Question

Your company runs an HA VPN connection between an on-premises data center and a Google Cloud VPC, using a Cloud Router with BGP. During periods of transient network latency on the WAN link, the BGP sessions repeatedly drop and re-establish, causing routes to flap and briefly interrupting traffic. The on-premises router administrator asks what BGP timer setting on the Cloud Router side you can adjust to make the session more tolerant of brief connectivity interruptions before it is declared down. What should you do?

Accepted Answer

Increase the BGP keepalive interval on the Cloud Router, which raises the effective hold timer and gives the session more time to recover before it is torn down

Answer

Enable Bidirectional Forwarding Detection (BFD) with the shortest possible interval to detect failures faster and prevent flapping

Answer

Lower the BGP keepalive interval on the Cloud Router so that keepalives are sent more frequently and the peer never times out

Answer

Set the Cloud Router ASN to match the on-premises ASN so the session becomes iBGP and uses a longer default hold time