2.2.1.5 X-MS-ADFS-Proxy-Client-IP

The value of this header MUST be set to the IP address of the client's TCP/IP connection to the proxy. This header SHOULD be included when the proxy is processing incoming requests from clients that are trying to access the server.<1>

 String = *(%x20-7E)
 X-MS-ADFS-Proxy-Client-IP = String