Download Print this page

Cisco Nexus 2000 Series Manual

Fabric extender
Hide thumbs

Advertisement

Overview
This chapter provides an architectural overview of the Cisco Nexus 2000 Series Fabric Extender and includes
the following sections:
VLANs, page 6
Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series
Switches, Release 5.2
1

Advertisement

loading

  Related Manuals for Cisco Nexus 2000 Series

  Summary of Contents for Cisco Nexus 2000 Series

  • Page 1: Table Of Contents

    Overview This chapter provides an architectural overview of the Cisco Nexus 2000 Series Fabric Extender and includes the following sections: • Information About the Cisco Nexus 2000 Series Fabric Extender, page 2 • Fabric Extender Terminology, page 2 • Fabric Interface Features , page 3 •...
  • Page 2: Information About The Cisco Nexus 2000 Series Fabric Extender

    Information About the Cisco Nexus 2000 Series Fabric Extender The Cisco Nexus 2000 Series Fabric Extender, also known as FEX, is a highly scalable and flexible server networking solution that works with Cisco Nexus Series devices to provide high-density, low-cost connectivity for server aggregation.
  • Page 3: Fabric Interface Features

    In Cisco NX-OS Release 5.1 and earlier releases, the default port mode is Layer 2. To run a host interface in Layer 2 mode, use the switchport command. For Cisco NX-OS Release 5.2 and later releases, to change the port mode to Layer 3, use the no switchport command.
  • Page 4: Host Interface Port Channels

    • You can connect any edge switch that leverages a link redundancy mechanism not dependent on spanning tree such as Cisco FlexLink or vPC (with the BPDU Filter enabled) to a Fabric Extender host interface. Because spanning tree is not used to eliminate loops, you should ensure a loop-free topology below the Fabric Extender host interfaces.
  • Page 5 This process allows for a NIC switchover on the connection between the host and the FEX. The automatic recovery of Cisco Nexus 2000 Series interfaces to the standby FEX is triggered when the number of FPC links reaches the specified threshold.
  • Page 6: Vlans

    Note Protocol Offload To reduce the load on the control plane of the Cisco Nexus Series device, Cisco NX-OS allows you to offload link-level protocol processing to the Fabric Extender CPU. The following protocols are supported: • Link Layer Discovery Protocol (LLDP) •...
  • Page 7: Igmp Snooping

    • 1.2 to 1 oversubscription (48 host interfaces for four fabric interfaces) • 4.8 to 1 oversubscription (48 host interfaces for one fabric interface) Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...
  • Page 8: Management Model

    Overview Management Model The Cisco Nexus 2248TP can be run with no oversubscription when its host interfaces are running in 100-Mb mode. The Cisco Nexus 2248TP-E Fabric Extender has 4 10-Gigabit Ethernet fabric interfaces and 48 100/1000BASE-T (100-Mb/1-Gigabit) Ethernet host interfaces. When its host interfaces are running in Gigabit Ethernet mode, it offers 1.2 to 1 oversubscription (48 host interfaces for four fabric interfaces).
  • Page 9: Forwarding Model

    Forwarding Model Forwarding Model The Cisco Nexus 2000 Series Fabric Extender does not perform any local switching. All traffic is sent to the parent switch that provides central forwarding and policy enforcement, including host-to-host communications between two systems that are connected to the same Fabric Extender as shown in the following figure.
  • Page 10: Port Channel Fabric Interface Connection

    • chassis is configured by the administrator. A Fabric Extender must be directly connected to its parent Cisco Nexus Series device via a port channel fabric interface. You configure a chassis ID on a port channel on the switch to identify the Fabric Extender that is discovered through those interfaces.
  • Page 11: Fabric Extender Image Management

    • port identifies the port number on a specific slot and chassis ID. Fabric Extender Image Management No software ships with the Cisco Nexus 2000 Series Fabric Extender. The Fabric Extender image is bundled into the system image of the parent switch. The image is automatically verified and updated (if required) during the association process between the parent switch and the Fabric Extender.
  • Page 12 • All the uplinks and host ports of a Fabric Extender belong to a single VDC. The ports cannot be allocated or split among multiple VDCs. • You must connect the Fabric Extender to its parent Cisco Nexus 7000 Series device with a 32-port 10-Gigabit M1 module (N7K-M132XP-12), a 32-port, 10-Gigabit M1-XL module (N7K-M132XP-12L), an M2-Series module, or an F2-Series module.
  • Page 13 The egress queuing parameters of the active network-QoS policy do not affect the FEX host-port queuing. Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...
  • Page 14 FEX host interfaces includes the number of queues used, the mapping for each queue, the corresponding queue MTU, the enforced hardware queue limit, and the ingress and egress queue statistics. Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...
  • Page 15 Port Statistics: rx drop rx mcast drop rx error tx drop mux ovflow ---------------+---------------+---------------+---------------+-------------- InActive Priority-flow-control enabled: no Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...
  • Page 16 Interface is not in this module. • ISSU Behavior In Cisco NX-OS Release 6.2(2) and later releases, FEX queuing is disabled by default on all existing FEXs after an in-service software upgrade (ISSU). FEX queuing is enabled upon flapping the FEX. You can reload the FEX to enable queuing on any FEX after an ISSU.
  • Page 17 The queue limit is enabled by default for all FEXs, regardless of whether queuing is enabled or disabled for the FEX. In Cisco NX-OS Release 6.2(2), all FEXs come up with the default hardware queue-limit value. Any user-defined queue limit that is configured after an ISSU by using the hardware queue-limit command takes effect even if queuing is not enabled for the FEX.
  • Page 18 The MTU that is configured on a FEX port must match the MTU in the network-QoS policy map so that the FEX MTU can be applied to the FEX host interfaces. For more information, see the Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide.
  • Page 19: Default Settings

    Disabled Port mode Layer 3 (Cisco NX-OS Release 5.2 and later releases). Layer 2 (Cisco NX-OS Release 5.1 and earlier releases). Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...
  • Page 20 Overview Default Settings Cisco Nexus 2000 Series NX-OS Fabric Extender Software Configuration Guide for Cisco Nexus 7000 Series Switches, Release 5.2...