topic Re: traffic disruption on routing change in Next-Generation Firewall Discussions

traffic disruption on routing change

COsterbrink-LIS — Tue, 21 Apr 2026 13:02:01 GMT

hi folks,

I deleted a vlan subinterface from the VR config and from the ospf redist options. after comitting the change we had a partial service disruption where sessions where dropped. I can see a visible drop in thoughput but not in number of sessions. according to monitoring traffic I can says that it lasted roughly 15 seconds which is quite long. I can see in the system log that the route daemon was restarted but that seems to happen with every commit and usually case zero impact. but in this case the routing config was changed. I can't see any ospf messages in the system log and also not on the router behind the fw. so the traffic disruption seems just to be internal on the fw. has anyone experienced the same? I would be interested if this is expected behavior?

Chris

Re: traffic disruption on routing change

BPry — Fri, 24 Apr 2026 16:32:50 GMT

@COsterbrink-LIS,

Might help if you post your PAN-OS version that you were running at the time. You'll have more detailed OSPF event logging within routed.log, but that file rotates pretty quickly so unless you pulled it at the time of the disruption you'll want to probably look at routed.log.old and see if it still has the logs for the time period of the issue.

Re: traffic disruption on routing change

COsterbrink-LIS — Mon, 27 Apr 2026 07:02:37 GMT

Hi @BPry

thanks for your reply. PANOS is 10.2.16-h6 - unfortunately the logs in routed.log.old also rotated out.

but we have planned further migrations of vlan sub-interfaces which need then to be deleted and I will have a close look to the routed.log and also on the upstream ospf router

in system log there were no suspicious messages. will keep this post updated.