Configure Proxy Settings for the Linux

gistfile1.txt

Configure the proxy settings in the .bashrc
If you want set the proxy for all the users you can do it in the system wide .bashrc file.
sudo vi /etc/bash.bashrc

#proxy settings
export http_proxy=http://DOMAIN\USERNAME:PASSWORD@SERVER:PORT/
export ftp_proxy=http://DOMAIN\USERNAME:PASSWORD@SERVER:PORT/

Additionally if you want APT to use a proxy server you can configure it in the /etc/apt/apt.conf configuration file.
sudo vi /etc/apt/apt.conf 
#
# Proxy configuration 
#
Acquire::http::Proxy "http://DOMAIN\USERNAME:PASSWORD@SERVER:PORT";

Configuring GIT
vi ~/.gitconfig
[http]
  proxy = http://DOMAIN\USERNAME:PASSWORD@SERVER:PORT
[https]
  proxy = http://DOMAIN\USERNAME:PASSWORD@SERVER:PORT