So, we have some testing labs and some equipment in those labs that can connect to a PC with a direct network connection - no router or switch, just a loopback cable to the device. Device is ...

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 ...