BGP Notification received, configuration change

[h.natarajan.bmc]

Hi,

We are  monitoring a BGP peering flap for a fraction of seconds approximately every three days for a particular neighbor. We are seeing this behavior consistently for a Month.

Jun 10 08:55:15.566 NST: bgp[1041]: %ROUTING-BGP-5-ADJCHANGE : neighbor x.x.x.x Down - BGP Notification received, configuration change (VRF: default)
Jun 10 08:55:15.565 NST: bgp[1041]: %ROUTING-BGP-5-NBR_NSR_DISABLED_STANDBY : NSR disabled on neighbor x.x.x.x on standby due to BGP Notification received (VRF: default)

Would like to know what does the error messge indicates  "BGP Notification received, configuration change"

[skondala]

there was a configuration chnage on BGP from other side

[h.natarajan.bmc]

Yes. I understand but there is no configuration change from the other side. But still we are facing a fraction of second BGP flap with above mentioned down notification once for every 3 days.

Please assist.

[xthuijs]

There might be a clue in the bgp trace on the device that experienced this condition:

show bgp trace and look around the time of the notification down.

Depending on what is on the other side, I think that hte investigation is better done on that node as that was the originator of the change hence bringing the peer down.

This can be as simple as an address family add or remove, things like that. When capabilities of a peer change, they have to bring down the peering since they are only sent in the OPEN message.

IF it is very periodic, I would also verify and check what might be happening during those time windows, especially on the peer. Maybe there is a config script that could induce things.

If that peer is an XR device, the bgp trace will be very helpful in that regard.

If itis an IOS device, then maybe you need to keep running some debug bgp event for around the time that you expect this flap, and a syslog analysis (sh log) around that time for clues.

xander