By default, an LSP routes itself hop-by-hop toward the egress router. The LSP tends to follow the shortest path as dictated by the local routing table, usually taking the same path as destination-based, best-effort traffic. These paths are “soft” in nature because they automatically reroute themselves whenever a change occurs in a routing table or in the status of a node or link.
To configure the path so that it follows a particular route, create a named path using the path statement, as described in Creating a Named Path. Then apply the named path by including the primary or secondary statement. A named path can be referenced by any number of LSPs.
To configure primary and secondary paths for an LSP, complete the steps in the following sections: