The purpose of this article is to talk about Domain Fronting . We will therefore focus on the “Host” header field.
1. The HTTP “Host” header, the art of Virtual Hosting
The Host request header specifies the host and port number of the server to which the request is being sent.
In our previous example (“Host: mydomain.xyz”), the host is “mydomain.xyz” and the port is either 80 (HTTP) or 443 (HTTPS). The port is usually implicitly enforced by the URL scheme (http:// or https://).
However, there is a difference between the host in the URL, and the Host header in the message request. In fact, the URL (http://mydomain.xyz/) tells your browser and computer to send the HTTP packets to the IP associated with mydomain.xyz, on port TCP/443……..