Ubuntu is a Debian GNU / Linux operating system with an interface similar to the usual Windows users. It is used on PC laptops and servers. Which means that it also needs to configure a proxy server. In Ubuntu, this process has certain features that you should be paying attention to the following recommendations.
To activate the settings, you must perform a complete reboot.
You can refine the configuration using the command: wget -q0 - eth0.me or wget google.com
The problems that arise configuring proxies in Ubuntu can be the following nuances, which should be paid special attention:
the inability to specify the proxy login and password, which requires authorization settings by IP address according to the standard scheme;
due to the fact that some utilities do not work with global type parameters, special settings or a login and password are required.
Do you know for what are proxy chains used for?