Synthetic Transaction Monitor for Exchange 2010 not working

I am still pounding my head on our Exchange 2007 OWA health monitor. ISA handles all traffic manipulation inbound to our Exchange Client Access servers. I've tried custom monitors, built-in monitors, even generic HTTPS monitors and nothing seems to work right. I wonder why this isn't documented very well? I have seen the extensive documentation on configuring Exchange 2007 to run through the LTM, but what if you're already running Exchange OA/OWA/Autodiscover through an ISA proxy and just need the LTM to do very basic LB to two ISA proxies?

 

 

The ISA servers require the host field in the HTTP header as they only accept requests that have the correct SSL cert bound to the ISA matching rule. They are also issuing a Basic authentication challenge before passing the traffic into our Exchange org. We are using the LTM to just round robin traffic to the two ISA servers, and use the source IP as the persistence mechanism.

 

 

That said, I just can't get any of the monitors to work in this configuration, so I've no way of informing the LTMs about the status of the Exchange mail services. Has anyone properly setup OWA health monitoring in this type of configuration?

 

 

Thanks

 

Brian