Hi,
The BGP connect states are: IDLE, ACTIVE, CONNECT, OPENSENT, OPENCONFIRM, and ESTABLISHED.
The connect state is established by active negotiations between the peers.
In the IDLE state, the router will not accept connections from the peer. This state is entered briefly after a connection has timed out, to prevent too-rapid up-and-down transitions of peers.
In the ACTIVE state, the router is listening on its server port for connection requests from the peer.
In the CONNECT state, the router has sent out an active TCP connection request to the peer.
In the OPENSENT (The first BGP message to be sent is Open message (to negotiate the parameters for session establishmnet)) and OPENCONFIRM states (When the remote peer accepts the parameters in the Open message it respond with its own Open message --> The router enters "OpenConfirm" mode), the two peers are exchanging preliminary packets in order to establish their BGP session. If the exchanges are successful, the peers will enter the ESTABLISHED state.
When the local router accepts the parameters in the Open message replied by its remote peer --> The router enters "Established" mode and sends its first keepalive packet to ack this. The peers must continue to exchange periodic KEEPALIVE packets to remain in the established state, unless the negotiated hold time is 0.
http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a008009425c.shtml
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093fb8.shtml
HTH, please do rate all helpful replies,
Mohammed Mahmoud.
