IPv6 Support in Firebird
I have implemented IPv6 support in Firebird 2.5.2 that works with Windows XP and Server 2003 as well as on Linux.
I first implemented this patch back in November 2010 but for some reason it was not included in Firebird 3... anyway, I will try again.
See the discussion on SF.net from 2010.
Dual Stack problems on Windows
It is best explained by Microsoft, after all they wrote the OS!
As Firebird currently supports Windows XP and Server 2003 we must implement the two sockets and two threads option.