Yes, the old Perl version is the problem. The core Socket module didn't start supporting IPv6 (and the address family independent routines get*info()) until at least 5.14 or so.

Socket is now dual-lived so you can get the latest copy from CPAN, but not sure how a new version of Socket will work on such an old Perl.

You could try Socket6 and / or Socket::GetAddrInfo. I've used in the past and the API was a bit different than the "standard" supplied directly in the new Socket module versions.