Resolved Disabling IPv6 Caused Plesk to Crash - 502 Bad Gateway

[J.Wick]

Server operating system version

Rocky Linux release 8.7 (Green Obsidian)

Plesk version and microupdate number

Plesk Obsidian Version 18.0.50 Update #2,

I disabled IPv6 on my server, which caused Plesk to crash with a 502 Bad Gateway.

Undoing my changes fixed the problem. Why is this happening?

/var/log/sw-cp-server/error_log
2023/03/01 14:43:08 [emerg] 1015#0: socket() [::]:8443 failed (97: Address family not supported by protocol)
2023/03/01 14:43:13 [emerg] 1441#0: socket() [::]:8443 failed (97: Address family not supported by protocol)
2023/03/01 14:43:18 [emerg] 2191#0: socket() [::]:8443 failed (97: Address family not supported by protocol)

How I disabled IPv6 was to modify /etc/default/grub by adding ipv6.disable=1 then running grub2-mkconfig -o /boot/grub2/grub.cfg then rebooting the server.

Plesk is biding to IPv6 :: and should be on 127.0.0.1.

What's the proper way to disable IPv6?

 

[Peter Debik]

Maybe this article can help:

How to disable IPv6 addresses on a Plesk server?

Applicable to: Plesk Obsidian for Linux Plesk Onyx for Linux Question How to disable IPv6 addresses on a Plesk server? Answer In order to disable IPv6, the following steps should be performed: ...

support.plesk.com

 

[J.Wick]

Maybe this article can help:

How to disable IPv6 addresses on a Plesk server?

Applicable to: Plesk Obsidian for Linux Plesk Onyx for Linux Question How to disable IPv6 addresses on a Plesk server? Answer In order to disable IPv6, the following steps should be performed: ...

support.plesk.com

Yes, I found that and decided to turn on IPv6 and enable it for all customers now that we have the proper firewall to handle it.