How to enable IPV6 on c-lightning in docker properly?

Question

Helping to run v0.10.1 node for a client, who wants to enable IPV6. Now listconfigs say:

"bind-addr": "0.0.0.0:9735"

"autolisten": true

Reading this: https://lightning.readthedocs.io/lightningd-config.5.html?highlight=bind-dir

It's unclear to me. Is the way to enable IPV6 to put another bind-addr for it and have:

"bind-addr": "0.0.0.0:9735"

"bind-addr": "[MYIPV6ADDRESS]:9735"

Or can there only be one bind-addr? The installation is docker on VPS. So, the host has many other inet6 addresses from all that, and seems that should not set

"bind-addr": "::9735"

Answer 1

The solution is to leave the IP empty, like this:

bind-addr=:9735

will bind on both IPv4 and IPv6.

An empty ‘IPADDRESS’ is a special value meaning bind to IPv4 and/or IPv6 on all interfaces, ‘0.0.0.0’ means bind to all IPv4 interfaces, ‘::’ means ‘bind to all IPv6 interfaces’.