This statement controls whether Location: and
Content-location: headers in HTTP responses are modified before
sending them back to the client.
If n is 0, both headers are left intact.
If n is 1, the headers are changed as follows. If they point to the backend itself or to the listener (but with the wrong protocol), the request host name will be used instead. This is the default.
If n is 2, do the same, but compare only the backend address; this is useful for redirecting a request to an HTTPS listener on the same server as the HTTP listener.
To check whether the location points to the listener or to the
backend, its hostname part is resolved and the obtained IP address (or
addresses) are compared with that of listener or backend. This
process is affected by the dns feature setting
(see dns). If it is disabled (-W no-dns option is
given), no resolving takes place. In this case the location is deemed
to point to the listener if its hostname part matches that of the
incoming request. For backends, the hostname is compared with the
value of the ServerName setting of that backend
(see ServerName), if any.