Good morning hive mind!

I've had a weird thing happen on a couple sites now. When the internet connection has gone out at the remote site, the IP phones haven't come back up once the internet has been restored. This is with both 6021 and 3105 phones.

I did manage to get them to reconnect by doing a couple different things.

On the ones site, we have a 7200 running 5.01 with an mgi64 card behind a Fortinet router. On that site, the phones at the remote (home office) have come back up when the Fortinet at the main site was restarted. ( I did once manage to get it back by walking the user through a factory reset and re-entering the server information)

The second site is a 7400 with OAS cards running 4.92. The remote site here is connected on a MPLS to the main site with the phones running on a separate VLAN. These ones I've been able to get connected by factory resetting and re-entering the sever info.

I thought it might be a phone version issue but a newly installed 6021 with the latest version also had the problem.

I looked through the recent release notes but didn’t see anything related in the fixes.

Any thoughts?

Try downgrading the 7200 to 4.98 and upgrading the 7400 to 4.98. I know 5.01 was still sketchy. Sounds like at the main site the Fortinet isn't letting the connections come through once the internet service is restored. Do they have static public IP's at the locations?

Yup Static IPs.

I've had this issue, never figured out what the cause was.

Never could manually replicate the issue either (even when dropping the connection at the system end by removing a cable)