Explanation
To deploy Netskope using proxy chaining with Symantec BlueCoat proxy on-premises, you need to enable two prerequisites first: Enable SSL decryption on your Symantec BlueCoat proxy. This is required for proxy chaining because Netskope needs to inspect the SSL traffic that is sent from your proxy to the Netskope cloud.
To enable SSL decryption, you need to configure your Symantec BlueCoat proxy to trust the Netskope certificate for SSL interception. You can download the certificate from Settings > Manage > Certificates > Signing CA in the Netskope UI. Enable the X-Forwarded-For HTTP header on your Symantec BlueCoat proxy. This is required for proxy chaining because Netskope needs to identify the original source IP address of the user behind your proxy. The X-Forwarded-For header is used to pass this information from your proxy to Netskope. To enable this header, you need to configure your Symantec BlueCoat proxy to send X-Forwarded-For HTTP header for all HTTP requests. The other options are not valid prerequisites for this scenario. You do not need to disable SSL decryption on your Symantec BlueCoat proxy, as this would prevent Netskope from inspecting the SSL traffic. You do not need to disable the X-Authenticated-User header on your Symantec BlueCoat proxy, as this is an optional header that can be used to pass additional user information from your proxy to Netskope. References: Proxy Chaining3, Configure Forcepoint for Proxy Chaining