Check IPv6 gateway ansible/gw address
We need to test and double check if what we say in docs, put in the example hosts.yml and what arrives in eip.json and actually is getting used (and how).
ip (mandatory) is the IPv4 address of this host that other hosts
(i.e. internal services) should use to reach it
ip6 (optional) is the IPv6 version of the above
public_ip (optional) is the IPv4 address that will be advertised in
the public-facing DNS zones, if unset it defaults to ip
public_ip6 (optional) is the IPv6 version of the above