Q & A

If you are  behind proxy server then you need to configure yum to pass proxy server.

Open /etc/yum.conf

[main]
cachedir=/var/cache/yum
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
distroverpkg=redhat-release
tolerant=1
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1

and the following lines  in yum.conf.

proxy=http://proxyservername:3128/
proxy_username=proxyusername
proxy_password=proxypassword

Now your  yum  able to pass through the proxy server.

export http_proxy=”http://proxyserver:port”