How do I obtain client IP Address?

So, that solution doesn't require any iApp or anything other than the rule? My boss dug something up about iApp.

i do not think you really need iapp.

So, we have both http and https VS objects. So I need to do both the steps for the profile and the irule for the x-forwarded, is that correct?

either http profile or irule.

Then we need to get the IIS ISAPI filter installed/configured on the web servers?

i am not familiar with iis. anyway, i believe iis administrator should know how to log x-forwarded-for header value. :)