Coldfusion - Get user's IP when application is behind a load balancer

Question

My coldfusion web app is located behind a load balancer. I need to get the user's ip address. I have used the following but I am still not getting the user's ip but the load balancer's ip.

My Coldfusion version is 10.

<cfif StructKeyExists(GetHttpRequestData().headers, "X-Forwarded-For") >
<cfset ip = Trim(ListFirst(GetHttpRequestData().headers["X-Forwarded-For"]))  > 
<cfelse>
<cfset ip = CGI.REMOTE_ADDR >
</cfif> 

The GetHttpRequestData().headers does not contain X-Forwarded-For.

Is there anything that I am missing? Have you experienced the same?