Lubuntu proxy set

Terminal Proxy

First you need to edit /etc/bash.bashrc file

sudo vi /etc/bash.bashrc

Add your proxy server details in the following format

export http_proxy="http://username:password@proxyhost:port/"
export ftp_proxy="http://username:password@proxyhost:port/"

if your proxy is anonymous, just ditch theusername:password@ part.

n some releases sudo is configured in such a way that all environment variables all cleared when running the command. To keep the value for your http_proxy and fix this, you need to edit /etc/sudoers, run:

visudo

Then find a line that states:

Defaults env_reset 

and add after it:

Defaults env_keep = "http_proxy ftp_proxy" 

Things will start working as expected.

solution from this website

For Chromium

sudo vi /etc/chromium-browser/default

Also add  your proxy server details in the following format

export http_proxy="http://username:password@proxyhost:port/"