Accessing a Jetty server from an external machine

I have made a simple Jetty server using this tutorial here, http://www.seas.upenn.edu/~cis550/jetty.html

Now that I have the initial steps completed, I can succesfully connect to my server by entering localhost:8080/hello or 127.0.0.1:8080/hello in my browser. Everything is going great up until this point. The servlet is working properly.

I am now interested in connecting to the server using "Machine B". I want to build a server that can be connected by any browser, anywhere.

My IP is XX.173.XXX.216, parts hidden for obvious privacy reasons. On my "Machine B" I try and enter XX.173.XXX.216:8080/hello into the browser URL. The website cannot be found. From experience I questioned my port mapping and opened my 8080 port.

After a few google searches and a while of reading, I give up. Does anyone know a possible solution to my problem? Are there any further steps I need to do in the setup of the Jetty server to make it accessible from external machines?

It is usually not hard getting from the inside of a firewall and out. It is much trickier to get from the outside and in (just have a look at the hoops Skype jumps through to be able to get two computers each behind a firewall to talk to each other directly).

First of all you need to ensure that Jetty listens to the right network devices.

Identify the IP-number of the computer running Jetty (not 127.0.0.1) and see if you can connect to "http://that-ip-number:8080" from the machine itself. If this doesn't work, fix your jetty configuration. Then put another computer on the same network and connect to "http://that-ip-number:8080" too. This MUST work before you go any further. If this doesn't work, fix your firewall configuration on the computer running Jetty.

When the above works,then you can start thinking about exposing the port through your router. The router most likely has a web interface where you can configure this, but the easiest way to do that is to use a uPNP tool (if your router supports that) which can redirect an external port to a specific host and port on your internal network. I use "Port Map" under OS X which has a very simple interface.

Good luck