Readonly my $udp_pinger => Net::Ping->new( 'udp', 1 );
Readonly my $syn_pinger => Net::Ping->new( 'syn', 1 );

foreach my $x ( 0 .. 5 ) {

    #test the syn prot with two loops
    my $t0 = [ gettimeofday() ];
    foreach my $host (@host_list) {
        $syn_pinger->ping($host) || die "syn ping failed for $host";
    }
    foreach my $host (@host_list) {
        $syn_pinger->ack($host) || die "syn ack failed for $host";
    }
    my $e0 = tv_interval($t0);
    print "$e0 seconds to ping $NUM_HOSTS hosts with syn";

    #test the udp prot with one loop
    $t0 = [ gettimeofday() ];
    foreach my $host (@host_list) {
        $udp_pinger->ping($host) || die "udp ping failed for $host";
    }
    $e0 = tv_interval($t0);
    print "$e0 seconds to ping $NUM_HOSTS hosts with udp";
    print "---------------------------";
} ## end foreach my $x ( 0 .. 5 )