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Static Routes and NSF in IOS XR

Oescalan
Level 1
Level 1

Hi ,

Im researching about NSF, I get the main idea, "if a RP switchover happens, the NSF-capable router that does the RP switchover, sends a message to the NSF- aware so the sessions of the peer dont go down, and the forwarding of the packets can continue because the forwarding plane is separated from the control plane." My question is. What happens with the static routes? Does the traffic that is routed staticly continues to be forwarded? 

What I understand is that the NSF is enabled be default in IOS-XR, so when a switchover ocurres all traffic continues to be forwarded with CEF independetly of what happens in the control plane. You enable NSF in the routing protocols so the session reestablishment doesnt happen and the routes that are known via dynamic protocol dont get refreshed when the backup RP comes up. But the staticly routed traffic doesnt get affected beacause a route reconvergation never happens.

Is this correct?

1 Reply 1

Aleksandar Vidakovic
Cisco Employee
Cisco Employee

Correct, static routes are local to the router. NSF and NSR are about keeping the control plane communication with the peers up during RP switchover. Since static routes don't require any control plane communication with the next-hop, NSF and NSR don't apply.