MS knowledge base article which is of interest:

Consider the following scenario:

  • You have multiple servers that are running Microsoft Exchange Server.
  • The servers that are running Exchange Server are hosted in a VMware ESX environment.
  • The servers that are running Exchange Server are part of a Windows Network Load Balancing cluster.
  • Windows Network Load Balancing is configured to run in unicast mode.
In this scenario, Windows Network Load Balancing may not work correctly. For example, network traffic is routed to one node in the cluster. Technorati Tags: ,,,,,,,,,,,,,,,