Performing an Implicit Commit

MPLS allows the user to modify the configurable parameters for RSVP LSPs while the LSP is operational.

After modifying the parameters for an operational LSP, the user must execute the commit command to apply the changes. Applying these configuration changes requires a new instance of the LSP to be signaled with a modified or new set of parameters, also known as make-before-break. Once the new instance of the LSP is up, the old instance is removed.

By default, if the adaptive parameters of an LSP have changed, but the changes are not yet committed, any system-initiated make-before-break, such as an LSP re-optimization event, is ignored. To allow changes to be automatically applied, the user can use the implicit-commit lsp-reoptimize-timer command under the router MPLS policy command to enable certain types of events to trigger implicit commit.

Configure the device.
```
device# configure
```
Enable the MPLS router.
```
device(config)# router mpls
```
Enable policy parameter configuration.
```
device(config-router-mpls)# policy
```

Enable implicit commit.

device(config-router-mpls-policy)# implicit-commit lsp-reoptimize-timer

The following example enable the LSP re-optimize timer to trigger an implicit commit.

device# configure
device(confoig)# router mpls
device(config-router-mpls)# policy
device(config-router-mpls-policy)# implicit-commit lsp-reoptimize-timer