Something for the geeks.
At a site today with restricted access to the internet and needed the server to update its self. YUM not working becuase of the need to use the proxy and have a user name and password.
This is what you do.
At the end of the [General] section of /etc/yum.conf add the following lines, change to make them correct for you.
# The proxy server - proxy server:port number proxy=http://192.168.20.1:3128 # The account details for yum connections proxy_username=me proxy_password=qwerty