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BGP flap on qfx5100 with BFD configured when running 'request support information'

  [KB34061] Show Article Properties


QFX5100 has a hardware limitation with the number of PPM adjacencies.  This number is variable depending on the switch load.  When there is over 20 PPM adjacencies, the switch is at risk.


When running a RSI, the PPM will drop BFD hello packets. Then the BGP session will drop.

root@lab-switch> start shell
root@lab-switch:RE:0% vty fpc0
FPC0(lab-switch vty)# sh ppm adjacencies

PPM distributed adjacencies

Protocol   Holdtime (msec) PPM handle  Inline

BFD        3000            7           No
BFD        3000            8           No
LACP       3000            17          No
LACP       3000            21          No
LACP       3000            22          No
LACP       3000            18          No
LACP       3000            19          No
LACP       3000            20          No

Total adjacencies: 8    <-- at risk if this number is 20 or higher

This is a product/hardware limitation.  You can either lower the PPM adjacencies, or raise the BFD timer.  You can also deactivate BFD, then collect the RSI.

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