A Peek Into Active Directory

Overview of Active Directory (AD), Domain Name System (DNS) and Dynamic Host Configuration Protocol (DHCP)

Active Directory is simply a database of objects - Users, Groups, and Computers. The cluster of Computers that maintains this database is known as domain controllers. Each object has an attribute and can be structured logically in a hierarchical manner.

A Domain Name System is a hierarchical and distributed system used to translate human-readable domain names such as www.example.com into the numerical IP addresses that computers use to identify each other on a network. DNS servers are the computers that maintain a database of domain names and their corresponding IP addresses.

Dynamic Host Configuration Protocol is a network protocol used to automatically assign IP addresses and other network configuration information to devices on a network.

Download and Install VMWare Workstation Player, Windows Server 2022 and Windows 11

Download VMWare Workstation Player, Windows Server 2022 and Windows 11 from their respective websites and follow the instructions below to install.
VMWare Installation: Double Click the downloaded Windows Vmware Workstation Player, Click Yes then Click Next -> Check I accept the terms in the License Agreement and Click Next -> Click Next -> Click Next -> Click Next -> Click Next -> Click Install -> Click Finish. See a visual of this installation below:

Windows Server 2022 Installation: Double Click the now installed VMWare Workstation Player -> Click Create a New Virtual Machine -> Select I will install the operating system later. and Click Next -> Click Next -> Enter a name in Virtual machine name: box and navigate to a desired storage location using Browse... and Enter a name in Location: box then Click Next -> Enter a disk size in Maximum disk size(GB): box, Select Store virtual disk as a single file and Click Next -> Click Customize Hardware; Click Printer, Click Remove; Click Memory and ramp it upto 4GB; Click New CD/DVD(SATA), on the right pane Select Use ISO image file, browse to the location of the downloaded ISO and upload the ISO then Click Close -> Click Finish. Now with the created VM selected on the left pane Click Play virtual machine -> Accept all prompts and Press any key to boot from CD or DVD -> Select desired options from the dropboxes and Click Next -> Click Install now -> Select Windows Server 2022 Standard Evaluation(Desktop Experien.. then Click Next -> Check I accept the Microsoft Software License Terms. If an organization is licensing it, I am authorized to bind the organization. Click Next -> Click Custom: Install Microsoft Server Operating System only (advanced) -> with the Drive 0 Unallocated Space selected Click Next -> Enter and confirm a Password for Administrator then Click Finish -> Click Player on the top Menu bar, Select Send CTRL + ALT + DEL and Enter the administrator password to login.

Windows 11 Installation: Double Click the now installed VMWare Workstation Player -> Click Create a New Virtual Machine -> Select Installer disc image file (iso) and browse to the location of the downloaded iso then Click Next -> Enter a name in Virtual machine name: box and navigate to a desired storage location using Browse... and Enter a name in Location: box then Click Next -> Select All the files (.vmdk,vmx, etc) for this virtual machine are encrypted, Enter and confirm the Password in the textbox, and Check Remember the password on this machine in Credential Manager then Click Next -> Enter a disk size in Maximum disk size(GB): box, Select Store virtual disk as a single file and Click Next -> Click Customize Hardware; Click Printer, Click Remove; Click Memory and ramp it upto 4GB; then Click Close -> Click Finish -> Accept all prompts and Press any key to boot from CD or DVD -> Click Next -> Click Install now -> Click I don't have a product key -> Select Windows 11 Pro and Click Next. Now Select your language of choice and Click Yes -> Choose your keyboard layout and Click Yes -> You may skip Do you want to add a second keyboard layout? -> Enter a device name and Click Next -> Choose Set up for work or school and Click Next -> You may sign or create an account to proceed, a quick hack was to enter a wrong credentials multiple times to display an error page and activate the Next Tab, Click Next -> Enter a name and Click Next -> Enter a Password and Click Next -> Confirm the Password and Click Next -> Give an answer to three Security questions and Click Next -> Turn on/off the settings you desire and Click Accept -> Click Player on the top Menu bar, Select Send CTRL + ALT + DEL, and Enter the user password to login.

Power off both machines. Right Click on a machine and Click Settings... -> Click CD/DVD(SATA), Click Remove, and Click OK. Please do same for the Win11 VM.

/images/ad/vmware-disconnect-media.png — Disconnect CD/DVD Media

Install and Configure Windows Server with AD, DNS and DHCP services

Having installed Windows Server 2022. Login with the credentials. Type ‘About PC’ on Windows Search Bar and Click on the highlighted result -> Click Rename this PC, type your preferred name and Click Next -> Click Restart now. Re-login and Right Click the Network Icon on the Taskbar and Click Open Network & Internet settings -> Click Change adapter options -> Right Click on Ethernet0 and Click Properties -> Uncheck Internet Protocol Version 6 (TCP/IPv6), Click Internet Protocol Version 4 (TCP/IPv4) and Click Properties -> Select Use the following IP address, Enter desired settings then Click OK -> Click Close. Now open a command prompt and type the following:

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C:\Users\Administrator> ipconfig /flushdns       :: purge dns resolver cache
C:\Users\Administrator> ipconfig /registerdns    :: re-register dns
C:\Users\Administrator> ipconfig /all            :: show the new network configuration
C:\Users\Administrator> ping 192.168.20.4        :: test the network connection

/images/ad/configure-static-ipv4.png — Configure Static IPv4

Install AD,DNS,DHCP Services: On the already open ‘Server Manager > Dashboard’ Click on Manage on the right end of the menu bar. Click Add Roles and Feature -> Click Next -> Select Role-based or feature-based installation and Click Next -> Select Select a server from the server pool and Click Next -> Check Active Directory Domain Services and Click Add Features -> Check DHCP Server and Click Add Features -> Check DNS Server and Click Add Features -> Now Click Next -> Click Next -> Click Next -> Click Next -> Click Next -> Click Install. After the installation is complete Click Promote this server to a domain controller -> Select Add a new forest and Enter a Domain name then Click Next -> Enter and Confirm the Password then Click Next -> Click Next -> “The NetBIOS domain name” automatically populates, Click Next -> Click Next -> Click Next -> Click Install. The server automatically restarts once installation is complete. Re-login to the server.

/images/ad/ad-installation.png — Active Directory Installation

Configure the DNS server Reverse Lookup Zone and Forward Lookup Zone: On the Server Manager > Dashboard, Click Tools -> Click DNS -> Click the Server Name on the left pane, -> Click Reverse Lookup Zones on the right pane and Right Click, Click New Zone -> Click Next -> Select Primary zone and Click Next -> Select To all DNS servers running on domain controllers in this domain and Click Next -> Select IPv4 Reverse Lookup Zone and Click Next -> Enter the first three octet block of the server IP and Click Next -> Select Allow only secure dynamic updates(recommended for Active Directory) and Click Next then Click Finish. Now on the left pane Click Forward Lookup Zones, Double Click the domain name on the right pane -> Double Click the server name -> Check Update associated pointer(PTR) record and Click OK. Now Right Click the Network Icon on the Taskbar and Click Open Network & Internet settings -> Click Change adapter options -> Right Click on Ethernet0 and Click Properties -> Click Internet Protocol Version 4 (TCP/IPv4) and Click Properties -> on the Use the following IP address section change the Preferred DNS Server to the Servers IP then Click OK-> ClickClose`. Open a command prompt and run the following command:

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C:\Users\Administrator> nslookup 192.168.20.4      :: notice the default server is our server`s fully qualified domain name

Configure the DHCP: On the Server Manager > Dashboard Click the flag with the warning icon -> Click Complete DHCP Configuration -> Click Next -> Select Use the following user's credentials then Click Commit -> Click Close

/images/ad/dhcp-configuration.png — DHCP Configuration

Now from the Server Manager > Dashboard Click Tools -> Click DHCP -> Double Click on the server’s FQDN on the right pane -> Click IPv4 on the left pane, Right Click and Click New Scope -> Click Next -> Enter a Name and Description for this DHCP scope and Click Next -> Fill up the details, this should match the min host, max host and subnet mask of your network CIDR, then Click Next -> Enter IP range to exclude, Click Add and Click Next -> Change the lease duration to 6 hours and Click Next -> Select Yes, I want to configure these options now and Click Next -> Enter the Default Gateway IP, Click Add and Click Next -> Click Next -> Click Next -> Select Yes, I want to activate this scope now and Click Next -> Click Finish. On command prompt run:

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C:\Users\Administrator> netsh dhcp show server     :: list server details

Join Windows 11 to the Domain

Type ‘Network Connections’ on Windows Search Bar and Click on the highlighted result. Right Click on Ethernet0 and Click Properties -> Click Internet Protocol Version 4 (TCP/IPv4) and Click Properties -> Select Use the following IP address, Enter network details and Select Use the following DNS server addresses and Enter the Server’s DNS IP then Click OK -> Click Close. On the command prompt check for connectivity between the hosts.

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C:\Users\Administrator> ping 192.168.20.5     :: client is reachable from server
C:\Users\bug-hunter> ping 192.168.20.4        :: server is reachable from client

To Configure the client to obtain its IP from the DHCP server, shutdown both machines, create a LAN segment from VMWare Workstation Player and add the machines to it: Double Click the downloaded Windows Vmware Workstation Player -> Right Click on Server VM and Click Settings -> Click Network Adapter, Select LAN segment, Click LAN Segments -> Click Add, Enter a name for the LAN Segment then Click OK -> Click the dropdown box and Select the just added segment then Click OK. For the Client, Right Click on Client VM and Click Settings -> Click Network Adapter, Select LAN segment, Click the dropdown box and Select the same name of the LAN segment as the server, then Click OK.

Now power on both machines. On the Client machine let’s change the network TCP/IPv4 setting to use DHCP. Type ‘Network Connections’ on Windows Search Bar and Click on the highlighted result. Right Click on Ethernet0 and Click Properties -> Click Internet Protocol Version 4 (TCP/IPv4) and Click Properties -> Select Obtain an IP address automatically also Select Obtain DNS server address automatically then Click OK -> Click Close. Notice the adapter now has the network domain name underneath it. Open command prompt to confirm connectivity:

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C:\Users\bug-hunter> ipconfig /all          :: DHCP enabled and client IP assigned
C:\Users\bug-hunter> ping 192.168.20.4      :: server is reachable from client
C:\Users\bug-hunter> nslookup 192.168.20.1  :: resolves via DNS server

To join a Client Computer to the Domain: Enter ‘Device specification’ on Windows Search and Click on it -> Locate Related links and Click on Domain or workgroup -> Click Change -> Select Domain, Enter the domain name and Click OK -> Enter the domain server Administrator credentials and Click OK -> Click OK -> Click OK -> Click Close -> Click Restart Now.

Create Organizational Units, Groups and Users on the Domain Server

Now go back to the Domain Server to can see that the Client Computer is now part of the Domain: From the ‘Server Manager > Dashboard’ Click Tools -> Click Active Directory Users and Computers -> Double the domain on the right pane -> Double Click Computers.

/images/ad/verify-client-joined-domain.png — Confirm Client Joined Domain

It is important to structure your AD by Organizational Unit instead of creating objects directly in Container. Create a New Organizational Unit: Right Click Tools -> Click Active Directory Users and Computers -> Right Click the domain name from the left pane -> Click on New and Click Organizational Unit -> Enter a name and Click OK. Now create groups within this OU: Right Click the OU name -> Click New and Click Group -> Enter a group name, retain the default settings and Click OK. Let’s create users within this OU: Right Click the OU name -> Click New and Click User -> Enter user details and Click Next (notice the user details have “User Principal Name(UPN)” type logon) -> Enter and confirm a password for the user, Check/UnCheck desired options then Click Next -> Click Finish. Assign the user to a group: With the OU name selected on the left pane, Right Click on the user from the left pane -> Click Add to a group -> Enter the group name and Click OK -> Click OK.

Now jumping back to the Client VM let’s log on to the domain with the user: Click Other user -> Enter the credentials of the user created on the domain server and hit the Enter button.

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