Major Hayden has a wonderful blogpost about using Fedora CoreOS at my favourite cloud service provider, Hetzner Cloud. However, a machine deployed this way doesn’t have a working IPv6 connection. Since Fedora CoreOS ships with Network Manager, it’s easy to fix this with just a few nmcli commands.
The command actually gives you the first address of the subnet, which has a prefix of /64. So the subnet assigned to your instance is 2a01:4f8:c17:a049::/64. If you are not using the CLI client, you can find the subnet in the instance’s overview.
Now, you need to decide which address from the subnet you actually want to use for the server. Conveniently, you can use the first one (which is actually the output from the hcloud command above), so we will use 2a01:4f8:c17:a049::1 for this example.
It’s time to change the network configuration on the server! Run the following commands as root. I assume that your connection is called Wired connection 1 which is the default name for Fedora CoreOS.