Question
- What is BGP Flapping?
- When is BGP Flapping a problem? When should I alert the SOC?
Environment
- Silverline DDoS
- BGP Routing
- GRE Tunnels
Answer
- "BGP Flapping" is a normal part of the internet, and is the result of carriers working to prevent instability in BGP networking.
- Up to 3 minutes (180 seconds) flap is considered normal / standard.
- Carriers implement BGP Timeouts to keep the network stable.
- When this is happening, the BGP route disappears and reappears in the routing table.
- This is one of the reasons that the SOC requires 2 GRE tunnels or 2 IP-IP tunnels per router, in order to ensure redundancy to each of our scrubbing centers.
- Continual flaps are problematic, as well as BGP that goes down and stays down.
- If it's been >180 seconds and it's not reconverged, open a ticket with the SOC to troubleshoot!