Add a custom "X-forwarded-for" header name

Hi Nandhi, I am not able to get the profile suggestions by Paulius or zamroni777 working in my local lab (happy to be told what I'm doing wrong!) but I am able to a) remove any existing X-Forwarded-For that arrives and b) insert new based on the requests client IP address both via iRule and local traffic policy. I find the traffic policy overly complicated as it requires Tcl anyway, so personally I'd use the iRule, but both solutions work.

iRule

when HTTP_REQUEST {
    if { [HTTP::header exists "X-Forwarded-For"] } {
        HTTP::header remove "X-Forwarded-For"
    }
    HTTP::header insert "X-Custom-XFF" [IP::client_addr]
}

Policy

ltm policy insert_custom_xff {
    last-modified 2024-01-10:15:50:09
    requires { http }
    rules {
        custom_xff {
            actions {
                0 {
                    http-header
                    insert
                    name X-Custom-XFF
                    value tcl:[IP::client_addr]
                }
            }
            ordinal 1
        }
        remove_std_xff {
            actions {
                0 {
                    http-header
                    remove
                    name X-Forwarded-For
                }
            }
        }
    }
    status published
    strategy all-match
}