ubuntu proxy

Proxy setttings not working in Ubuntu 11.10
use dconf-editor to edit the proxy setup

How to Configure Ubuntu desktop to use your proxy server
For Network Proxy, Synaptic Package Manager, Firefox, Terminal

407 Proxy Authentication Required
for apt-get

Making the most of Ubuntu through Windows Proxies
The solution to this authentication problem lies with NTLMaps, which is a proxy server that installs on the computer locally.