I have had many customers who have asked for a step by step guide to configure IIS as a reverse proxy, specially for external facing tableau dashboards use-cases. I have created this document (please see attached word document) to serve as a guide based on a simple setup. The standard disclaimer- *This is not supported by tableau, just my personal views. And also there is no guarantee of this working in your specific environment given the number of variables and variations in network, firewalls, ssl, sso, etc. This is just to give a conceptual overview of the setup and steps for the benefit of tableau server community. Please do work with your Web-server admin & network team closely to get things working for your case.
Hope this helps.
Thanks for sharing the guide with the Tableau Community!
Cheers, Byrne, Patrick