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New Member

BGP Neighbor drop

I have a Metro -Ethernet connection to my service provider running BGP.  My BGP session dropped (neighbor) and I am not sure why.  There are no errors on my interface.  There was an increase in traffic at the time it went down, but the link was not completely saturated.  The service provider is stating BGP went down due to congestion on the link, but I do not see any congestion on my end.  Is this possible?  Will BGP drop due to congestion?  Thanks.

3 REPLIES
VIP Super Bronze

Re: BGP Neighbor drop

Hi,

Congestion should not cause a BGP link/peer to drop. 

What does "sh log" shows?

HTH

Reza

New Member

Re: BGP Neighbor drop

Thanks for the reply.  Here is the output of my show log when the event occured:

Apr 30 19:27:33.017 GMT: %BGP-5-ADJCHANGE: neighbor "IP" Down BGP Notification sent

Apr 30 19:27:33.017 GMT: %BGP-3-NOTIFICATION: sent to neighbor "IP" 4/0 (hold time expired) 0 bytes

Apr 30 19:30:08.755 GMT: %BGP-5-ADJCHANGE: neighbor "IP" Up

Hall of Fame Super Silver

Re: BGP Neighbor drop

Hello IT Ninja,

not all Cisco platforms have a system hidden queue for routing protocol messages you may need to implement a QoS scheduler to provide resources for BGP message exchange.

Ideally you should use hierarchical QoS (two levels) with parent policy shaping all traffic to stated CIR with metro ethernet provider and child policy that implements a queueing system with one queue/class for BGP and other routing  protocols

Congestion may have happened also in service provider network but you should take the above measures on all metroE connected devices.

Hope to help

Giuseppe

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