You have multiple servers that are running Microsoft Forefront Threat Management Gateway (TMG) 2010 and that have Microsoft Forefront Threat Management Gateway 2010 Service Pack 1 (SP1) Update 1 installed.
You configure an array with two or more TMG 2010 servers that have two nodes each and that have network load balancing configured for both front-end (workgroup) and back-end (domain member) scenarios.
In this scenario, the back-end TMG servers may crash, and you receive the following Stop error message:
An attempt was made to access a pageable (or completely invalid) address at an interrupt request level (IRQL) that is too high. This is usually caused by drivers using improper addresses.
If kernel debugger is available get stack backtrace.