Easy program to recognize local IP addresses within Internet IP addresses doesn't work correctly. 
# local addresses are 192.168.x.x 10.x.x.x 127.0.0.1 172.16.x.x

    my @addrs = qw(61.177.172.64 110.53.183.252 195.154.47.194
           110.53.183.252 190.96.252.188 221.194.47.243 10.1.1.1
           100.1.1.1 192.168.0.1 127.0.0.1 172.16.0.1 172.17.0.1 );

$local_ip_match = "m/^192\.168\.|^10\.|^127\.0\.|^172\.16\./";

    while (@addrs)  {
        my $s = shift @addrs;
    if ($s =~ $local_ip_match) {
        print "got Local IP $s\n";
      } else {
        print "got Internet IP $s\n";
        }
    }

[download]
Results:
got Internet IP 61.177.172.64
got Internet IP 110.53.183.252
got Internet IP 195.154.47.194
got Internet IP 110.53.183.252
got Internet IP 190.96.252.188
got Internet IP 221.194.47.243
got Local IP 10.1.1.1 YES
 got Local IP 100.1.1.1 NO NO - didn't I say 10 followed by a . ??
 got Internet IP 192.168.0.1 NO NO - doesn't this match the first part?
 got Local IP 127.0.0.1 Right
 got Internet IP 172.16.0.1 NO NO -- I thought I had this fingered out?
 got Internet IP 172.17.0.1

In reply to I THOUGHT I'd finally understood regex by JEDtoo

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