IPv6 QoS: MQC Packet Classification
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IPv6 QoS: MQC Packet ClassificationLast Updated: April 11, 2012
Finding Feature InformationYour software release may not support all the features documented in this module. For the latest feature information and caveats, see 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 document. 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 Packet ClassificationImplementation Strategy for QoS for IPv6IPv6 packets are forwarded by paths that are different from those for IPv4. QoS features supported for IPv6 environments include packet classification, queueing, 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 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:
Packet Classification in IPv6Packet classification is available with both process and Cisco Express Forwarding switching path. Classification can be based on IPv6 precedence, differentiated services control point (DSCP), and other IPv6 protocol-specific values that can be specified in IPv6 access lists in addition to other non-IPv6 protocol specific values such as COS, packet length, and QOS group. Once you determine which applications need QoS, you can create classes based on the characteristics of the applications. You can use a variety of match criteria to classify traffic. You can combine various match criteria to segregate, isolate, and differentiate traffic. The enhancements to the modular QoS CLI (MQC) allow you to create matches on precedence, DSCP, and IPv6 access group values in both IPv4 and IPv6 packets. The match command allows matches to be made on DSCP values and precedence for both IPv4 and IPv6 packets. How to Configure IPv6 QoS: MQC Packet Classification
Classifying Traffic in IPv6 NetworksThe set cos and match cos commands for 802.1Q (dot1Q) interfaces are supported only for Cisco Express Forwarding-switched packets. Process-switched packets, such as router-generated packets, are not marked when these options are used. Using the Match Criteria to Manage IPv6 Traffic FlowsYou can use multiple match statements. Depending on the type of class, you can specify whether to match all classes or any of the classes. DETAILED STEPS Confirming the Service PolicyEnsure that the traffic flow matches the input or output parameter of the policy. For example, downloading a file from an FTP server generates congestion in the receive direction because the server sends large MTU-sized frames, and the client PC returns small acknowledgments (ACKs). Before you begin this task, simulate congestion with an extended ping using a large ping size and a large number of pings. Also, try downloading a large file from an FTP server. The file constitutes "disturbing" data and fills the interface bandwidth. DETAILED STEPS Configuration Examples for IPv6 QoS: MQC Packet ClassificationExample: Matching DSCP ValueThe following example shows how to configure the service policy called priority50 and attach service policy priority50 to an interface. In this example, the match dscp command includes the optional ip keyword, meaning that the match is for IPv4 packets only. The class map called ipdscp15 will evaluate all packets entering interface Fast Ethernet 1/0. If the packet is an IPv4 packet and has a DSCP value of 15, the packet will be treated as priority traffic and will be allocated with bandwidth of 50 kbps. Router(config)# class-map ipdscp15 Router(config-cmap)# match ip dscp 15 Router(config)# exit Router(config)# policy-map priority50 Router(config-pmap)# class ipdscp15 Router(config-pmap-c)# priority 50 Router(config-pmap-c)# exit Router(config-pmap)# exit Router(config)# interface fa1/0 Router(config-if)# service-policy input priority55 To match on IPv6 packets only, use the match dscp command without the ip keyword preceded by the match protocol command. Ensure that the class map has the match-all attribute (which is the default). Router(config)# class-map ipdscp15 Router(config-cmap)# match protocol ipv6 Router(config-cmap)# match dscp 15 Router(config)# exit To match packets on both IPv4 and IPv6 protocols, use the match dscp command: Router(config)# class-map ipdscp15 Router(config-cmap)# match dscp 15 Additional ReferencesRelated Documents
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Feature Information for IPv6 QoS: MQC Packet ClassificationThe 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.
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.
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