From 4a5678f571f11b56f56968af489574f84cc222e5 Mon Sep 17 00:00:00 2001 From: Simonmicro Date: Sat, 5 Sep 2020 12:16:21 +0200 Subject: [PATCH] Added explaining message about the current ipv6 problem --- docs/faq.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/docs/faq.rst b/docs/faq.rst index c59a8c2d..c90fbc6a 100644 --- a/docs/faq.rst +++ b/docs/faq.rst @@ -170,6 +170,13 @@ Lets start with quoting everything that's wrong: (`docker/libnetwork#1099 `_). -- `Robbert Klarenbeek `_ (docker-ipv6nat author) + +Okay, but I still want to use IPv6! Can I just use the installers IPv6 checkbox? **NO, YOU SHOULD NOT DO THAT!** Why you ask? +Mailu has its own trusted IPv4 network, every container inside this network can use e.g. the SMTP container without further +authentication. If you enabled IPv6 inside the setup assistant (and fixed the ports to also be exposed on IPv6) Docker will +still rewrite any incoming IPv6 requests to an IPv4 address, *which is located inside the trusted network*. Therefore any +incoming connection to the SMTP container will bypass the authentication stage by the front container regardless of your +settings and causes an Open Relay. And you really don't want this! So, how to make it work? Well, by using `docker-ipv6nat`_! This nifty container will set up ``ip6tables``, just as Docker would do for IPv4. We know that nat-ing is not advised in IPv6,