sub is_private { my $nummy_ip = unpack('N', shift); return ($nummy_ip & 0xFF000000) == 0x0A000000 # 10.0.0.0/8 || ($nummy_ip & 0xFFF00000) == 0xAC100000 # 172.16.0.0/12 || ($nummy_ip & 0xFFFF0000) == 0xC0A80000; # 192.168.0.0/16 }