LTM monitors with IIS host headers, can it be done?

In BIG-IP Local Traffic Manager, I can set up something called a "Monitor". In the monitor I tell it what page to request and what the response should be if it is successful. I can then apply this monitor to a Pool as a health monitor.

 

The problem is that this Health Monitor request gets sent to each IP/Server in the Pool, but on each server IIS is configured to use the same IP address for many different web sites. IIS is expecting to see a host header value (Ex: www.app1.somedomain.com or www.app2.somedomain.com)

 

in order to determine which website (home directory) to direct the request to. But I don't know how to attach a host header to a BIG-IP Health Monitor.

 

Thanks,

 

SF