Administrating Organizations : About third-party proxy chaining configuration : Enabling and disabling proxy chaining
  
Enabling and disabling proxy chaining
1. Choose Configure > Proxy Chaining.
2. Enable Proxy Chaining Interoperability.
3. In the Configuration section, perform these actions:
Enter any arbitrary name for the third-party service.
Select whether you want to specify the third-party proxy endpoint by using a URL to a PAC file, an IP address and port number, or a hostname and port number.
Enter the URL, IP address and port number, or hostname and port number.
Optionally, move the Forward client internal IP in the XFF header slider to the right to enable the feature. Move the slider to the left to disable it. See About the XFF header.
Optionally, enable DNS mode.
4. In the Advanced Configuration section, upload the third-party’s CA certificate.
5. Upload the third-party’s CA certificate to all end-user client systems.
To disable the feature, move the Proxy Chaining Interoperability slider to the left.