In which state does BGP wait to receive a keepalive message before transitioning?

BGP, or Border Gateway Protocol, operates through a well-defined state machine as it goes through various stages of establishing a peer relationship. In the context of the OpenConfirm state, this is where BGP is waiting for a keepalive message from its peer to confirm that the connection is alive and that both ends are agreeable to the previously exchanged open message.

During the OpenConfirm state, BGP has just sent an Open message to the peer and is now waiting for a response. If the keepalive message is received, BGP can transition to the Established state, where it will begin to exchange routing information.

In other states such as OpenSent, the BGP process is still in the phase of sending its Open message and has not yet completed the initial handshake, so it does not wait for a keepalive. In the Connect state, the connection hasn't been fully established yet, and it is not in a position to handle keepalives either. Lastly, in the Established state, the BGP session is fully operational and keepalives are simply part of ongoing communication rather than a triggering event for state transition.

Thus, the OpenConfirm state specifically is focused on the need to receive a keepalive message as part of its transition to