BGP Active State

BD

The BGP Active state is a temporary state that indicates that the BGP speaker is still attempting to establish a BGP session with a peer. There are various reasons why a BGP session may fail to establish, causing the BGP speaker to enter the Active state. The two events that could cause the BGP Active state to appear are:

B. The local router failed to establish a TCP connection with the peer device: BGP runs over TCP, and establishing a TCP connection is the first step in establishing a BGP session. If the local router is unable to establish a TCP connection with the peer device, it will enter the Active state. There are various reasons why a TCP connection may fail to establish, such as incorrect IP addresses or port numbers, network connectivity issues, or firewall configuration issues.

D. The BGP configuration is incomplete: BGP requires a complete and accurate configuration to establish a session with a peer. If the BGP configuration is incomplete or contains errors, the local router may not be able to establish a BGP session with the peer device. This could cause the router to enter the Active state.

A. The local router does not have a route to the peer device: This is not a direct cause of the BGP Active state. However, if the local router does not have a route to the peer device, it will not be able to establish a TCP connection with the peer, which would cause the router to enter the Active state. Therefore, this could be considered an indirect cause of the BGP Active state.

C. A firewall is stopping all UDP packets: This is not a direct cause of the BGP Active state. BGP runs over TCP, not UDP. Therefore, if a firewall is stopping all UDP packets, it would not directly affect the BGP session. However, if the firewall is misconfigured and is blocking BGP traffic, it could indirectly cause the BGP Active state.