Sometimes, you may need to use URL rewrite to overwrite the HTTP header. For example, if you are using Cloudflare or any CDN, the REMOTE_ADDR and REMOTE_HOST will be appeard as internal IP of the CDN provider.

If you are using IIS, there is no option to do URL rewrite by default. You will need to download and install an app call “URL Rewrite” and then you will get an option to edit the rule.

The tool can be downloaded from https://www.iis.net/downloads/microsoft/url-rewrite