How to use X-Forwarded-For with Load Balancer (NetScaler VPX)?
Please refer to the following for the setting of X-Forwarded-For, which has been verified by us.
Tutorial - Notifying client IP address to a registered Web Server
We have also confirmed that Client IP header can be inserted in Service Group.
Please check the Client IP and enter "X - Forwarded - For" in the Header in the Service Group Settings.