A FEC can be added to the LDP IP prefix database with a specific label operation on the node. Permitted operations are pop or swap. For a swap operation, an incoming label can be swapped with a label in the range of 16 to 1048575. If a swap- label is not configured then the default value is 3.
A route table entry is required for a FEC with a pop operation to be advertised. For a FEC with a swap operation, a route-table entry must exist and user configured next-hop for swap operation must match one of the next-hops in route-table entry.
Use the following syntax to configure FEC originate parameters:
config>router>ldp
— fec-originate ip-prefix/mask [advertised-label in-label] next-hop ip-address [swap-label out-label]
— fec-originate ip-prefix/mask [advertised-label in-label] pop
The following displays a FEC originate configuration example:
A:ALA-5>config>router# info
----------------------------------------------
fec-originate 10.1.1.1/32 pop
fec-originate 10.1.2.1/32 advertised-label 1000 next-hop 10.10.1.2
fec-originate 10.1.3.1/32 advertised-label 1001 next-hop 10.10.2.3
swap-label 131071
session-parameters
exit
interface-parameters
exit
targeted-session
exit
exit
----------------------------------------------
A:ALA-5>config>router>ldp#