1. On a Mac, choose Apple > System Preferences and click Network.
2. In the list, select the network service you use, such as Ethernet or Wi-Fi.
3. Click Advanced and click Proxy.
4. To automatically configure proxy server Settings, perform one of the following operations:
To automatically discover proxy servers, select Automatic proxy Discovery.
If your network administrator has provided you with the address of the Proxy Automatic Configuration (PAC) file, select the Automatic Proxy Configuration and enter the address of the PAC file in the URL field.
5. To manually configure the proxy Settings, perform the following operations:
Select a proxy server, such as an FTP proxy, and type its address and port number in the field on the right.
If the proxy server is password protected, select the Proxy Server Requires password check box. Enter your account name and password in the Username and Password field.