$p = Net::Ping->new("tcp", 2);
           # Try connecting to the www port instead of the echo port
           $p->{port_num} = getservbyname("http", "tcp");
           #while ($stop_time > time())
           #{
               print "$host not reachable ", scalar(localtime()), "\n"
                   unless $p->ping($host);
               sleep(300);
           #}
           undef($p);