The Yellowdog Updater, Modified (yum) is an open-source command-line package-management utility for Linux operating systems using the RPM Package Manager.Though yum has a command-line interface, several other tools provide graphical user interfaces to yum functionality. (wikipedia)
Schools and companies are introducing proxy servers to have more control about them network.
lets show you how to use yum bind proxy.
My system
Problem:
[[email protected] certs]# yum  install firefox
Solution: Configure Yum to use the Proxy.
edit /etc/yum.conf
vi /etc/yum.conf
and add this bellow of the file
# PUT YOUR REPOS HERE OR IN separate files named file.repo # in /etc/yum.repos.d # The proxy server - proxy server:port number proxy=http://proxy-ip:8080 # in this example the port 8080.it can be other ports # The account details for yum connections proxy_username=domain\username    # if you don't have domain put only username proxy_password=mypassword
save and exit
you dont have to reboot or restart things
Try again :
[[email protected] certs]# yum  install firefox Loaded plugins: fastestmirror, langpacks base                                                                                                               | 3.6 kB 00:00:00 extras                                                                                                             | 3.4 kB 00:00:00 updates                                                                                                            | 3.4 kB 00:00:00 (1/4): base/7/x86_64/group_gz                                                                                      | 155 kB 00:00:00 (2/4): extras/7/x86_64/primary_db                                                                                  | 101 kB 00:00:00 (3/4): updates/7/x86_64/primary_db                                                                                 | 3.1 MB 00:00:00 (4/4): base/7/x86_64/primary_db                                                                                    | 5.3 MB 00:00:00 Determining fastest mirrors  * base: centos.mirror1.spango.com  * extras: centos.ams.host-engine.com  * updates: centos.mirror.transip.nl Resolving Dependencies --> Running transaction check ---> Package firefox.x86_64 0:38.6.1-1.el7.centos will be installed --> Finished Dependency Resolution Dependencies Resolved ===========================================================================================================================================  Package                      Arch                        Version                                   Repository                    Size =========================================================================================================================================== Installing:  firefox                      x86_64                      38.6.1-1.el7.centos                       updates                       72 M Transaction Summary =========================================================================================================================================== Install 1 Package Total download size: 72 M Installed size: 131 M Is this ok [y/d/N]: y Downloading packages: firefox-38.6.1-1.el7.centos.x86_64.rpm                                                                             | 72 MB 00:00:09 Running transaction check Running transaction test Transaction test succeeded Running transaction  Installing : firefox-38.6.1-1.el7.centos.x86_64                                                                                     1/1  Verifying : firefox-38.6.1-1.el7.centos.x86_64                                                                                     1/1 Installed:  firefox.x86_64 0:38.6.1-1.el7.centos Complete! [[email protected] certs]#
Done
