I'm just debugging the last couple of issues with the IPv6-aware UDP/TCP DNS code. The Internal DNS resolver still only understands IPv4 code (and, more importantly, the ipcache/fqdncache layer too!) but the code itself will communicate with IPv4/IPv6 DNS servers.
I think I'll stop the development here and concentrate on getting the Cacheboy-1.5 release out the door. I'll then work on IPv6 record resolution in a seperate branch in preparation for Cacheboy-1.6. I may even break out the ipcache/fqdncache code into external libraries so I can reuse/debug/test that code during development.