MPLS Configuration

Make sure “ip cef” is running by using “show running” command

R2(config) # ip cef
R2(config) # mpls label protocol ldp

To make LDP router-id (using loopback address)

R2(config) # mpls ldp router-id loopback 0

Perform these steps on R3 and R4 ?

We will enable MPLS on those interface on which neighbor exists.

R2(config) # interface serial 1/1
R2(config-if) # mpls ip

R3(config) # interface serial 1/0
R3(config-if) # mpls ip

R4(config) # interface serial 1/0
R4(config-if) # mpls ip


Operations and Verify

R2 # show mpls ldp discovery
R2 # show mpls interfaces

R2 # show mpls ldp neighbors
Min label: 16
As 0-15 are reserved

R2# show mpls ldp discovery detail

R2# show ip route-------------------------Control Plane

R2# show ip cef----------------------------Data Plane

R2# show mpls ldp bindings-----------LIB

1. Here we will see one local binding and one remote binding as we have one neighbor so onw remote binding

2. For directly connected it will assign implicit Null label
e.g. 2.0.0.0-------imp-null

For 10.0.0.0------------Local Binding 22
and Remote binding 23

R3# show mpls ldp binding
10.0.0.0--------Local Binding 23
Remote Binding 22

R4# show mpls ldp binding

1. Local and Remote can be same on R4.
2. On R4 for network 2.0.0.0------Local Binding 18
--------Remote binding “imp null”
This imp null means that R3 state that 2.0.0.0 is my directly connected so if you want to send some traffic for this network so remove the label as to get rid of the double lookup.

This was just a window to the MPLS configuration. I Hope this will be informative for you.

Cheers :)