LDP route injection example

The following example describes LDP route injection of routes 10.2.2.2/32 and 10.5.5.2/32 into the LDP label information database.

By default, the LDP label information database only contains labels learned for IP addresses of loopback interfaces, as demonstrated in this example, where only prefixes 10.3.3.3/32 and 10.5.5.5/32 are displayed by the show mpls ldp database command.

device# show mpls ldp database
Session 10.3.3.3:0 - 10.5.5.2:0
 Downstream label database:
   Label     Prefix          State
   1024      10.3.3.3/32     Retained
 Upstream label database:
   Label     Prefix
   3         10.3.3.3/32
   3         10.5.5.5/32

A filter is configured to inject route 10.2.2.2/32.

device# configure terminal
device(config)#ip prefix-list list1 permit 10.2.2.2/32
device(config)# router mpls
device(config-mpls)# ldp
device(config-router-mpls-ldp)# advertise-fec list1
device(config-router-mpls-ldp)# Ctrl-z

The show mpls ldp database command displays that route 10.2.2.2/32 has been injected into the LDP Label information database.

device# show mpls ldp database
Session 10.3.3.3:0 - 10.5.5.2:0
 Downstream label database:
   Label     Prefix          State
 Upstream label database:
   Label     Prefix
   3	        10.2.2.2/32

A second filter is configured to inject route 10.5.5.2/32.

device# configure terminal
device(config)# ip prefix-list list1 permit 10.5.5.2/32
device(config)# exit

The show mpls ldp database command displays that route 10.5.5.2/32 has been injected into the LDP label information database.