Hi.
I’m trying to setup a Transform Rule, Modify Request Header.
I want (need) to set a specific http.host for my webserver to accept the proxied traffic. However, when I want to save the rule I am getting an error:
‘http.host’ is not a valid value for header because invalid header name (Code: 20087)
I read the docs and there is no exception on http.host. Also the value I want to set for http.host is a subdomain of my own and same domain, just a sibling of the subdomain I am trying to set that rule for.
My use-case: Redirect traffic to another sub-domain, because my webserver won’t answer requests when DNS is configured to be answered elsewhere (=cloudflare).
With other words (excuse my english):
NS of subdomain abc.example. com is pointing to CF, so my webserver won’t allow to take any traffic with the header Host: abc.example. com.
Solution: Modify the Host in the header to xyz.example. com so my webserver will accept the traffic coming from CFs Proxy.
I can provide DNS A or CNAME for xyz.example. com, tried around with it, but with no success. Only that error-message.
The Docs list “http.host” under “Available fields and functions for HTTP request header modification” and I can’t understand why this rule should not be allowed/applied.
I tried to divert it throught a additional CNAME, but that won’t work, it will resolve the IP via that CNAME, but since the original Header is unchanged requesting Host:abc , so my webserver denies to take the traffic.
Help, solution and enlightment is very welcome.