ColdFusion load balancer fooled by logon pop-up

Load Balancer cannot tell when ColdFusion site is up or not due to logon pop-up.

We have a load balancer to ensure that if one of our ColdFusion services goes down, we switch all traffic to the other server.

The problem we have is that we want to check the web site is responsive – not just that the service is running, as the ColdFusion Application Server service can be running but the web site does not respond.

But when the Load Balancer checks the web page the Edge account logon popup appears, and confuses it as it thinks the site is running.  This can be mimicked by entering the monitor page URL into Chrome incognito (networks team said if it works in Incognito, it will work in the Load Balancer).

Is there any way to get this working?

In IIS the main site is set up so we are automatically logged in via our window using Windows Authentication.  The  “monitor” site has Anonymous Authentication. 
In testing Chrome Incognito works for a simple html page (no account logon pop up), but account logon appear for both the main and the monitor ColdFusion sites.
The ColdFusion set up is as close to vanilla as we can get, with no extra security setup.  IIS handles the security.

A key issue is not to break the existing security of the main ColdFusion site, just to get the load balancer working.

If it cannot be done, then at least that would be good to know so we don’t spend even more time on this.

We used to run a PowerShell script to check and restart it on a regular basis – but that kind of defeats the purpose of the Load Balancer.  This is our fall back plan.