Cisco Nexus 7000 Series User manual

Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide
Last Modified: 2016-05-11
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CONTENTS
Preface xi
PREFACE
Audience xi
Document Conventions xi
Related Documentation for Cisco Nexus 7000 Series NX-OS Software xii
Documentation Feedback xiv
Obtaining Documentation and Submitting a Service Request xv
New and Changed Information 1
CHAPTER 1
New and Changed Information 1
Overview 3
CHAPTER 2
Information About QoS Features 3
Using QoS 4
Classification 4
Marking 4
Mutation 5
Policing 5
Queuing and Scheduling 5
Sequencing of QoS Actions 5
Sequencing of Ingress Traffic Actions 6
Sequencing of Egress Traffic Actions 6
High Availability Requirements for QoS Features 6
QoS Feature Configuration with MQC 7
QoS Statistics 7
Default QoS Behavior 7
QoS Policies on Fabric Extenders 8
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Using Modular QoS CLI 9
CHAPTER 3
Finding Feature Information 9
Information About MQC 9
Licensing Requirements 10
Using an MQC Object 11
Type qos Policies 11
Type Queuing Policies 13
System-Defined MQC Objects 14
Configuring an MQC Object 18
Configuring or Modifying a Class Map 19
Configuring or Modifying a Table Map 20
Configuring or Modifying a Policy Map 21
Applying Descriptions to MQC Objects 22
Verifying an MQC Object 23
Attaching and Detaching a QoS Policy Action 23
Attaching a QoS Policy Action to an Interface or Tunnel 25
Attaching a QoS Policy Action to a VLAN 26
Session Manager Support for QoS 26
Feature History for Using Modular QoS CLI 26
Configuring Classification 29
CHAPTER 4
Finding Feature Information 29
Information About Classification 29
Licensing Requirements 31
Prerequisites for Classification 31
Guidelines and Limitations 31
Configuring Traffic Classes 32
Configuring ACL Classification 32
Configuring a Deny ACE 33
Configuring DSCP Classification 34
Configuring IP Precedence Classification 35
Configuring Protocol Classification 37
Configuring QoS Group Classification 38
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Contents

Configuring Discard Class Classification 39
Configuring Layer 3 Packet Length Classification 39
Configuring CoS Classification 40
Configuring IP RTP Classification 41
Configuring Class Map Classification 42
Verifying the Classification Configuration 43
Configuration Examples for Classification 43
Feature History for Classification 43
Configuring Marking 45
CHAPTER 5
Finding Feature Information 45
Information About Marking 45
Licensing Requirements 46
Prerequisites for Marking 46
Guidelines and Limitations 47
Configuring Marking 47
Configuring DSCP Marking 48
Configuring IP Precedence Marking 50
Configuring CoS Marking 51
Configuring QoS Group Marking 52
Configuring Discard Class Marking 52
Configuring Ingress and Egress Marking 53
Configuring DSCP Port Marking 54
Configuring Table Maps for Use in Marking 55
Configuring Marking Using Table Maps 56
Verifying the Marking Configuration 57
Configuration Examples for Marking 58
Feature History for Marking 58
Configuring Mutation Mapping 59
CHAPTER 6
Finding Feature Information 59
Information About Mutation Mapping 59
Licensing Requirements 60
Prerequisites for Mutation Mapping 60
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Guidelines and Limitations 61
Configuring Mutation Mapping 61
Verifying the Mutation Mapping Configuration 62
Configuration Examples for Mutation Mapping 63
Feature History for Mutation Mapping 63
Configuring Policing 65
CHAPTER 7
Finding Feature Information 65
Information About Policing 65
Shared Policers 66
Licensing Requirements 66
Prerequisites for Policing 66
Guidelines and Limitations 67
Configuring Policing 68
Configuring 1-Rate and 2-Rate, 2-Color and 3-Color Policing 68
Configuring Color-Aware Policing 72
Configuring Ingress and Egress Policing 75
Configuring Markdown Policing 76
Configuring Shared Policers 77
Verifying the Policing Configuration 78
Configuration Examples for Policing 79
Feature History for Policing 80
Configuring Fabric QoS Mapping 81
CHAPTER 8
Finding Feature Information 81
Information About Fabric QoS Mapping 81
COS-to-Queue Fabric Mapping 81
Ingress Buffer Policy 82
Egress Queue Bandwidth Allocation 82
Guidelines and Limitations 82
Configuring Fabric QoS Mapping 83
Copying a Default Policy 83
Configuring Cos2q Fabric Mapping 83
Configuring Ingress Buffer Policy 84
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Configuring Egress Queue Bandwidth Allocation 84
Configuring the New User-defined Policy on Fabric 85
Configuration Examples for Fabric QoS Mapping 86
Example: Copying Default Policy to Create a new User-defined Ingress and Egress Policy 86
Example: Configuring Cos2q Fabric Mapping 86
Example: Configuring the User-defined Policy on Fabric 86
Example: Verifying System Fabric Configuration 86
Example: Verifying the QoS Mapping on Fabric 87
Feature History for Fabric QoS Mapping 88
Configuring Queuing and Scheduling on M-Series I/O Modules 89
CHAPTER 9
Finding Feature Information 89
Information About Queuing and Scheduling 89
Setting Ingress Port CoS 91
Modifying Class Maps 91
Congestion Avoidance 92
Congestion Management 92
Virtualization Support 92
Licensing Requirements 92
Prerequisites for Queuing and Scheduling 93
Guidelines and Limitations 93
Configuring Queuing and Scheduling 94
Configuring Ingress Port CoS 95
Modifying Queuing Class Maps for COS 96
Modifying Queuing Class Maps for DSCP 97
Configuring Congestion Avoidance 98
Configuring Tail Drop by COS Values 99
Configuring Tail Drop by DSCP Values 100
Configuring WRED by COS Values 101
Configuring WRED by DSCP Values 102
Configuring Congestion Management 104
Configuring Bandwidth and Bandwidth Remaining 104
Configuring Priority 105
Configuring Shaping 106
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Configuring Queue Limits 108
Enabling DSCP to Queue Mapping 109
Verifying the Queuing and Scheduling Configuration 109
Configuration Examples for Queuing and Scheduling 110
Example: Setting Ingress Port CoS Configuration 110
Example: Priority and Queue Limit Configuration 110
Example: Shaping and Tail Drop Configuration 111
Example: Bandwidth and WRED Configuration 111
Example: Verifying the Status of DSCP-to-queue Mapping 112
Feature History for Queuing and Scheduling 112
Configuring Queuing and Scheduling on F-Series I/O Modules 113
CHAPTER 10
Finding Feature Information 113
Information About Queuing and Scheduling 113
Ingress Queuing 114
Egress Queuing 120
Shared Buffer Queuing on the F3 Series Module 122
Prerequisites for Queuing and Scheduling 123
Guidelines and Limitations 123
Configuring Queuing and Scheduling 126
Configuring an Ingress Queuing Policy 126
Configuring an Egress Queuing Policy 128
Enabling DSCP to Queue Mapping 129
Configuring Shared Buffer Queuing 129
Verifying the Queuing and Scheduling Configuration 130
Configuration Examples for Queuing and Scheduling on F-Series Modules 131
Example: Ingress Queuing Policy Configuration 131
Example: Egress Queuing Policy Configuration 131
Example: Hierarchical Queuing Policy Configuration 132
Example: Verifying the Status of DSCP-to-queue Mapping 132
Feature History for Queuing and Scheduling for F-Series Modules 132
Configuring Network QoS 135
CHAPTER 11
Finding Feature Information 135
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Information About Network QoS 135
Differences in Drop CoS and No-Drop CoS Values 136
Queue Names and Default Mappings of CoS Values to Egress/Ingress Queues 137
Default DSCP Mappings 140
Licensing Requirements 141
Prerequisites for Network QoS 141
Guidelines and Limitations 142
Configuring Network QoS Policies 143
Configure a User-Defined Network 144
Applying a Network QoS Policy on a Target 145
Verifying the Network QoS 145
Configuration Examples for Network QoS 146
Feature History for Network QoS 146
Configuring Priority Flow Control 147
CHAPTER 12
Finding Feature Information 147
Information About Priority Flow Control 147
Licensing Requirements 148
Prerequisites for Priority Flow Control 148
Guidelines and Limitations 148
Default Settings for Priority Flow Control 149
Configuring Priority Flow Control 149
Verifying the Priority Flow Control Configuration 150
Configuration Examples for Priority Flow Control 150
Feature History for Priority Flow Control 150
Configuring Local Policy-Based Routing 151
CHAPTER 13
Finding Feature Information 151
Information About Local Policy-Based Routing 151
Route Maps 152
Match Criteria 152
Set Changes 152
Licensing Requirements 152
Prerequisites for Local Policy-Based Routing 153
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Guidelines and Limitations 153
Default Settings for Local Policy-Based Routing 153
Configuring Local Policy-Based Routing 154
Configuring Route Maps 154
154
154
Enabling the Policy-Based Routing Feature 155
Configuring a Local Route Policy 155
Verifying the Local Policy-Based Routing Configuration 156
Configuration Example for Local Policy-Based Routing 156
Feature History for Local Policy-Based Routing 156
Monitoring QoS Statistics 157
CHAPTER 14
Finding Feature Information 157
Information About QoS Statistics 157
Licensing Requirements 157
Prerequisites for Monitoring QoS Statistics 158
Enabling Statistics 158
Monitoring the Statistics 158
Clearing Statistics 159
Configuration Examples For Monitoring QoS Statistics 159
Feature History for Statistics 161
Configuration Limits for Quality of Service Configuration Features 163
APPENDIX A
Configuration Limits for QoS 163
Additional References Appendix 165
APPENDIX B
Related Documents 165
RFCs 165
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Preface
The preface contains the following sections:
•Audience, on page xi
•Document Conventions, on page xi
•Related Documentation for Cisco Nexus 7000 Series NX-OS Software, on page xii
•Documentation Feedback, on page xiv
•Obtaining Documentation and Submitting a Service Request, on page xv
Audience
This publication is for network administrators who configure and maintain Cisco Nexus devices.
Document Conventions
As part of our constant endeavor to remodel our documents to meet our customers' requirements, we have
modified the manner in which we document configuration tasks. As a result of this, you may find a deviation
in the style used to describe these tasks, with the newly included sections of the document following the new
format.
Note
Command descriptions use the following conventions:
DescriptionConvention
Bold text indicates the commands and keywords that you enter literally
as shown.
bold
Italic text indicates arguments for which the user supplies the values.
Italic
Square brackets enclose an optional element (keyword or argument).[x]
Square brackets enclosing keywords or arguments separated by a vertical
bar indicate an optional choice.
[x | y]
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DescriptionConvention
Braces enclosing keywords or arguments separated by a vertical bar
indicate a required choice.
{x | y}
Nested set of square brackets or braces indicate optional or required
choices within optional or required elements. Braces and a vertical bar
within square brackets indicate a required choice within an optional
element.
[x {y | z}]
Indicates a variable for which you supply values, in context where italics
cannot be used.
variable
A nonquoted set of characters. Do not use quotation marks around the
string or the string will include the quotation marks.
string
Examples use the following conventions:
DescriptionConvention
Terminal sessions and information the switch displays are in screen font.screen font
Information you must enter is in boldface screen font.boldface screen font
Arguments for which you supply values are in italic screen font.
italic screen font
Nonprinting characters, such as passwords, are in angle brackets.< >
Default responses to system prompts are in square brackets.[ ]
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:
Means reader take note. Notes contain helpful suggestions or references to material not covered in the manual.
Note
Means reader be careful. In this situation, you might do something that could result in equipment damage or
loss of data.
Caution
Related Documentation for Cisco Nexus 7000 Series NX-OS
Software
The entire Cisco Nexus 7000 Series NX-OS documentation set is available at the following URL:
http://www.cisco.com/en/us/products/ps9402/tsd_products_support_series_home.html
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Preface
Related Documentation for Cisco Nexus 7000 Series NX-OS Software

Release Notes
The release notes are available at the following URL:
http://www.cisco.com/en/US/products/ps9402/prod_release_notes_list.html
Configuration Guides
These guides are available at the following URL:
http://www.cisco.com/en/US/products/ps9402/products_installation_and_configuration_guides_list.html
The documents in this category include:
•Cisco Nexus 7000 Series NX-OS Configuration Examples
•Cisco Nexus 7000 Series NX-OS FabricPath Configuration Guide
•Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide
•Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide
•Cisco Nexus 7000 Series NX-OS IP SLAs Configuration Guide
•Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide
•Cisco Nexus 7000 Series NX-OS LISP Configuration Guide
•Cisco Nexus 7000 Series NX-OS MPLS Configuration Guide
•Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide
•Cisco Nexus 7000 Series NX-OS OTV Configuration Guide
•Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide
•Cisco Nexus 7000 Series NX-OS SAN Switching Guide
•Cisco Nexus 7000 Series NX-OS Security Configuration Guide
•Cisco Nexus 7000 Series NX-OS System Management Configuration Guide
•Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide
•Cisco Nexus 7000 Series NX-OS Verified Scalability Guide
•Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide
•Cisco Nexus 7000 Series NX-OS Virtual Device Context Quick Start
•Cisco Nexus 7000 Series NX-OS OTV Quick Start Guide
•Cisco NX-OS FCoE Configuration Guide for Cisco Nexus 7000 and Cisco MDS 9500
•Cisco Nexus 2000 Series Fabric Extender Software Configuration Guide
Command References
These guides are available at the following URL:
http://www.cisco.com/en/US/products/ps9402/prod_command_reference_list.html
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Preface
Preface

The documents in this category include:
•Cisco Nexus 7000 Series NX-OS Command Reference Master Index
•Cisco Nexus 7000 Series NX-OS FabricPath Command Reference
•Cisco Nexus 7000 Series NX-OS Fundamentals Command Reference
•Cisco Nexus 7000 Series NX-OS High Availability Command Reference
•Cisco Nexus 7000 Series NX-OS Interfaces Command Reference
•Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference
•Cisco Nexus 7000 Series NX-OS LISP Command Reference
•Cisco Nexus 7000 Series NX-OS MPLS Configuration Guide
•Cisco Nexus 7000 Series NX-OS Multicast Routing Command Reference
•Cisco Nexus 7000 Series NX-OS OTV Command Reference
•Cisco Nexus 7000 Series NX-OS Quality of Service Command Reference
•Cisco Nexus 7000 Series NX-OS SAN Switching Command Reference
•Cisco Nexus 7000 Series NX-OS Security Command Reference
•Cisco Nexus 7000 Series NX-OS System Management Command Reference
•Cisco Nexus 7000 Series NX-OS Unicast Routing Command Reference
•Cisco Nexus 7000 Series NX-OS Virtual Device Context Command Reference
•Cisco NX-OS FCoE Command Reference for Cisco Nexus 7000 and Cisco MDS 9500
Other Software Documents
You can locate these documents starting at the following landing page:
http://www.cisco.com/en/us/products/ps9402/tsd_products_support_series_home.html
•Cisco Nexus 7000 Series NX-OS MIB Quick Reference
•Cisco Nexus 7000 Series NX-OS Software Upgrade and Downgrade Guide
•Cisco Nexus 7000 Series NX-OS Troubleshooting Guide
•Cisco NX-OS Licensing Guide
•Cisco NX-OS System Messages Reference
•Cisco NX-OS XML Interface User Guide
Documentation Feedback
To provide technical feedback on this document, or to report an error or omission, please send your comments
to: .
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Preface
Documentation Feedback

We appreciate your feedback.
Obtaining Documentation and Submitting a Service Request
For information on obtaining documentation, using the Cisco Bug Search Tool (BST), submitting a service
request, and gathering additional information, see What's New in Cisco Product Documentation.
To receive new and revised Cisco technical content directly to your desktop, you can subscribe to the What's
New in Cisco Product Documentation RSS feed. RSS feeds are a free service.
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Preface
Obtaining Documentation and Submitting a Service Request

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Preface
Obtaining Documentation and Submitting a Service Request

CHAPTER 1
New and Changed Information
•New and Changed Information, on page 1
New and Changed Information
The table below summarizes the new and changed features for this document and shows the releases in which
each feature is supported. Your software release might not support all the features in this document. For the
latest caveats and feature information, see the Bug Search Tool at https://tools.cisco.com/bugsearch/ and the
release notes for your software release.
Table 1: New and Changed QoS Features
Changed in ReleaseDescriptionFeature
7.3(0)DX(1)Support for M3 series modules.Support for M3 modules
6.2(10)Support for shared memory buffer
queues on the F3 Series modules
only.
Shared buffer queuing on the F3
Series modules
6.2(2)The Fabric QoS Mapping feature
allows copying the default
configuration and modifying the
copied system queues that perform
flow control on fabric traffic within
the Cisco NX-OS device.
Fabric QoS Mapping
6.2(2)Four 4q8q policy templates that
support eight egress queues on the
Cisco Nexus 7710 switch and Cisco
Nexus 7718 switch only.
4q8q policy templates that support
8 egress queues
6.2(2)You can now configure local
policy-based routing.
Local Policy-Based Routing (PBR)
6.1.3The default-nq-8e-4q4q-policy
template supports four ingress
buffers.
default-nq-8e-4q4q- policy
template for F2 modules
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Changed in ReleaseDescriptionFeature
6.1(1)Support for DSCP mapping for F2
modules .
DSCP mapping for F2 modules
5.1(1)You can now configure a network
qos policy, which defines the
characteristics of each CoS that is
applicable network wide, across
virtual device contexts (VDCs), and
switches.
Network QoS policy
5.1(1)You can now configure PFC, which
prevents frame loss that is due to
congestion.
Priority flow control (PFC)
5.1(1)You can now configure QoS
policies on the FEX interfaces.
Fabric Extender (FEX) support
4.2(1)The qos-dynamic variable lists
already configured class-map and
policy-map names.
QoS dynamic variable lists
4.2(1)Allows you to verify the
configuration and required
resources prior to committing them
to the running configuration.
Support for Session Manager
4.1(2)You can now match IPv6, as well
as IPv4, addresses.
Match IPv6 ACLs.
4.1(2)You can match only the same
variable with different values for
mutation mapping.
Only same variable for mutation
mapping
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New and Changed Information
New and Changed Information

CHAPTER 2
Overview
This chapter describes the configurable Cisco NX-OS quality of service (QoS) features on the Cisco NX-OS
device.
QoS allows you to classify the network traffic, police and prioritize the traffic flow, and help avoid traffic
congestion in a network.
•Information About QoS Features, on page 3
•High Availability Requirements for QoS Features, on page 6
•QoS Feature Configuration with MQC, on page 7
•QoS Statistics, on page 7
•Default QoS Behavior, on page 7
•QoS Policies on Fabric Extenders, on page 8
Information About QoS Features
You use the QoS features to provide the most desirable flow of traffic through a network. QoS allows you to
classify the network traffic, police and prioritize the traffic flow, and provide congestion avoidance. The
control of traffic is based on the fields in the packets that flow through the system. You use the Modular QoS
CLI (MQC) to create the traffic classes and policies of the QoS features.
QoS features are applied using QoS policies and queuing policies are as follows:
• QoS policies include the policing feature and the marking features.
• Queuing policies use the queuing and scheduling features as well as a limited set of the marking feature.
The system-defined QoS features and values that are discussed in another chapter of this configuration guide
apply globally to the entire switch and cannot be modified. For complete information on virtual device contexts
(VDCs), see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide.
Note
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Before you attempt a downgrade from Cisco NX-OS Release 5.2(x) or newer release to any release prior to
Release 5.2(1), you should clear the QoS MIB and MPLS QoS defaults by using the clear qos mpls-snmp
command. The downgrade might fail if the defaults are not cleared.
Before you downgrade from Cisco NX-OS Release 5.2(x) or 5.1(x) or newer release to Cisco NX-OS Release
5.0(x) or an earlier release, remove all system QoS and QoS policies configured on F-Series I/O modules.
Use the clear qos policies command to remove the defaults for F-Series modules. An internal process failure
can result if the QoS policies are not removed prior to the downgrade.
Caution
Using QoS
Traffic is processed based on how you classify it and the policies that you create and apply to traffic classes.
To configure QoS features, you use the following steps:
1. Create traffic classes by classifying the incoming and outgoing packets that match criteria such as IP
address or QoS fields.
2. Create policies by specifying actions to take on the traffic classes, such as limiting, marking, or dropping
packets.
3. Apply policies to a port, port channel, VLAN, or a subinterface.
You use MQC to create the traffic classes and policies of the QoS features.
The queuing and scheduling operations of the overall QoS feature are applicable to both IPv4 and IPv6.
Note
Classification
You use classification to partition traffic into classes. You classify the traffic based on the port characteristics
(class of service [CoS] field) or the packet header fields that include IP precedence, Differentiated Services
Code Point (DSCP), Layer 2 to Layer 4 parameters, and the packet length.
The values used to classify traffic are called match criteria. When you define a traffic class, you can specify
multiple match criteria, you can choose to not match on a particular criterion, or you can determine the traffic
class by matching any or all criteria
Traffic that fails to match any class is assigned to a default class of traffic called class-default.
Marking
Marking is the setting of QoS information that is related to a packet. You can set the value of a standard QoS
field IP precedence, DSCP and CoS, and internal labels that can be used in subsequent actions. Marking is
used to identify the traffic type for policing, queuing, and scheduling traffic (only CoS is used in scheduling).
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Overview
Using QoS