A domain controller is responsible for providing security policies and permissions for sharing resources on a network. It sets policies for installing or updating software, using drives and ports, changing passwords, and controls access permissions to files, folders, and shared printers. Without a domain controller, a network administrator would need to manually set these policies on each individual computer. When a user logs into a computer, the domain controller checks its security policies and permissions for that user or group and sends an access key to allow or restrict access accordingly. Active Directory services are required to set up a domain controller, and different types of domain controllers like primary, backup, and read-only can distribute the load and provide redundancy. Trust relationships between domain controllers allow users on one

1. Domain Controller

2. What is domain controller
• responsible for providing security policies for each computer on
network and also permissions for sharing of resources.

3. Security policies
• to install a software
• to update a software
• to use cd drive
• to use usb
• can change password or not

4. permissions
• access to particular files or folders, what type of access
• can share printer or not
• access to resources

5. what if no domain controller
• network administrator will sit at each computer and set the security
policies

6. how domain controller works
• a computer log on with a username and password
• domain controller checks security policies and permissions for that
computer and sends that bundle of permissions as an access key to
logged on computer
• separate policies can be set for users as well as group

7. units
• users
• groups (a collection of users)
• organisational units (OU)(resources(printers) + users + groups)

8. Products
• Active directory services are neccessity to setup domain controller
• web edition of windows server 2008 does not have active directory
services
• clients which want to access active directory services should have
windows business addtion os, home or premium addition wont work
• SAMBA is the open source domain controller for Linux

9. Types of Domain Controllers
• Primary DC
• Backup DC
• BDC is copy of PDC, if PDC fails, adminsitrator will promote BDC to act
as PDC, every function is performed by PDC
• SAMBA still has PDC and BDC
• Microsoft and Novell softwares has only DC

10. Types od DCs
• IN DC
• their are number of DCs in a big network, if one fails, other works for
it and everytime there are some changes on one of DC, it is
automatically replicated to all DCs, so their is no need of BDC

11. Trust Relationships
• If two companies are providing some services to each other, but they
have their separate DCs, an employee whose login is on First
company, can access his accounts from a computer on network in
another company only if the DC of second company has a trust
relationship with the domain controller of first company
• Trust relationships can be one way, two way or transitive