all-in-one/docker-ipv6-support.md

IPv6-Support for Docker

Before you can use IPv6 in Docker containers or swarm services, you need to enable IPv6 support in the Docker daemon. Afterward, you can choose to use either IPv4 or IPv6 (or both) with any container, service, or network.

Docker on Linux and Docker-rootless

1. Edit /etc/docker/daemon.json (or ~/.config/docker/daemon.json in case of docker-rootless), set the ipv6 key to true and the fixed-cidr-v6 key to your IPv6 subnet. In this example we are setting it to fd12:3456:789a:1::/64. Additionally set experimental to true and ip6tables to true as well. If you are using mailcow and enabled IPv6 with the update.sh, you can keep their daemon.json, it will work too.

   {
     "ipv6": true,
     "fixed-cidr-v6": "fd12:3456:789a:1::/64",
     "experimental": true,
     "ip6tables": true
   }
   

   Save the file.

2. Reload the Docker configuration file.

   sudo systemctl restart docker
   

3. Make sure that ipv6 is enabled for the internal nextcloud-aio network by running sudo docker network inspect nextcloud-aio | grep EnableIPv6. On a new instance, this command should return that it did not find a network with this name. Then you can run sudo docker network create --subnet="fd12:3456:789a:2::/64" --driver bridge --ipv6 nextcloud-aio in order to create the network with ipv6-support. However if it finds the network and its value EnableIPv6 is set to false, make sure to follow https://github.com/nextcloud/all-in-one/discussions/2045 in order to recreate the network and enable ipv6 for it.

Docker Desktop (Windows and macOS)

On Windows and macOS which use Docker Desktop, you need to go into the settings, and select Docker Engine. There you should see the currently used daemon.json file.

1. You need to now adjust this json file by setting the ipv6 key to true and the fixed-cidr-v6 key to your IPv6 subnet. In this example we are setting it to fd12:3456:789a:1::/64. Additionally set experimental to true and ip6tables to true as well.

   "ipv6": true,
   "fixed-cidr-v6": "fd12:3456:789a:1::/64",
   "experimental": true,
   "ip6tables": true
   

2. Add these values to the json and make sure to keep the other currently values and that you don't see Unexpected token in JSON at position ... before attempting to restart by clicking on Apply & restart.

3. Make sure that ipv6 is enabled for the internal nextcloud-aio network by running docker network inspect nextcloud-aio. On a new instance, this command should return that it did not find a network with this name. Then you can run docker network create --subnet="fd12:3456:789a:2::/64" --driver bridge --ipv6 nextcloud-aio in order to create the network with ipv6-support. However if it finds the network and its value EnableIPv6 is set to false, make sure to follow https://github.com/nextcloud/all-in-one/discussions/2045 in order to recreate the network and enable ipv6 for it.

---

Note: This is a copy of the original docker docs at https://docs.docker.com/config/daemon/ipv6/ which apparently are not correct. However experimental is set to true which the ip6tables feature needs. Thus it will not get included into the official docs. However it is needed to make it work in our testing.