49
-/1277(L)
21.1.1.0/24 1150/-
The output shows that Switch A and Switch C have received FEC-label mappings only from Switch B.
Switch B has received FEC-label mappings from both Switch A and Switch C. Switch D does not receive
FEC-label mappings from Switch A or Switch C. LDP has established an LSP only over the link Switch
A—Switch B—Switch C.
# Test the connectivity of the LDP LSP from Switch A to Switch C.
[SwitchA] ping mpls -a 11.1.1.1 ipv4 21.1.1.0 24
MPLS Ping FEC: 21.1.1.0/24 : 100 data bytes
100 bytes from 20.1.1.2: Sequence=1 time=1 ms
100 bytes from 20.1.1.2: Sequence=2 time=1 ms
100 bytes from 20.1.1.2: Sequence=3 time=8 ms
100 bytes from 20.1.1.2: Sequence=4 time=2 ms
100 bytes from 20.1.1.2: Sequence=5 time=1 ms
--- FEC: 21.1.1.0/24 ping statistics ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max = 1/2/8 ms
# Test the connectivity of the LDP LSP from Switch C to Switch A.
[SwitchC] ping mpls -a 21.1.1.1 ipv4 11.1.1.0 24
MPLS Ping FEC: 11.1.1.0/24 : 100 data bytes
100 bytes from 10.1.1.1: Sequence=1 time=1 ms
100 bytes from 10.1.1.1: Sequence=2 time=1 ms
100 bytes from 10.1.1.1: Sequence=3 time=1 ms
100 bytes from 10.1.1.1: Sequence=4 time=1 ms
100 bytes from 10.1.1.1: Sequence=5 time=1 ms
--- FEC: 11.1.1.0/24 ping statistics ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max = 1/1/1 ms
LDP FRR configuration example
Network requirements
Switch S, Switch A, and Switch D reside in the same OSPF domain. Configure OSPF FRR so LDP can
establish a primary LSP and a backup LSP on the Switch S—Switch D and the Switch S—Switch
A—Switch D links, respectively.
When the primary LSP operates correctly, traffic between subnets 11.1.1.0/24 and 21.1.1.0/24 is
forwarded through the LSP.
When the primary LSP fails, traffic between the two subnets can be immediately switched to the backup
LSP.