sub ping_servers {
        foreach $host (@my_servers) {
        my $p = Net::Ping ->new("icmp"); #create ping object
        my $res = $p -> ping ($host); #ping the hosts from array list
        $output .= "Unknown host $host\n" unless defined $resolve;
        if (!$res) {
                $output .= "$host doesn't respond to ping requests!\n";
        } else {
                $output .= "$host is alive.\n";
        }

        }
}