please note that you'll probably be unable to test other IPs/hostnames now - so if you want to do so, repeat the process without this line.
Now you have the tool "Netselect" available for the system you compiled it on, and it's time to try it out.
You should do this with root privileges - so either login as root now, or prefix any commands with "sudo".
As you can see, the tool has tested both IPs and displays the faster one.
Running netselect to choose 1 out of 2 addresses.
So, for testing which server out of a bunch of servers is the fastest based on latency (ping), just add the server IPs to the command-line.