Using a proxy server for updates
If your system sits behind a firewall, you might want to configure a www proxy first if there is one on the network that provides internet access:
export http_proxy=http://www-proxy.example.com:80 export no_proxy=localhost,127.0.0.1,example.com,us.example.com,*.example.com
Making these settings permanent across logins can be done by editing the file
As this file might be overwritten by newer versions during YUM updates, a better way is to copy the proxy.sh file to a new file, i.e. proxy-mysite.sh, and edit accordingly.
If that does not work (i.e. your network is completely isolated from the internet) then you may want to set up a separate YUM server for updates (this can be the same server or a centrally located FTP server for example).
If you need a proxy to access FTP servers (i.e. local site YUM repositories) use: