful restart for EIGRP over IPv6 using the default timer values: switch# config t switch(config)# router eigrp Test1 switch(config-router)# address-family ipv6 unicast switch(config-router-af)# graceful-restart switch(config-router-af)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-24 OL-20002-02...
  • Page 231: Adjusting The Interval Between Hello Packets And The Hold Time

    By default, split horizon is enabled on all interfaces. To disable split horizon, use the following command in interface configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-25 OL-20002-02...
  • Page 232: Tuning Eigrp

    Routes over this maximum are advertised as Example: unreachable. The range is from 1 to 255. The switch(config-router-af)# metric max-hops default is 100. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-26 OL-20002-02...
  • Page 233 {prefix-list name | route-map name} {in | and route map name can be any case-sensitive out} alphanumeric string up to 20 characters. Example: switch(config-if)# ip distribute-list eigrp Test1 route-map EigrpTest in Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-27 OL-20002-02...
  • Page 234: Configuring Virtualization For Eigrp

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t vrf context vrf-name router eigrp instance-tag interface ethernet slot/port vrf member vrf-name {ip | ipv6} router eigrp instance-tag copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-28 OL-20002-02...
  • Page 235 NewVRF switch(config-vrf)# router eigrp Test1 switch(config-router)# interface ethernet 1/2 switch(config-if)# ip router eigrp Test1 switch(config-if)# vrf member NewVRF switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-29 OL-20002-02...
  • Page 236: Verifying Eigrp Configuration

    The following example shows how to configure EIGRP: feature eigrp interface ethernet 1/2 ip address 192.0.2.55/24 ip router eigrp Test1 no shutdown router eigrp Test1 router-id 192.0.2.1 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-30 OL-20002-02...
  • Page 237: Related Topics

    NSF route-hold time NSF signal time Redistribution Disabled Split horizon Enabled Additional References For additional information related to implementing EIGRP, see the following sections: Related Documents, page 8-32 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-31 OL-20002-02...
  • Page 238: Related Documents

    EIGRP IPv6 support 4.1(2) Added support for IPv6. Authentication 4.0(3) Added the ability to configure authentication within a VRF for EIGRP. EIGRP 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 8-32 OL-20002-02...
  • Page 239: Configuring Is-is

    IS-IS is an Interior Gateway Protocol (IGP) based on Standardization (ISO)/International Engineering Consortium (IEC) 10589. Cisco NX-OS supports Internet Protocol version 4 (IPv4). IS-IS is a dynamic link-state routing protocol that can detect changes in the network topology and calculate loop-free routes to other nodes in the network.
  • Page 240: Is-is Overview

    Level1/Level2 router that the Level 1 routers use as the default route to the Level 2 area. You can configure which Level1/Level2 router sets the attached bit. See the “Verifying IS-IS Configuration” section on page 9-28. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 241: Net And System Id

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Each IS-IS instance in Cisco NX-OS supports either a single Level 1 or Level 2 area, or one of each. By default, all IS-IS instances automatically support Level 1 and Level 2 routing.
  • Page 242: Mesh Groups

    In addition, IS-IS includes a sequence number in each packet to protect against replay attacks. You can use also keychains for hello and LSP authentication. See Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x for information on keychain management.
  • Page 243: Route Redistribution

    Cisco NX-OS issues a warning that ISSU cannot be supported with this configuration. Multiple IS-IS Instances Cisco NX-OS supports a maximum of four instances of the IS-IS protocol that run on the same node. You cannot configure multiple instances over the same interface. Every instance uses the same system router ID.
  • Page 244 • You can configure a maximum of four IS-IS instances per VDC. • Because the default reference bandwidth is different for Cisco NX-OS and Cisco IOS, the advertised tunnel IS-IS metric is different for these two operating systems. Configuring IS-IS...
  • Page 245: Is-is Configuration Modes

    Configuring Virtualization, page 9-23 • Tuning IS-IS, page 9-26 If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 246: Creating An Is-is Instance

    Ensure that you have enabled the IS-IS feature (see the “Enabling the IS-IS Feature” section on page 9-7). Ensure that you are in the correct VDC (or use the switchto vdc command). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 247 Use the no router isis command to remove the IS-IS instance and the associated configuration. Command Purpose Deletes the IS-IS instance and all associated no router isis instance-tag configuration. Example: switch(config)# no router isis Enterprise Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 248: Restarting An Is-is Instance

    You can restart an IS-IS instance. This clears all neighbors for the instance. To restart an IS-IS instance and remove all associated neighbors, use the following command: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-10 OL-20002-02...
  • Page 249: Shutting Down Is-is

    SUMMARY STEPS config t interface interface-type slot/port medium { broadcast | p2p} (Optional) ip router isis instance-tag show isis [vrf vrf-name] [instance-tag] interface [interface-type slot/port] copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-11 OL-20002-02...
  • Page 250 Prevents the interface from forming adjacencies but isis passive {level-1 | level-2 | level-1-2} still advertises the prefix associated with the interface. Example: switch(config-if)# isis passive level-2 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-12 OL-20002-02...
  • Page 251: Shutdown Is-is On An Interface

    SUMMARY STEPS config t router isis instance-tag authentication-type {cleartext | md5} {level-1 | level-2} authentication key-chain key {level-1 | level-2} authentication-check {level-1 | level-2} copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-13 OL-20002-02...
  • Page 252: Configuring Is-is Authentication On An Interface

    Ensure that you have enabled the IS-IS feature (see the “Enabling the IS-IS Feature” section on page 9-7). Ensure that you are in the correct VDC (or use the switchto vdc command). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-14 OL-20002-02...
  • Page 253 The following example shows how to configure cleartext authentication on an IS-IS instance: switch# config t switch(config)# interface ethernet 1/2 switch(config-if)# isis authentication-type cleartext level-2 switch(config-if)# isis authentication key-chain ISISKey switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-15 OL-20002-02...
  • Page 254: Configuring A Mesh Group

    In addition to setting the overload bit, you might also want to suppress certain types of IP prefix advertisements from LSPs for Level 1 or Level 2 traffic. To set the overload bit, use the following command in router configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-16 OL-20002-02...
  • Page 255: Configuring The Attached Bit

    You can create aggregate addresses that are represented in the routing table by a summary address. One summary address can include multiple groups of addresses for a given level. Cisco NX-OS advertises the smallest metric of all the more-specific routes.
  • Page 256 [vrf vrf-name ] ip summary-address ip-prefix information. [longer-prefixes]] Example: switch(config-if)# show isis ip summary-address Step 6 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config--if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-18 OL-20002-02...
  • Page 257: Configuring Redistribution

    Example: switch# config t switch(config)# Step 2 Creates a new IS-IS instance with the configured router isis instance-tag instance tag. Example: switch(config)# router isis Enterprise switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-19 OL-20002-02...
  • Page 258: Limiting The Number Of Redistributed Routes

    Route redistribution can add many routes to the IS-IS route table. You can configure a maximum limit to the number of routes accepted from external protocols. IS-IS provides the following options to configure redistributed route limits: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-20 OL-20002-02...
  • Page 259 {bgp id | direct | eigrp id | isis id | ospf id | rip id | static} the configured route map. route-map map-name Example: switch(config-router)# redistribute bgp route-map FilterExternalBGP Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-21 OL-20002-02...
  • Page 260: Configuring A Graceful Restart

    Create the VDCs and VRFs. Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router isis instance-tag graceful-restart graceful-restart t3 manual time Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-22 OL-20002-02...
  • Page 261: Configuring Virtualization

    Configure all other parameters for an interface after you configure the VRF for an interface. Configuring Note a VRF for an interface deletes all the configuration for that interface. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-23 OL-20002-02...
  • Page 262 Exits VRF configuration mode. exit Example: switch(config-vrf)# exit switch(config)# Step 4 Creates a new IS-IS instance with the configured router isis instance-tag instance tag. Example: switch(config)# router isis Enterprise switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-24 OL-20002-02...
  • Page 263 [ interface-type slot/port ] in a VRF. Example: switch(config-if)# show isis Enterprise ethernet 1/2 Step 13 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-25 OL-20002-02...
  • Page 264: Tuning Is-is

    Enables IS-IS to generate and accept both narrow metric-style transition metric-style Type Length Value (TLV) objects and Example: wide metric-style TLV objects. The default is switch(config-router)# metric-style disabled. transition Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-26 OL-20002-02...
  • Page 265 Sets the interval in milliseconds between LSPs sent isis lsp-interval milliseconds on this interface during flooding. The range is from Example: 10 to 65535. The default is 33. switch(config-if)# isis lsp-interval 20 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-27 OL-20002-02...
  • Page 266: Verifying Is-is Configuration

    [detail] Displays the technical support details for IS-IS. For detailed information about the fields in the output from these commands, see the Cisco NX-OS Command Reference. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 267: Displaying Is-is Statistics

    [instance-tag] traffic [* | interface] [vrf Clears the IS-IS traffic statistics. vrf-name] IS-IS Example Configuration The following example shows how to configure IS-IS: router isis Enterprise Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-29 OL-20002-02...
  • Page 268: Related Topics

    Metric Reference bandwidth 40 Gbps Additional References For additional information related to implementing IS-IS, see the following sections: Related Documents, page 9-31 • Standards, page 9-31 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-30 OL-20002-02...
  • Page 269: Related Documents

    Added support to set or unset the hello padding mode. Attached bit 4.1(2) Added support to set or unset the attached bit. IS-IS 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 9-31 OL-20002-02...
  • Page 270 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 271: Configuring Basic Bgp

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . C H A P T E R Configuring Basic BGP This chapter describes how to configure Border Gateway Protocol (BGP) on a Cisco NX-OS device. This chapter includes the following sections: Information About Basic BGP, page 10-1 •...
  • Page 272: Bgp Autonomous Systems

    BGP (iBGP) peering sessions. 4-Byte AS Number Support BGP supports 2-byte or 4-byte AS numbers. Cisco NX-OS displays 4-byte AS numbers in plain-text notation (that is, as 32-bit integers). You can configure 4-byte AS numbers as either plain-text notation (for example, 1 to 4294967295), or AS.dot notation (for example, 1.0).
  • Page 273: Bgp Peers

    Dynamis AS Numbers for Prefix Peers Cisco NX-OS accepts a range or list of AS numbers to establish BGP sessions. For example, if you configure BGP to use IPv4 prefix 192.0.2.0/8 and AS numbers 33, 66, and 99, BGP establishes a session with 192.0.2.1 with AS number 66 but rejects a session from 192.0.2.2 with AS number 50.)
  • Page 274: Bgp Router Identifier

    A, B, and C. When Cisco NX-OS compares A and B, it chooses A. When Cisco NX-OS compares B and C, it chooses B. But when Cisco NX-OS compares A and C, it might not choose A because some BGP metrics apply only among paths from the same neighboring autonomous system and not among all paths.
  • Page 275 11-9 for more information. If one path is from an internal peer and the other path is from an external peer, then Cisco NX-OS chooses the path from the external peer. If the paths have different IGP metrics to their next-hop addresses, then Cisco NX-OS chooses the path with the lower IGP metric.
  • Page 276: Step 2-determining The Order Of Comparisons

    If the path includes an originator attribute, then Cisco NX-OS uses that attribute as the router ID to compare to; otherwise, Cisco NX-OS uses the router ID of the peer that sent the path. If the paths have different router IDs, Cisco NX-OS chooses the path with the lower router ID.
  • Page 277: Bgp And The Unicast Rib

    BGP supports Virtual Routing and Forwarding instances (VRFs). VRFs exist within virtual device contexts (VDCs). By default, Cisco NX-OS places you in the default VDC and default VRF unless you specifically configure another VDC and VRF. For more information, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 4.x and...
  • Page 278: Guidelines And Limitations For Bgp

    For more information, see Chapter 11, “Configuring Advanced BGP.” The following example shows how to enter router configuration mode: switch# configuration switch(config)# router bgp 64496 switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-8 OL-20002-02...
  • Page 279: Address Family Configuration Mode

    Neighbor Configuration Mode Cisco NX-OS provides the neighbor configuration mode to configure BGP peers. You can use neighbor configuration mode to configure all parameters for a peer. The following example shows how to enter neighbor configuration mode: switch(config)# router bgp 64496 switch(config-router)# neighbor 192.0.2.1...
  • Page 280: Neighbor Address Family Configuration Mode

    Configuring Dynamic AS Numbers for Prefix Peers, page 10-16 • Clearing BGP Information, page 10-18 If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 281: Creating A Bgp Instance

    Ensure that you have enabled the BGP feature (see the “Enabling the BGP Feature” section on page 10-10). BGP must be able to obtain a router ID (for example, a configured loopback address). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-11 OL-20002-02...
  • Page 282 192.0.2.0 For exterior protocols, the network command controls which networks are advertised. Interior protocols use the network command to determine where to send updates. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-12 OL-20002-02...
  • Page 283: Restarting A Bgp Instance

    You can shut down the BGP protoco and gracefully disable BGP and retains the configuration. To shut down BGP, use the following command in router configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-13 OL-20002-02...
  • Page 284: Configuring Bgp Peers

    {ip-address | ipv6-address} remote-as as-number description text timers keepalive-time hold-time shutdown address-family {ipv4 | ipv6} {unicast | multicast} show bgp {ipv4 | ipv6} {unicast | multicast} neighbors copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-14 OL-20002-02...
  • Page 285 {ipv4 | ipv6}{unicast | multicast} neighbors Example: switch(config-router-neighbor-af)# show bgp ipv4 unicast neighbors Step 9 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-router-neighbor-af) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-15 OL-20002-02...
  • Page 286: Configuring Dynamic As Numbers For Prefix Peers

    32-bit integer in the form of a higher 16-bit switch(config)# router bgp 64496 decimal number and a lower 16-bit decimal numbe in switch(config-router)# xx.xx format. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-16 OL-20002-02...
  • Page 287 192.0.2.0/8 remote-as route-map BGPPeers switch(config-router-neighbor)# description Peer Router B switch(config-router-neighbor)# address-family ipv4 unicast switch(config-router-neighbor-af)# copy running-config startup-config Chapter 16, “Configuring Route Policy Manager.” for information on route maps. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-17 OL-20002-02...
  • Page 288: Clearing Bgp Information

    {ip | ipv6} {unicast | multicast} Clears route flap statistics in the selected address flap-statistics [vrf vrf-name] family. The vrf-name can be any case-sensitive alphanumeric string up to 64 characters. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-18 OL-20002-02...
  • Page 289 All neighbors in that • VRF are cleared. The name can be any case-sensitive alphanumeric string up to 64 characters. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-19 OL-20002-02...
  • Page 290 All neighbors in that • VRF are cleared. The name can be any case-sensitive alphanumeric string up to 64 characters. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-20 OL-20002-02...
  • Page 291: Verifying Basic Bgp Configuration

    {ip | ipv6} {unicast | multicast} Displays the BGP routes that match a BGP [ip-address | ipv6-prefix] extcommunity-list extended community list. list-name [exact-match]} [vrf vrf-name] Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-21 OL-20002-02...
  • Page 292 Displays the information about BGP peer templates. Use the clear bgp peer-template command to clear all neighbors in a peer template. show bgp process Displays the BGP process information. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-22 OL-20002-02...
  • Page 293: Displaying Bgp Statistics

    64496 neighbor 2001:ODB8:0:1::55 remote-as 64496 address-family ipv6 unicast next-hop-self Related Topics The following topics relate to BGP: Chapter 16, “Configuring Route Policy Manager.” • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-23 OL-20002-02...
  • Page 294: Where To Go Next

    Always disabled Additional References For additional information related to implementing BGP, see the following sections: Related Documents, page 10-25 • • RFCs, page 10-25 • MIBs, page 10-25 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-24 OL-20002-02...
  • Page 295: Related Documents

    BGP table. Dynamic AS number for prefix peers 4.1(2) Added support for a range of AS numbers for BGP prefix peer configuration. 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 10-25 OL-20002-02...
  • Page 296 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 297: Configuring Advanced Bgp

    BGP is an interdomain routing protocol that provides loop-free routing between organizations or autonomous systems. Cisco NX-OS supports BGP version 4. BGP version 4 includes multiprotocol extensions that allow BGP to carry routing information for IP multicast routes and multiple Layer 3 protocol address families.
  • Page 298: Peer Templates

    A peer-policy template can inherit from a set of peer-policy templates. Cisco NX-OS evaluates these peer-policy templates in the order specified by the preference value in the inherit configuration. The lowest number is preferred over higher numbers.
  • Page 299: Route Policies And Resetting Bgp Sessions

    If you change the inbound route policy, Cisco NX-OS passes these stored routes through the modified inbound route policy to update the route table without tearing down existing peering sessions. Soft reconfiguration inbound can use significant memory resources to store the unfiltered BGP routes.
  • Page 300 Each subautonomous system is fully meshed within itself and has a few connections to other subautonomous systems in the same confederation. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-4...
  • Page 301: As Confederations

    11-3, router B is the route reflector. When the route reflector receives routes advertised from router A, it advertises (reflects) the routes to routers C and D. Router A no longer has to advertise to both routers C and D. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-5 OL-20002-02...
  • Page 302: Capabilities Negotiation

    Capabilities negotiation allows BGP to use only the set of features supported by both BGP peers on a link. If a BGP peer does not support capabilities negotiation, Cisco NX-OS will attempt a new session to the peer without capabilities negotiation if you have configured the address family as IPv4. Any other multiprotocol configuration (such as IPv6) requires capabilities negotiation.
  • Page 303: Load Sharing And Multipath

    BGP sets the administrative distance of the summary discard to 220 and sets the route type to discard. BGP does not use discard routes for next-hop resolution. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-7...
  • Page 304: Bgp Conditional Advertisement

    Non-critical events are related to next hops being added without affecting the best path or changing • the IGP metric to a single next hop. See the “Configuring BGP Next-Hop Address Tracking” section on page 11-23 for more information. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-8 OL-20002-02...
  • Page 305: Route Redistribution

    MED attribute and the router ID. Multiprotocol BGP BGP on Cisco NX-OS supports multiple address families. Multiprotocol BGP (MP-BGP) carries different sets of routes depending on the address family. For example, BGP can carry one set of routes for IPv4 unicast routing, one set of routes for IPv4 multicast routing, and one set of routes for IPv6 multicast routing.
  • Page 306: Graceful Restart And High Availability

    If a Cisco NX-OS router experiences a cold reboot, the network does not forward traffic to the router and removes the router from the network topology. In this scenario, BGP experiences a nongraceful restart and removes all routes.
  • Page 307: Issu

    • Keepalive and hold timers must not be smaller than their default values If either of these requirements is not met, Cisco NX-OS issues a warning. You can proceed with the upgrade or downgrade, but service might be disrupted. Note Cisco NX-OS cannot guarantee ISSU for non-default timer values if the negotiated hold time between BGP peers is less than the system switchover time.
  • Page 308: Prerequisites For Bgp

    License Requirement Cisco NX-OS BGP requires an Enterprise Services license. For a complete explanation of the NX-OS licensing scheme and how to obtain and apply licenses, see the Cisco NX-OS Licensing Guide Prerequisites for BGP BGP has the following prerequisites: You must enable the BGP feature (see the “Enabling the BGP Feature”...
  • Page 309: Configuring Advanced Bgp

    Configuring a Graceful Restart, page 11-39 Configuring Virtualization, page 11-40 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 310 Step 2 Enables BGP and assigns the autonomous system router bgp autonomous-system-number number to the local BGP speaker. Example: switch(config)# router bgp 65536 switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-14 OL-20002-02...
  • Page 311 Use the show bgp neighbor command to see the template applied. See the Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference for details on all commands available in the template. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 312: Configuring Bgp Peer-policy Templates

    Cisco NX-OS evaluates multiple peer policies for an address family using the preference value. The lowest preference value is evaluated first. Any attributes configured for the neighbor take priority over any attributes inherited by that neighbor from a BGP template.
  • Page 313 Applies a peer-policy template to the peer address inherit peer-policy template-name preference family configuration and assigns the preference value for this peer policy. Example: switch(config-router-neighbor-af)# inherit peer-policy BasePolicy 1 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-17 OL-20002-02...
  • Page 314: Configuring Bgp Peer Templates

    Use the show bgp neighbor command to see the template applied. See the Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference for details on all commands available in the template. This example shows how to configure a BGP peer-session template and apply it to a BGP peer:...
  • Page 315 (Optional) Applies a peer template to the neighbor inherit peer template-name address family configuration. Example: switch(config-router-neighbor-af)# inherit peer BasePolicy Step 7 Exits BGP neighbor address family configuration exit mode. Example: switch(config-router-neighbor-af)# exit switch(config-router-neighbor)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-19 OL-20002-02...
  • Page 316 Use the show bgp neighbor command to see the template applied. See the Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference for details on all commands available in the template. This example shows how to configure a BGP peer template and apply it to a BGP peer:...
  • Page 317: Configuring Prefix Peering

    When a BGP peer that is part of a prefix peering disconnects, Cisco NX-OS holds its peer structures for a defined prefix peer timeout value. An established peer can reset and reconnect without danger of being blocked because other peers have consumed all slots for that prefix peering.
  • Page 318: Resetting A Bgp Session

    If you modify a route policy for BGP, you must reset the associated BGP peer sessions. If the BGP peers do not support route refresh, you can configure a soft reconfiguration for inbound policy changes. Cisco NX-OS automatically attempts a soft reset for the session.
  • Page 319: Configuring Bgp Next-hop Address Tracking

    BGP marks all next hops that are rejected by the route policy as invalid and does not calculate the best path for the routes that use the invalid next-hop address. To configure BGP next-hop filtering, use the following command in address-family configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-23 OL-20002-02...
  • Page 320: Disabling Capabilities Negotiation

    Disables checking whether or not a single-hop disable-connected-check eBGP peer is directly connected. You must Example: manually reset the BGP sessions after using this switch(config-router-neighbor)# command. disable-connected-check Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-24 OL-20002-02...
  • Page 321: Configuring Ebgp Multihop

    5 Disabling a Fast External Fallover By default, the Cisco Nexus 7000 Series device supports fast external fallover for for neighbors in all VRFs and address-families (IPv4 or IPv6). Typically, when a BGP router loses connectivity to a directly connected eBGP peer, BGP triggers a fast external fallover by resetting the eBGP session to the peer.
  • Page 322: Configuring Route Reflector

    {ipv4 | ipv6} {unicast | multicast} client-to-client reflection exit neighbor ip-address remote-as as-number address-family {ipv4 | ipv6} {unicast | multicast} route-reflector-client Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-26 OL-20002-02...
  • Page 323 Step 8 Enters neighbor address family configuration mode for address-family {ipv4 | ipv6}{unicast | multicast} the unicast IPv4 address family. Example: switch(config-router-neighbor)# address-family ipv4 unicast switch(config-router-neighbor-af)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-27 OL-20002-02...
  • Page 324: Configuring Route Dampening

    1 to 20000. • switch(config-router-af)# dampening route-map bgpDamp suppress-limit—The range is from 1 to 20000. • max-suppress-time—The range is from 1 to • 255. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-28 OL-20002-02...
  • Page 325: Configuring Load Sharing And Ecmp

    Enables dynamic capability. This command dynamic-capability triggers an automatic notification and session reset Example: for the BGP neighbor sessions. switch(config-router-neighbor)# dynamic-capability This command is disabled by default. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-29 OL-20002-02...
  • Page 326: Configuring Aggregate Addresses

    Ensure that you have enabled the BGP feature (see the “Enabling the BGP Feature” section on page 10-10). Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-30 OL-20002-02...
  • Page 327 Example: switch(config-router)# neighbor 192.168.1.2 remote-as 65537 switch(config-router-neighbor)# Step 4 Enters address family configuration mode. address-family {ipv4 | ipv6} {unicast | multicast} Example: switch(config-router-neighbor)# address-family ipv4 multicast switch(config-router-neighbor-af)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-31 OL-20002-02...
  • Page 328: Configuring Route Redistribution

    You can configure BGP to accept routing information from another routing protocol and redistribute that information through the BGP network. Optionally, you can assign a default route for redistributed routes. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-32...
  • Page 329 (Optional) Generates a default route into BGP. default-metric value Example: switch(config-router-af)# default-metric Step 6 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-router-af)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-33 OL-20002-02...
  • Page 330 This example shows how to redistribute EIGRP into BGP: switch# config t switch(config)# router bgp 65536 switch(config-router)# address-family ipv4 unicast switch(config-router-af)# redistribute eigrp 201 route-map Eigrpmap switch(config-router-af)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-34 OL-20002-02...
  • Page 331: Configuring Multiprotocol Bgp

    {ipv4 | ipv6} {unicast | multicast} Example: switch(config-router-neighbor)# address-family ipv4 multicast switch(config-router-neighbor-af)# Step 5 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-router-neighbor-af)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-35 OL-20002-02...
  • Page 332: Tuning Bgp

    AS number listed in the AS_path attribute for Example: eBGP. switch(config-router)# enforce-first-as Generates a system message when a neighbor log-neighbor-changes changes state. Example: switch(config-router)# log-neighbor-changes Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-36 OL-20002-02...
  • Page 333 To tune BGP, use the following optional commands in neighbor configuration mode: Command Purpose Sets a descriptive string for this BGP peer. The description string string can be up to 80 alphanumeric characters. Example: switch(config-router-neighbor)# description main site Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-37 OL-20002-02...
  • Page 334 {in | out} or outbound route updates. This command triggers Example: an automatic soft clear or refresh of BGP neighbor switch(config-router-neighbor-af)# sessions. prefix-list PrefixFilter in Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-38 OL-20002-02...
  • Page 335: Configuring A Graceful Restart

    Example: switch# config t switch(config)# Step 2 router bgp as-number Creates a new BGP process with the configured autonomous system number. Example: switch(config)# router bgp 65536 switch(config-router)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-39 OL-20002-02...
  • Page 336: Configuring Virtualization

    Configuring Virtualization You can configure one BGP process in each VDC. You can create multiple VRFs within each VDC and use the same BGP process in each VRF. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-40 OL-20002-02...
  • Page 337 65536 switch(config-router)# Step 5 Enters the router VRF configuration mode and vrf vrf-name associates this BGP instance with a VRF. Example: switch(config-router)# vrf RemoteOfficeVRF switch(config-router-vrf)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-41 OL-20002-02...
  • Page 338: Verifying Advanced Bgp Configuration

    {ip | ipv6} {unicast | multicast} Displays the BGP routes that match a BGP [ip-address | ipv6-prefix] extcommunity-list extended community list. list-name [exact-match]} [vrf vrf-name] Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-42 OL-20002-02...
  • Page 339 Displays the information about BGP peer templates. Use the clear bgp peer-template command to clear all neighbors in a peer template. show bgp process Displays the BGP process information. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-43 OL-20002-02...
  • Page 340: Displaying Bgp Statistics

    Chapter 16, “Configuring Route Policy Manager” • Default Settings Table 11-1 lists the default settings for BGP parameters. Table 11-1 Default BGP Parameters Parameters Default BGP feature disabled Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-44 OL-20002-02...
  • Page 341: Additional References

    MIBs Link BGP4-MIB To locate and download MIBs, go to the following URL: CISCO-BGP4-MIB http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml Feature History for BGP Table 11-2 lists the release history for this feature. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-45 OL-20002-02...
  • Page 342 BGP table. Dynamic AS number for prefix peers 4.1(2) Added support for a range of AS numbers for BGP prefix peer configuration. 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 11-46 OL-20002-02...
  • Page 343: Configuring Rip

    Route Filtering, page 12-3 • Route Summarization, page 12-3 • Route Redistribution, page 12-3 • Load Balancing, page 12-4 • High Availability, page 12-4 • Virtualization Support, page 12-4 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-1 OL-20002-02...
  • Page 344: Rip Overview

    Key-chain management allows you to control changes to the authentication keys used by an MD5 authentication digest or simple text password authentication. See the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x for more details about creating key-chains.
  • Page 345: Route Filtering

    By default, split horizon is enabled on all interfaces. Route Filtering You can configure a route policy on a RIP-enabled interface to filter the RIP updates. Cisco NX-OS updates the route table with only those routes that the route policy allows.
  • Page 346: Load Balancing

    Virtual Routing and Forwarding instances (VRFs). VRFs exist within virtual device contexts (VDCs). You can configure up to four RIP instances on a VDC. By default, Cisco NX-OS places you in the default VDC and default VRF unless you specifically configure another VDC and VRF. See the Cisco NX-OS Virtual Device Context Configuration Guide and Chapter 14, “Configuring Layer 3 Virtualization.”...
  • Page 347: Configuring Rip

    • • Tuning RIP, page 12-15 If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Enabling the RIP Feature You must enable the RIP feature before you can configure RIP.
  • Page 348: Creating A Rip Instance

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router rip instance-tag address-family ip unicast show ip rip [instance instance-tag] [vrf vrf-name] copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-6 OL-20002-02...
  • Page 349 Configures the maximum number of equal-cost maximum-paths number Example: paths that RIP maintains in the route table. The switch(config-router-af)# maximum-paths 6 range is from 1 to 16. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-7 OL-20002-02...
  • Page 350: Restarting A Rip Instance

    Enter the correct VDC if necessary before configuring RIP. SUMMARY STEPS config t interface interface-type slot/port ip | router rip instance-tag show ip rip [instance instance-tag] interface [interface-type slot/port] [vrf vrf-name] [detail] copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-8 OL-20002-02...
  • Page 351: Configuring Rip Authentication

    “Enabling the RIP Feature” section on page 12-5). Ensure that you are in the correct VDC (or use the switchto vdc command). Configure a key chain if necessary before enabling authentication. See the Cisco NX-OS Security Configuration Guide for details on implementing key chains. SUMMARY STEPS config t Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 352: Configuring A Passive Interface

    Configuring a Passive Interface You can configure a RIP interface to receive routes but not send route updates by setting the interface to passive mode. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-10 OL-20002-02...
  • Page 353: Configuring Split Horizon With Poison Reverse

    Configuring Route Summarization You can create aggregate addresses that are represented in the routing table by a summary address. Cisco NX-OS advertises the summary address metric that is the smallest metric of all the more-specific routes.
  • Page 354 (Optional) Sets the default metric for all redistributed routes. The range is from 1 to 15. The default is 1. Example: switch(config-router-af)# distribute level-1 into level-2 all Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-12 OL-20002-02...
  • Page 355: Configuring Virtualization

    SUMMARY STEPS config t vrf context vrf_name exit router rip instance-tag vrf vrf-name address-family ipv4 unicast configure optional parameters interface ethernet slot/port vrf member vrf-name ip-address ip-prefix/length Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-13 OL-20002-02...
  • Page 356 Example: switch(config-router-vrf-af)# redistribute eigrp 201 route-map RIPmap Step 8 Enters interface configuration mode. interface ethernet slot/port Example: switch(config-router-vrf-af)# interface ethernet 1/2 switch(config-if)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-14 OL-20002-02...
  • Page 357: Tuning Rip

    You can adjust these timers to tune routing protocol performance to better suit your internetwork needs. You must configure the same values for the RIP timers on all RIP-enabled routers in your network. Note Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-15 OL-20002-02...
  • Page 358 Specifies a route map to filter incoming or outgoing ip rip route-filter {prefix-list list-name | route-map map-name | [in | out] RIP updates. Example: switch(config-if)# ip rip route-filter route-map InputMap in Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-16 OL-20002-02...
  • Page 359: Verifying Rip Configuration

    [vrf vrf-name] Use the clear ip rip policy command to clear policy statistics. Use the clear ip rip statistics command to clear RIP statistics. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-17 OL-20002-02...
  • Page 360: Rip Example Configuration

    RIP feature Disabled Split horizon Enabled Additional References For additional information related to implementing RIP, see the following sections: Related Documents, page 12-19 • Standards, page 12-19 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-18 OL-20002-02...
  • Page 361: Related Documents

    Feature History for RIP Table 12-2 lists the release history for this feature. Table 12-2 Feature History for RIP Feature Name Releases Feature Information 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 12-19 OL-20002-02...
  • Page 362 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 363: Configuring Static Routing

    (a default router to which all unroutable packets are sent). This section includes the following topics: Administrative Distance, page 13-2 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 13-1 OL-20002-02...
  • Page 364: Administrative Distance

    By default, a router prefers a static route to a dynamic route because a static route has a smaller Note administrative distance than a dynamic route. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 13-2 OL-20002-02...
  • Page 365: Remote Next Hops For Static Routes

    License Requirement NX-OS Static routing requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS...
  • Page 366: Configuring A Static Route

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 367: Configuring Virtualization

    Enters configuration mode. config t Example: switch# config t switch(config)# Step 1 Creates a VRF and enters VRF configuration mode. vrf context vrf-name Example: switch(config)# vrf context StaticVrf Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 13-5 OL-20002-02...
  • Page 368: Verifying Static Routing Configuration

    Displays the configured static routes. Static Routing Example Configuration This example shows how to configure static routing: config t ip route 192.0.2.0/8 192.0.2.10 copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 13-6 OL-20002-02...
  • Page 369: Default Settings

    Table 13-2 lists the release history for this feature. Table 13-2 Feature History for Static Routing Feature Name Releases Feature Information Static Routing 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 13-7 OL-20002-02...
  • Page 370 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 371: Configuring Layer 3 Virtualization

    (VDCs). Each VDC acts as a standalone device with both Layer 2 and Layer 3 services available. You can configure up to 4 VDCs, including the default VDC. See the Cisco NX-OS Virtu- alization Configuration Guide for more information on VDCs.
  • Page 372 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco NX-OS further virtualizes each VDC to support virtual routing and forwarding instances (VRFs). You can configure multiple VRFs in a VDC.
  • Page 373: Vrf And Routing

    Router C By default, Cisco NX-OS uses the VRF of the incoming interface to select which routing table to use for a route lookup. You can configure a route policy to modify this behavior and set the VRF that Cisco NX-OS uses for incoming packets.
  • Page 374: Reachability

    VRRP—See Chapter 20, “Configuring VRRP” for more information. • XML—See the Cisco Nexus 7000 Series NX-OS XML Management Interface User Guide for more • information. See the appropriate configuration guide for each service for more information on configuring VRF support in that service.
  • Page 375: Combining Reachability And Filtering

    For example, you can configure a syslog server to support a particular VRF. Figure 14-4 shows two syslog servers with each server supporting one VRF. syslog server A is configured in VRF Red, so Cisco NX-OS sends only system messages generated in VRF Red to syslog server A. Figure 14-4...
  • Page 376: Prerequisites For Vrf

    Setting the VRF Scope, page 14-12 Note If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature might differ from the Cisco IOS commands that you would use. Creating a VRF You can create a VRF in a VDC.
  • Page 377 The following example shows how to create a VRF and add a static route to the VRF: switch# config t switch(config)# vrf context Enterprise switch(config-vrf)# ip route 192.0.2.0/8 192.0.2.10 switch(config-vrf)# exit switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-7 OL-20002-02...
  • Page 378: Assigning Vrf Membership To An Interface

    Configures an IP address for this interface. You must ip address ip-prefix/length do this step after you assign this interface to a VRF. Example: switch(config-if)# ip address 192.0.2.1/16 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-8 OL-20002-02...
  • Page 379: Configuring Vrf Parameters For A Routing Protocol

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t router protocol tag vrf vrf-name configure optional parameters for the protocol in the VRF. copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-9 OL-20002-02...
  • Page 380 Example: switch(config-if)# ip router ospf 201 area 0 Step 9 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-10 OL-20002-02...
  • Page 381: Configuring A Vrf-aware Service

    VRF that Cisco NX-OS uses to reach the service Use the filter-vrf keyword to filter information from the Example: selected VRF to this server. switch(config)# snmp-server host 192.0.2.1 use-vrf Red switch(config-vrf)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-11 OL-20002-02...
  • Page 382: Setting The Vrf Scope

    Default routing context is the default VRF. Example: switch# routing-context vrf red switch%red# To return to the default VRF scope, use the following command in EXEC mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-12 OL-20002-02...
  • Page 383: Verifying Vrf Configuration

    Lab vrf Red router ospf Production vrf Blue router-id 1.1.1.1 vrf Green router-id 2.2.2.2 !Configure one interface to use ospf Lab on VRF Red Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-13 OL-20002-02...
  • Page 384: Related Topics

    Related Topics The following topics can give more information on VRFs: Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide, Release 4.x • Cisco Nexus 7000 Series NX-OS System Management Configuration Guide, Release 4.x • Default Settings Table 14-1 lists the default settings for VRF parameters.
  • Page 385: Additional References

    Feature History for VRF Table 14-2 lists the release history for this feature. Table 14-2 Feature History for VRF Feature Name Releases Feature Information 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 14-15 OL-20002-02...
  • Page 386 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 387: Managing The Unicast Rib And Fib

    • Feature History for Unicast RIB and FIB, page 15-14 Information About the Unicast RIB and FIB The unicast RIB (IPv4 RIB and IPv6 RIB) and FIB are part of the Cisco NX-OS forwarding architecture, as shown in Figure 15-1.
  • Page 388: Layer 3 Consistency Checker

    “Clearing Forwarding Information in the FIB” section on page 15-10. Dynamic TCAM Allocation Cisco NX-OS divides the FIB to support multiple address families. The FIB TCAM has 128K physical entries. Table 15-1 describes the default FIB TCAM allocation. Table 15-1...
  • Page 389: Virtualization Support

    The unicast RIB and FIB require no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 390: Managing The Unicast Rib And Fib

    Clearing Routes in the Unicast RIB, page 15-13 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 391: Configuring Load Sharing In The Unicast Fib

    Universal ID—Sets the random seed for the hash algorithm. You do not need to configure the • Universal ID. Cisco NX-OS chooses the Universal ID if you do not configure it. Note Load sharing uses the same path for all packets in a given flow. A flow is defined by the load-sharing method that you configure.
  • Page 392: Configuring Per-packet Load Sharing

    You can use per-packet load sharing to evenly distribute data traffic in an IP network over multiple equal-cost connections. Per-packet load sharing allows the router to send successive data packets over paths on a packet-by-packet basis rather than on a per-flow basis. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-6 OL-20002-02...
  • Page 393: Displaying Routing And Adjacency Information

    You configure per-packet load sharing on the input interface. This configuration determines the output interface that Cisco NX-OS chooses for the packet. For example, if you have ECMP paths on two output interfaces, Cisco NX-OS uses the following load-sharing methods for input packets on Ethernet 1/1: Per-packet load sharing if you configure per-packet load sharing on Ethernet 1/1.
  • Page 394 IP Adjacency Table for context default Total number of entries: 2 Address MAC Address Pref Source Interface Best 10.1.1.1 02:20:54 00e0.b06a.71eb mgmt0 10.1.1.253 00:06:27 0014.5e0b.81d1 mgmt0 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-8 OL-20002-02...
  • Page 395: Triggering The Layer 3 Consistency Checker

    { slot | all}] up to 64 characters. The slot range is from 1 to 10. Example: switch(config)# show forwarding inconsistency Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-9 OL-20002-02...
  • Page 396: Clearing Forwarding Information In The Fib

    You can disable dynamic TCAM allocation only if the current TCAM usage is below the default Note allocation. See the “Returning the TCAM to Default Settings” section on page 15-11 for more information. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-10 OL-20002-02...
  • Page 397: Returning The Tcam To Default Settings

    TCAM usage below the default allocation limits. Returning the TCAM to Default Settings You must return the TCAM to default settings before you can start a nondisruptive downgrade to Cisco NX-OS release earlier than Cisco NX-OS 4.2(1). If you attempt a nondisruptive downgrade, the downgrade may fail with the following error: TCAM allocation has changed.
  • Page 398: Estimating Memory Requirements For Routes

    1000 to 112000. The num-nexthops range is from 1 to 16. Example: switch# show routing memory estimate routes 5000 next-hops 16 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-12 OL-20002-02...
  • Page 399: Clearing Routes In The Unicast Rib

    Displays the FIB distribution information. fib-state} show forwarding interfaces module slot Displays the FIB information for a module. show forwarding {ip | ipv4 | ipv6} route Displays routes in the FIB. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-13 OL-20002-02...
  • Page 400: Additional References

    Added support to load balance per packet on an interface. Unicast RIB and FIB 4.0(3) Added support to clear individual routes in unicast RIB and FIB. Unicast RIB and FIB 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 15-14 OL-20002-02...
  • Page 401: Configuring Route Policy Manager

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . C H A P T E R Configuring Route Policy Manager This chapter describes how to configure the Route Policy Manager on the Cisco NX-OS device. This chapter includes the following sections: Information About Route Policy Manager, page 16-1 •...
  • Page 402: Prefix Lists

    IP packet. When Cisco NX-OS processes a route or packet through a route map, it compares the route or packet to each of the match statements configured. If the route or packet matches the configured criteria, Cisco NX-OS processes it based on the permit or deny configuration for that match entry in the route map and any set criteria configured.
  • Page 403: Set Changes

    Precedence • • You can use ACLs in a route map for policy-based routing only. See the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x for more information on ACLs. AS Numbers for BGP You can configure a list of AS numbers to match against BGP peers. If a BGP peer matches an AS number in the list and matches the other BGP peer configuration, BGP creates a session.
  • Page 404: Community Lists For Bgp

    A regular expression. • See the Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference for more information on regular expressions. Extended Community Lists for BGP Extended community lists support 4-byte AS numbers. You can configure community attributes in the...
  • Page 405: Policy-based Routing

    Route Policy Manager requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 406: Configuring Route Policy Manager

    • Configuring Route Maps, page 16-11 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring IP Prefix Lists IP prefix lists match the IP packet or route against a list of prefixes and prefix lengths.
  • Page 407 20 permit 209.165.201.0/27 eq 27 switch(config)# router bgp 65536:20 switch(config-router)# neighbor 192.0.2.1/16 remote-as 65535:20 switch(config-router-neighbor)# address-family ipv4 unicast switch(config-router-neighbor-af)# prefix-list allowprefix in Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-7 OL-20002-02...
  • Page 408: Configuring As-path Lists

    AllowAS permit 64496 switch(config)# copy running-config startup-config switch(config)# router bgp 65536:20 switch(config-router)# neighbor 192.0.2.1/16 remote-as 65535:20 switch(config-router-neighbor)# address-family ipv4 unicast switch(config-router-neighbor-af)# filter-list AllowAS in Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-8 OL-20002-02...
  • Page 409: Configuring Community Lists

    65536:20 Creates an expanded BGP community list using a ip community-list expanded list-name {deny | permit} expression regular expression. Example: switch(config)# ip community-list expanded BGPComplex deny 50000:[0-9][0-9]_ Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-9 OL-20002-02...
  • Page 410: Configuring Extended Community Lists

    {deny | permit} generic {transitive | nontransitive} aa4:nn ip extcommunity-list expanded list-name {deny | permit} generic {transitive | nontransitive} show ip extcommunity-list name copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-10 OL-20002-02...
  • Page 411: Configuring Route Maps

    Configuring a route map for BGP triggers an automatic soft clear or refresh of BGP neighbor sessions. SUMMARY STEPS config t route-map map-name [permit | deny] [seq] Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-11 OL-20002-02...
  • Page 412 You can configure the following optional match parameters for route maps in route-map configuration mode: The default-information originate command ignores match statements in the optional route Note map. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-12 OL-20002-02...
  • Page 413 Matches an IPv6 multicast packet based on the [[group ipgroup ] [ rp iprp ]] multicast source, group, or rendezvous point. Example: switch(config-route-map)# match ip multicast source 2001:0DB8::1 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-13 OL-20002-02...
  • Page 414 [ tagid... ] filtering or redistribution. Example: switch(config-route-map)# match tag 2 You can configure the following optional set parameters for route maps in route-map configuration mode: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-14 OL-20002-02...
  • Page 415 Example: BGP route update. Use the ip extcommunity-list switch(config-route-map)# set extcomm-list command to create the extended community list. BGPextCommunity delete Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-15 OL-20002-02...
  • Page 416 255 (100 percent reliable). metric3—Loading. The range is from 1 to 200 • (100 percent loaded). metric4—MTU of the path. The range is from • 1 to 4294967295. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-16 OL-20002-02...
  • Page 417: Verifying Route Policy Manager Configuration

    This example shows how to use an address family to configure Route Policy Manager so that any unicast and multicast routes from neighbor 209.0.2.1 are accepted if they match prefix-list AllowPrefix: router bgp 64496 neighbor 209.0.2.1 remote-as 64497 address-family ipv4 unicast Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-17 OL-20002-02...
  • Page 418: Related Topics

    Default Route Policy Manager Enabled Additional References For additional information related to implementing IP, see the following sections: Related Documents, page 16-19 • Standards, page 16-19 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-18 OL-20002-02...
  • Page 419: Related Documents

    Added support for generic specific extended community lists. Match AS numbers 4.1(2) Added support to match a range of AS numbers in a route map. Route Policy Manager 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 16-19 OL-20002-02...
  • Page 420 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 421: Configuring Policy-based Routing

    If the statement is marked as permit and the packets do not match any route map statements, the packets are sent back through the normal forwarding channels and destination-based routing is performed. See the “Route Maps” section on page 16-2. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 17-1 OL-20002-02...
  • Page 422: Policy Route Maps

    You can optionally configure the set criteria for next-hop addresses to load balance traffic across Note up to 16 IP addresses. In this case, Cisco NX-OS sends all traffic for each IP flow to a particular IP next-hop address. List of default next-hop IP addresses—Route to the interface or the next-hop address specified by this set statement only if there is no explicit route for the destination address of the packet in the routing table.
  • Page 423: Licensing Requirements For Policy-based Routing

    NX-OS Policy-based routing requires an Enterprise Services license. For a complete explanation of the NX-OS licensing scheme and how to obtain and apply licenses, see the Cisco NX-OS Licensing Guide. Prerequisites for Policy-Based Routing Policy-Based Routing has the following prerequisites: Install the correct license.
  • Page 424: Enabling The Policy-based Routing Feature

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 425: Configuring A Route Policy

    Step 5 (Optional) Exits route-map configuration mode. exit Example: switch(config)# exit Step 6 (Optional) Saves this configuration change. copy running-config startup-config Example: switch# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 17-5 OL-20002-02...
  • Page 426 192.0.2.2 Use the optional load-share keyword to load balance traffic across up to 16 next-hop addresses. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 17-6 OL-20002-02...
  • Page 427: Verifying Policy-based Routing Configuration

    Example: switch(config-route-map)# set vrf MainVRF Cisco NX-OS routes the packet as soon as it finds a next hop and an interface. Verifying Policy-Based Routing Configuration To display policy-based routing configuration information, perform one of the following tasks:...
  • Page 428: Related Topics

    Parameters Default Policy-based routing disabled Additional References For additional information related to implementing IP, see the following sections: Related Documents, page 17-9 • • Standards, page 17-9 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 17-8 OL-20002-02...
  • Page 429: Related Documents

    Table 17-2 Feature History for Policy-Based Routing Feature Name Releases Feature Information IPv6 policies 4.2(1) Added support for IPv6 policies. policy-based routing 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 17-9 OL-20002-02...
  • Page 430 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 431: First-hop Redundancy Protocols

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . A R T First-Hop Redundancy Protocols...
  • Page 432 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m .
  • Page 433: Configuring Glbp

    GLBP Virtual Forwarder Redundancy, page 18-3 • GLBP Authentication, page 18-4 • GLBP Load Balancing and Tracking, page 18-5 • • High Availability, page 18-6 • Virtualization Support, page 18-6 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-1 OL-20002-02...
  • Page 434: Glbp Overview

    The AVG also answers Address Resolution Protocol (ARP) requests for the virtual IP address. Load sharing is achieved when the AVG replies to the ARP requests with different virtual MAC addresses. In Cisco NX-OS Release 4.1(2) and later, packets received on a routed port destined for the GLBP virtual Note IP address will terminate on the local router, regardless of whether that router is the active GLBP router or a redundant GLBP router.
  • Page 435: Glbp Virtual Gateway Redundancy

    0007.b400.0101 that points to router A. Client 2 shares the same default gateway IP address but receives the gateway MAC address 0007.b400.0102 because router B is sharing the traffic load with router A. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-3 OL-20002-02...
  • Page 436: Glbp Authentication

    The authentication schemes differ on the router and in the incoming packet. MD5 digests differ on the router and in the incoming packet. • • Text authentication strings differ on the router and in the incoming packet. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-4 OL-20002-02...
  • Page 437: Glbp Load Balancing And Tracking

    120, lower 85, upper 110 weight: 100 (default) AVF for vMAC1 secondary VF for vMAC1 load balance: weighted load balance: weighted vMAC1 vMAC2 Host 1 Host 2 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-5 OL-20002-02...
  • Page 438: High Availability

    License Requirement NX-OS GLBP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 439: Guidelines And Limitations

    Enabling a GLBP Group, page 18-14 • Note If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature might differ from the Cisco IOS commands that you would use. Enabling the GLBP Feature You must enable the GLBP feature before you can configure and enable any GLBP groups.
  • Page 440: Configuring Glbp Authentication

    Configuring GLBP Authentication You can configure GLBP to authenticate the protocol using cleartext or an MD5 digest. MD5 authentication uses a key chain (see the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x). BEFORE YOU BEGIN Ensure that you are in the correct VDC (or use the switchto vdc command).
  • Page 441 Example: switch(config-if-glbp)# copy running-config startup-config The following example shows how to configure MD5 authentication for GLBP on Ethernet 1/2 after creating the key chain: switch# config t Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-9 OL-20002-02...
  • Page 442: Configuring Glbp Load Balancing

    18-7). SUMMARY STEPS config t track object-id interface interface-type number {ip routing | line-protocol} track object-id ip route ip-prefix/length reachability interface interface-type slot/port ip ip-address/length glbp group-number Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-10 OL-20002-02...
  • Page 443 Configures the IPv4 address for the interface. ip ip-address /length Example: switch(config-if)# ip 192.0.2.1/8 Step 5 Creates a GLBP group and enters GLBP configuration glbp group-number mode. Example: switch(config-if)# glbp 1 switch(config-if-glbp)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-11 OL-20002-02...
  • Page 444 2 interface ethernet 2/2 ip routing switch(config)# interface ethernet 1/2 switch(config-if)# glbp 1 switch(config-if-glbp)# weighting 110 lower 95 upper 105 switch(config-if-glbp)# weighting track 2 decrement 20 switch(config-if-glbp)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-12 OL-20002-02...
  • Page 445: Customizing Glbp

    AVG takes place. The seconds range is from 0 to 3600 seconds. The minimum delay default is 3600 seconds. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-13 OL-20002-02...
  • Page 446: Enabling A Glbp Group

    Configures the IPv4 address for the interface. ip ip-address /length Example: switch(config-if)# ip 192.0.2.1/8 Step 4 Creates a GLBP group and enters GLBP configuration glbp group-number mode. Example: switch(config-if)# glbp 1 switch(config-if-glbp)# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-14 OL-20002-02...
  • Page 447: Verifying Glbp Configuration

    [listen] [standby] brief selected state. GLBP Example Configuration The following example enables GLBP on an interface, with MD5 authentication, interface tracking, and weighted load balancing: Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-15 OL-20002-02...
  • Page 448: Default Settings

    Redirect timer 600 seconds Weighting Additional References For additional information related to implementing GLBP, see the following sections: Related Documents, page 18-17 • Standards, page 18-17 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-16 OL-20002-02...
  • Page 449: Related Documents

    Feature History for GLBP Feature Name Releases Feature Information Extended hold timers 4.2(1) Added support for extended hold timers for extended NSF support. GLBP 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 18-17 OL-20002-02...
  • Page 450 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 451: Configuring Hsrp

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . C H A P T E R Configuring HSRP This chapter describes how to configure the Hot Standby Router Protocol (HSRP) on the Cisco NX-OS device. This chapter includes the following sections: Information About HSRP, page 19-1 •...
  • Page 452: Hsrp Overview

    HSRP. By sharing a virtual MAC address and a virtual IP address, two or more interfaces can act as a single virtual router. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-2 OL-20002-02...
  • Page 453: Hsrp Versions

    From the host perspective, the virtual router remains the same. In Cisco NX-OS Release 4.1(2) and later, packets received on a routed port destined for the HSRP virtual Note IP address will terminate on the local router, regardless of whether that router is the active HSRP router or the standby HSRP router.
  • Page 454: Hsrp Authentication

    HSRP groups to load share traffic from the connected hosts while providing the default router redundancy expected from HSRP. Figure 19-2 shows an example of a load-sharing HSRP configuration. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-4 OL-20002-02...
  • Page 455: Object Tracking And Hsrp

    HSRP interoperates with virtual port channels (vPCs). vPCs allow links that are physically connected to two different Cisco Nexus 7000 series devices to appear as a single port channel by a third device. See the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 4.x for more information on vPCs.
  • Page 456: High Availability And Extended Non-stop Forwarding

    License Requirement NX-OS HSRP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 457: Guidelines And Limitations

    Configuring Extended Hold Timers for HSRP, page 19-16 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 458: Enabling The Hsrp Feature

    “Enabling the HSRP Feature” section on page 19-8). Cisco NX-OS enables an HSRP group once you configure the virtual IP address on any member interface in the group. You should configure HSRP attributes such as authentication, timers, and priority before you enable the HSRP group.
  • Page 459 (Optional) Displays HSRP information. show hsrp [group group-number ] Example: switch(config-if)# show hsrp group 2 Step 9 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-if)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-9 OL-20002-02...
  • Page 460: Configuring The Hsrp Version

    Configuring the HSRP Version You can configure the HSRP version. If you change the version for existing groups, Cisco NX-OS reinitializes HSRP for those groups because the virtual MAC address changes. The HSRP version applies to all groups on the interface.
  • Page 461: Authenticating Hsrp

    Authenticating HSRP You can configure HSRP to authenticate the protocol using cleartext or MD5 digest authentication. MD5 authentication uses a key chain (see the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x). BEFORE YOU BEGIN Ensure that you have enabled the HSRP feature (see the “Enabling the HSRP Feature”...
  • Page 462: Configuring Hsrp Object Tracking

    HSRP interface for preemption. HSRP supports tracked objects and track lists. See Chapter 21, “Configuring Object Tracking” for more information on track lists. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-12 OL-20002-02...
  • Page 463 {ip | ipv6} route ip-prefix/length reachability configuration mode. The object-id range is from 1 to 500. Example: switch(config)# track 2 ip route 192.0.2.0/8 reachability switch(config-track# Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-13 OL-20002-02...
  • Page 464: Configuring The Hsrp Priority

    If you configure HSRP on a vPC-enabled interface, you can optionally configure the upper and lower threshold values to control when to fail over to the vPC trunk Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-14...
  • Page 465: Customizing Hsrp

    Specifies the IP redundancy name for an HSRP group. name string The string is from 1 to 255 characters. The default string Example: has the following format: switch(config-if-hsrp)# name HSRP-1 hsrp-<interface-short-name>-<group-id>. For example, hsrp-Eth2/1-1. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-15 OL-20002-02...
  • Page 466: Configuring Extended Hold Timers For Hsrp

    You must configure extended hold timers on all HSRP routers if you configure extended hold timers. If you configure a non-default hold timer, you should configure the same value on all HSRP routers when you configure HSRP extended hold timers. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-16 OL-20002-02...
  • Page 467: Verifying Hsrp Configuration

    00:00:00 Jun 01 2008 23:59:59 Sep 12 2008 send-lifetime 00:00:00 Jun 01 2008 23:59:59 Aug 12 2008 key 1 key-string 7 uaeqdyito accept-lifetime 00:00:00 Aug 12 2008 23:59:59 Dec 12 2008 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-17 OL-20002-02...
  • Page 468: Default Settings

    Derived from HSRP group number Additional References For additional information related to implementing HSRP, see the following sections: Related Documents, page 19-19 • • MIBs, page 19-19 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-18 OL-20002-02...
  • Page 469: Related Documents

    Added support for extended hold timers for extended NSF support. CISCO-HSRP-MIB 4.2(1) Added support for CISCO-HSRP-MIB. Priority thresholds 4.1(3) Added support for vPC threshold values on HSRP priority. HSRP 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 19-19 OL-20002-02...
  • Page 470 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 471: Configuring Vrrp

    • • vPC and VRRP, page 20-5 • VRRP Advertisements, page 20-5 • VRRP Authentication, page 20-5 VRRP Tracking, page 20-5 • High Availability, page 20-6 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-1 OL-20002-02...
  • Page 472: Vrrp Operation

    Router C Virtual router Virtual router Virtual router Virtual master backup backup router group IP address = 10.0.0.1 10.0.0.1 10.0.0.2 10.0.0.3 Client 1 Client 2 Client 3 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-2 OL-20002-02...
  • Page 473: Vrrp Benefits

    Router Priority and Preemption” section. In Cisco NX-OS Release 4.1(2) and later, packets received on a routed port destined for the VRRP virtual Note IP address will terminate on the local router, regardless of whether that router is the master VRRP router or a backup VRRP router.
  • Page 474: Vrrp Router Priority And Preemption

    Router C as the new master, even though Router B has not failed. If you disable preemption, VRRP will only switch if the original master recovers or the new master fails. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-4...
  • Page 475: Vpc And Vrrp

    VRRP interoperates with virtual port channels (vPCs). vPCs allow links that are physically connected to two different Cisco Nexus 7000 series devices to appear as a single port channel by a third device. See the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 4.x for more information on vPCs.
  • Page 476: High Availability

    License Requirement NX-OS VRRP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 477: Configuring Vrrp

    • Configuring VRRP Interface State Tracking, page 20-17 • If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use.
  • Page 478: Configuring Vrrp Groups

    IP address because the VRRP master is only intended as a next-hop router to forward packets. Some applications require that Cisco NX-OS accept packets addressed to the virtual router IP. Use the secondary option to the virtual IP address to accept these packets when the local router is the VRRP master.
  • Page 479: Configuring Vrrp Priority

    The default priority value for backups is 100. For devices whose interface IP address is the same as the primary virtual IP address (the master), the default value is 255. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-9...
  • Page 480 Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port vrrp number shutdown priority level [forwarding-threshold lower lower-value upper upper-value] no shutdown show vrrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-10 OL-20002-02...
  • Page 481: Configuring Vrrp Authentication

    (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-if-vrrp)# copy running-config startup-config Configuring VRRP Authentication You can configure simple text authentication for a VRRP group. BEFORE YOU BEGIN Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-11 OL-20002-02...
  • Page 482 Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port vrrp number shutdown authentication text password no shutdown show vrrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-12 OL-20002-02...
  • Page 483: Configuring Time Intervals For Advertisement Packets

    You can configure the time intervals for advertisement packets. BEFORE YOU BEGIN Ensure that you have enabled the VRRP feature (see the “Configuring VRRP” section on page 20-7). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-13 OL-20002-02...
  • Page 484 Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port vrrp number shutdown advertisement-interval seconds no shutdown show vrrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-14 OL-20002-02...
  • Page 485: Disabling Preemption

    Preemption is enabled by default. BEFORE YOU BEGIN Ensure that you have enabled the VRRP feature (see the “Configuring VRRP” section on page 20-7). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-15 OL-20002-02...
  • Page 486 Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port vrrp number shutdown no preempt no shutdown show vrrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-16 OL-20002-02...
  • Page 487: Configuring Vrrp Interface State Tracking

    Interface state tracking changes the priority of the virtual router based on the state of another interface in the device. When the tracked interface goes down or the IP address is removed, Cisco NX-OS assigns the tracking priority value to the virtual router. When the tracked interface comes up and an IP address is configured on this interface, Cisco NX-OS restores the configured priority to the virtual router (see the“Configuring VRRP Priority”...
  • Page 488 Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t interface interface-type slot/port vrrp number shutdown track interface type number priority value no shutdown show vrrp copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-18 OL-20002-02...
  • Page 489: Verifying The Vrrp Configuration

    To verify VRRP configuration information, use the following commands: Command Purpose show vrrp Displays the VRRP status for all groups. show vrrp vr group-number Displays the VRRP status for a VRRP group. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-19 OL-20002-02...
  • Page 490: Displaying Vrrp Statistics

    Router A will become the master for this group first because it has a higher IP address (10.1.0.2). Advertising interval is the default 1 second. – Preemption is disabled. – Router A interface ethernet 1/0 ip address 10.1.0.2/16 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-20 OL-20002-02...
  • Page 491: Default Settings

    VRRP parameters. Table 20-1 Default VRRP Parameters Parameters Default advertisement interval 1 seconds authentication no authentication preemption enabled priority VRRP feature disabled Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-21 OL-20002-02...
  • Page 492: Additional References

    4.2(1) Added support for priority thresholds and vPC. VRRP object tracking 4.2(1) Added support for tracking multiple object types in VRRP. VRRP 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 20-22 OL-20002-02...
  • Page 493: Configuring Object Tracking

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . C H A P T E R Configuring Object Tracking This chapter describes how to configure object tracking on Cisco NX-OS devices. This chapter includes the following sections: Information About Object Tracking, page 21-1 •...
  • Page 494: Object Tracking Overview

    Other entities, such as virtual Port Channels (vPCs) can use an object track list to modify the state of a vPC based on the state of the multiple peer links that create the vPC. See the Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 4.x for more information on vPCs.
  • Page 495: High Availability

    License Requirement NX-OS Object tracking requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For a complete explanation of the NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
  • Page 496: Configuring Object Tracking

    Configuring Object Tracking for a Nondefault VRF, page 21-12 Note If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature might differ from the Cisco IOS commands that you would use.
  • Page 497: Configuring Object Tracking For Route Reachability

    Configuring Object Tracking for Route Reachability You can configure Cisco NX-OS to track the existence and reachability of an IP route. BEFORE YOU BEGIN Ensure that you are in the correct VDC (or use the switchto vdc command).
  • Page 498: Configuring An Object Track List With A Boolean Expression

    BEFORE YOU BEGIN Ensure that you are in the correct VDC (or use the switchto vdc command). Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-6 OL-20002-02...
  • Page 499 Step 4 (Optional) Displays object tracking information. show track Example: switch(config-track)# show track Step 5 (Optional) Saves this configuration change. copy running-config startup-config Example: switch(config-track)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-7 OL-20002-02...
  • Page 500: Configuring An Object Track List With A Percentage Threshold

    Configures the threshold percent for the tracked list. threshold percentage up up-value down down-value The range from 0 to 100 percent. Example: switch(config-track)# threshold percentage up 70 down 30 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-8 OL-20002-02...
  • Page 501: Configuring An Object Track List With A Weight Threshold

    Ensure that you are in the correct VDC (or use the switchto vdc command). SUMMARY STEPS config t track track-number list threshold weight threshold weight up up-value down down-value object object-number weight value show track copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-9 OL-20002-02...
  • Page 502 In this example, the track list is up if object 10 and object 20 are up, and the track list goes to the down state if all three objects are down. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-10...
  • Page 503: Configuring An Object Tracking Delay

    The tracked object or track list starts the delay timer when a state change occurs but does recognize a state change until the delay timer reaches zero. At that point, Cisco NX-OS checks the object state again and records a state change only if the object or list currently has a changed state.
  • Page 504: Configuring Object Tracking For A Nondefault Vrf

    20 down 30 Configuring Object Tracking for a Nondefault VRF You can configure Cisco NX-OS to track an object in a specific VRF. BEFORE YOU BEGIN Ensure that you are in the correct VDC (or use the switchto vdc command).
  • Page 505 This example shows how to modify tracked object 2 to use VRF Blue instead of VRF RED to look up reachability information for this object: switch# config t switch(config)# track 2 switch(config-track)# vrf member Blue switch(config-track)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-13 OL-20002-02...
  • Page 506: Verifying Object Tracking Configuration

    Default Tracked Object VRF Member of default VRF Additional References For additional information related to implementing object tracking, see the following sections: Related Documents, page 21-15 • Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-14 OL-20002-02...
  • Page 507: Related Documents

    Object track list 4.2(1) Added support for object track lists and Boolean expressions. IPv6 support 4.1(2) Added support for IPv6. Object tracking 4.0(1) This feature was introduced. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x 21-15 OL-20002-02...
  • Page 508 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 509: Appendix

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . A P P E N D I X IETF RFCs supported by Cisco NX-OS Unicast Features, Release 4.x This appendix lists the IETF RFCs supported in Cisco NX-OS Release 4.x. BGP RFCs RFCs Title...
  • Page 510: First-hop Redundancy Protocols Rfcs

    RADIUS and IPv6 RFC 3513 Internet Protocol Version 6 (IPv6) Addressing Architecture RFC 3596 DNS Extensions to Support IP version 6 RFC 4193 Unique Local IPv6 Unicast Addresses Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 511: Is-is Rfcs

    The OSPF Opaque LSA Option RFC 3137 OSPF Stub Router Advertisement draft-ietf-ospf-ospfv3-graceful-restart-04.txt OSPFv3 Graceful Restart RIP RFCs RFCs Title RFC 2453 RIP Version 2 RFC 2082 RIP-2 MD5 Authentication Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 512 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 513: G L O S S A R Y

    Active virtual gateway. One virtual gateway within a GLBP group is elected as the active virtual gateway and is responsible for the operation of the protocol. See BDR. backup designated router Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x GL-1 OL-20002-02...
  • Page 514 All neighbors establish adjacency with only the designated router and the backup designated router. Diffusing Update Algorithm. EIGRP algorithm used to select optimal routes to a destination. DUAL Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x GL-2 OL-20002-02...
  • Page 515 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . External Border Gateway Protocol (BGP). Operates between external systems. eBGP Enhanced Interior Gateway Protocol. A Cisco routing protocol that uses the Diffusing Update EIGRP Algorithm to provide fast convergence and minimized bandwidth utilization.
  • Page 516 IS-IS A special message sent between routing peers to verify and maintain communications between the pair. keepalive A method of controlling authentication keys. See the Cisco NX-OS Security Configuration Guide. key-chain management An arbitrary number configured on an OSPF interface which is in shortest path first calculations.
  • Page 517 Sum of all link costs or the hop count that a packet experiences when routed from the source to the path length destination. The method of using route maps to alter the route selected for a packet. policy-based routing Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x GL-5 OL-20002-02...
  • Page 518 A router that has no direct connection to the main network and which routes to that network using a stub router known remote router. Switched Virtual Interface. Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x GL-6 OL-20002-02...
  • Page 519 A method of making a physical entity act as multiple, independent logical entities. virtualization Virtual Routing and Forwarding. A method used to create separate, independent Layer 3 entities within a system. Virtual Router Redundancy Protocol. VRRP Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x GL-7 OL-20002-02...
  • Page 520 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...
  • Page 521: Appendix

    VLAN interface. 100 HSRP groups per port-channel interface. Object tracking 500 objects. OSPF 200 interfaces 1000 routers 300 adjacencies 200,000 LSAs 4 instances per VDC 200 VRFs per instance Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 522: Configuration Limits For Cisco Nx-os Layer 3 Unicast Features, Release 4.x

    S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Table 2-1 Cisco NX-OS Release 4.x Configuration Limits (continued) Feature Verified Limit Maximum Limit VRFs 200 per VDC VRRP 255 groups Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x OL-20002-02...
  • Page 523: I N D E X

    10-10 configuring 11-25 example configuration 10-23 description 11-4 feature history (table) 10-25, 16-19 AS numbers generic specific extended community lists 16-4 4-byte support. guidelines 10-8, 11-12 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-1 OL-20002-02...
  • Page 524 16-4 BGP extended community lists description 16-4 3-12 BGP graceful restart communication cost configuring 11-39 community lists description 11-10 configuring 16-9, 16-10 BGP instance description 16-4 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-2 OL-20002-02...
  • Page 525 8-17 description configuring with VRFs 8-28 example configuration creating an instance 8-10 feature history (table) default settings 8-31 guidelines deleting an instance 8-12 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-3 OL-20002-02...
  • Page 526 18-7 equal cost multipath example configuration 18-15 extended community lists feature history (table) 5-13, 18-17 description verifying configuration 16-4 5-12, 18-15 external BGP. See eBGP graceful restart Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-4 OL-20002-02...
  • Page 527 19-6 feature history (table) Internet Control Message Protocol. See ICMP 19-19 guidelines 19-7 hold timers 19-6 addresses licensing requirements ARP. See ARP 19-6 limitations configuring addresses 19-7 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-5 OL-20002-02...
  • Page 528 3-24 guidelines feature history (table) licensing requirements 3-25 guidelines limitations 3-18 ICMP limit redistributed routes 3-12 9-20 interface ID LSPs licensing requirements 3-18 limitations prerequisites 3-18 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-6 OL-20002-02...
  • Page 529 9-16 Local Proxy ARP description configuring 2-11 IS-IS route redistribution description configuring 9-19 LSAs description for OSPFv3 (table) IS-IS route summarization configuring 9-17 description ISSU MIBs 11-11 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-7 OL-20002-02...
  • Page 530 6-29 feature history (table) 21-15 configuring with VRFs 6-42 guidelines 21-3 creating an instance 6-15 high availability 21-3 dead interval licensing requirements 21-3 default settings 6-45 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-8 OL-20002-02...
  • Page 531 7-41 description feature history (table) 6-10 7-43 shutting down an instance 6-19 guidelines 7-13 SPF optimization licensing requirements 6-12 7-12 stub area limitations 7-13 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-9 OL-20002-02...
  • Page 532 17-4 16-4 enabling related documents 17-4 iii-v example configuration reliability 17-7 feature history (table) 17-9 Reverse ARP guidelines description 17-3 licensing requirements limitations 17-3 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-10 OL-20002-02...
  • Page 533 16-5 configuring licensing requirements 12-7 16-5 description limitations 12-4 16-5 RIP route distribution prerequisite 16-5 description route policy manager 12-3 RIP route redistribution description 16-1 to 16-5 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-11 OL-20002-02...
  • Page 534 15-3 link-state Layer 3 consistency checker 15-2 next hop licensing requirements 15-3 redistribution 1-5, 1-6 limitations 15-3 virtualization 1-10 verifying 15-13 virtualization support 15-3 documentation feed iii-vi Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-12 OL-20002-02...
  • Page 535 Web Cache Communication Protocol. See WCCP example configuration 14-12 VRRP benefits 20-3 clearing statistics 20-20 configuring time intervals for advertisement packets 20-13 default settings 20-21 description 20-1 to 20-6 Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x IN-13 OL-20002-02...
  • Page 536 S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m . Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x...

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