use strict;
use Socket;
my $len = '/29';
print "IP                   IPN        Mask      Subnet\n";
for my $i (1...31){
  print_subnet('192.168.1.'.$i ,$len);
}

sub print_subnet { 
  my ( $ip, $len ) = @_; 
  my $ipn = unpack "N", Socket::inet_aton $ip;
  $len =~ s/^\///; 
  my $maskn = 0xFFFFFFFF << ( 32 - $len ); 
  my $subnet_ipn = $ipn & $maskn; 
  my $subnet_ip = Socket::inet_ntoa pack "N", $subnet_ipn; 
  printf "%-20s %s %x %s\n","$ip/$len",$ipn,$maskn,$subnet_ip;
}