I'm not sure I follow the question, so sorry if this is not what your looking for.
BFD runs separately and when it detects an issue based solely on BFD timers and status it tells the partner routing protocol to immediately tear down and withdraw routes.
Then the partner protocol starts its normal process to connect with neighbors which will work from step 1 of start up process and continue until the connection is restored.
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Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home------------------------------
Original Message:
Sent: 04-15-2021 07:37
From: Unknown User
Subject: BFD and IGP
I just need some clarity regarding the role that BFD plays along side IGP for example ISIS or OSPF. Does BFD still work independently and only signals to the protocol that it detected a failure and therefore should also check if they (the protocol) experience the same. For example BDF recieves no response, tells OSPF please ignore your timers and send a keep alive now. Should the protocol receive nothing then it goes into the down state should it still revieve is response from it neighbor it will remain up although BFD is down.