Where is the proxy server settings saved during the OS installation?
 

During the OS installation, I was prompted for the proxy server settings. As I need to change the IP address of the proxy server, where is the original proxy server's IP address saved during the OS installation?

Thanks !

I believe it is in the /etc/apt/apt.conf file in a line something like Aquire::HTTP:Proxy ... or ::FTP.. if using this method.

You're right :)

Is there a place to configure the Proxy server IP address systemwide for all applications?

Thanks.

Well for KDE applications you go into the control center in the network settings then you can set the proxy for its applications I would think Gnome has something similar. Just did a quick search and this thread seems to have what your looking for in post #2.