Use X-Forwarded-For address if it exists, otherwise use cgi.remote_addr

x-forwarded-for.cfm

<cfset req = GetHttpRequestData() />
<cfif structKeyExists(req.headers, "X-Forwarded-For")
        AND Len(Trim(req.headers["X-Forwarded-For"])) GT 0>
    <cfset ipAddress = req.headers["X-Forwarded-For"] />
<cfelse>
    <cfset ipAddress = cgi.remote_addr />
</cfif>