H3C Technologies H3C S6800 Series Switches - Manual (Page 56)

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[SwitchD-ldp] quit
5. Configure label acceptance policies:
# On Switch A, create an IP prefix list prefix-from-b that permits 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 an IP prefix list prefix-from-d that denies 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 an IP prefix list prefix-from-b that permits 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 an IP prefix list prefix-from-d that denies 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
Status Flags: * - stale, L - liberal, B - backup
Statistics:
FECs: 2 Ingress LSPs: 1 Transit LSPs: 1 Egress LSPs: 1
FEC In/Out Label Nexthop OutInterface
11.1.1.0/24 1277/-
-/1148(L)
21.1.1.0/24 -/1149(L)
-/1276 10.1.1.2 Vlan-int2
1276/1276 10.1.1.2 Vlan-int2
The output shows that the next hop of the LSP for FEC 21.1.1.0/24 is Switch B (10.1.1.2). The LSP has been
established over the link Switch A—Switch B—Switch C, not over the link Switch A—Switch D—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