I am not an enterprise expert. I know security well. I was told the BEST place to cluster when considering web servers is IIS. Microsoft web sites say cluster at the OS, not at IIS. Those are easy to find. I have always done load balancing at the load balancer level. I was told that is "stupid" because if a process fails in IIS during a transaction, a load balancer would not pick up the transaction. I'd like to hear from people who know technology better than I.