networking – Add a route to my computer as gateway asks for ARP [INET]

I am trying to do extclient example of inet emulation section.

The readme says:

On your server, add a route to the host and set the gateway to the
  IP address of the computer, on which the simulation is running.

where is the host address inside the simulator.
So I added the route as:

route add gw enp0s25

where is my local IP and enp0s25 is eth interface.

But if I try to ping nothing works. Checking with wireshark I found that an ARP request (who is tells is raised? Why this? Where am I wrong?