Node.js connect only works on localhost

Most probably your server socket is bound to the loopback IP address 127.0.0.1 instead of the "all IP addresses" symbolic IP 0.0.0.0 (note this is NOT a netmask). To confirm this, run sudo netstat -ntlp (If you are on linux) or netstat -an -f inet -p tcp | grep LISTEN (OSX) and check which IP your process is bound to (look for the line with ":3000"). If you see "127.0.0.1", that's the problem. Fix it by passing "0.0.0.0" to the listen call:

var app = connect().use(connect.static('public')).listen(3000, "0.0.0.0");

To gain access for other users to your local machine, i usually use ngrok. Ngrok exposes your localhost to the web, and has an NPM wrapper that is simple to install and start:

$ npm install ngrok -g
$ ngrok http 3000

See this example usage:

In the above example, the locally running instance of sails at: localhost:3000 is now available on the Internet served at: http://69f8f0ee.ngrok.io or https://69f8f0ee.ngrok.io

Binding to 0.0.0.0 is half the battle. There is an ip firewall (different from the one in system preferences) that blocks TCP ports. Hence port must be unblocked there as well by doing:

sudo ipfw add <PORT NUMBER> allow tcp from any to any