I have just completed the server modules for MCSE 2003. Strangely there a few things in the administrator’s life that are critical but not listed. I will attempt to cover them here.
DHCP servers are important. Without them, the users will not have an IP address and as you know without an IP address, nothing works. Beyond the well-covered benefits of having two DHCP servers, what is not covered is Conflict Detection.
Active Directory is the “go-to” guy if need to find, well nearly everything. What is not covered is that if you have a multi-site, multi-domain controller setup, domain controllers need regular close attention. Replication needs to be monitored, and the same goes for event logs. If the Active Directory in the domain controller dies on you, eg due to a power trip, you can recover it but you will need to use Ntdsutil and you get to put your hands on where the Active Directory is located, NTDS.dit.
The Active Directory relies on the DNS and File Replication services to work. If either, well usually both are not working, it means the Active Directory just crashed on you. It also means that you will need to use the Windows Support Tools, found on the Windows CD.
One day if you are housekeeping your AD, deleting old computer accounts and accidentally deleted your Exchange server, you can add it back.