Domain Name System ( DNS )

Domain Name System (DNS) is one of the industry-standard suite of protocols that comprise TCP/IP. Windows Server DNS is implemented using two software components: the DNS server and the DNS client (or resolver). Both components are run as background service applications.

By default, Windows Server DNS is used for all name resolution in a Windows Server network. In the most typical scenario, when a Windows Server network user specifies the name of a network host or an internet DNS domain name, the DNS Client service running on the Windows Server computer of the user contacts a DNS server to resolve the name to an IP address. 

DNS in TCP/IP 

 

Technologies that use DNS

DNS and AD DS

Active Directory Domain Services (AD DS) uses DNS as its domain controller location mechanism. When any of the principal Active Directory operations is performed, such as authentication, updating, or searching, computers running Windows Server 2008 use DNS to locate Active Directory domain controllers and these domain controllers use DNS to locate each other. 

DNS and WINS

The earlier method of name resolution for a Windows network was Windows Internet Name Service (WINS). DNS is different from WINS in that DNS is a hierarchical namespace and WINS is a flat namespace. Clients and applications that rely on NetBIOS names continue to use WINS for name resolution. Because Windows Server 2008 DNS is WINS-aware, a combination of both DNS and WINS can be used in a mixed environment to achieve maximum efficiency in locating various network services and resources.

DNS and DHCP

The DHCP service provides default support to register and update information for legacy DHCP clients in DNS zones. Legacy clients typically include other Microsoft TCP/IP client computers that were released prior to Windows 2000. The Windows Server 2008 DNS-DHCP integration enables a DHCP client that is unable to dynamically update DNS resource records directly to have this information updated in DNS forward and reverse lookup zones by the DHCP server.

How DNS Works

Domain Name System (DNS) is the default name resolution service used in a Windows Server network. Previously, we have Windows Internet Name Service (WINS) in Windows NT for the same purpose. A DNS Client resolver is included as a default service in all client and server versions of the Windows operating system. 

Typically, Windows Server 2008 DNS is deployed in support of Active Directory Domain Services (AD DS). In this environment, DNS namespaces mirror the Active Directory forests and domains used by an organization. Network hosts and services are configured with DNS names so that they can be located in the network, and they are also configured with DNS servers that resolve the names of Active Directory domain controllers. 

DNS architecture is a hierarchical distributed database and an associated set of protocols that define:

• A mechanism for querying and updating the database.
• A mechanism for replicating the information in the database among servers.
• A schema of the database.

DNS originated in the early days of the Internet when the Internet was a small network established by the United States Department of Defense for research purposes.

The Domain Name System introduced in 1984 became this new system. DNS supports hierarchical names and allows registration of various data types in addition to host name-to-IP address mapping used in HOSTS files.

The original DNS was based on Request for Comment (RFC) 882 (Domain Names: Concepts and Facilities) and RFC 883 (Domain Names–Implementation and Specification), which were superseded by RFC 1034 (Domain Names–Concepts and Facilities), and RFC 1035 (Domain Names–Implementation and Specification). Additional RFCs that describe DNS security, implementation, and administrative issues later augmented the original design specifications. 

DNS domain names

The Domain Name System is implemented as a hierarchical and distributed database containing various types of data, including host names and domain names. The names in a DNS database form a hierarchical tree structure called the domain namespace. Domain names consist of individual labels separated by dots, for example: mydomain.microsoft.com.

A fully qualified domain name (FQDN) uniquely identifies the host’s position within the DNS hierarchical tree by specifying a list of names separated by dots in the path from the referenced host to the root. The following figure shows an example of a DNS tree with a host called mydomain within the microsoft.com. domain. The FQDN for the host would be mydomain.microsoft.com.

Installation of Windows Server 2008

                 Windows Server 2008 can also be installed as a Server Core installation, which is a cut-down version of Windows without the Windows Explorer GUI. Because you don’t have the Windows Explorer to provide the GUI interface that you are used to, you configure everything through the command line interface or remotely using a Microsoft Management Console (MMC). The Server Core can be used for dedicated machines with basic roles such as Domain controller/Active Directory Domain Services, DNS Server, DHCP Server, file server, print server, Windows Media Server, IIS 7 web server and Windows Server Virtualization virtual server.

To use Windows Server 2008 you need to meet the following hardware requirements:

Component	Requirement
Processor	• Minimum: 1GHz (x86 processor) or 1.4GHz (x64 processor) • Recommended: 2GHz or faster Note: An Intel Itanium 2 processor is required for Windows Server 2008 for Itanium-based Systems
Memory	• Minimum: 512MB RAM • Recommended: 2GB RAM or greater • Maximum (32-bit systems): 4GB (Standard) or 64GB (Enterprise and Datacenter) • Maximum (64-bit systems): 32GB (Standard) or 2TB (Enterprise, Datacenter and Itanium-based Systems)
Available Disk Space	• Minimum: 10GB • Recommended: 40GB or greater Note: Computers with more than 16GB of RAM will require more disk space for paging, hibernation, and dump files
Drive	DVD-ROM drive
Display and Peripherals	• Super VGA (800 x 600) or higher-resolution monitor • Keyboard • Microsoft Mouse or compatible pointing device

Upgrade notes:
               I will not discuss the upgrade process in this article, but for your general knowledge, the upgrade paths available for Windows Server 2008 shown in the table below:

If you are currently running:	You can upgrade to:
Windows Server 2003 Standard Edition (R2, Service Pack 1 or Service Pack 2)	Full Installation of Windows Server 2008 Standard Edition Full Installation of Windows Server 2008 Enterprise Edition
Windows Server 2003 Enterprise Edition (R2, Service Pack 1 or Service Pack 2)	Full Installation of Windows Server 2008 Enterprise Edition
Windows Server 2003 Datacenter Edition (R2, Service Pack 1 or Service Pack 2)	Full Installation of Windows Server 2008 Datacenter Edition

Follow this procedure to install Windows Server 2008:

1. Insert the appropriate Windows Server 2008 installation media into your DVD drive. If you don't have an installation DVD for Windows Server 2008, you can download one for free from Microsoft's Windows 2008 Server Trial website.
2. Reboot the computer.

3. When prompted for an installation language and other regional options, make your selection and press Next.

4. Next, press Install Now to begin the installation process.

5. Product activation is now also identical with that found in Windows Vista. Enter your Product ID in the next window, and if you want to automatically activate Windows the moment the installation finishes, click Next.

If you do not have the Product ID available right now, you can leave the box empty, and click Next. You will need to provide the Product ID later, after the server installation is over. Press No.

6. Because you did not provide the correct ID, the installation process cannot determine what kind of Windows Server 2008 license you own, and therefore you will be prompted to select your correct version in the next screen, assuming you are telling the truth and will provide the correct ID to prove your selection later on.

7. If you did provide the right Product ID, select the Full version of the right Windows version you're prompted, and click Next.

8. Read and accept the license terms by clicking to select the checkbox and pressing Next.

9. In the "Which type of installation do you want?" window, click the only available option – Custom (Advanced).

10. In the "Where do you want to install Windows?", if you're installing the server on a regular IDE hard disk, click to select the first disk, usually Disk 0, and click Next.

If you're installing on a hard disk that's connected to a SCSI controller, click Load Driver and insert the media provided by the controller's manufacturer.


11. The installation now begins, and you can go and have lunch. Copying the setup files from the DVD to the hard drive only takes about one minute. However, extracting and uncompressing the files takes a good deal longer. After 20 minutes, the operating system is installed. The exact time it takes to install server core depends upon your hardware specifications. Faster disks will perform much faster installs… Windows Server 2008 takes up approximately 10 GB of hard drive space.

The installation process will reboot your computer, so, if in step #10 you inserted a floppy disk (either real or virtual), make sure you remove it before going to lunch, as you'll find the server hanged without the ability to boot (you can bypass this by configuring the server to boot from a CD/DVD and then from the hard disk in the booting order on the server's BIOS)
12. Then the server reboots you'll be prompted with the new Windows Server 2008 type of login screen. Press CTRL+ALT+DEL to log in.

13. Click on Other User.

14. The default Administrator is blank, so just type Administrator and press Enter.

15. You will be prompted to change the user's password. You have no choice but to press Ok.

16. In the password changing dialog box, leave the default password blank (duh, read step #15…), and enter a new, complex, at-least-7-characters-long new password twice. A password like "topsecret" is not valid (it's not complex), but one like "T0pSecreT!" sure is. Make sure you remember it.

17. Someone thought it would be cool to nag you once more, so now you'll be prompted to accept the fact that the password had been changed. Press Ok.


18. Finally, the desktop appears and that's it, you're logged on and can begin working. You will be greeted by an assistant for the initial server configuration, and after performing some initial configuration tasks, you will be able to start working.

Installing Active Directory on Windows Server 2008

         Microsoft Active Directory provides the structure to centralize the network management and store information about network resources across the entire domain.

Prerequisites:

When you install AD to create the first domain controller in a new Windows Server 2008 forest, you must keep the following considerations in mind:

• You must make forest and domain functional level decisions that determine whether your forest and domain can contain domain controllers that run Windows 2000 Server, Windows Server 2003, or both. To read more about forest and domain functional levels please refer to the links below.
• Domain controllers running the Microsoft Windows NT Server 4.0 operating system are NOT supported with Windows Server 2008.
• Servers running Windows NT Server 4.0 are NOT supported by domain controllers that are running Windows Server 2008, meaning you MUST have additional DCs running Windows 2000/2003 to support older NT 4.0 servers.
• The first Windows Server 2008 domain controller in a forest must be a global catalog server and it cannot be an RODC.

Installing Active Directory Domain Services (AD-DS)

In Windows Server 2008, unlike previous server operating Systems, there is an additional step that needs to be taken before running DCPROMO to promote the server to Domain Controller and installing Active Directory on it. This step is the installation of Active Directory Domain Services (AD-DS) role on the server. In fact, the AD-DS role is what enables the server to act as a Domain Controller, but you will still need to run DCPROMO the regular way.

Server Manager/Initial Configuration Tasks

Roles can and should be added from Server Manager (but they can also be initiated from the Initial Configuration Tasks wizard that auto-opens the first time you log on to the server).

1. Open Server Manager by clicking the icon in the Quick Launch toolbar, or from the Administrative Tools folder.
2. Wait till it finishes loading, then click on Roles > Add Roles link.



3. In the Before you begin window, click Next.


4. In the Select Server Roles window, click to select Active Directory Domain Services, and then click Next.


5. In the Active Directory Domain Services window read the provided information if you want to, and then click Next.


6. In the Confirm Installation Selections, read the provided information if you want to, and then click Next.


7. Wait till the process completes.


8. When it ends, click Close.


9. Going back to Server Manager, click on the Active Directory Domain Services link, and note that there's no information linked to it, because the DCPROMO command has not been run yet.


10. Now you can click on the DCPROMO link, or read on.
    1. To run DCPROMO, enter the command in the Run command, or click on the DCPROMO link from Server Manager > Roles > Active Directory Domain Services.
    
    
    2. Depending upon the question if AD-DS was previously installed or not, the Active Directory Domain Services Installation Wizard will appear immediately or after a short while. Click Next.
    
    Note: The Advanced features of DCPROMO will be discussed in a future article.
    
    
    3. In the Operating System Compatibility window, read the provided information and click Next.
    4. In the Choosing Deployment Configuration window, click on "Create a new domain in a new forest" and click Next.
    5. Enter an appropriate name for the new domain. Make sure you pick the right domain name, as renaming domains is a task you will not wish to perform on a daily basis. Click Next.
       Note: Do NOT use single label domain names such as "mydomain" or similar. You MUST pick a full domain name such as "mydomain.local" or "mydomain.com" and so on.
       The wizard will perform checks to see if the domain name is not already in use on the local network.
       
    6. Pick the right forest function level. Windows 2000 mode is the default, and it allows the addition of Windows 2000, Windows Server 2003 and Windows Server 2008 Domain Controllers to the forest you're creating. Read my "Understanding Windows Server 2008 Active Directory Domain and Forest Functional Levels" article for more information on that.
    
11. Pick the right domain function level. Windows 2000 Native mode is the default, and it allows the addition of Windows 2000, Windows Server 2003 and Windows Server 2008 Domain Controllers to the domain you're creating.

Note: If you select "Windows Server 2008" for the forest function level, you will Not be prompted to pick a domain function level. Read more about domain and forest function levels on my "Understanding Windows Server 2008 Active Directory Domain and Forest Functional Levels" article.

1. 
   
2. The wizard will perform checks to see if DNS is properly configured on the local network. In this case, no DNS server has been configured, therefore, the wizard will offer to automatically install DNS on this server.

Note: The first DCs must also be a Global Catalog. Also, the first DCs in a forest cannot be a Read Only Domain controller.

3. It's most likely that you'll get a warning telling you that the server has one or more dynamic IP Addresses. Running IPCONFIG /all will show that this is not the case, because as you can clearly see, I have given the server a static IP Address. So, where did this come from? The answer is IPv6. I did not manually configure the IPv6 Address, hence the warning. In a network where IPv6 is not used, you can safely ignore this warning.


4. You'll probably get a warning about DNS delegation. Since no DNS has been configured yet, you can ignore the message and click Yes.


5. Next, change the paths for the AD database, log files and SYSVOL folder. For large deployments, carefully plan your DC configuration to get the maximum performance. When satisfied, click Next.


6. Enter the password for the Active Directory Recovery Mode. This password must be kept confidential, and because it stays constant while regular domain user passwords expire (based upon the password policy configured for the domain, the default is 42 days), it does not. This password should be complex and at least 7 characters long. I strongly suggest that you do NOT use the regular administrator's password, and that you write it down and securely store it. Click Next.


7. In the Summary window review your selections, and if required, save them to an unattend answer file. When satisfied, click Next.


8. The wizard will begin creating the Active Directory domain, and when finished, you will need to press Finish and reboot your computer.

Note: You can automate the rebooting process by checking the Reboot on Completion checkbox.

DHCP Server

Introduction

Dynamic Host Configuration Protocol (DHCP) is a core infrastructure service on any network that provides IP addressing and DNS server information to PC clients and any other device. DHCP is used so that you do not have to statically assign IP addresses to every device on your network and manage the issues that static IP addressing can create. More and more, DHCP is being expanded to fit into new network services like the Windows Health Service and Network Access Protection (NAP). However, before you can use it for more advanced services, you need to first install it and configure the basics. Let’s learn how to do that.

Installing Windows Server 2008 DHCP Server

Installing Windows Server 2008 DCHP Server is easy. DHCP Server is now a “role” of Windows Server 2008 – not a windows component as it was in the past.
To do this, you will need a Windows Server 2008 system already installed and configured with a static IP address. You will need to know your network’s IP address range, the range of IP addresses you will want to hand out to your PC clients, your DNS server IP addresses, and your default gateway. Additionally, you will want to have a plan for all subnets involved, what scopes you will want to define, and what exclusions you will want to create.
To start the DHCP installation process, you can click Add Roles from the Initial Configuration Tasks window or from Server Manager à Roles à Add Roles.

Figure 1: Adding a new Role in Windows Server 2008
When the Add Roles Wizard comes up, you can click Next on that screen.
Next, select that you want to add the DHCP Server Role, and click Next.

Figure 2: Selecting the DHCP Server Role
If you do not have a static IP address assigned on your server, you will get a warning that you should not install DHCP with a dynamic IP address.
At this point, you will begin being prompted for IP network information, scope information, and DNS information. If you only want to install DHCP server with no configured scopes or settings, you can just click Next through these questions and proceed with the installation.
On the other hand, you can optionally configure your DHCP Server during this part of the installation.
In my case, I chose to take this opportunity to configure some basic IP settings and configure my first DHCP Scope.
I was shown my network connection binding and asked to verify it, like this:

Figure 3: Network connection binding
What the wizard is asking is, “what interface do you want to provide DHCP services on?” I took the default and clicked Next.
Next, I entered my Parent Domain, Primary DNS Server, and Alternate DNS Server (as you see below) and clicked Next.

Figure 4: Entering domain and DNS information
I opted NOT to use WINS on my network and I clicked Next.
Then, I was promoted to configure a DHCP scope for the new DHCP Server. I have opted to configure an IP address range of 192.168.1.50-100 to cover the 25+ PC Clients on my local network. To do this, I clicked Add to add a new scope. As you see below, I named the Scope WBC-Local, configured the starting and ending IP addresses of 192.168.1.50-192.168.1.100, subnet mask of 255.255.255.0, default gateway of 192.168.1.1, type of subnet (wired), and activated the scope.

Figure 5: Adding a new DHCP Scope
Back in the Add Scope screen, I clicked Next to add the new scope (once the DHCP Server is installed).
I chose to Disable DHCPv6 stateless mode for this server and clicked Next.
Then, I confirmed my DHCP Installation Selections (on the screen below) and clicked Install.

Figure 6: Confirm Installation Selections
After only a few seconds, the DHCP Server was installed and I saw the window, below:

Figure 7: Windows Server 2008 DHCP Server Installation succeeded
I clicked Close to close the installer window, then moved on to how to manage my new DHCP Server.