Rerouting of Inter-Area LSP

In prior implementation, an inter-area LSP path would have been re-routed if a failure or a topology change occurred in the local or a remote area while the ABR loose-hop in the path definition was still up. If the exit ABR node went down, went into IS-IS overload, or was put into node TE graceful shutdown, the LSP path remains down at the ingress LER.

One new behavior introduced by the automatic selection of ABR is the ability of the ingress LER to reroute an inter-area LSP primary path via a different ABR in the following situations: