Ubuntu and The University of Nottingham's Proxy

{% img http://cdn.robgolding.com/uploads/2008/11/nottingham-ubuntu.png %}

I have recently enrolled on a Computer Science course at The University of Nottingham, and as such have had to make sure my machines correctly use their proxy server for web access. This post outlines the process of configuring Ubuntu for exactly that purpose - and could be applied to any network with a similar layout.

Network Proxy

First and foremost, Ubuntu has a setting in gnome for the Network Proxy, which should set gnome's proxy - but I can't see as it affects anything at all - still, better to be safe than sorry.

At Nottingham University, the recommended configuration is a proxy auto-configuration script (proxy.pac) which is downloaded by the client and parsed to configure the appropriate proxy server. In this case, it is located at http://wwwcache.nottingham.ac.uk/proxy.pac. This URL is entered into the correct field of the gnome Network Proxy settings dialogue.

{% img http://cdn.robgolding.com/uploads/2008/11/network-proxy-300x241.png "Network proxy" %}

Terminal Proxy

Secondly, the terminal has a proxy configuration option, so that programs that run inside the terminal making HTTP requests can access the internet - namely wget and aptitude. This is slightly more difficult to configure than the previous, and is achieved like so:

The terminal proxy is set using a variable called http_proxy, which is set using the export command, i.e. export http_proxy="http://proxy_server_ip:port"

In this case, the proxy server's IP and port for the SNS (Student Network Service) is 128.243.253.119:8080.

This change can be made permanent by editing /etc/bash.bashrc, and adding the above line to the end of the file. Otherwise, the change is only effective in the terminal window currently open by the user, and disappears when it is closed.

Synaptic

Lastly, Synaptic Package Manager must have the proxy set, in order to update your installation using the in-built Update Manager or Synaptic GUI. This is done by opening Synaptic, and choosing Settings, Preferences, and setting the above proxy information using the Network tab. Unfortunately Synaptic cannot read auto-configuration scripts, so the IP and port must be manually entered here.

{% img http://cdn.robgolding.com/uploads/2008/11/synaptic-proxy-300x266.png "Synaptic proxy" %}

Obviously once all this is done, Firefox must be configured to use the correct proxy - but I trust you know how to do that! This turns out to be quite a pain, so I'll be looking at ways to do this in one fell swoop. If anyone has any suggestions, then please let me know.

Note: These changes can be made much less painful by adding an entry to the hosts file for each of the proxy IPs you need to configure - so you only need to type, for example, proxy, instead of the entire IP. I will document this process shortly in a separate post.