For your first code, Perl 5.6.1 lets you do this kind of niftiness:

my ($s,$e) = unpack 'N2',1.2.3.4 . 1.2.4.2;
printf("%vd\n",pack 'N',$_) for ($s..$e)
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If you use this code, though (complete with whitespace sensitivity that makes Python look like a Good Idea), you might well be shot. Replace the unpacks with a more direct translation of dotted quadruplets into ints, e.g.

sub ip_to_num {
  my $ip = shift;
  my $n;
  $n = $n*256+$_ for (split /\./,$ip);
  $n
}
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For the second question (and, indeed, for the first), it would be best to post some code, or at the very least some sample input/output.