Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
 

Applying MPLS EXP Classifiers to Routing Instances

This topic shows how to apply 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 Library for Routing Devices.

The default MPLS EXP classification table contents are shown in Table 1.

Table 1: Default MPLS EXP Classifier

MPLS EXP Bits

Forwarding Class

Loss Priority

000

best-effort

low

001

best-effort

high

010

expedited-forwarding

low

011

expedited-forwarding

high

100

assured-forwarding

low

101

assured-forwarding

high

110

network-control

low

111

network-control

high

Note:

At times you might need to maintain the original classifier—for example with bridge domains, where you neither want to configure a custom classifier for the routing instance nor accept the default classifier, which would override the original classifier. Starting with Junos OS Release 16.1, on MX Series devices only, you can maintain the original MPLS EXP classifier. To do so, apply the no-default option for the routing instance. For example:

Configuring and Applying Custom MPLS EXP Classifiers to Routing Instances

For routing instances with VRF table labels enabled, you can override the default MPLS EXP classifier and apply a custom classifier to a routing instance.

The following procedure requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.

To apply a custom classifier to a routing instance:

  1. Filter traffic based on the IP header.
  2. Configure the custom MPLS EXP classifier.
  3. Apply the custom MPLS EXP classifier to the routing instance..
  4. Commit and confirm your configuration.

Applying Global Classifiers and Wildcard Routing Instances

To apply a classifier to all routing instances:

  • Specify that the MPLS EXP classifier is for all routing instances.

For routing instances associated with specific classifiers, the global configuration is ignored.

To use a wildcard to apply a classifier to all routing instances:

  • 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:

The wildcard * 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*, 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 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.

Note that the * wildcard must be appended to an instance name at these configuration levels. The * wildcard should not be intended as a stand-alone substitute for the all keyword.

Applying Global MPLS EXP Classifiers to Routing Instances

This example shows how to apply a global classifier to all routing instances and then 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.

The following procedure requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.

To configure a global classifier for all routing instances and override the global classifier for a specific routing instance:

  1. Enable the VRF table label for all three routing instances.
  2. Apply the EXP classifier exp-classifier-global to all routing instances.
  3. Apply the EXP classifier exp-classifier-3 to only the routing-instance vpn3.
  4. Confirm your configuration.

Applying Classifiers by Using Wildcard Routing Instances

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.

The following procedure requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.

To configure a wildcard routing instance and override the wildcard with a specific routing instance:

  1. Enable the VRF table label for all three routing instances.
  2. Apply the EXP classifier exp-class-wildcard to all routing instances by using a wildcard.
  3. Apply the EXP classifier exp-class-red to only the routing-instance vpn-red.
  4. Commit and confirm your configuration.

Verifying the Classifiers Associated with Routing Instances

Purpose

Display the MPLS EXP classifiers associated with two routing instances:

Action

To verify the MPLS EXP classifiers associated with two routing instances, enter the following Junos OS CLI operational mode command:

Release History Table
Release
Description
16.1
Starting with Junos OS Release 16.1, on MX Series devices only, you can maintain the original MPLS EXP classifier.