gistfile1.pl

#!/opt/perlbrew/perls/current/bin/perl

use utf8;
use strict;
use warnings;

use v5.16;

use Algorithm::Permute;
use Data::Validate::IP;

my @a = qw(0 1 8 16 46 74 96 106 109 126 127 186 192 255);
my $p = new Algorithm::Permute(\@a, 4);

use LWP::UserAgent;
use Data::Dumper;

my $ua = LWP::UserAgent->new();                                                                                                                                                                                      $ua->timeout(1);

while (my @res = $p->next) {
    my $ip = join(".", @res);
    if(is_public_ipv4($ip)){
        my $url = "http://$ip/hackerolympics.json";
        my $res = $ua->post( $url, { name => "parkan" } );
        if($res->is_success && $res->content_type =~ m/json/i){
            print "RESPONSE FROM: $ip\n";
            print Dumper($res->decoded_content());
        }
    } else {
        #print "NOT VALID: $ip\n";
    }
}