Network issue with IPv6 following update to version 20.10.6

[j-clavoie]

Hello,

Following the update Docker-ce from 20.10.5 to 20.10.6, I was no longer able to start my containers that use network.

I'm using Ubuntu 20.04 and the official docker repository.
In my syslog I got this message:
dockerd: time="2021-04-12T19:09:21.964156271-04:00" level=error msg="failed to start container" container=[number removed] error="driver failed programming external connectivity on endpoint tvheadend ([number removed]): Error starting userland proxy: listen tcp6 [::]:9982: socket: address family not supported by protocol"

The IPv6 is not enabled on my computer. I disabled the IPv6 at the kernel boot up (in the grub config file).
I don't need and I don't want to use IPv6 for many reasons.

I tried to uninstall docker, deleted config files, flushed images and containers, reinstalled everything and nothing worked.
I tried many settings, and nothing still worked.
I checked the default bridge network and parameter "EnableIPv6" was set to false.

So, my solution (temporary I hope) was to downgrade to previous version 20.10.5 and all my containers have re-started as expected.

I took a quick look to the release note for version 20.10.6 and I see that some changes was occurred related to IPv6 networking but I don't know how to fix my issue.

Someone can help me to configure Docker to ignore IPv6?

Thanks!!!

[Gui13]

We have the exact same issue, this broke our entire network of 300+ containers :/

If we can help, please tell us. We backed to 20.10.05 as well.