The tools perform router mpls update-path {lsp lsp-name path current-path-name new-path new-path-name} command instructs MPLS to replace the path of the primary or secondary LSP.
The primary or secondary LSP path is indirectly identified via the current-path-name value. In existing implementation, the same path name cannot be used more than once in a specific LSP name.
This command is also supported on an SNMP interface.
This command applies to both CSPF LSP and to a non-CSPF LSP. However, it is only honored when the specified current-path-name has the adaptive option enabled. The adaptive option can be enabled the LSP level or at the path level.
The new path must be first configured in CLI or provided via SNMP. The configure >router>mpls>path path-name command is used to enter the path.
The command fails if any of the following conditions are satisfied:
The specified current-path-name of this LSP does not have the adaptive option enabled.
The specified new-path-name value does not correspond to a previously defined path.
The specified new-path-name value exists but is being used by any path of the same LSP, including this one.
When the command is executed, MPLS performs a single MBB attempt to move the LSP path to the new path.
If the MBB is successful, MPLS updates the new path.
MPLS writes the corresponding NHLFE in the data path if this path is the current backup path for the primary.
If the current path is the active LSP path, it updates the path, writes the new NHLFE in the data path, which causes traffic to switch to the new path.
If the MBB is not successful, the path retains its current value.
The update-path MBB has the same priority as the manual resignal MBB.