Configure the Address of the Egress Router

When configuring an LSP, you must specify the address of the egress router by including the to statement:

to address; 

You can configure this statement at the following hierarchy levels:

• [edit logical-routers logical-router-name protocols mpls label-switched-path lsp-path-name]
• [edit protocols mpls label-switched-path lsp-path-name]

When you are setting up an LSP, the to statement is the only required statement. All other statements are optional.

After the LSP is established, the address of the egress router is installed as a host route in the routing table. This route can then be used by BGP to forward traffic.

To have the software send BGP traffic over an LSP, the address of the egress router is the same as the address of the BGP next hop. You can specify the egress router's address as any one of the router's interface addresses or as the BGP router ID. If you specify a different address, even if the address is on the same router, BGP traffic is not sent over the LSP.

To determine the address of the BGP next hop, use the show route detail command. To determine the destination address of an LSP, use the show mpls lsp command. To determine whether a route has gone through an LSP, use the show route or show route forwarding-table command. In the output of these last two commands, the label-switched-path or push keyword included with the route indicates it has passed through an LSP. Also, use the traceroute command to trace the actual path to which the route leads. This is another indication as to whether a route has passed through an LSP.

You also can manipulate the address of the BGP next hop by defining a BGP import policy filter that sets the route's next-hop address.