c:\@Work\Perl\monks>perl -wMstrict -le
"use Regexp::Common qw(net);
 ;;
 my $s = '123456.4.32.123456';
 ;;
 print qq{A: match, captured '$1'} if $s =~ m{ ($RE{net}{IPv4}) }xms;
 ;;
 my $my_ip = qr{ \b $RE{net}{IPv4} \b }xms;
 print qq{B: match, captured '$1'} if $s =~ m{ ($my_ip) }xms;
"
A: match, captured '56.4.32.123'