1. do the command "export http_proxy=xxx.xxx.xxx.xxx:yyyy" assuming that you will be using ip address as your proxy and you are login as user or root, the proxy will be exported on your environment.
example:
export http_proxy=192.168.1.1:8080
2. for directly set the proxy at yum configuration. Append the line
proxy=http://192.168.1.1:8080
at /etc/yum.conf
that way, proxy is directly set at yum
thanks to those document found when googling. this is just my reference.
