When I feed it the number you posted into it. It throws an error.
What did it do when you did it?

--Chris

#!/usr/bin/perl -Tw
use Perl::Always or die;
my $perl_version = (5.12.5);
print $perl_version;

No errors, though several warnings. I really don't believe you're using the code you posted.

Again - using my fix instead of yours in sub validip, the program immediately exits with invalid address, as it ought.