How to connect two Elixir nodes via local network?

You have to name your nodes and use the same cookie on both nodes.

In machine 1:

iex --name node1@machine1.com --cookie a_cookie_string

In machine 2:

iex --name node2@machine2.com --cookie a_cookie_string

Now the two machines can communicate. To test it, you can do something like this, on machine1:

iex(node1@machine1.com)1> Node.connect :"node2@machine2.com"
true

iex(node1@machine1.com)2> print_node_name = fn -> IO.puts Node.self end
#Function<erl_eval.20.80484245>

iex(node1@machine1.com)3> Node.spawn(:"node2@machine2.com", print_node_name)
node2@machine2.com
#PID<7789.49.0> 

Domain names machine1.com and machine2.com can be changed with the ip addresses of the machines as well.