OSPF Loop-Free Alternate (LFA) Fast Reroute (FRR)

Hello Staut

Remember that OSPF is a link state routing protocol. One of the characteristics of a link state protocol is that it has a full picture of the network’s topology, including costs of particular links. This information is enough for a router, when node protection as a tie breaker is enabled, to know what the next hop of another router will be to reach a particular destination. If that next hop is the same as the primary next hop for the particular destination, then the node protection tie breaker kicks in and chooses another route as the repair route.

I hope this has been helpful!

Laz

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