Originally Posted by smallpond
Most distros of Linux require interface lo in order to come up. Since the loopback interface returns all packets to the sender, you can't use it for communications.
Sure you can, I'm not sure why you're saying this would be a problem? I use 127.0.0.1 to communicate between networked processes on the same machine all the time.
What I'm curious about is why the OP needs two of them. All you need is one interface and a port number to open up a TCP connection. If you have two processes running, then use two different ports.