I found the following problems with the way Vanilla 1.1.2 handles IPv6 addresses:
1) The function GetRemoteIp() in Framework.Functions.php truncates IPv6 addresses to 19 characters The following line is causing the problem. [Line 513] if (strlen($sReturn) > 20) $sReturn = substr($sReturn, 0, 19); A suggested fix would be: [Line 513] if (strlen($sReturn) > 39) $sReturn = substr($sReturn, 0, 39); IPv6 addresses can have upto 39 characters e.g. 2001:0db8:0000:0000:0000:0000:1428:57ab
2) The database table LUM_IpHistory also truncates IPv6 addresses to 30 characters. By using a varchar(40) for the column RemoteIP in this table as opposed to varchar(30) this problem can be fixed.
There may be other IPv6 issues but these are the ones I've come across so far. Hopefully the above fixes can be included in a future release of Vanilla.
Bump for Mark or someone else versed in IPv6 as I have not yet seen an IPv6 address out in the wild to deal with.
Currently Vanilla is relying on IPv4 addresses to record and match as an admin option and doesn't heavily rely on this data by default or at all. IPv6 is still a bit mind-boggling (for me anyway) with the number of ways you can treat a single address and I don't think anyone is going to rush in a patch to address this. Although it would benefit Vanilla later down the road when and where depending on a users IP might be more relevant.