use Net::Ping;

    @host_array=("serveur1","serveur2","serveur3","serveur4");
    $p = Net::Ping->new("icmp");
    foreach $host (@host_array)
    {
        $res=$p->ping($host, 2);
        if ( $res )
        {
        	print "$res $p: $host reachable.\n";
        }
        else
        {
        	print "$res $p: $host not reachable\n";
        }
        sleep(1);
    }
    $p->close();