We had encountered an issue after move our web application from Apache web proxy to Azure Application Gateway, in which our web application will authenticate an incoming user session from internet via his/her incoming public IP address, technically from http header field called ‘Remote_Addr’, however after move our web application to Azure application gateway, the same header field does not contains the actual public IP address instead it contains the private IP address of Azure Application Gateway.
After we did some research, we knew that the header field is changed to ‘x-forwarded-for’. Our question is do we have ways to re-configure Azure application Gateway to log/write user’s incoming public address to ‘Remote_Addr’? Otherwise, our application might have a bunch of internal modules need to be rewritten in order to cater for this header field changes.