Configure Primary and Secondary Paths for an LSP

The primary statement creates the primary path, which is the LSP's preferred path. The secondary statement creates an alternative path. If the primary path can no longer reach the egress router, the alternative path is used.

To configure primary and secondary paths, include the primary and secondary statements:

primary path-name { 

    ...

}

secondary path-name { 

    ...

}

You can configure these statements 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 the software switches from the primary to a secondary path, it continuously attempts to revert to the primary path, switching back to it when it is again reachable, but no sooner than the retry time specified in the retry-timer statement. (For more information, see Configure Path Connection Retry Information.)

You can configure zero or one primary path. If you do not configure a primary path, the first secondary path that is established is selected as the path.

You can configure zero or more secondary paths. All secondary paths are equal, and the software tries them in the order that they are listed in the configuration. The software does not attempt to switch among secondary paths. If the current secondary path is not available, the next one is tried. To create a set of equal paths, specify secondary paths without specifying a primary path.

If you do not specify any named paths, or if the path that you specify is empty, the software makes all routing decisions necessary to reach the egress router.