Ok, so here is all that I'm trying to accomplish.
Back Ground I have multiple IIS web servers, each running multiple web sites each with their own IP address. Each IIS "Web Site" through programming and host headers runs hundreds of web sites. I want to insert a reverse proxy server for each web server that I have.
Here is what I want Reverse Proxy to Accept all traffic on a given IP address (184.108.40.206), and pass traffic to IIS site (220.127.116.11) - This I can accomplish in nginx, or varnish.
The Reverse Proxy would have about 10 defined Listen IP addresses (18.104.22.168 - 22.214.171.124), each forwarding traffic to its own corresponding IIS site (126.96.36.199 - 188.8.131.52).
IT IS NOT A LOAD BALANCE, WE SPECIFIC ARE ROUTING IP TO SPECIFIC IP. I think this is possible in nginx or varnish.
Now the Interesting Part I want to create a new Backup IIS Server, which would have web sites and in this example have IP addresses of 184.108.40.206 - 220.127.116.11). I would want to Manually fail over traffic to this backup server. I will eventually configure ALL of my IIS servers to use this one backup server, which I will use for running updates on my web servers, and this is why I only want to use it as a Manual failover server.
I know I saw somewhere there was a 'command line' to failover to a backup server, but I can't find what product it was, but I thought it was nginx.
I don't need to cache anything, as we cache objects in IIS, and that is why I need to specifically send traffic from 18.104.22.168 to 22.214.171.124 and 126.96.36.199 to 188.8.131.52, etc.