Applying MPLS EXP Classifiers to Routing Instances
When you enable VRF table labels and you do not explicitly apply a classifier configuration to the routing instance, the default MPLS EXP classifier is applied to the routing instance. For detailed information about VRF table labels, see the Junos OS VPNs Configuration Guide.
The default MPLS EXP classification table contents are shown in Table 1.
Table 1: Default MPLS EXP Classification Table
Forwarding Class | Loss Priority | CoS Value |
---|---|---|
best-effort | low | 000 |
best-effort | high | 001 |
expedited-forwarding | low | 010 |
expedited-forwarding | high | 011 |
assured-forwarding | low | 100 |
assured-forwarding | high | 101 |
network-control | low | 110 |
network-control | high | 111 |
For PICs that are installed on enhanced FPCs, you can override the default MPLS EXP classifier and apply a custom classifier to the routing instance. To do this, perform the following configuration tasks:
- Filter traffic based on the IP header by including the vrf-table-label statement at the [edit routing-instances routing-instance-name] hierarchy level:[edit routing-instances routing-instance-name]vrf-table-label;
- Configure a custom MPLS EXP classifier by including the
following statements at the [edit class-of-service] hierarchy
level:[edit class-of-service]classifiers {exp classifier-name {import (classifier-name | default);forwarding-class class-name {loss-priority level code-points [ aliases ] [ bit-patterns ];}}}
- Configure the routing instance to use the custom MPLS
EXP classifier by including the exp statement at the [edit class-of-service routing-instances routing-instance-name classifiers] hierarchy level:[edit class-of-service routing-instances routing-instance-name classifiers]exp classifier-name;
To display the MPLS EXP classifiers associated with all routing instances, issue the show class-of-service routing-instances command.
![]() | Note: The following caveats apply to custom MPLS EXP classifiers for routing instances:
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For more details, see the following sections:
Configuring Global Classifiers and Wildcard Routing Instances
To configure a global routing instance classifier, include the all statement at the [edit class-of-service routing-instances] hierarchy level:
For routing instances associated with specific classifiers, the global configuration is ignored.
To use a wildcard in the routing instance classifier configuration, include an asterisk (*) in the name of the routing instance:
The wildcard configuration follows the longest match. If there is a specific configuration, it is given precedence over the wildcard configuration.
![]() | Note: Wildcards and the all keyword are supported at the [edit class-of-service routing-instances] hierarchy level but not at the [edit routing-instances] hierarchy level. If you configure a routing instance at the [edit routing-instances] hierarchy level with, for example, the name vpn*, the Junos OS treats vpn* as a valid and distinct routing instance name. If you then try to apply a classifier to the vpn* routing instance at the [edit class-of-service routing-instances] hierarchy level, the Junos OS treats the vpn* routing instance name as a wildcard, and all the routing instances that start with vpn and do not have a specific classifier applied receive the classifier associated with vpn*. This same behavior applies with the all keyword. |
Examples: Applying MPLS EXP Classifiers to Routing Instances
Configure a global classifier for all routing instances and override the global classifier for a specific routing instance. In this example, there are three routing instances: vpn1, vpn2, and vpn3, each with VRF table label enabled. The classifier exp-classifier-global is applied to vpn1 and vpn2 (that is, all but vpn3, which is listed separately). The classifier exp-classifier-3 is applied to vpn3.
Configuring a Global Classifier
Configure a wildcard routing instance and override the wildcard with a specific routing instance. In this example, there are three routing instances: vpn-red, vpn-yellow, and vpn-green, each with VRF table label enabled. The classifier exp-class-wildcard is applied to vpn-yellow and vpn-green. The classifier exp-class-red is applied to vpn-red.
Configuring a Wildcard Routing Instance
Display the MPLS EXP classifiers associated with two routing instances:
Monitoring a Configuration
user@host> show class-of-service routing-instances
Routing Instance : vpn1 Object Name Type Index Classifier exp-default exp 8 Routing Instance : vpn2 Object Name Type Index Classifier class2 exp 57507