The capabilities of ICM are somewhat limited. When a request first comes into ICM, ICM looks at a few things to decide which server it should send the request to (based on availability). Once ICM decides, it redirects the browser to that server, and all communication from this point on happens between the browser and target server, ICM is no longer in the picture. This being said, it is impossible for ICM to redirect you back to another server. For example, in your primary & backup scenario, if primary is down, on the initial request ICM will send the browser to backup, but once primary comes back up, the user will not be sent back until they initiate a brand new request into ICM. Additionally, if you are working on your primary and it goes down while you are using it, because after the initial request ICM is no longer in the picture, you will NOT automatically be redirected to backup, you must come back in through the ICM. Here’s some reading