To prevent this you alias the 10.1.1.1 address (cluster address as it is called) on the loopback adapter of the www1 and www2 servers and trick them into to thinking that 10.1.1.1 is a valid address ...
Step 2 is creating a Virtual Network in Virtual Server that links to that Loopback adapter. Step 3 is mapping that Virtual Network to the Guest OS under your VM Configuration. When you start your VM, ...