In this module, we're going to look at how group policy gets applied from the client's perspective.
In Module three, we looked at group policy processing from the perspective of you as the administrator
defining, linking and filtering GPOs in order to get the right settings to the right computers and
users.
But on this module, what I want to do is kind of drill into what happens at the client when group policy
processing is happening.
So let's look at the group policy processing cycle.
Computer or user objects will start processing.
And just keep in mind that depending on how it's happening and when it's happening, computer processing
might be happening separate from user processing.
And I'll talk about that in a little bit, but let's just assume that both are running at the same time
in this cycle.
The first thing that happens is what's called the core or group policy infrastructure phase.
And in that phase the client via the server workstation will query AD just like any client in an Active
Directory domain will do to find its closest DC.
Typically that is done by locating a DC in the same site as the client machine, and it does that to
determine based on where the computer or user resides in the ad hierarchy, which GPOs apply, which
GPOs are linked to this particular computer or user object.
So next what happens is the client also part of the core or group policy infrastructure phase?
The client builds its list of GPOs that apply to it.
And this takes into account things like filtering and takes into account GPOs that have changed or have
not changed.
Keep in mind that as I mentioned in a previous module, group policy processing only does work at the
client if GPOs have changed.
And what that comes down to is when the client builds its list of GPOs to process.
If that list has changed between time one and time to then a time to processing has to occur.
So if nothing has changed in your group policy infrastructure between, you know, one processing cycle
and the next, then group policy engine will wake up, see that nothing has changed and basically do
no work.
But during this phase, what happens is I get that list built of GPOs that apply to me and then I also
get the list of client side extensions that need to do work in this phase.
And then we move into the CSC phase, which is essentially that each client side extension once wakes
up and does its work for the ones that are called or the ones that required for the previous section
or in the previous part of the cycle.
And it processes the GPOs that implement those policy areas of those CCS in that local site domain OYU
or LSW order that I talked about previously and then the cycle starts all over again.
So that's basically how group policy processing occurs at the client.