Net::Telnet-new(host => 'IPv6.host.com'); #### use IO::Socket::IP -register; use Net::Telnet; ... my $socket = IO::Socket::IP->new( PeerHost => $IPv4orv6Host, PeerPort => 23, Family => AF_INET # or AF_INET6 ) or die "not connected\n"; my $session = Net::Telnet->new( fhopen => $socket ); ...