QoS: Congestion Avoidance Configuration Guide, Cisco IOS XE Release 3S (ASR 1000)
IPv6 QoS: MQC WRED-Based Drop
Downloads: This chapterpdf (PDF - 106.0KB) The complete bookPDF (PDF - 569.0KB) | The complete bookePub (ePub - 706.0KB) | Feedback

IPv6 QoS: MQC WRED-Based Drop

IPv6 QoS: MQC WRED-Based Drop

Last Updated: November 21, 2012

WRED implements the RED-based drop policy on the packets that are likely to overflow the limits of CBWFQ.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Information About IPv6 QoS: MQC WRED-Based Drop

Implementation Strategy for QoS for IPv6

IPv6 packets are forwarded by paths that are different from those for IPv4. QoS features supported for IPv6 environments include packet classification, queuing, traffic shaping, weighted random early detection (WRED), class-based packet marking, and policing of IPv6 packets. These features are available at both the process switching and Cisco Express Forwarding switching paths of IPv6.

All of the QoS features available for IPv6 environments are managed from the modular QoS command-line interface (MQC). The MQC allows you to define traffic classes, create and configure traffic policies (policy maps), and then attach those traffic policies to interfaces.

To implement QoS in networks that are running IPv6, follow the same steps that you would follow to implement QoS in networks running only IPv4. At a very high level, the basic steps for implementing QoS are as follows:

  • Know which applications in your network need QoS.
  • Understand the characteristics of the applications so that you can make decisions about which QoS features would be appropriate.
  • Know your network topology so that you know how link layer header sizes are affected by changes and forwarding.
  • Create classes based on the criteria that you establish for your network. In particular, if the same network is also carrying IPv4 traffic along with IPv6 traffic, decide if you want to treat both of them the same way or treat them separately and specify match criteria accordingly. If you want to treat them the same, use match statements such as match precedence, match dscp, set precedence, and set dscp. If you want to treat them separately, add match criteria such as match protocol ip and match protocol ipv6 in a match-all class map.
  • Create a policy to mark each class.
  • Work from the edge toward the core in applying QoS features.
  • Build the policy to treat the traffic.
  • Apply the policy.

Congestion Avoidance for IPv6 Traffic

WRED implements the RED-based drop policy on the packets that are likely to overflow the limits of class-based weighted fair queueing (CBWFQ). WRED supports class-based and flow-based queueing (using DSCP or precedence values).

Additional References

Related Documents

Related Topic Document Title

IPv6 addressing and connectivity

IPv6 Configuration Guide

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

IPv6 commands

Cisco IOS IPv6 Command Reference

Cisco IOS IPv6 features

Cisco IOS IPv6 Feature Mapping

QoS Congestion Avoidance

"Congestion Avoidance Overview" module

Standards and RFCs

Standard/RFC Title

RFCs for IPv6

IPv6 RFCs

MIBs

MIB

MIBs Link

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

Technical Assistance

Description Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for IPv6 QoS: MQC WRED-Based Drop

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1 Feature Information for IPv6 QoS: MQC WRED-Based Drop
Feature Name Releases Feature Information

IPv6 QoS: MQC WRED-Based Drop

Cisco IOS XE Release 2.1

WRED implements the RED-based drop policy on the packets that are likely to overflow the limits of CBWFQ.

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. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2012 Cisco Systems, Inc. All rights reserved.