This article will provide information about BFD flap log messages and data that needs to be captured.

The BFD session is flapping between QFX and peer device

• Observing BFD flap and we could see below log messages

bfdd[18001]: BFDD_STATE_UP_TO_DOWN: BFD Session X.X.X.X (IFL 850) state Up -> Down LD/RD(1285/17) Up time:00:01:11 Local diag: NbrSignal Remote diag: CtlExpire Reason: Received DOWN from PEER.

bfdd[18001]: BFDD_TRAP_SHOP_STATE_DOWN: local discriminator: 1285, new state: down, interface: XX, peer addr: X.X.X.X


bfdd[18001]: BFDD_STATE_UP_TO_DOWN: BFD Session X.X.X.X (IFL 853) state Up -> Down LD/RD(1213/7) Up time:00:00:29 Local diag: NbrSignal Remote diag: CtlExpire Reason: Received DOWN from PEER.

bfdd[18001]: BFDD_TRAP_SHOP_STATE_DOWN: local discriminator: 1213, new state: down, interface: XX, peer addr: X.X.X.X

bfdd[18001]: BFDD_TRAP_SHOP_STATE_UP: local discriminator: 1213, new state: up, interface: ae1.1005, peer addr: X.X.X.X

• As per the above log messages, the switch says it’s Local Diag as Neighbor signaled, and down Reason shows as Down from Peer.
• We are receiving down message from the peer end device, need to check the keep-alive status during the issue time.
• Please capture the below information during the issue time to debug the issue.

• Collect below command output during the issue time:

user@switch> show bfd session detail

user@switch> show bfd session extensive

user@switch> show ppm adjacencies summary

user@switch> show ppm interfaces detail

user@switch> show ppm adjacencies detail

user@switch> show ppm connections detail

• Enable the below trace-option

set routing-options ppm traceoptions file ppm size 10m count 10

set routing-options ppm traceoptions flag all

set protocols bfd traceoptions file bfd size 10m count 10

set protocols bfd traceoptions flag all

• Based on the above information, we can provide few other inputs about the flaps.

• Please raise a Jtac case if you are having any other queries related to the BFD flap