Fixing Authentication is requried to set the network proxy used for download packages

Non-root users

Step 1: Launch a Terminal Console and type

# gnome-session-properties

Step 2: Uncheck PackageKit Update Applet .

Root User

Step 1: Disabled /etc/yum/pluginconf.d

# vim /etc/yum/pluginconf.d/refresh-packagekit.conf

[main]
enabled=0