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Available features

The following sections describe the features currently supported by Origin Rules.

Host Header Override

This feature allows you to rewrite the HTTP Host header of incoming requests.

A common use case for this functionality is when your content is hosted on a third-party server that only accepts Host headers with their own server names. In this situation, you must update the Host HTTP header in incoming requests from Host: example.com to Host: thirdpartyserver.example.net.

You must specify a valid hostname in a Host Header Override that is either:

  • A hostname on the same Cloudflare account (possibly on a different zone).
  • A hostname for which Cloudflare is not proxying traffic (gray-clouded).

Resolve Override

This feature allows you to override the resolved hostname of incoming requests.

A common use case for this functionality is when you are serving an application from the URI (for example, mydomain.com/app). In this case, the app may be hosted on a different server or by a third party. Resolve Override allows you to redirect requests to this endpoint to the server for that third-party application.

You must specify a valid hostname in a Resolve Override that is either:

  • A hostname on the same Cloudflare account (possibly on a different zone).
  • A hostname for which Cloudflare is not proxying traffic (gray-clouded).

Destination Port Override

This feature allows you to override the destination port of a request.

When you configure Destination Port Override, you can redirect incoming requests to a different port. For example, you could override the destination port for requests received for mydomain.com so that they are served by the application running on port 9000 (mydomain.com:9000).

The destination port must be between 1 and 65,535.