Socket programming in Ruby

What are the requirements for the IP address passed to

require ‘socket’
=> true

s = ‘’, 6500
Errno::ECONNREFUSED: Connection refused - connect(2)
from (irb):2:in initialize' from (irb):2:innew’
from (irb):2

In other words, what relationship does the machine on which the Ruby
code is being run have with the IP address referenced in the code?

Never mind – turns out you have to create a TCPServer first.