# PDC:Primary Domain Controller,ADC:

**Primary Domain Controller**: **A service in a Windows server that manages security for its local domain**. Every domain has one PDC, which contains a database of usernames, passwords and permissions.

Primary Domain Controller is a Microsoft Windows NT domain controller that contains the master copy of the [Security Account Manager](https://networkencyclopedia.com/security-account-manager-sam-database/) (SAM) database.

![Primary Domain Controller](https://networkencyclopedia.com/wp-content/uploads/2019/09/primary-domain-controller.gif align="left")

To configure time synchronization via Group Policy:

1. Open **Group Policy Management Console**
    
2. Create a new **GPO**
    
3. Open the GPO and navigate to **Computer Settings -> Administrative Templates -> System -> Windows Time Service -> Time Providers**
    
4. Double click the **Configure Windows NTP Client.**
    
5. Set the state to **Enabled**
    
6. Configure the **Type**to **NTP**
    
7. Configure **NTPServer**to point to an IP address of a time server, followed by **,0x8**, for example:  **131.107.13.100,0x8**
    
8. Close the Group Policy Editor
    
9. In the **Security Filtering**pane of the Group Policy management console remove **Authenticated users** for the newly created policy and add the machine that holds the **PDC Emulator**role
    
10. Link the GPO to **Domain Controllers**OU
    
    ## **How To Troubleshoot**
    
    To see current configuration of the Windows Time service, use the following command in an elevated command prompt:
    
    **w32tm /query /configuration**
    
    to see the current source for time synchronization use the following command:
    
    **w32tm /query /source**
    
    BDC is a Backup Domain Controller
    
    A **primary** [**domain controller**](https://www.easytechjunkie.com/what-is-a-domain-controller.htm) (PDC) is a server used in computer networks for managing users and groups on a particular segment of a local area network (LAN). The server stores user information and access permissions for network resources, such as other computers or printers, throughout the network. The PDC then provides a single access point for users to log-on to the network and gain access to its resources, thereby alleviating multiple user-name and [**password**](https://www.easytechjunkie.com/how-often-should-i-change-my-password.htm) combinations.
    
      
    ***Delegation of control*** is when an organizational unit (OU) — an object or group in a computer directory — is given a certain amount of control over functions. The control is usually minimal compared to the task, so the user can only perform the specified task and nothing else. Administrators and people in high positions, such as managers and owners, are given the highest delegation of control, with few restrictions on actions. The control is usually split into departments, giving managers control of a single OU that allows the [**manager**](https://www.practicaladultinsights.com/what-is-a-manager.htm) to add or delete users.
    
    An OU is a directory of users and serves several purposes. It allows redundant data, such as two people with the same name but in different departments. This also gives users a way to organize employees and other users in terms of department, employee level and overall delegation of control.
    
    Under the [**Domain Name**](https://www.easytechjunkie.com/what-is-a-domain-name.htm) System (DNS) which is used to allow people to type in words rather than numeric web addresses to reach a particular website, a top level domain is the last part of a domain name, after the final dot. Here at wiseGEEK, for example, the top level domain is “com.” Top level domains fall into a number of different categories, depending on who is allowed to use them.