Issue Sites are repeatedly inaccessible even after repair

[camthor]

Server operating system version

Debian 11

Plesk version and microupdate number

18.0.70 #4

After an automatic update to 18.0.70 Update 2 all sites were inaccessible. We managed to recover them with plesk repair dns, particularly "Restore the user DNS configuration file from the template? [Y/n] Restoring the user DNS configuration file" seems to have helped.

Now, however, it happened again several times after hours that all sites are unreachable and we have to do the repair again. It seems that we still have a wrong configuration or something is missing. After the first incident we had some trouble with Debian, did a distro upgrade, lost some components of Plesk and reinstalled Plesk. So it is possible that some required components or packages are missing. We've done plesk repair for fs, web and installation.

Any idea what to do? Thanks!

 

[camthor]

Update: After the update to 18.0.70 #4 even plesk repair dns doesn't seem to help. Sites remain offline.

 

[camthor]

I changed now the DNS settings, disabling the local DNS service, which brought the sites back. Keeping fingers crossed ...

 

[Sebahat.hadzhi]

Hello, @camthor . It will help to know what's the exact error returned by the websites in order to attempt to further guide you on how to find more details about what the issue could have been.

 

[camthor]

Now the problem reappeared. It looks like some information at the nameservers expires and is not updated automatically.

Firefox says "Hmm. We’re having trouble finding that site. We can’t connect to the server at abc-def.51-38-52-181.plesk.page." The developer tools of the browser also mention NS_ERROR_UNKNOWN_HOST..

This error appears for all sites with the pattern abc-def.51-38-52-181.plesk.page, except for one site, which has exactly the same DNS Settings (two nameservers) but it is reachable. Strangely, only the site that is working shows an error message in the Plesk backend:

 

[scsa20]

I recommend to not keep using the Plesk's plesk.page URLs as they're meant to be used as a temporary means until actual domains are set up.

With that said, if you check your DNS records using DNS tools (such as dig) outside of the server, does it come back with anything? Does it point to the same IP address that is assigned to the site and what not? The way those temporary domain works is based off of the IPs assigned to the server since it updates on Plesk's DNS servers so if the IP isn't resolving correctly you could try following the guide of https://support.plesk.com/hc/en-us/...-another-Plesk-server-with-another-IP-address but all you need to do is change the IP address of the site then change it back and see if it triggers (if you only have 1 IP address then just add another one using 192 or 10. or something temporary then change it back) and see if it helps.

But, otherwise, as I've mention earlier, I highly recommend getting proper domains instead of using those temp ones so you have more control over it.

 

[camthor]

Thank you for your reply! Yes, the plesk.page sites are only temporary and internal.

I waited until the sites disappeared again and checked with DNS tools: There was no entry on the NS.
Changing the IP address from the Plesk backend was not possible, because it was in use by an active session.
I used SSH and these instructions but could not change the IP address. It was refused with the error "Unable to set IP address for hosting: IP address 'xxx.xxx.xxx.xxx' does not exist". Even addresses listed with arp -e were rejected.
Lastly, I changed the addresses of all subscription to the current IP address. That was accepted, the sites came back and the DNS server show an entry for the correct IP address. It seems that saving the current value reset something.
I will see whether this fix will last.