Issue Plesk web interface only accessible via IP and SSH service refused

[spool]

Server operating system version

Debian 11, Almalinux 9.2

Plesk version and microupdate number

18.0.72 #3

Plesk web interface only accessible via IP and SSH service refused.

Since the (automatic) update to Plesk 18.0.72, the web interface can only be accessed directly via the IP address, no longer via the server domain as before. Furthermore, the SSH service is also blocked from the outside. This runs on an individual port. A connection refused message always appears.

Restarting services does not help, automatic Plesk repair does not help, resetting the server name does not help. Although the certificates for the server name are successfully reissued, the server is still not accessible under this name, even if the name can be resolved via DNS.

Exactly the same effect occurs on two servers, one with Debian and one with AlmaLinux.

 

[Kaspar]

I can't think of any Plesk features that would cause this behavior after an Plesk update. If I had to make an educated guess I would say there is an firewall issue, since you're mentioning that a certificate for the server can be re-issued without any issue. Certificate validation when (re-)issuing goes over http(s), which means your server host name is reachable for some. As for SSH, Plesk actually does very little in terms of managing SSH and should not interfere.

What I would suggest checking, if you haven't already:

• Check if you own IP address isn't banned by any of the fail2ban jails.
• Since your running AlmaLinux, check of firewalld is installed and running. If it is, disabled and uninstall it. It can interfere with iptables (the firewall backend used by Plesk and fail2ban).

If that does not bear any fruit, try to temporary disable any firewall application, Including the Plesk Firewall, Fail2ban, and any firewall that your (cloud) provider may have running in front of your server. After that flush any left over firewall rules in iptable. Hopefully that will get you closer to the source of the problem.