A proxy server is a server that acts as an intermediary between your network and the Internet. It also filters the requests from each computer for content. Two pieces of information are necessary to configure a proxy server connection on your machine: the IP address of the server and the port number. The proxy server is usually a computer system on your network, but you can check the settings, including the port number, from your machine.
Open your Internet Explorer browser.
Click on "Tools" tab in the top menu bar.
Click on "Internet Options."
Click on the "Connections" tab.
Click on the "LAN Settings" button in the bottom portion of the window.
Click on "Advanced" under the "Proxy Server" section to see the proxy server settings of your local area network. The port number will be next to the IP address.