Ubuntu – Proxy setttings not working in Ubuntu 11.10

First of all make sure you click on "Apply system-wide..." whenever you change proxy settings in the gnome-network-properties (System -> Preferences -> Network Proxy). This sets http_proxy and related environment variables. This should be available to all programs started after the proxy setting is "Applied system-wide...". To be really sure, you can logout and back-in to double-check this.

If you open a terminal and use the command set | grep -i proxy you would see the relevant environment variables set. Ideally this should be enough.

However, I have faced situations where all the above still doesn't work: Synaptic or apt-get (over commandline) can't connect to the internet through the proxy even after it is set in the above way. In such cases, one solution is to add a file in /etc/apt/apt.conf.d with specific proxy configuration for apt (this will be used by apt-get, aptitude, synaptic and Ubuntu software center).

Follow the below steps:

1. Create /etc/apt/apt.conf.d/40proxy

   gksudo gedit /etc/apt/apt.conf.d/40proxy

2. Put the following contents into it - modify the contents to suit your situation.

   Acquire::http::Proxy "http://proxy.site.com:8080";

If you have a user-name & password you could encode the same in the proxy url (like so, http://username:password@proxy.site.com:8080) or you can use something like ntlmaps for better control.

More info could be found here.

This is a longstanding bug in Empathy. There is currently no fix available but perhaps others can post work arounds.