You've almost got it.
You need not put the IP of every client machine in the trusted_hosts list. Just the IP address of your web application is required and you've done that. Good.
Your mistake is in putting the IP address of the web application in as the client_ip parameter. The client_ip parameter should be the IP address of the client (where the browser is running).
In your second experiment, you did the right thing, but you didn't need to add the browser's IP address to the trusted_host list.
Give that a try and let me know if it solves your problem.
I am trying to implement the trust relationship between Tableau Server and my ASP.Net application, but its not working. I have seen the video. I think I am missing out something. Since you have also implemented this in can you please help me with the code sample?
Thanks in advance.