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:
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Go to Tools & Settings > IP Addresses > 2001:db8:f61:a1ff:0:0:0:80 > the Sites column. If there are sites hosted on IPv6, go to Domains > example.com > Web Hosting Access and set the field IPv6 address to None:
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Log in to the server via SSH and add the following lines to
/etc/sysctl.conf:# grep ipv6 /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1 -
Apply the settings from the
/etc/sysctl.confvia the following command:# sysctl -p
-
Remove IPv6 addresses from the Plesk
Note: It can be done either manually or by pressing the Reread IPs button in Tools & Settings > IP Addresses
Additional Information
nginx cannot bind to IPv6 interface: Cannot assign requested address
Comments
12 comments
Please link this article to this one:
https://support.plesk.com/hc/en-us/articles/115002836393-nginx-cannot-bind-to-IPv6-interface-Cannot-assign-requested-address
It is absolutely essential, else Nginx cannot be started and the reconfiguration of web server configuration files does not work.
@Peter Debik
Thank you for the comment! I have re-checked the nginx behaviour after disabling of IPv6. In general, the issue can arise if there are some domains hosted on IPv6. I have edited the article accordingly and linked the proposed article as well.
This does not work for Centos 8, you have to actually modify the /etc/default/grub in order to disable the ipv6 with ipv6.disable=1
@Alexander Garzon
Disabling the corresponding kernel module is an alternative to using sysctl. Can you confirm that the steps described in the article were not enough to disable IPv6 on a CentOS server?
I confirm they were not enought. They work only if you execute sysctl -p manually after a reboot.
We have systems with hundreds of domains. Plus on subscriptions where the only domain is a forward domain, step (1) cannot be executed, because the corresponding settings are unavailable in the control panel. This makes it impossible to remove the IPv6 address from Plesk, because it cannot be removed from the forwarded domains.
Can we run a database query that executes step (1) to remove the IPv6 IP from all domain configurations at once? What query would that be?
I have already tried to experiment with the ipv6_addr_id field in the dom_param table, but a change there is not mirrored to the panel, so there must be additional entries somewhere that define the setting that is shown in step (1).
How to disable IPv6 for just one domain ?
To disable IPv6 for a single domain, click on the "Web Hosting Access" icon and select "None" from the IPv6 address drop down.
Thanks for you fast answer. I already see that, but under thes Settings, there is : I am in Web Settings of single domain
IPv6 will be disabled for just single domain ?
I see what you are asking for. Actually: No, the settings will apply to all domains that are associated with the same subscription (the same system user account). In your case you will need to move the domain in question into a separate subscription to disable IPv6 for only that single domain. However: Be aware that such a configuration will not protect your server against DDoS against that domain via IPv6 just because you have disabled IPv6 in the web server. Maybe a better solution for you could be to leave the IPv6 setting intact and to remove the IPv6 route from your DNS settings instead, so that name resolution does not resolve the domain to any IPv6 address from start.
Thanks. I want to disable it for just domain for testing. But as you say. It will apply for all other domain. I will not change it
The method of:
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
Does not work on ubuntu 18.04 and to disable ipv6 grub configuration has to be modified.
Also, my plesk installation did not detect the IPv6 ips, and after I disable the IPv6 support on the OS, plesk was not able to start because Mysql and sw_cp_server where configured to also listen on local IPv6.
Plesk repair utility did not work (because it could not connect to the database) and plesk reinstall did not fix the issue either.
I eventually had to modify plesk configuration files to disable those services on IPv6.
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