Which Configuration Manager discovery method should you use?

Your network contains a single Active Directory domain.
You plan to deploy System Center 2012 Configuration Manager. The hierarchy will have a
Central Administration site and five primary sites.
You need to ensure that you can target user groups for software distribution. The solution
must minimize network traffic.
Which Configuration Manager discovery method should you use?

A.
Active Directory User Discovery on the primary sites

B.
Active Directory User Discovery on the primary sites and Active Directory Group
Discovery on every site

C.
Active Directory User Discovery on the Central Administration site and Active Directory
Group Discovery on the primary sites

D.
Active Directory User Discovery and Active Directory Group Discovery on the Central
Administration site

Explanation:
Active Directory User Discovery on the primary sites and Active Directory Group

Discovery on every site Personal comment:
From my point of view, the correct answer would be Active Directory User Discovery and
Active Directory
Group Discovery on the primary sites
The remaining possible correct answers might be:
Active Directory User Discovery on the primary sites and Active Directory Group Discovery
on every site or Active Directory User Discovery and Active Directory Group Discovery on
the Central Administration site Update:
It seems that more recent exams contain the answer “Active Directory User Discovery and
Active Directory
Group Discovery on the primary sites”
http://technet.microsoft.com/en-us/library/gg712681.aspx#BKMK_ChooseCAS
Determine Whether to Install a Central Administration Site
Install a central administration site if you plan to install multiple primary sites. Use a central
administration site to configure hierarchy-wide settings and to monitor all sites and objects in
the hierarchy. This site type does not manage clients directly but it does coordinate intersite
data replication, which includes the configuration of sites and clients throughout the
hierarchy.
Use the following information to help you plan for a central administration site: You can
manage all clients in the hierarchy and perform site management tasks for any primary site
when you use a Configuration Manager console that is connected to the central
administration site.
You can configure discovery operations throughout the hierarchy from the central
administration site by assigning discovery methods to run at individual sites.
http://technet.microsoft.com/en-us/library/gg712308.aspx
Planning for Discovery in Configuration Manager System Center 2012 Configuration
Manager discovery identifies computer and user resources that you can manage by using
Configuration Manager. It can also discover the network infrastructure in your environment.
Discovery Methods in Configuration Manager Before you enable discovery methods for
Configuration Manager, ensure you understand what each method can discover. Because
discovery can generate a large volume of network traffic, and the resultant DDRs can result
in a significant use of CPU resources during processing, plan to use only those discovery
methods that you require to meet your goals. You could use only one or two discovery
methods to be successful, and you can always enable additional methods in a controlled
manner to extend the level of discovery in your environment. Active Directory User
Discovery Discovers user accounts from the specified locations in Active Directory Domain
Services. Active Directory Group Discovery Discovers local, global, and universal security
groups, the membership within these groups, and the membership within distribution groups
from the specified locations in Active directory Domain Services. Distribution groups are not
discovered as group resources. About Discovery Data Records Discovery data records
(DDRs) are files created by a discovery method that contain information about a resource
you can manage in Configuration Manager. DDRs contain information about computers,
users and in some cases, network infrastructure. They are processed at primary sites or at
central administration sites. After the resource information in the DDR is entered into the
database, the DDR is deleted and the information replicates as global data to all sites in the
hierarchy. The site at which a DDR is processed depends on the information it contains:
DDRs for newly discovered resources that are not in the database are processed at the toplevel site of the hierarchy. The top-level site creates a new resource record in the database
and assigns it a unique identifier. DDRs transfer by file-based replication until they reach the
top-level site. DDRs for previously discovered objects are processed at primary sites. Child
primary sites do not transfer DDRs to the central administration site when the DDR contains

information about a resource that is already in the database. Secondary site do not process
discovery data records and always transfer them by filebased replication to their parent
primary site. DDR files are identified by the .ddr extension, and have a typical size of about 1
KB. Decide Which Discovery Methods to Use Discover Users When you want to discover
information about users, you can use Active Directory User Discovery. Similar to Active
Directory System Discovery, this method discovers users from Active Directory and includes
basic information in addition to extended Active Directory information. You can use this
information to build complex queries and collections similar to those for computers. Discover
Group Information When you want to discover information about groups and group
memberships, use Active Directory Group Discovery. This discovery method creates
resource records for security groups. You can use this method to search a specific Active
Directory group to identify the members of that group in addition to any nested groups within
that group. You can also use this method to search an Active Directory location for groups,
and recursively search each child container of that location in Active Directory Domain
Services. This discovery method can also search the membership of distribution groups.
This can identify the group relationships of both users and computers. When you discover a
group, you can also discover limited information about its members. This does not replace
Active Directory System or User Discovery and is usually insufficient to build complex
queries and collections or serve as the bases of a client push installation. Decide Where to
Run Discovery When you plan to use discovery in Configuration Manager, you must
consider where to run each discovery method. After Configuration Manager adds discovery
data to a database, it is quickly shared between all sites in the hierarchy. Because there is
no benefit to discovering the same information at multiple sites in your hierarchy, consider
configuring a single instance of each discovery method that you use to run at a single site
instead of running multiple instances of a single method at different sites.

Further information:
Best Practices for Discovery
Run Active Directory System Discovery and Active Directory User Discovery before you run
Active Directory
Group Discovery
When Active Directory Group Discovery identifies a previously undiscovered user or
computer as a member of a group, it attempts to discover basic details for the user or
computer. Because Active Directory Group Discovery is not optimized for this type of
discovery, this process can cause Active Directory Group Discovery to run slow. Additionally,
Active Directory Group Discovery identifies only the basic details about users and computers
is discovers, and does not create a complete user or computer discovery record. When you
run Active Directory System Discovery and Active Directory User Discovery, the additional
Active Directory attributes for each object type are available, and as a result, Active Directory
Group Discovery runs more efficiently. When you configure Active Directory Group
Discovery, only specify groups that you use with Configuration Manager To help control the
use of resources by Active Directory Group Discovery, specify only those groups that you
use with Configuration Manager. This is because Active Directory Group Discovery

recursively searches each group it discovers for users, computers, and nested groups. The
search of each nested group can expand the scope of Active Directory Group Discovery and
reduce performance. Additionally, when you configure delta discovery for Active Directory
Group Discovery, the discovery method monitors each group for changes. This further
reduces performance when the method must search unnecessary groups. Run Active
Directory Discovery methods at primary site that has a network location that is closest to
your Active Directory domain controller To improve the performance of Active Directory
discovery, it is recommended to run discover at a primary site that has a fast network
connection to your domain controllers. If you run the same Active Directory discovery
method at multiple sites, it is recommended to configure each discovery method to avoid
overlap. Unlike past versions of Configuration Manager, discovery data is shared between
sites. Therefore, it is not necessary to discovery the same information at multiple sites.
http://configmgrblog.com/2011/12/29/discovery-methods-in-configuration-manager-2012/
Discovery Methods in Configuration Manager 2012 Active Directory User Discovery can be
configured on Central Administration Sites and Primary Sites. Active Directory Group
Discovery can be configured on Central Administration Sites and Primary Sites.