A proxy server acts as an intermediary between the client and the server. Proxy servers are required on computers connected to networks like LAN and are not necessarily needed on stand-alone systems. The proxy server settings can be obtained from the network admin.

Verify a proxy server setting on Internet Explorer

Open Internet Explorer. On the "Tools" menu, click on "Internet Options." In the "Internet Options" dialogue box that opens, click on the "Connections" tab and then click on the "LAN Settings" button. In the local area network (LAN) dialogue box, under "Proxy Server," click on the "Use a Proxy Server for Your LAN" check box and then enter the "Address" and the "Port" number as given by the network admin. Click on "OK" and then again click on "OK."

Verify a proxy server setting on Mozilla Firefox

Open Mozilla Firefox. On the "Tools" menu, click on "Options." In the "Options" dialogue box that opens, click on "Advanced," click on "Network" tab and then click on the "Settings" button. In the "Connection Settings" dialogue box that opens, click on "Manual Proxy Configuration" and then enter the values as given by the network admin.

Verify a proxy server setting on Safari

Open the Safari browser, click on "Action" menu (Action menu is near the upper right corner of the Safari window and looks like a gear) and then click on "Preferences." In the dialogue box that opens, click on the "Advanced" tab and then click on the "Change Settings" button. In the "Internet Options" dialogue box that opens, click on the "Connections" tab and then click on the "LAN Settings" button. In the local area network (LAN) dialogue box, under "Proxy Server," click on the "Use a Proxy Server for Your LAN" check box and then enter the "Address" and the "Port" number as given by the network admin. Click on "OK" and then again click on "OK." Close the Safari preferences dialogue box.

Source:

Web Proxy Servers; Ari Luotonen; 2005