The purpose of this article is to mend situations where a specific site is allowed but it refers to some externally-sourced content that is being blocked by policy, causing the website to display poorly or not display altogether.
In order to allow traffic to those sites, we need to apply policy based on the "Referer" HTTP header. This header contains the URL of the site that initiated the request. We can find out the Referer of a specific request by using the Developer Tools in any browser.
Note: For HTTPS sites, SSL Interception must be enabled on each the request URLs in order for the ProxySG to be able to see the Referer HTTP header.
In this example, we will allow all traffic that contains "example.com" within the Referer request header:
Users should now be able to view all externally-sourced content that example.com is referencing. If this is not the case, further investigation of the Referer headers may be required by using the Developer Tools and adding extra Referer sites as needed.