AD DNS

Active Directory (AD) relies on Domain Name System (DNS) to function properly. DNS in an AD environment is responsible for translating domain names into IP addresses so that resources (like computers, servers, and services) can communicate with each other. Specifically, AD uses DNS to locate domain controllers, manage replication, and support various other critical directory services.

Forward and Reverse Lookup Zones:

• Forward Lookup Zone: This zone allows DNS to resolve domain names (like server.example.com) to their corresponding IP addresses. It's used when a client needs to find the IP address of a server or service by its name.

• Reverse Lookup Zone: This zone does the opposite. It maps an IP address back to a domain name. It's used when a client needs to find the domain name associated with an IP address (for example, reverse DNS lookup).

Why It Is Compulsory to Configure Forward & Reverse Lookup Zones:

1. Correct Name Resolution: AD heavily depends on DNS for proper name resolution. Without forward and reverse lookup zones configured, domain controllers and other network resources may fail to resolve names correctly, disrupting communication across the network.

2. AD Functionality: AD services, such as locating domain controllers and services like Global Catalog, depend on proper DNS configuration. Without DNS, clients won't be able to authenticate, or locate resources like printers or shared files.

3. Replication: In a multi-domain controller setup, replication between domain controllers relies on DNS for finding and communicating with each other. Misconfigured DNS can cause replication failures.

4. Security and Troubleshooting: Reverse lookup zones also enhance security (e.g., verifying client IP addresses) and troubleshooting (e.g., identifying the source of a connection) by allowing easy resolution from IP to domain name.

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We will now be configuring windows AD DNS :

We will now create the Reverse lookup zones and configure Forward lookup zone to configure the FQDN resolution and functioning of AD DNS

We will keep the default selected values until here and now we have to enter the revers arpa IP address of the domain controller First 3 Network Bytes of the AD servers IP address and continue

We have now configured the reverse lookup zone and now we will update the PTR record of the forward lookup zone to sucessfully configure the FQDN resolution

Check the box to update the reverse PTR record and then apply and continue

Now we have configured the AD DNS and we will now check the resolution using nslookup utility built in under the DNS application

If the forward & reverse lookup is sucessfull then we have sucessfully configured the AD DNS onto our sever. Now we will configure the DHCP server inside your domain to issue and lease the IP Addresses to our AD clients in the next section