Actual Client IP and Proxy IP in X-Forwarded-For

Hi Ganesh,

to consolidate multiple occourences of

X-Forwarded-For

when HTTP_REQUEST {
    if { [set x_forwarded [HTTP::header values "X-Forwarded-For"]] ne "" } then {
        HTTP::header remove "X-Forwarded-For" 
        HTTP::header insert "X-Forwarded-For" "[join $x_forwarded ", "], [getfield [IP::client_addr] "%" 1]"
    } else {
        HTTP::header insert "X-Forwarded-For" "[getfield [IP::client_addr] "%" 1]"
    }
}

The iRule will collect any existing X-Forwarded-For header values, then remove any existing X-Forwarded-For headers and finally create a new one with the collected values + the current "X-Forwarded-For" value. E.g.:

Incomming HTTP request headers
GET / HTTP/1.1  
Host: site.domain.de  
... 
X-Forwarded-For: 1.1.1.1  
X-Forwarded-For: 2.2.2.2, 3.3.3.3
X-Forwarded-For: 4.4.4.4 

Outgoing HTTP request headers

GET / HTTP/1.1  
Host: site.domain.de  
... 
X-Forwarded-For: 1.1.1.1, 2.2.2.2, 3.3.3.3, 4.4.4.4, 5.5.5.5

Note: Make sure to disable the automatic X-Forwarded-For insert option in your HTTP profile. The insert will be already handled by this iRule...

Cheers, Kai

Would the following fix this for you?

In Configuration Utility go:

• Local Traffic ›› Profiles : Services : HTTP ›› your_http_profile

   

• and tick the box for "Accept XFF"

   

• Fill the field of "XFF Alternative Names"

   

Hi Ganesh,

I've just checked the provided iRule and it works for me. Please use the iRule below to troubleshoot the issue and post back the resulting logs...

when HTTP_REQUEST {

    log local0.debug "Orig XFF: [HTTP::header values "X-Forwarded-For"]"

    if { [set x_forwarded [HTTP::header values "X-Forwarded-For"]] ne "" } then {
        HTTP::header remove "X-Forwarded-For" 
        HTTP::header insert "X-Forwarded-For" "[join $x_forwarded ", "], [getfield [IP::client_addr] "%" 1]"
    } else {
        HTTP::header insert "X-Forwarded-For" "[getfield [IP::client_addr] "%" 1]"
    }

    log local0.debug "New XFF: [HTTP::header values "X-Forwarded-For"]"

}

Note: Also make sure, the

Insert X-Forwarded-For

disable

Cheers, Kai