BGP peer lost

[mediaworksnz]

Hello, we have a WAN (private IP) telco circuit. I have noticed over the last few days that the BGP neighbor relationship between us and the Telco has been continuously going up and down for periods of about one hour.

Could this be due to heavy traffic on this link ? i.e. can heavy user traffic flood the link and cause our router to temporarily lose it's BGP peer relationship ?

If so, how can I prevent this ?

Thank you for any help.

[Reza Sharifi · Accepted solution]

Hi,

Heavy traffic will not cause BGP peering to go down. The issue could be your router or the one you are peering with. Inspect your router for any recent changes and also talk to your provider and see if they have made any changes on their side.

HTH

[Harold Ritter]

Any interesting information in the log.

Regards,

[mediaworksnz]

My router's BGP peering just bounces like this for about 1 hour, then stable until the next time it occurs:

Apr 5 19:30:49: %BGP-5-NBR_RESET: Neighbor 192.168.2.57 reset (Peer closed the session)
Apr 5 19:30:49: %BGP-3-NOTIFICATION: received from neighbor 192.168.2.57 4/0 (hold time expired) 0 bytes
Apr 5 19:30:49: %BGP-5-ADJCHANGE: neighbor 192.168.2.57 Down Peer closed the session
Apr 5 19:30:49: %BGP_SESSION-5-ADJCHANGE: neighbor 192.168.2.57 IPv4 Unicast topology base removed from session Peer closed the session
Apr 5 19:31:01: %BGP-5-ADJCHANGE: neighbor 192.168.2.57 Up
Apr 5 19:32:31: %BGP-5-NBR_RESET: Neighbor 192.168.2.57 reset (Peer closed the session)
Apr 5 19:32:31: %BGP-3-NOTIFICATION: received from neighbor 192.168.2.57 4/0 (hold time expired) 0 bytes
Apr 5 19:32:31: %BGP-5-ADJCHANGE: neighbor 192.168.2.57 Down Peer closed the session
Apr 5 19:32:31: %BGP_SESSION-5-ADJCHANGE: neighbor 192.168.2.57 IPv4 Unicast topology base removed from session Peer closed the session

[paul driver · Accepted solution]

Hello

Do you see any errors in the physical interface?

If this is a p2p peering suggest check the physical connection with your isp however if the peering is between logical interfaces (ie loopbacks) I would then also suggest to check your routing and see if  path between the peers is being 

lost 

res

paul

[Julio E. Moisa · Accepted solution]

Hi

You could execute: show ip bgp neighbor x.x.x.x, and it could show a reason of the last reset. Also a debug could be used once it is happening. 

[ปลาวาฬทราย RMUTT CPE IX]

Last reset 00:11:10, due to Peer closed the session

https://community.cisco.com/t5/routing/bgp-peer-closed-status/td-p/1879804

Thank you very much.

[mediaworksnz]

I looked in the logs of our router and it says:

'Last reset 1d12h, due to Peer closed the session of session 1'

Out of interest, the Telco just responded with:

'I have looked into the fault and it appears that there has been high utilization.'.