After Installing Ubuntu 16.04 to make some monitoring tests, I was not able to get or update behind the http/https/ftp  proxy  . Here how i solved this. i think this solution should work also  for  Debian 7/8 and LinuxMint 16/17 my machine : Trying  to update root@ubuntu:~# apt-get  update Err:1 http://security.ubuntu.com/ubuntu xenial-security InRelease   Could … Continue reading How to Configure apt-get behind proxy server for Ubuntu 14/15/16