use Socket qw( inet_aton inet_ntoa );

sub fr_dotted { unpack 'N', inet_aton @_ ? $_[0] : $_ }
sub to_dotted { inet_ntoa pack 'N', @_ ? $_[0] : $_ }

my $next = fr_dotted('100.1.3.41');
my $max  = fr_dotted('100.1.3.50');

die if $next > $max;
my $new = $next++;

print(to_dotted($new), "\n");