Why does erlang use random ports for distribution

Question

When nodes connect to each other on Erlang, why not just use the original port the connection is made on? Why cause the firewall issues that using random ports causes. I know how to get around this, but I don't understand why.

Edit: I realize that this is frequently done, and this isn't necessarily an Erlang question, but it was a design choice made in Erlang, and I'm curious what the advantage of this method is.

Answer 1

It's not abnormal for classic RPC services wanting do ad-hoc communication.

You can specify the ports with kernel parameters, e.g.:

-kernel inet_dist_listen_min 21100 inet_dist_listen_max 21199