What is the role of a BGP Keepalive Message?

A BGP Keepalive message plays a crucial role in maintaining the stability of the Border Gateway Protocol (BGP) peer relationship. Specifically, it serves the purpose of notifying BGP peers that the originating device is actively connected and operational. By sending these Keepalive messages at regular intervals, BGP routers can ensure that the link to their peers is still valid. If a router does not receive a Keepalive message from a peer within a defined timeframe, it may assume that the peer has become inactive or unreachable, potentially leading to the withdrawal of routes associated with that peer.

The frequency of these messages is typically determined by the Keepalive interval configured on the BGP session. This mechanism is essential for ensuring that both peers remain aware of each other's operational status, helping to prevent unnecessary disruptions in routing.