Symptom/Cause | Solution |
|---|---|
BGP L3VPN sessions are operationally up but: • The labels are not allocated for the originating routes • No routes are received from the peer | If the originating routes are directly connected, check if “redistribute connected” is configured under the “address-family ipv4 vrf NAME” is configured. If the originating routes are statically configured, check if “redistribute static” is configured under the “address-family ipv4 vrf NAME” is configured. If the originating routes are received via the OSPF session with the customer edge (CE) node, check if “redistribute ospf” is configured under the “address-family ipv4 vrf NAME” is configured. Check if the “rd” and “route-target” configured for a particular VRF matches the ones configured at the peer for the same VRF. Check if the neighbors’ identifiers are configured correctly. show ip bgp vpnv4 vrf NAME label Validate the labels distributed between the BGP VPNv4 address-family peers: • The “In Label” column shows the labels distributed for the originating routes at the local node to its peer. For these labels there has to be corresponding ILM entries in the NSM. • The “Out Label” column shows the labels received for the routes from the peer node. For these labels there has to be corresponding L3VPN FTN entries in the NSM. |
BGP shows the labels as installed but the L3VPN FTNs are operationally down in NSM | show mpls forwarding-table Check if there is at least on MPLS path (LSP/tunnel) to the BGP peer. When there are multiple paths to the BGP peer, there could be a case where the interface used by the MPLS LSP to reach the BGP peer is different from the one that BGP uses to reach its peer. In such cases, check if “label-switching” is enabled on all the interfaces through which BGP could possibly connect to its peer. show mpls vrf-table Validate the presence of L3VPN FTNs and ILMs in the MPLS FIB: This shows the all the routes received from the BGP peer with the routes segregated per VRF. The “out label” shows the label to be used for that route. This has to match the “Out Label” shown as an output for the “show ip bgp vpnv4 vrf NAME label” command for that particular route. The “show mpls vrf-table” command also shows the operational state of the L3VPN FTNs. show mpls ilm-table The “In-Label” shown must match the “In Label” shown as an input for the “show ip bgp vpnv4 vrf NAME label” command for that particular route. |