All tools described in this chapter consider Active Directory to be a distributed data base that along with serving clients must support its own integrity and consistency. This global system task has different aspects, or problem areas, the most important of which are the following:
Connectivity (including RPC connectivity) between domain controllers, and between a DC and a client
Proper name resolving
Mutual authentication (existence of secure channels, or trusts, between domains, domain controllers, and between a client and a DC)
Synchronizing Active Directory replicas (all directory partitions including Global Catalog) stored on different domain controllers
As you can conclude from the list of problem areas, there are many sources of possible faults, which can prevent Active Directory services from working and responding to client queries properly. The tools described below help administrators to test Active Directory's network infrastructure and monitor its state on different domain controllers.