Well, my coding style isn't the bible. I would say it doesn't differ much from the average one of most perl programmers with some experience, but I'm sure some people would disagree. For example I like very much to use short-circuiting logical operators for flow control. And at times I tend to overuse $_. If it were me chances are that the main loop may have looked like this:

for my $net (@net) {
    for (16..250) {
            local $_="$net.$_";
            warn "$_ not responding!\n" and next
              if !$p->ping($_);
            print;
        }
}
[download]

And while it's very clear and immediate to me I understand that others' opinion may vary, and expressive variable name like $host may be preferable for maintainability resons.

Also, if the script were only just a bunch of lines longer, I would have never used the -l switch. Of course I'm eagerly waiting for (Perl6's) say().