ISAPI Filter / Apace Module for REMOTE_ADDR Var Change

We are using SNAT in order to route remote nodes back to the correct LTMs which we have in mutliple geographic datacenters. I know there is an ISAPI filter and apache module available to extract and log the contents of the X-Forwarded-For header but we have an additional requirement.

 

 

Basically when we change the original source IP using SNAT there is an issue since our web-based applications reference the REMOTE_ADDR attribute which uses the source IP in the actual TCP packet as seen by the web server, which is the SNAT address and not the original client IP address.

 

 

Is there an ISAPI filter and/or apache module available that can basically copy the contents of the XFF header or some other custom header that we insert with BigIP (assume there is one source ip address in the header) and push that IP address into the REMOTE_ADDR attribute? That way our web-applications will see the original source IP and not the SNAT.

 

 

If not a filter or module is there some other method to accomplish this?

 

 

Thank You.