Already in a previous document of the version 4.1 we saw as a novelty that we could include our ESXi hosts in an Active Directory to authenticate directly with centralized accounts; one of the new features of vSphere 5 is the possibility of deploying an intermediate proxy between the hosts and our domain. All this to help in the deployment with Auto Deploy not to put users with passwords in configuration files, we will also be able to use it with hosts not deployed with Auto Deploy!