airpaste silently fails.

On one machine I did:
$ echo hello world | airpaste
$

On another on the same network (and switch) I did:
$ airpaste
$

I tried the opposite order as well, nothing. No errors. Both machines are ubuntu-14.04 LTS. I installed it last night with "npm install -g airpaste". Some additional info:
$ which airpaste
/usr/local/bin/airpaste
$ ls -al /usr/local/bin/airpaste
lrwxrwxrwx 1 root root 35 Jul 8 20:13 /usr/local/bin/airpaste -> ../lib/node_modules/airpaste/bin.js

Start by reproducing the silent failure with the airpaste command on two Ubuntu 14.04 machines, using the installed entry point at /usr/local/lib/node_modules/airpaste/bin.js. Trace the peer-discovery and pipe-handling path to determine why neither command reports an error or transfers data. Done means two machines can exchange the piped text, or a clear error is shown when discovery or connection fails.

Written by the indexing model from the issue text.