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I've got an F5 Big-IP that is mangaged by our hosting provider. It's dedicated to our private VLAN, etc. Works great :)

We requested them to add in an X-Forwarded-For HTTP-Header field. They've done that and we can now access that in the code. Awesome :)

But .. for our IIS logs, it's still the IP of the F5 machine. I think I was told that we need to apply an ISAPI filter (cringe!) to the IIS server(s).

  1. Can someone confirm this?
  2. If #1 == yes, is there a file/instructions how to do this for our IIS7 web servers on windows 2008 machines.
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up vote 7 down vote accepted

I published an ISAPI filter to work with our BIG-IP's and have just updated it with full x86 and x64 support. Check out the blog post I wrote on it a while ago. Just copy the enclosed F5XForwardedFor.dll to your server and reference it in the ISAPI section of your virtual site.

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This is discussed in this thread of the IIS Microsoft Community. It seems there is a helper to do that for IIS (Especifically stated to work with Microsoft ARR but it should work for any reverse proxy or load balancer).

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Cheers! that looks like the answer i need :) I wonder why it wasn't added to IIS7 itself? weird. – Pure.Krome Jul 28 '09 at 6:47

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