Concrete now has IPv6 connectivity but the IRC daemon does not listen on the v6 address. If the current instance has been compiled with v6 support, a restart should be enough otherwise  says "Your OS needs to have IPv6 support and you need to enable IPv6 support in UnrealIRCd during ./Config as well." If we have to recompile it, it's maybe a good opportunity to upgrade to the latest build . It would be nice to have this at least 1 week before IPv6 launch day (6-6-12).  http://www.vulnscan.org/UnrealIRCd/unreal32docs.html#feature_ipv6  http://www.unrealircd.com/txt/unreal3_2_9_release_notes.txt thx
fyi, its IP is 2620:101:8008:74::1:3
For the record, I just checked, and our build was indeed compiled without IPv6 support, so we will need to rebuild to get it.
Any progress on this? There are a load of irccloud.com users on irc.mozilla.org and in general IPv6 is far more resilient to the DDoS attacks we receive from time to time. This would greatly help us maintain connectivity for our and your users.
This is currently on hold. We're working on a larger project to improve IRC and IPv6 support will be included then.
I'm in the process of building a new irc network to take over the current one, and it will be hosted in EC2, which does not support ipv6. I might set up an ipv6-only server, hosted in scl3, but that's coming a bit later. WONTFIXing this.
Our test network now has an ipv6 server, and if all goes well, it will go into production soon. There's an AAAA record on irc.allizom.org for it.