Active Directory uses DNS to locate domain controllers as
well as specific FSMO roles, such as the global catalog server and the PDC emulator.
Domain and Forest Functional Levels
When Active Directory was first launched with Windows 2000, you could run it in either
native mode or mixed mode. In mixed mode, Windows 2000 can interact with NT 4.0
domain controllers by pretending to be an NT 4.0 domain controller. This makes it easier
to migrate to Windows 2000 from an NT 4.0 domain model. Windows 2003 introduced
the concept of domain functional levels, which provide capabilities similar to those available
with a mixed mode that allows a newer version of Active Directory to coexist with a
previous version. (It is no longer called mixed mode because that name doesn??™t indicate
what it can mix with.)
Active Directory can run in one of five domain functional levels: Windows 2000
mixed, Windows 2000 native, Windows Server 2003 interim, Windows Server 2003, and
Windows Server 2008. This governs what functionality is enabled in Active Directory.
For example, if you install Active Directory in Windows Server 2003 mode, you cannot
Figure 4-5. A simple multisite domain
Site 1 - New York Site 2 - Los Angeles
Inter-Site
Link
Bridgehead
Server
Bridgehead
Server
106 Microsoft Windows Server 2008 Administration
have Windows 2000 domain controllers participating in your domain.
Pages:
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150