In many companies/Universities, the web access is granted through Proxy Server (Usually SQUID; hence port 3128).
There are many terminal applications (run on command line interface), which access Internet/Web. For example:
wget (to download file), ftp, lynx/links (to access website), apt/yum (to download and install package). If we are behind
proxy, these applications do not work. The easy solution is to set some shell environment variables, explained below:
For accessing web(lynx/links) using a non-authenticated proxy:
$ export http_proxy="http://proxy.yourcompany.com:3128"
Verify that the setting took place
$ echo $http_proxy
For accessing web(lynx/links) using a authenticated proxy:
$ export http_proxy="http://username:email@example.com:3128"
If you want the change to be permanent (there each time you open a terminal),
add the export line to .bashrc in your 'home' directory.
$ echo 'export http_proxy="http://proxy.yourcompany.com:3128"'″ >> ~/.bashrc
Secure HTTP (over SSL) access
$ export https_proxy="https://proxy.yourcompany.com:3128"
$ export ftp_proxy="ftp://proxy.yourcompany.com:3128"