You would have to get over a few hurdles to do this. I haven't actually tried to run multi-servers in a single network. One thing you would have to consider is that the server you are running ISPC on is taking requests from port 80. That means your other server will need to take requests from a different port. It can not be port 81 because ISPC uses port 81, unless you change the port where ISPC listens to.
Thats where you router comes into play. You need to forward requests to and from ISPC server 1 and also server 2. For my own home network config, I have my router forward port 80 to the Linux server. In order for my second server to take requests, I would have to forward the requests to server 2 on port 8080.
It would be allot more simple IF I had 2 different IP leases though
. You would have more room to work with if I had more than 1 IP address on my DSL modem. Of course, your scenario would be different. It all depends on your network setup.
PS. With some searching and researching, I'm sure there are other ways around it. But from what I wanted to do, forwarding the IP address from the registrar to a multi-IP home network would be the easiest but not necessarily the cheapest.