grab sockets using specific range of local ports all at once; how many in range are available (wait a couple of minutes before checking again on the same range, because obviously that range will be in time_wait).

grabsocket.pl

use strict;
use IO::Socket::INET;

sub socketConnect {
    my ($localPort) = @_;
    my $err;

    my $sock = IO::Socket::INET
        ->new(PeerAddr => '127.0.0.1',
              PeerPort => '63300',
              LocalAddr => 'localhost',
              LocalPort => $localPort,
              Proto    => 'tcp') || ($err = $!);
    if ($err) {
        print STDERR "localPort: $localPort :", $!, $/;
        return;
    }
    return unless $sock;
    print STDERR join(' ', 
               $sock->sockhost, $sock->sockport, 
               $sock->peerhost, $sock->peerport), $/;
    return 1;
}

my $start = 32768;
my $end = $start + 10000 - 1;
my $range = $end - $start;

my ($good, $bad, $total) = (0, 0, 0); 

for my $i (0 .. $range) {
    $total++;
    if (socketConnect($start + $i)) {
        $good++;
    } else {
        $bad++;
    };
}

print "($good, $bad, $total)\n";