Step 1: Verify MPLS Interfaces

Purpose

If the MPLS protocol is not configured correctly on the routers in your network, the interfaces are not able to perform MPLS switching.

Action

To verify MPLS interfaces, enter the following JUNOS command-line interface (CLI) operational mode command:

user@host> show mpls interface

Sample Output 1

The following sample output is for all routers in the network shown in Figure 5.

user@R1> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

user@R2> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

so-0/0/3.0       Up         <none>

user@R3> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

so-0/0/3.0       Up         <none>

user@R4> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

so-0/0/3.0       Up         <none>

user@R5> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

user@R6> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/2.0       Up         <none>

so-0/0/3.0       Up         <none>

Sample Output 2

user@R6> show mpls interface 

Interface        State       Administrative groups

so-0/0/0.0       Up         <none>

so-0/0/1.0       Up         <none>

so-0/0/3.0       Up         <none>                            #so-0/0/2.0 is missing

Sample Output 3

user@host> show mpls interface 

MPLS not configured

What It Means

Sample Output 1 shows that all MPLS interfaces on all routers in the network are enabled (Up) and can perform MPLS switching. If you fail to configure the correct interface at the [edit protocols mpls] hierarchy level or include the family mpls statement at the [edit interfaces type-fpc/pic/port unit number] hierarchy level, the interface cannot perform MPLS switching, and does not appear in the output for the show mpls interface command.

Administrative groups are not configured on any of the interfaces shown in the example network in Figure 5. However, if they were, the output would indicate which affinity class bits are enabled on the router.

Sample Output 2 shows that interface so-0/0/2.0 is missing and therefore might be incorrectly configured. For example, the interface might not be included at the [edit protocols mpls] hierarchy level, or the family mpls statement might not be included at the [edit interfaces type-fpc/pic/port unit number] hierarchy level. If the interface is configured correctly, RSVP might not have signaled over this interface yet. For more information on determining which interface is incorrectly configured, see Verify Protocol Families.

Sample Output 3 shows that the MPLS protocol is not configured at the [edit protocols mpls] hierarchy level.

For more information on configuring MPLS on routers in your network, see Configuring MPLS on a Network.