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Scott123456789's avatar
Scott123456789
Icon for Cirrus rankCirrus
Mar 23, 2017

X-Forwarded-For through proxy and F5

My organization recently got the ASM module when they purchased a pair of 5250Vs. I've never used ASM before and we don't have anyone in our organization that has either, so I'm learning on the fly. ...
ASM Advanced WAF
security
x-forwarded-for
DevBabu's avatar
DevBabu
Icon for Cirrus rankCirrus
Mar 27, 2017

The below code will check for X-Forwarded-For header. If id does not exist it will grab the client address and insert X-Forwarded-For Header in the request.

 

i.e if proxy already inserted X-Forwarded-For no need to worry as it will have the client IP. If not coming through proxy, insert XFF header with the client IP. Will this help ? Bit modified from Soda's iRule.

 

when HTTP_REQUEST {     
        if {not ([HTTP::header exists "X-Forwarded-For"])} {
          set XFF [IP::remote_addr]
          HTTP::header insert "X-Forwarded-For" $XFF
        }
 }