My workaround is to recompile the Socket module as per http://vinsworldcom.blogspot.com/2012/08/ipv6-in-perl-on-windows_20.html.

Of course, this may not work for Windows XP which you're running since ws2_32.dll won't have the inet_pton() function full stop.

I went ahead and proved that your guess was right - this did not work on Windows XP. When I get to dmake test I get a Windows dialogue error:

The procedure entry point inet_ntop could not be located in the dynamic link library WS2_32.dll

I've come across this suggestion to create wrappers for the two missing functions. I don't know what to do with these...could they be implemented in your ws2tcpip-win.h header file and put into that new dll that your dlltool command creates?