Advanced IP Network Design (CCIE Professional Development)

Neighbor Loss and LSP Regeneration

Look at what happens when Router B in Figure B-1 reboots for some unknown reason.

Figure B-1. An IS-IS Adjacency

Router A will not immediately flush the LSPs that Router B has advertised as you might expect. Instead, Router A waits until the Remaining Lifetime field of these LSPs reaches 0 (they time out). Then, it floods to the rest of the network that the LSPs are unreachable. Finally, Router A flushes the LSPs from its database.

Therefore, Router A will not flush the LSP advertised by Router B for NSAP 47.0189.00C0.AF56.25B6.00 until its Maxage timer reaches 0. When Router B finishes rebooting and rebuilds ...