Cisco Nexus 5000 Series Configuration Manual

Nx-os quality of service
Hide thumbs Also See for Nexus 5000 Series:
Table of Contents

Advertisement

Cisco Nexus 5000 Series NX-OS Quality of Service Configuration
Guide
Americas Headquarters
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA
http://www.cisco.com
Tel: 408 526-4000
800 553-NETS (6387)
Fax: 408 527-0883
Text Part Number: OL-20921-01

Advertisement

Table of Contents
loading

Summary of Contents for Cisco Nexus 5000 Series

  • Page 1 Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883 Text Part Number: OL-20921-01...
  • Page 2 Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks . Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company.
  • Page 3: Table Of Contents

    Information About QoS System Classes Default System Classes Policy Types Link-Level Flow Control Priority Flow Control Trust Boundaries Ingress Queuing Policies Ingress Classification Policies Egress Queuing Policies QoS for Multicast Traffic Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 4 Configuring Priority Flow Control and Link-Level Flow Control Configuring Priority Flow Control Configuring Link-Level Flow Control Enabling Virtual Output Queuing Limits for Unicast Traffic on the Cisco Nexus 5548 Switch Verifying QoS Configuration Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide...
  • Page 5 Contents Example QoS Configurations QoS Example 1 QoS Example 2 QoS Example 3 Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 6 Contents Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 7: Preface

    Preface This preface describes the audience, organization, and conventions of the Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide. It also provides information on how to obtain related documentation. • Audience, page vii • Document Organization, page vii •...
  • Page 8: Document Conventions

    !, # An exclamation point (!) or a pound sign (#) at the beginning of a line of code indicates a comment line. This document uses the following conventions: Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide viii OL-20921-01...
  • Page 9: Related Documentation For Nexus 5000 Series Nx-Os Software

    Related Documentation for Nexus 5000 Series NX-OS Software Cisco NX-OS documentation is available at the following URL: http://www.cisco.com/en/US/products/ps9670/tsd_products_support_series_home.htmll The documentation set for the Cisco Nexus 5000 Series NX-OS software includes the following documents: Release Notes • Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Release Notes •...
  • Page 10: 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 11: New And Changed Information

    The information in these new guides previously existed in the Cisco Nexus 5000 Series NX-OS Configuration Guide which remains available on Cisco.com and should be used for all software releases prior to Cisco Nexus 5000 NX-OS Software Rel 4.1(3). Each new configuration guide addresses the features that are introduced...
  • Page 12 Part 6: Quality of Service of the Cisco Nexus 5000 Series CLI Configuration Guide. For a complete list of Nexus 5000 Series document titles, see the list of Related Documentation in the Preface. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide...
  • Page 13: Overview

    C H A P T E R Overview Cisco Nexus 5000 Series switches support the Quality of Service features that are described in this guide. • Overview, page 3 Overview This document describes the configurable Cisco Nexus 5000 Series NX-OS Quality of Service (QoS) features.
  • Page 14 Overview Overview Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 15: Configuring Qos

    C H A P T E R Configuring QoS This chapter describes how to configure quality of service (QoS) on Cisco Nexus 5000 Series switches. It contains the following sections: • Information About QoS, page 5 • QoS Configuration Guidelines and Limitations, page 14 •...
  • Page 16: Mqc

    FCoE, Ethernet has been enhanced with a priority flow control (PFC) mechanism to prevent congestion. The Cisco Modular QoS CLI (MQC) provides a standard set of commands for configuring QoS. You can use MQC to define additional traffic classes and to configure QoS policies for the whole system and for individual interfaces.
  • Page 17: System Classes

    On the Cisco Nexus 5000 Series switch, a system class is uniquely identified by a qos-group value. A total of six system classes are supported. Two of the six system classes are defaults and are always present on the switch.
  • Page 18: Policy Types

    Policy Types The Cisco Nexus 5000 Series switch supports a number of policy types. You create class maps in the policy types. There are three policy types. The following QoS parameters can be specified for each type of class: •...
  • Page 19 For the Cisco Nexus 5020 switch and the Cisco Nexus 5010 switch, the marking value for a system class needs to be unique and cannot be used as a marking value for any other system class. The marking value does not need to be unique for the Cisco Nexus 5548 switch.
  • Page 20: Link-Level Flow Control

    The transmit and receive directions are separately configurable. By default, link-level flow control is disabled for both directions. On the Cisco Nexus 5000 Series switch, Ethernet interfaces do not automatically detect the link-level flow control capability. You must configure the capability explicitly on the Ethernet interfaces.
  • Page 21: Mtu

    If you do not enable PFC on an interface, you can enable IEEE 802.3X link-level pause. By default, link-level pause is disabled. The Cisco Nexus 5000 Series switch is a Layer 2 switch, and it does not support packet fragmentation. A maximum transmission unit (MTU) configuration mismatch between ingress and egress interfaces may result in packets being truncated.
  • Page 22: Ingress Queuing Policies

    If you add a system class, a queue is assigned to the class. You must reconfigure the bandwidth allocation on all affected interfaces. Bandwidth is not dedicated automatically to user-defined system classes. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 23: Qos For Multicast Traffic

    For the Cisco Nexus 5548 switch, Cisco NX-OS Release 5.0(2)N1(1) provides 128 multicast queues at ingress. For the Cisco Nexus 5020 switch and the Cisco Nexus 5020 switch, the system provides six multicast queues per interface and allocates one queue for each system class. By default, all multicast Ethernet traffic is classified into the default drop system class.
  • Page 24: Qos For Traffic Directed To The Cpu

    CoS value of 7. CoS 7 is reserved for control traffic transiting the Fabric Extender. • On the Cisco Nexus 5548 Switch, the FCoE class-fcoe system class is not enabled by default in the QoS configuration. Before enabling FCoE, you must include class-fcoe in each of the three policy types (network-qos, queuing, and qos).
  • Page 25: Configuring System Classes

    CoS and the ACL criteria matches) • match-any—Classifies traffic if packets match any criteria that is defined for a specified class map. (for example, if the CoS or the ACL criteria matches). Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 26: Configuring Acl Classification

    Removes the match from the traffic class. This example shows how to classify traffic by matching packets based on existing ACLs: switch# configure terminal switch(config)# class-map type qos class_acl switch(config-cmap-qos)# match access-group name acl-01 Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 27: Configuring Cos Classification

    Specifies the CoS value to match for classifying packets into this class. You can configure a CoS value in the range of 0 to 7. cos-value When a Cisco Nexus 2148T Fabric Extender is connected and in Note use, data traffic should never be marked with a CoS value of 7.
  • Page 28: Configuring Dscp Classification

    CS2 (precedence 2) dscp (010000)—decimal value CS3 (precedence 3) dscp (011000)—decimal value CS4 (precedence 4) dscp (100000)—decimal value CS5 (precedence 5) dscp (101000)—decimal value CS6 (precedence 6) dscp (110000)—decimal value Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 29: Configuring Ip Rtp Classification

    The IP Real-time Transport Protocol (RTP) is a transport protocol for real-time applications that transmits data such as audio or video and is defined by RFC 3550. Although RTP does not use a common TCP or UDP Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 30: Configuring Precedence Classification

    You can classify traffic based on the precedence value in the type of service (ToS) byte field of the IP header (either IPv4 or IPv6). The following table shows the precedence values: Table 2: Precedence Values Value List of Precedence Values <0-7> IP precedence value Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 31 This example shows how to classify traffic by matching packets based on the precedence value in the ToS byte field of the IP header: switch# configure terminal switch(config)# class-map type qos class_precedence switch(config-cmap-qos)# match precedence 1-2, critical Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 32: Configuring Protocol Classification

    Step 3 switch(config-cmap-qos)# match protocol {arp | Configures the traffic class by matching packets based on the clns_es | clns_is | dhcp | ldp | netbios} specified protocol. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 33: Configuring Qos Group Classification

    0 and 1 are reserved for default classes and cannot Note be configured. Step 4 switch(config-cmap-que)# no match (Optional) qos-group qos-group-value Removes the match from the traffic class. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 34: Configuring Policy Maps

    • Input qos: default-in-policy • Input queuing: default-in-policy • Output queuing: default-out-policy Beginning with Cisco NX-OS Release 5.0(2)N1(1), for the Cisco Nexus 5548 switch, there are four pre-defined policy maps for FCoE: • service-policy type qos input fcoe-default-in-policy • service-policy type queuing input fcoe-default-in-policy •...
  • Page 35 The three class-map configuration modes are as follows: class-name • network-qos—Network-wide (global) mode. CLI prompt: switch(config-pmap-c-nq)# • qos—Classification mode; this is the default mode. CLI prompt: switch(config-pmap-c-qos)# • queuing—Queuing mode. CLI prompt: switch(config-pmap-c-que)# Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 36: Configuring Type Qos Policies

    A type qos policy can be attached to the system or to individual interfaces (including Fabric Extender host interfaces) for ingress traffic only. Beginning with Cisco Release NX-OS Release 5.0(2)N1(1), for the Cisco Nexus 5548 switch, you can set a maximum of five qos groups for ingress traffic.
  • Page 37: Configuring Type Network Qos Policies

    Configuring QoS Configuring Policy Maps Command or Action Purpose The Cisco Nexus 5000 Series switch can only support a maximum Note of five qos-groups within this range. Step 5 switch(config-pmap-c-qos)# no set (Optional) qos-group qos-group-value Removes the qos-group values from this class.
  • Page 38 CLI will return an error. Use the pause no-drop buffer size option to change the buffer size and pause threshold for the no-drop class. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 39: Configuring Type Queuing Policies

    Creates a named object that represents a set of policies that are to be policy-name applied to a set of traffic classes. Policy-map names can contain alphabetic, hyphen, or underscore characters, are case sensitive, and can be up to 40 characters. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 40: Information About Marking

    • CoS Configuring CoS Marking You can set the value of the CoS field in the high-order three bits of the VLAN ID Tag field in the IEEE 802.1Q header. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 41: Attaching The System Service Policy

    4. (Optional) switch(config-sys-qos)# service-policy type {network-qos | qos | queuing} [input | output] fcoe default policy-name DETAILED STEPS Command or Action Purpose Step 1 switch# configure terminal Enters configuration mode. Step 2 switch(config)# system qos Enters system class configuration mode. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 42: Restoring The Default System Service Policies

    • service-policy type queuing output fcoe-default-out-policy • service-policy type network-qos fcoe-default-nq-policy Note Befoe enabling FCoE on the Cisco Nexus 5548 switch, you must attach the pre-defined FCoE policy maps to the type qos, type network-qos, and type queuing policy maps.
  • Page 43 Type qos policy-maps ==================== policy-map type qos default-in-policy class type qos class-fcoe set qos-group 1 class type qos class-default set qos-group 0 Type queuing policy-maps ======================== Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 44: Configuring The Queue Limit For Fabric Extenders

    Enters configuration mode. Step 2 switch(config)# system qos Enters system class configuration mode. Step 3 switch(config-sys-qos)# fex queue-limit Limits the amount of input buffer space allocated to each Fabric Extender port. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 45: Enabling The Jumbo Mtu

    Verifying the Jumbo MTU To verify that the jumbo MTU is enabled, enter the show interface ethernet slot/port command for an Ethernet interface that carries traffic with jumbo MTU. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 46: Configuring Qos On Interfaces

    Any incoming packet not tagged with an 802.1p CoS value is assigned the default untagged CoS value of zero (which maps to the default Ethernet drop system class). You can override the default untagged CoS value for an Ethernet or EtherChannel interface. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 47: Configuring Interface Service Policy

    On the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch, untagged CoS and type QoS input policies are mutually exclusive on an Ethernet or EtherChannel interface. If a type qos policy is configured at the interface, untagged frames received over that interface will not match any match cos 0 commands in the policy.
  • Page 48: Configuring The Queue Limit For A Specified Fabric Extender

    ("head-of-line blocking"). A higher queue limit provides better burst absorption and less head-of-line blocking protection. You can use the no form of this command to allow the Fabric Extender to use all available hardware space. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 49 This example shows how to restore the default queue limit on a Cisco Nexus 2248T Fabric Extender: switch# configure terminal switch(config-if)# fex 101 switch(config-fex)# hardware N2248T queue-limit 327680 This example shows how to remove the queue limit that is set by default on a Cisco Nexus 2248T Fabric Extender: switch# configure terminal switch(config)# fex 101...
  • Page 50: Configuring No-Drop Buffer Thresholds

    Beginning with Cisco NX-OS Release 5.0(2)N1(1), you can configure the no-drop buffer threshold settings for 3000m lossless Ethernet. To achieve lossless Ethernet for both directions, the devices connected to the Cisco Nexus 5548 switch Note must have the similar capability. The default buffer and threshold value for the no-drop can ensure lossless Ethernet for up to 3000 meters.
  • Page 51: Configuring The Buffer Threshold For The Cisco Nexus 2148T Fabric Extender

    Configuring the Buffer Threshold for the Cisco Nexus 2148T Fabric Extender In the Fabric Extender configuration mode, you can configure the buffer threshold for the Cisco Nexus 2148T Fabric Extender. The buffer threshold sets the consumption level of input buffers before an indication is sent...
  • Page 52: Configuring Priority Flow Control And Link-Level Flow Control

    Extender. The buffer threshold is specified in bytes. The range is from 81920 to 316160 for the Cisco Nexus 2148T Fabric Extender. This example shows how to restore the default buffer threshold on the Cisco Nexus 2148T Fabric Extender: switch# configure terminal...
  • Page 53: Configuring Priority Flow Control

    1/2 switch(config-if)# priority-flow-control mode on Configuring Link-Level Flow Control By default, LLC on Ethernet interfaces is disabled. You can enable LLC for the transmit and receive directions. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 54: Switch

    Configuring QoS Enabling Virtual Output Queuing Limits for Unicast Traffic on the Cisco Nexus 5548 Switch SUMMARY STEPS 1. switch# configure terminal 2. switch(config)# interface type slot/port 3. switch(config-if)# flowcontrol [receive {on | off}] [transmit {on | off}] 4. (Optional) switch(config-if)# no flowcontrol [receive {on | off}] [transmit {on | off}]...
  • Page 55: Verifying Qos Configuration

    [interface number] Displays the queue configuration and statistics. You can clear the QoS policy statistics. Command Purpose switch# clear qos statistics Clears the policy statistics. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 56 2 class-map type network-qos c2 match qos-group 3 class-map type network-qos c3 match qos-group 4 class-map type network-qos c4 match qos-group 5 class-map type network-qos class-fcoe match qos-group 1 Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 57 2240 class type network-qos class-default mtu 1538 This example shows how to display the policy maps attached on the system qos: switch# show policy-map system Type network-qos policy-maps =============================== Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 58 This example shows how to display the policy maps attached to an interface: switch# show policy-map interface ethernet 1/1 Global statistics status : disabled Ethernet1/1 Service-policy (qos) input: policy statistics status: disabled Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 59 (match-any) Match: qos-group 2 bandwidth percent 5 priority Class-map (queuing): c2 (match-any) Match: qos-group 3 bandwidth percent 20 Class-map (queuing): c3 (match-any) Match: qos-group 4 bandwidth percent 20 Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 60 Mcast pkts sent to the cross-bar Ucast pkts received from the cross-bar Pkts sent to the port Pkts discarded on ingress : 0 (0) Per-priority-pause status : Rx (Inactive), Tx (Inactive) Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 61: Qos Example 1

    3. Set up the system class allocation and rewrite policy. Allocate the system class for qos-group 4 and define the rewrite action. 4. Attach the allocation and rewrite policy to the system. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 62: Qos Example 2

    QoS Example 2 This example shows how to use an access control list to apply 50% bandwidth to traffic on Ethernet interface 1/3 that matches traffic on Ethernet interface 1/1. Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 63 (config-pmap-c-que)# bandwidth percent 10 (config-pmap-c-que)# exit (config-pmap-que)# class type queuing class-fcoe (config-pmap-c-que)# bandwidth percent 40 (config-pmap-c-que)# exit (config-pmap-que)# class type queuing cmap-que-bandwidth (config-pmap-c-que)# bandwidth percent 50 (config-pmap-c-que)# exit (config-pmap-que)# exit Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 64: Qos Example 3

    Step 1 Set up the ingress classification policy (the access control (config)# interface Ethernet 1/15 list was defined previously). (config-if)# untagged cos 3 (config-if)# priority-flow-control mode on (config-if)# exit Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01...
  • Page 65 I N D E X changed information new information description description Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide OL-20921-01 IN-1...
  • Page 66 Index Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide IN-2 OL-20921-01...

Table of Contents