# Like tcp protocol, but with many hosts
    $p = Net::Ping->new("syn");
    $p->{port_num} = getservbyname("http", "tcp");
    foreach $host (@host_array) {
      $p->ping($host);
    }
    while (($host,$rtt,$ip) = $p->ack) {
      print "HOST: $host [$ip] ACKed in $rtt seconds.\n";
    }