A new BGP session has been configured. Upon monitoring the session state, you notice that the session has just transitioned from connect state to active state.
What does the active state indicate for this BGP session?
A.
Something is wrong with your configuration. You must check your configuration and try again.
B.
This is the expected behavior. You should wait longer for the BGP session to establish.
C.
The OPEN messages collided. One BGP peer must be configured with the passive option.
D.
No route exists to the neighbors peering address. Check the IGP for reachability.
Explanation:
Current state of the BGP session:* ActiveBGP is initiating a transport protocol connection in an attempt to connect to a peer. If the connection is successful, BGP sends an open message.
* ConnectBGP is waiting for the transport protocol connection to complete.
* EstablishedThe BGP session has been established, and the peers are exchanging update messages.
* IdleEither the BGP license checkfailed, or this is the first stage of a connection and BGP is waiting for a Start event.
* OpenConfirmBGP has acknowledged receipt of an open message from the peer and is waiting to receive a keepalive or notification message.
* OpenSentBGP has sent an open message and is waiting to receive an open message from the peer.Useful links:
http://www.juniper.net/techpubs/software/junos-security/junos-security95/junos-security-swconfig-interfaces-and-routing/section-bgp-overview.html
I have seen this question several times on this site and and I think it is wrong. I think answer should be D.
Explanation:
Idle is the first state. Connect is the second one, when it tries for the first time the TCP Session. If it suceeds it passes to the Open Sent directly, not to the Active State. If it fails, it passes to the Active State, so passing to the Active State IS NOT NORMAL and NOT the “Expected Behavior”. In the Active states it keeps trying the TCP Session, and will remain there until it achieves it.
Taken from JNCIS-ENT Routing guide, page 77:
“Idle state: The Idle state is the initial state… A start event
is required for the local system to initialize BGP resources and prepare for a transport connection with the other BGP peer.
Connect state: … BGP is waiting for the transport protocol connection to be
completed. If the transport protocol connection fails,… changes
its state to Active.
Active state: In the Active state, BGP is trying to acquire a peer by initiating a transport protocol connection… If the local system’s BGP state remains in the Active state, you should check physical connectivity as well as the configuration on both peers.”
I think D is the only answer that could make issues with the TCP Session…
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Agree with Jonathan.
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