Hi, If you use carrier-delay with BFD then the interface won't be signalled as up to the IGP until BFD has been established. Or am I miss-remembering this?
I belive that if you use something like "carrier-delay down 0 up 5000" on an interface with BFD, if the interface goes down hard down or a layer 2 hop in the middle goes down (which BFD catches) then the interface is signalled as down to the IGP without delay (also required global config command "ip routing protocol purge interface" I believe). When the interface comes hard up again (or BFD confirms end-to-end connectivity in the case of a layer 2 hop issue) then carrier delay will prevent the IGP from being signalled strait away (in this example for 5 seconds). Something like the following has worked for us (can't remember exactly off the top of my head and you should lab test to match the config to your needs etc.): conf t ip routing protocol purge interface int x/x carrier-delay down 0 up 5000 dampening bfd interval 50 min_rx 50 multiplier 3 We have had scenarios of third party links that flapped multiple times and were caught by the "damping" command which we see in syslog a message like "InterfaceX/X Routing state to DOWN, interface is suppressed" Cheers, James. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
