Issue 18.0.47 update #5 caused server to become unreachable

[dakkafex]

Server operating system version

AlmaLinux 8.6

Plesk version and microupdate number

18.0.47 Update #5

18.0.47 update #5 caused multiple of our servers to become unreachable.
It could also not be pinged and it was unreachable by ssh, the only thing that fixed was manually restarting the VPS instances.

I have tried digging through the logs, but I didn't see anything that looked like something that would prevent the server from starting.

Does anyone know what could have caused this? or what should I be looking for in the logs specifically.

 

[Bitpalast]

Looks like a Fail2Ban ban. Do you see the server's own IP address or 127.0.0.1 in /var/log/fail2ban.log?

 

[dakkafex]

Nope, neither shows up in the logfile

 

[Bitpalast]

You you see your own ADSL public IP in that log?
The point is that ping and SSH are two different things. If SSH crashes, the network interface itself and the kernel will still live.
What shows up in /var/log/messages at the time when the crash occured?

 

[Kaspar]

Do have firewalld running by any chance?