Supported Platforms
Related Documentation
- M, MX, PTX, T Series
- Overview of Class of Service Using IPv6 DiffServ
- System Requirements for CoS with DiffServ for IPv6
- Roadmap for Configuring CoS with IPv6 DiffServ
- Additional Information
- Class of Service Using IPv6 DiffServ Feature Guide for Routing Devices
Example: CoS with IPv6 DiffServ Configuration
Example: CoS with IPv6 DiffServ Configuration
The example assigns expedited forwarding to Q1 and a subset of the assured forwarding classes (af1x) to Q2, and distributes resources among all four forwarding classes.
Figure 1 shows the topology of the three routers and links that are used as a case study in this chapter.
Figure 1: Basic IPv6 DiffServ Topology

In this case study, the service provider has agreed to provide high-priority delivery of packets for two applications between the customer’s servers at two sites. The first application generates streams of high-definition audiovisual (television) packet flows and the second generates large quantities of time-sensitive financial information. In all cases, the packet flow is from server to server. The service provider marks the packets appropriately as they enter the network from either site, configures special queues and forwarding classes for this traffic on the three routers, and uses DiffServ for IPv6 for this purpose.
Routers 1 and 3 use multifield (MF) classifiers on the customer-facing interfaces to detect high-priority packets and rewrite the Differentiated Services code points (DSCPs) appropriately. Best-effort data and network control packets are not affected. All three routers are configured with consistent schedulers and resources to handle high-priority packets properly.
Figure 2: IPv6 DiffServ Configuration

Figure 2 shows the complete topology for IPv6 DiffServ, complete with interfaces and IPv6 addresses. The IPv4-mapped IPv6 address format described in RFC 5952 is used.
Begin your configuration on Router 2, the core router. This ensures that when DiffServ is enabled on the edge routers, class of service (CoS) is enabled end to end through the network. The core router configuration is a little simpler because no MF classification is configured in the core.
Router 2
Continue your configuration on Router 1 and Router 3, the edge routers. These routers get firewall-filter-based MF classifiers and rewrite rules for markers as well as schedulers and drop profiles on the core-facing interfaces.
Router 1
Router 3
Verifying Your Work
To verify that your CoS using IPv6 DiffServ configuration is correct, use the following commands:
- show class-of-service classifier type dscp-ipv6
- show class-of-service rewrite-rule type dscp-ipv6
- show class-of-service interface
- show class-of-service forwarding-table classifier mapping
- show class-of-service forwarding-table rewrite-rule mapping
- show class-of-service scheduler-map scheduler-map-name
- show class-of-service forwarding-table scheduler-map
The following section shows the output of these commands used with the configuration example.
DiffServ Classifiers
user@R1> show class-of-service classifier type
dscp-ipv6
Classifier: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 4 Code point Forwarding class Loss priority 000000 be-DATA-class low 000001 be-DATA-class low 000010 be-DATA-class low 000011 be-DATA-class low 000100 be-DATA-class low 000101 be-DATA-class low 000110 be-DATA-class low 000111 be-DATA-class low 001000 be-DATA-class low 001001 be-DATA-class low 001010 af-AV-class low 001011 be-DATA-class low 001100 af-AV-class high 001101 be-DATA-class low 001110 af-AV-class high 001111 be-DATA-class low 010000 be-DATA-class low 010001 be-DATA-class low 010010 be-DATA-class low 010011 be-DATA-class low 010100 be-DATA-class low 010101 be-DATA-class low 010110 be-DATA-class low 010111 be-DATA-class low 011000 be-DATA-class low 011001 be-DATA-class low 011010 be-DATA-class low 011011 be-DATA-class low 011100 be-DATA-class low 011101 be-DATA-class low 011110 be-DATA-class low 011111 be-DATA-class low 100000 be-DATA-class low 100001 be-DATA-class low 100010 be-DATA-class low 100011 be-DATA-class low 100100 be-DATA-class low 100101 be-DATA-class low 100110 be-DATA-class low 100111 be-DATA-class low 101000 be-DATA-class low 101001 be-DATA-class low 101010 be-DATA-class low 101011 be-DATA-class low 101100 be-DATA-class low 101101 be-DATA-class low 101110 ef-FIN-class low 101111 be-DATA-class low 110000 nc-CONTROL-class low 110001 be-DATA-class low 110010 be-DATA-class low 110011 be-DATA-class low 110100 be-DATA-class low 110101 be-DATA-class low 110110 be-DATA-class low 110111 be-DATA-class low 111000 nc-CONTROL-class low 111001 be-DATA-class low 111010 be-DATA-class low 111011 be-DATA-class low 111100 be-DATA-class low 111101 be-DATA-class low 111110 be-DATA-class low 111111 be-DATA-class low Classifier: IPv6-classifier, Code point type: dscp-ipv6, Index: 18301 Code point Forwarding class Loss priority 000000 be-DATA-class low 000001 be-DATA-class high 000010 be-DATA-class low 000011 be-DATA-class low 000100 be-DATA-class low 000101 be-DATA-class low 000110 be-DATA-class low 000111 be-DATA-class low 001000 be-DATA-class low 001001 be-DATA-class low 001010 af-AV-class low 001011 be-DATA-class low 001100 af-AV-class high 001101 be-DATA-class low 001110 af-AV-class high 001111 be-DATA-class low 010000 be-DATA-class low 010001 be-DATA-class low 010010 be-DATA-class low 010011 be-DATA-class low 010100 be-DATA-class low 010101 be-DATA-class low 010110 be-DATA-class low 010111 be-DATA-class low 011000 be-DATA-class low 011001 be-DATA-class low 011010 be-DATA-class low 011011 be-DATA-class low 011100 be-DATA-class low 011101 be-DATA-class low 011110 be-DATA-class low 011111 be-DATA-class low 100000 be-DATA-class low 100001 be-DATA-class low 100010 be-DATA-class low 100011 be-DATA-class low 100100 be-DATA-class low 100101 be-DATA-class low 100110 be-DATA-class low 100111 be-DATA-class low 101000 be-DATA-class low 101001 be-DATA-class low 101010 be-DATA-class low 101011 be-DATA-class low 101100 be-DATA-class low 101101 be-DATA-class low 101110 ef-FIN-class low 101111 ef-FIN-class high 110000 nc-CONTROL-class low 110001 nc-CONTROL-class high 110010 be-DATA-class low 110011 be-DATA-class low 110100 be-DATA-class low 110101 be-DATA-class low 110110 be-DATA-class low 110111 be-DATA-class low 111000 nc-CONTROL-class low 111001 be-DATA-class low 111010 be-DATA-class low 111011 be-DATA-class low 111100 be-DATA-class low 111101 be-DATA-class low 111110 be-DATA-class low 111111 be-DATA-class low
Rewrite Rules
user@R1> show class-of-service rewrite-rule
type dscp-ipv6
Rewrite rule: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 20 Forwarding class Loss priority Code point be-DATA-class low 000000 be-DATA-class high 000000 ef-FIN-class low 101110 ef-FIN-class high 101110 af-AV-class low 001010 af-AV-class high 001100 nc-CONTROL-class low 110000 nc-CONTROL-class high 111000 Rewrite rule: rewrite-IPv6-dscp, Code point type: dscp-ipv6, Index: 58077 Forwarding class Loss priority Code point be-DATA-class low 000000 be-DATA-class high 000001 ef-FIN-class low 101110 ef-FIN-class high 101111 af-AV-class low 001010 af-AV-class high 001100 nc-CONTROL-class low 110000 nc-CONTROL-class high 110001
Class-of-Service Interfaces
user@R1> show class-of-service interface
... Physical interface: so-0/0/1, Index: 141 Queues supported: 4, Queues in use: 4 Scheduler map: diffserv-cos-map, Index: -543019056 Logical interface: so-0/0/1.0, Index: 68 Object Name Type Index Rewrite rewrite-IPv6-dscp dscp-ipv6 58077 Rewrite exp-default exp 21 Classifier IPv6-classifier dscp-ipv6 18301 Classifier exp-default exp 5 ... Physical interface: so-0/1/1, Index: 144 Queues supported: 4, Queues in use: 4 Scheduler map: <default>, Index: -113795564 Logical interface: so-0/1/1.0, Index: 69 Object Name Type Index Rewrite exp-default exp 21 Classifier exp-default exp 5 Classifier ipprec-compatibility ip 8
Classifier Mapping
user@R1> show class-of-service forwarding-table
classifier mapping
Table Index/ Interface Index Q num Table type so-0/0/1.0 68 18301 IPv6 DSCP so-0/1/1.0 69 8 IPv4 precedence
Rewrite Rule Mapping
user@R1> show class-of-service forwarding-table
rewrite-rule mapping
Interface Index Table index Type so-0/1/1.0 68 58077 IPv6 DSCP
Scheduler Map
user@R1> show class-of-service scheduler-map
diffserv-cos-map
Scheduler map: diffserv-cos-map, Index: 1094596010 Scheduler: be-DATA-scheduler, Forwarding class: be-DATA-class, Index: 14343 Transmit rate: 40 percent, Rate Limit: none, Buffer size: 40 percent, Priority: low Drop profiles: Loss priority Protocol Index Name Low non-TCP 1 <default-drop-profile> Low TCP 1 <default-drop-profile> High non-TCP 1 <default-drop-profile> High TCP 1 <default-drop-profile> Scheduler: ef-FIN-scheduler, Forwarding class: ef-FIN-class, Index: 21707 Transmit rate: 10 percent, Rate Limit: none, Buffer size: 10 percent, Priority: high Drop profiles: Loss priority Protocol Index Name Low non-TCP 1 <default-drop-profile> Low TCP 1 <default-drop-profile> High non-TCP 1 <default-drop-profile> High TCP 1 <default-drop-profile> Scheduler: af-AV-scheduler, Forwarding class: af-AV-class, Index: 51704 Transmit rate: 45 percent, Rate Limit: none, Buffer size: 45 percent, Priority: high Drop profiles: Loss priority Protocol Index Name Low non-TCP 61474 af-AV-normal Low TCP 61474 af-AV-normal High non-TCP 65199 af-AV-with-PLP High TCP 65199 af-AV-with-PLP Scheduler: nc-CONTROL-scheduler, Forwarding class: nc-CONTROL-class, Index: 50404 Transmit rate: 5 percent, Rate Limit: none, Buffer size: 5 percent, Priority: low Drop profiles: Loss priority Protocol Index Name Low non-TCP 1 <default-drop-profile> Low TCP 1 <default-drop-profile> High non-TCP 1 <default-drop-profile> High TCP 1 <default-drop-profile>
user@R1> show class-of-service forwarding-table
scheduler-map
... Interface: so-0/0/1 (Index: 141, Map index: -543019056, Map type: FINAL,
Num of queues: 4): Entry 0 (Scheduler index: 14343, Queue #: 0): Tx rate: 0 Kb (40%), Buffer size: 40 percent Priority low PLP high: 1, PLP low: 1, TCP PLP high: 1, TCP PLP low: 1 Entry 1 (Scheduler index: 21707, Queue #: 1): Tx rate: 0 Kb (10%), Buffer size: 10 percent Priority high PLP high: 1, PLP low: 1, TCP PLP high: 1, TCP PLP low: 1 Entry 2 (Scheduler index: 51704, Queue #: 2): Tx rate: 0 Kb (45%), Buffer size: 45 percent Priority high PLP high: 65199, PLP low: 61474, TCP PLP high: 65199, TCP PLP low: 61474 Entry 3 (Scheduler index: 50404, Queue #: 3): Tx rate: 0 Kb (5%), Buffer size: 5 percent Priority low PLP high: 1, PLP low: 1, TCP PLP high: 1, TCP PLP low: 1 ...
Related Documentation
- M, MX, PTX, T Series
- Overview of Class of Service Using IPv6 DiffServ
- System Requirements for CoS with DiffServ for IPv6
- Roadmap for Configuring CoS with IPv6 DiffServ
- Additional Information
- Class of Service Using IPv6 DiffServ Feature Guide for Routing Devices
Published: 2013-07-19
Supported Platforms
Related Documentation
- M, MX, PTX, T Series
- Overview of Class of Service Using IPv6 DiffServ
- System Requirements for CoS with DiffServ for IPv6
- Roadmap for Configuring CoS with IPv6 DiffServ
- Additional Information
- Class of Service Using IPv6 DiffServ Feature Guide for Routing Devices