Make-Before-Break (MBB), Hitless Switchover for LSPs

Adaptive label-switched paths (LSPs) might need to establish a new LSP instance and transfer traffic from an old LSP instance onto the new LSP instance before tearing down the old one. This type of configuration is referred to as a make before break (MBB).

To avoid traffic loss during this process, you can use the optimize-adaptive-teardown CLI statement, which enables an optional feedback mechanism during MBB switchover.  Use this statement to ensure that the LSP data is established end-to-end before the old paths are torn down.