41
# On Switch B, create IP prefix list
switchb
, and configure LDP to use only the routes permitted
by the prefix list to establish LSPs.
[SwitchB] ip prefix-list switchb index 10 permit 11.1.1.0 24
[SwitchB] ip prefix-list switchb index 20 permit 21.1.1.0 24
[SwitchB] mpls ldp
[SwitchB-ldp] lsp-trigger prefix-list switchb
[SwitchB-ldp] quit
# On Switch C, create IP prefix list
switchc
, and configure LDP to use only the routes permitted
by the prefix list to establish LSPs.
[SwitchC] ip prefix-list switchc index 10 permit 11.1.1.0 24
[SwitchC] ip prefix-list switchc index 20 permit 21.1.1.0 24
[SwitchC] mpls ldp
[SwitchC-ldp] lsp-trigger prefix-list switchc
[SwitchC-ldp] quit
# On Switch D, create IP prefix list
switchd
, and configure LDP to use only the routes permitted
by the prefix list to establish LSPs.
[SwitchD] ip prefix-list switchd index 10 permit 11.1.1.0 24
[SwitchD] ip prefix-list switchd index 20 permit 21.1.1.0 24
[SwitchD] mpls ldp
[SwitchD-ldp] lsp-trigger prefix-list switchd
[SwitchD-ldp] quit
5.
Configure label acceptance policies:
# On Switch A, create IP prefix list
prefix-from-b
to permit subnet 21.1.1.0/24. Switch A uses
this list to filter FEC-label mappings received from Switch B.
[SwitchA] ip prefix-list prefix-from-b index 10 permit 21.1.1.0 24
# On Switch A, create IP prefix list
prefix-from-d
to deny subnet 21.1.1.0/24. Switch A uses this
list to filter FEC-label mappings received from Switch D.
[SwitchA] ip prefix-list prefix-from-d index 10 deny 21.1.1.0 24
# On Switch A, configure label acceptance policies to filter FEC-label mappings received from
Switch B and Switch D.
[SwitchA] mpls ldp
[SwitchA-ldp] accept-label peer 2.2.2.9 prefix-list prefix-from-b
[SwitchA-ldp] accept-label peer 4.4.4.9 prefix-list prefix-from-d
[SwitchA-ldp] quit
# On Switch C, create IP prefix list
prefix-from-b
to permit subnet 11.1.1.0/24. Switch C uses
this list to filter FEC-label mappings received from Switch B.
[SwitchC] ip prefix-list prefix-from-b index 10 permit 11.1.1.0 24
# On Switch C, create IP prefix list
prefix-from-d
to deny subnet 11.1.1.0/24. Switch A uses this
list to filter FEC-label mappings received from Switch D.
[SwitchC] ip prefix-list prefix-from-d index 10 deny 11.1.1.0 24
# On Switch C, configure label acceptance policies to filter FEC-label mappings received from
Switch B and Switch D.
[SwitchC] mpls ldp
[SwitchC-ldp] accept-label peer 2.2.2.9 prefix-list prefix-from-b
[SwitchC-ldp] accept-label peer 4.4.4.9 prefix-list prefix-from-d
[SwitchC-ldp] quit
Verifying the configuration
# Display LDP LSP information on switches, for example, on Switch A.
[SwitchA] display mpls ldp lsp