Global Catalog and Flexible Global Catalog and Flexible Single Master OperationsSingle Master Operations

(FSMO) Roles (FSMO) RolesBAI516

Global CatalogGlobal Catalog• Critical component of Active Directory.• Acts as a central repository by

holding:– A complete copy of all objects from the

host server’s local domain.– A partial copy of all objects from other

domains within the same forest• Used for logon, object searches, and

universal group memberships.

Global CatalogGlobal Catalog• Global catalog placement considerations

include:– The speed and reliability of the WAN link.– The amount of traffic that will be generated

by replication.– The size of the global catalog database.

• Global catalogs are identified with DNS through the SRV records (global catalog, or _gc, service).

Global CatalogGlobal Catalog• By default, the first domain controller

installed in the forest root domain is designated as a global catalog server.

• Any or all domain controllers in a domain can be designated as global catalog server.

Configuring an Additional Global Configuring an Additional Global Catalog ServerCatalog Server• Use Active

Directory Sites and Services from the Administrative Tools folder.

Enabling Universal Group Membership Enabling Universal Group Membership CachingCaching• Use Active

Directory Sites and Services.

Flexible Single Master Operations Flexible Single Master Operations (FSMO) Roles(FSMO) Roles• To keep a tight control on certain

sensitive or special operations, Active Directory uses Flexible Single Master Operations (FSMO) roles.– Relative Identifier Master.– Infrastructure Master.– Primary Domain Controller (PDC)

Emulator.– Domain Naming Master.– Schema Master.

Relative Identifier (RID) MasterRelative Identifier (RID) Master• Domain specific (one per domain).• Responsible for assigning relative

identifiers to domain controllers in the domain.

• Relative identifiers are variable-length numbers assigned by a domain controller when a new object is created.

Infrastructure MasterInfrastructure Master• Domain specific (one per domain).• Responsible for reference updates

from its domain objects to other domains. – Assists in tracking which domains

own which objects.

Primary Domain Controller (PDC) Primary Domain Controller (PDC) EmulatorEmulator• Domain specific (one per domain).• Provides backward compatibility with

Microsoft Windows NT 4.0 domains and other down-level clients.

• Manages account lockouts.• Manages time synchronization for the domain.• Manages password changes.

– When a password is changed, it provides immediate replication to other domain controllers in the domain.

• Managing edits to Group Policy Objects (GPOs)

Domain Naming MasterDomain Naming Master• Forest specific (one per forest).• Has the authority to manage the

creation and deletion of domains, domain trees, and application data partitions in the forest. – When any of these is created, the

Domain Naming Master ensures that the name assigned is unique to the forest.

Schema MasterSchema Master• Forest specific (one per forest).• Responsible for managing changes to

the Active Directory schema.

Flexible Single Master Operations Flexible Single Master Operations (FSMO) Roles(FSMO) Roles• When you install the first domain

controller in a new forest, that domain controller holds both of the forest-wide FSMOs as well as the three domain-wide FSMOs for the forest root domain.

Managing FSMO RolesManaging FSMO Roles• Role transfer - Used to move a

FSMO role gracefully from one domain controller to another.

• Role seizure - Used only when you have experienced a failure of a domain controller that holds a FSMO role and you forced an ungraceful transfer.

Viewing or transferring Domain-Wide Viewing or transferring Domain-Wide FSMO Role HoldersFSMO Role Holders• Open the Active

Directory Users and Computers MMC snap-in.

• Right-click the Active Directory Users and Computers node, click All Tasks, and select Operations Masters.

Viewing or Transferring the Domain Naming Viewing or Transferring the Domain Naming Master FSMO Role HolderMaster FSMO Role Holder• In Active

Directory Domains and Trusts, right-click the Active Directory Domains and Trusts node and select Change Operations Master.

Viewing or Transferring the Schema Viewing or Transferring the Schema Master FSMO Role HolderMaster FSMO Role Holder• Open the Active Directory Schema snap-

in.• Right-click Active Directory Schema from

the console tree and select Change Operations Master.

• Remember that before you can access the Active Directory Schema snap-in, you need to register the schmmgmt.dll DLL file using the following syntax:regsvr32 schmmgmt.dll

Seizing a FSMO RoleSeizing a FSMO Role• Use the ntdsutil command to access

the fmso maintenance prompt and use the seize command.

SummarySummary• The global catalog server acts as a

central repository for Active Directory by holding a complete copy of all objects within its local domain and a partial copy of all objects from other domains within the same forest.

• The global catalog has three main functions: the facilitation of searches for objects in the forest, resolution of UPN names, and provision of universal group membership information.

SummarySummary• A global catalog should be placed in

each site when possible. As an alternate solution when a site is across an unreliable WAN link, universal group membership caching can be enabled for the site to facilitate logon requests.

SummarySummary• The Schema Master and Domain

Naming Master roles are forest-wide. – Every forest must have one and only

one of each of these roles.• The RID Master, PDC Emulator, and

Infrastructure Master roles are domain-wide. – Every domain must have only one of

each of these roles.

SummarySummary• The default placement of FSMO roles

is sufficient for a single-site environment.– However, as your network expands,

these roles should be divided to increase performance and reliability.

SummarySummary• FSMO roles can be managed in two ways:

– Role transfer - Transfer a FSMO role to other domain controllers in the domain or forest to balance the load among domain controllers or to accommodate domain controller maintenance and hardware upgrades.

– Role seizure - Seize a FSMO role assignment when a server holding the role fails and you do not intend to restore it. • Seizing a FSMO role is a drastic step that

should be considered only if the current FSMO role holder will never be available again.

SummarySummary• Use repadmin to check the status of

the update sequence numbers (USNs) when seizing the FSMO role from the current role holder.

• Use ntdsutil to actually perform a seizure of the FSMO role.

Questions?Questions?

Hands – OnHands – On• Lab 7