My ISP has BFD enabled on their end which is configured on a Cisco NCS540. They told me their default timings are 500ms for tx/rx. I have a BGP session through them and that works fine but once I enable BFD it obviously cuts the BGP session but doesn’t seem to stay disabled. My ISP mentioned that my BGP session was flapping every 20 seconds with it coming up and going back down while I had BFD enabled.
Their NOC support told me their Cisco router is reporting this on my connection. BFD enabled (session down, BFD not configured on remote neighbor)
I did a test lab and that worked fine but obviously that was Mikrotik to Mikrotik and was over OSPF and BGP.
Didn’t know if there were any current incompatibilities atm.
BFD conf is
/routing bfd configuration
add disabled=no interfaces=ISP1 min-rx=500ms min-tx=500ms
Here’s a short recording of the BFD session
Edit
Yeah just found out it’s actually not my config, I guess my ISP learned that the IOS version they are running is outdated and it doesn’t support BFD over some virtual interface they have for me. (They had to open a ticket with Cisco)
So now I’m just waiting for them to update that