AD Question Answer - LDAP, FSMO, Master replication, Schema, Operation Master, Domain Naming, PDC, RID

 

What is LDAP?

LDAP is a communication protocol designed for use on TCP/IP networks. LDAP defines how a directory client can access a directory server and how the client can perform directory operations and share directory data.

Active Directory Lightweight Directory Service (AD LDS) provides directory services for directory-enabled applications. AD LDS does not require or rely on Active Directory domains or forests. AD LDS was previously known as Active Directory Application Mode (ADAM).

What is Single-master replication?

A type of replication where one domain controller is the master domain controller and operations are not permitted to occur at different places in a network at the same time. In Active Directory, one or more domain controllers can be assigned to perform single-master replication. Operations master roles are special roles assigned to one or more domain controllers in a domain to perform single-master replication. See also operations master role.

What is multimaster replication?

A replication model in which any domain controller accepts and replicates directory changes to any other domain controller. This differs from other replication models in which one computer stores the single modifiable copy of the directory and other computers store backup copies. See also domain controller; replication.

What is FSMO role?

Flexible Single-Master Operation role. Mechanism used by Active Directory to prevent update conflicts in multi master deployments. Some objects are updated in a single-master mode even if the deployment is multi master, which is very similar to the old concept of a Primary Domain Controller (PDC) in Windows NT domains. There are five FSMO Roles in an Active Directory deployment, but only the PDC-emulator role affects Identity Synchronization for Windows. Because password updates are replicated immediately only to the Active Directory domain controls with the PDC emulator role, Identity Synchronization for Windows use this domain controller for synchronization.

What is Operations Master?

A domain controller that has been assigned one or more special roles in an Active Directory domain. The domain controllers assigned these roles perform operations that are single master (not permitted to occur at different places on the network at the same time). Examples of these operations include resource identifier allocation, schema modification, primary domain controller (PDC) election, and certain infrastructure changes. The domain controller that controls the particular operation owns the operations master role for that operation. The ownership of these operations master roles can be transferred to other domain controllers. Also known as flexible single-master operations (FSMO).

What is Schema Master?

The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the entire forest.

 

 

What is Domain Naming Master?

The domain controller holding the domain naming master role controls the addition or removal of domains in the forest. There can be only one domain naming master in the entire forest.

Note: - 1. Forest-wide operations master roles are Schema Master and Domain Naming Master.

2. Domain-wide operations master roles are Rid Master, PDC Emulator Master and Infrastructure Master.

What is Relative ID (RID) Master?

The domain controller assigned to allocate sequences of relative IDs to each domain controller in its domain. Whenever a domain controller creates a security principal (user, group, or computer object), the domain controller assigns the object a unique security ID (SID). The SID consists of a domain SID that is the same for all SIDs created in a particular domain and a relative ID that is unique for each SID created in the domain. At any time, there can be only one relative ID master in a particular domain.

What is PDC Emulator master?

A domain controller that holds the PDC emulator operations master role in Active Directory. The PDC emulator services network clients that do not have Active Directory client software installed, and it replicates directory changes to any Microsoft Windows NT backup domain controllers (BDCs) in the domain. The PDC emulator handles password authentication requests involving passwords that have recently changed and not yet replicated. At any time, the PDC emulator master role can be assigned to only one domain controller in each domain.

What is infrastructure master?

The domain controller assigned to update group-to-user references whenever group memberships are changed and to replicate these changes to any other domain controllers in the domain. At any time, there can be only one infrastructure master in a particular domain. The infrastructure master should not be located on the same computer as the global catalog if there is more than one domain controller in the forest.

What happen if Schema Master Failure

Temporary loss of the schema operations master is not visible to network users. It is not visible to network administrators either, unless they are trying to modify the schema or install an application that modifies the schema during installation. If the schema master will be unavailable for an unacceptable length of time, you can seize the role to the domain controller you’ve chosen to act as the standby schema master. However, seizing this role is a step that you should take only when the failure of the schema master is permanent.

What happen if Domain Naming Master Failure

Temporary loss of the domain naming master is not visible to network users. It is not visible to network administrators either, unless they are trying to add a domain to the forest or remove a domain from the forest. If the domain naming master will be unavailable for an unacceptable length of time, you can seize the role to the domain controller you’ve chosen to act as the standby domain naming master. However, seizing this role is a step that you should take only when the failure of the domain naming master is permanent.

What happen if RID Master Failure

Temporary loss of the RID operations master is not visible to network users. It is not visible to network administrators either, unless they are creating objects and the domain in which they are creating the objects runs out of relative identifiers. If the RID master will be unavailable for an unacceptable length of time, you can seize the role to the domain controller you’ve chosen to act as the standby RID master. However, seizing this role is a step that you should take only when the failure of the RID master is permanent.

What happen if PDC Emulator Failure

The loss of the PDC emulator affects network users. Therefore, when the PDC emulator is not available, you might need to immediately seize the role. If the current PDC emulator will be unavailable for an unacceptable length of time and its domain has clients without Windows Server 2003 client software, or if it contains Windows NT backup domain controllers, seize the PDC emulator role to the domain controller you’ve chosen to act as the standby PDC emulator. When the original PDC emulator is returned to service, you can return the role to the original domain controller.

What happen if Infrastructure Master Failure

Temporary loss of the infrastructure master is not visible to network users. It is not visible to network administrators either, unless they have recently moved or renamed a large number of accounts. If the infrastructure master will be unavailable for an unacceptable length of time, you can seize the role to a domain controller that is not a global catalog but is well connected to a global catalog (from any domain), ideally in the same site as a global catalog server. When the original infrastructure master is returned to service, you can transfer the role back to the original domain controller

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