my ($s,$e) = unpack 'N2',1.2.3.4 . 1.2.4.2;
printf("%vd\n",pack 'N',$_) for ($s..$e)

##</code><code>##

sub ip_to_num {
  my $ip = shift;
  my $n;
  $n = $n*256+$_ for (split /\./,$ip);
  $n
}