Nearly every Net::* module is built on top of internal OS routines which can work with IPv4 or IPv6.

I think that's worded slightly too optimistically. There are certainly some modules which don't work with IPv6.  See also State of IPv6.

Note to the OP: instead of trying to get an authoritative theoretical answer, why not just try?  If a certain module doesn't work with IPv6, you'll usually realize rather soon.