BFD for LSP configuration example

Use LDP to establish an LSP from 1.1.1.9/32 to 3.3.3.9/32 and an LSP from 3.3.3.9/32 to 1.1.1.9/32. Use BFD to verify LSP connectivity.

1. Configure IP addresses for interfaces. (Details not shown.)

2. Configure OSPF to ensure IP connectivity between the switches:

   # Configure Switch A.

   <SwitchA> system-view
   [SwitchA] ospf
   [SwitchA-ospf-1] area 0
   [SwitchA-ospf-1-area-0.0.0.0] network 1.1.1.9 0.0.0.0
   [SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
   [SwitchA-ospf-1-area-0.0.0.0] quit
   [SwitchA-ospf-1] quit
   

   # Configure Switch B.

   <SwitchB> system-view
   [SwitchB] ospf
   [SwitchB-ospf-1] area 0
   [SwitchB-ospf-1-area-0.0.0.0] network 2.2.2.9 0.0.0.0
   [SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255
   [SwitchB-ospf-1-area-0.0.0.0] network 20.1.1.0 0.0.0.255
   [SwitchB-ospf-1-area-0.0.0.0] quit
   [SwitchB-ospf-1] quit
   

   # Configure Switch C.

   <SwitchC> system-view
   [SwitchC] ospf
   [SwitchC-ospf-1] area 0
   [SwitchC-ospf-1-area-0.0.0.0] network 3.3.3.9 0.0.0.0
   [SwitchC-ospf-1-area-0.0.0.0] network 20.1.1.0 0.0.0.255
   [SwitchC-ospf-1-area-0.0.0.0] quit
   [SwitchC-ospf-1] quit
   

3. Enable MPLS and LDP:

   # Configure Switch A.

   [SwitchA] mpls lsr-id 1.1.1.9
   [SwitchA] mpls ldp
   [SwitchA-ldp] quit
   [SwitchA] interface vlan-interface 2
   [SwitchA-Vlan-interface2] mpls enable
   [SwitchA-Vlan-interface2] mpls ldp enable
   [SwitchA-Vlan-interface2] quit
   

   # Configure Switch B.

   [SwitchB] mpls lsr-id 2.2.2.9
   [SwitchB] mpls ldp
   [SwitchB-ldp] quit
   [SwitchB] interface vlan-interface 2
   [SwitchB-Vlan-interface2] mpls enable
   [SwitchB-Vlan-interface2] mpls ldp enable
   [SwitchB-Vlan-interface2] quit
   [SwitchB] interface vlan-interface 3
   [SwitchB-Vlan-interface3] mpls enable
   [SwitchB-Vlan-interface3] mpls ldp enable
   [SwitchB-Vlan-interface3] quit
   

   # Configure Switch C.

   [SwitchC] mpls lsr-id 3.3.3.9
   [SwitchC] mpls ldp
   [SwitchC-ldp] quit
   [SwitchC] interface vlan-interface 3
   [SwitchC-Vlan-interface3] mpls enable
   [SwitchC-Vlan-interface3] mpls ldp enable
   [SwitchC-Vlan-interface3] quit
   

4. Enable MPLS BFD, and configure BFD to verify LSP connectivity.

   # Configure Switch A.

   [SwitchA] mpls bfd enable
   [SwitchA] mpls bfd 3.3.3.9 32
   

   # Configure Switch C.

   [SwitchC] mpls bfd enable
   [SwitchC] mpls bfd 1.1.1.9 32
   

# Display BFD information for LSPs on Switch A and Switch C. This example uses Switch A.

[SwitchA] display mpls bfd
 Total number of sessions: 2, 2 up, 0 down, 0 init

 FEC Type: LSP
 FEC Info:
   Destination: 1.1.1.9
   Mask Length: 32
 NHLFE ID: -
 Local Discr: 514                    Remote Discr: 514
 Source IP: 1.1.1.9                  Destination IP: 3.3.3.9
 Session State: Up                   Session Role: Active
 Template Name: -

 FEC Type: LSP
 FEC Info:
   Destination: 3.3.3.9
   Mask Length: 32
 NHLFE ID: 1025
 Local Discr: 513                    Remote Discr: 513
 Source IP: 1.1.1.9                  Destination IP: 127.0.0.1
 Session State: Up                   Session Role: Passive
 Template Name: -

The output shows that two BFD sessions have been established between Switch A and Switch C. One session verifies the connectivity of the LSP from 3.3.3.9/32 to 1.1.1.9/32 and the other session verifies the connectivity of the LSP from 1.1.1.9/32 to 3.3.3.9/32.