Scenario: ARR listening on port 80 set to load balance multiple sites listening on different ports on local host
Problem: Server Farm will refuse to add multiple localhost addresses - it does not use port number to differentiate between host aliases
Solution: locate the Windows\System32\drivers\etc\hosts file and add for example the following:
127.0.0.1 localhost1
127.0.0.1 localhost2
127.0.0.1 localhost3
127.0.0.1 localhost4
This will make the above aliases point to localhost