Learn AD in 15 Minutes a Week: Active Directory Group Policy Page 2
The Ctrl+Alt+Delete screen appears for
the first time since startup and the user can log on. When
the user finishes entering their ID and password, a list of
GPOs connected to the user is gathered and processed,
determined by factors such as the user's domain membership
(or lack thereof), whether the loopback setting is enabled
on the local system and which loopback policy setting is
being used, as well as a host of other factors, detailed
below. [NOTES FROM THE FIELD] - In
the section below titled Group Policy Processing
Exceptions I detail all of the exceptions to the group
policy rules, which covers a few things including the
loopback settings. Also, do not confuse domain accounts
and local accounts. If a workstation is in a domain and a
user logs on with a LOCAL account only, any domain user
account configuration GPO settings are not processed because
the account is local. Also, if you log on to a domain member
that is disconnected from the network with a CACHED DOMAIN
ID, you will not get your UPDATED user configuration
settings. You will log on with the CACHED credentials ONLY. Group Policy Settings Processing
Order All Windows 2000 systems have one Local
Group Policy Object, which is processed first when the
system is started. In a domain scenario, chances are, due to
the fact that subsequent GPOs are likely to overwrite these
settings, this GPO will have the least amount of impact on
the local system when it is in a domain. On a STANDALONE
Windows 2000 system it is usually the only GPO processed and
in this case will have a large impact. After this is complete, any and all
computer startup scripts that are set to run for the system
start, and the Ctrl+Alt+Delete screen appears when they
complete and the user can log on. [NOTES FROM THE FIELD] - The
same set of steps follow with the user configuration
settings. After a user logs on, the Local GPOs are run first,
then site GPOs, followed by domain GPOs, and finally OU
GPOs. With the OU level computer configuration GPOs, the
GPOs linked to the upper most OU in the inheritance tree are
executed first, followed by all that are in the next highest
and so on, until you reach the local OU, which is executed
last. At each OU in the hierarchy there may be several group
policies. They are all processed synchronously in a specific
order set by the domain administrator at each level. After all of the user configuration
GPOs have been processed, any and all group policy-based
user logon scripts run. These scripts run hidden and
asynchronously by default.
User Configuration Settings and Logon Scripts Overview
User configuration settings are used to set group policies
for specific groups of users. The settings are applied to
the users no matter where in the forest they log on and are
processed synchronously by default. (So long as that system
is in the domain. Domain user account configuration settings
will not apply when a user logs on to a machine locally
using a local account. The LOCAL user account settings from
the LOCAL GPO will be applied.) The synchronous setting can
be changed by the domain administrator. The user
configuration settings initialize as the user logs on to the
system and will overwrite any conflicting settings that were
processed at the computer configuration level and are set in
the following order; Local GPOs are first, then site GPOs,
followed by domain GPOs, and finally OU GPOs. No user
interface is displayed while user policies are being
processed. This is that little piece of time after the
Ctrl+Alt+Delete screen disappears and it seems as if
something is happening behind the scenes. (Now you know
what.) After all of the GPOs have been processed, all and
any group policy-based user logon scripts run. These scripts
are also run hidden, however, they run asynchronously by
default.
The GUI will appear once the last user logon script
completes.
The next set of group policy settings that are processed are
computer configuration settings for Site GPOs, if there are
any set to your site. These GPOs are processing
synchronously, meaning the domain administrator sets the
order in which these will execute.
After any and all Site GPOs are run, the next set of GPOs to
be deployed are Domain level computer configuration GPOs.
These too are processed synchronously, with the order set by
the domain administrator.
The final set of GPOs to be executed are OU level computer
configuration GPOs. All of the GPOs linked to the upper most
OU in the inheritance tree are executed first, followed by
all that are in the next highest and so on, until you reach
the local OU, which is executed last. At each OU in the
hierarchy there may be several group policies. They are all
processed synchronously in a specific order set by the
domain administrator at each level. This means that all of
the GPOs in the highest point of the inheritance tree are
executed first in the specific order set by the domain
administrator and then all of the GPOs at the next point of
the inheritance tree are executed in the specific order set
by the domain administrator and so on all the way down to
the local OU.
The GUI will appear once the last user logon script
completes.
