Well I "forgot" how I solved this problem in the past.

When I searched perlmonks I found this thread, but I was not happy with the answers. Here is my simple non-CPAN way to solve this issue.

use Socket;
foreach my $key ( keys %report ) {
   my $hostname="-= Not in DNS =-";
   $hostname=gethostbyaddr(inet_aton($key), AF_INET) or
                $hostname="-= Not in DNS =-";
   if ( $report{$key} > 0 ) {
      print "-=" x 2, " Host: $key ( $hostname )", "-=" x 2, "\n";
   } else {
      print "ERROR Why is this in hash? $key\n";
   }
}
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