05-07-2010 07:37 PM - edited 03-04-2019 08:24 AM
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.
05-07-2010 08:30 PM
Hi,
Congestion should not cause a BGP link/peer to drop.
What does "sh log" shows?
HTH
Reza
05-07-2010 09:06 PM
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
05-08-2010 12:54 AM
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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