dotnetnuke-settings

I'm having trouble figuring out if/how I can an internal webserver setup for testing with mutliple DNN portals. I'm pretty new to DotNetNuke, so I'm not sure if what I want to do is even possible. My server is at an IP of 192.168.15.16. I have the main portal set up with a portal alias of this IP. That site works fine. But then I have a couple other sites (lets call them A and B) to configure. I'd like to navigate to 192.168.15.16/A and 192.168.15.16/B to view these sites. Portal aliases to these don't seem to cut it. I get a 404 error and I believe it's because IIS adds A or B to the physical