Each LSP requires one and only one egress LER. After the LSP is successfully established, the address of the egress LER is installed as an internal host route on the ingress LER, allowing the ingress LER to direct BGP next-hop traffic into the LSP. The destination address does not necessarily have to be the final node in the primary path specified for the LSP. When the final node in the path differs from the destination address, the hop between the final node in the path and the egress LER is treated as a loose hop.
To specify 10.100.1.1 as the address of the egress LER for LSP tunnel1, complete the following steps.
The following example shows how to specify 10.100.1.1 as the address of the egress LER for LSP tunnel1.
device# configure device(config)# router mpls device(config-router-mpls)# lsp tunnel1 device(config-router-mpls-lsp)# to 10.100.1.1
Note
When IS-IS is used as the IGP, the egress LER advertises the tunnel destination must be in Extended IP Reachability TLV 135 in order for the LSP to be properly mapped by CSPF. To ensure that this happens, connect to the egress LER and enable IS-IS on the interface which has the IP address of the tunnel destination. When none of the interfaces on the egress LER has the IP address of the tunnel destination (for example, when the tunnel destination address is the egress LER‘s router ID) rather than an interface address -- to manually set the router ID, then the tunnel destination address must be included in Traffic Engineering router ID TLV 134 in the LSP originated by the egress LER. This is accomplished by setting the egress LER‘s traffic engineering policy to IS-IS with the traffic engineering isis level command