DNS - Configuring Forward and Reverse Lookup Zones

Things you should know 

Domain Name System (DNS) refers to the domain name resolution mechanism, which allows using domain names, instead of IP addresses to access a domain. E.g. you can use http://facebook.com/ instead of http://66.220.149.11/ to access the facebook website.

The process of converting a DNS name to an IP address is known as DNS name resolution process.

A forward lookup zone is a DNS zone in which hostname to IP address relations are stored. When a computer requests the IP address of a specific hostname, the forward lookup zone is queried and the result is returned.

A reverse lookup zone does just the opposite. When a computer requests the hostname of an IP address, the reverse lookup zone is queried and the result is returned.

Practical Implementation

Open DNS Window and uncheck IPv6

Start - Administrative Tools- DNS

Right Click on Server

Select Properties

Select only the following IP Address

Uncheck IPv6 entry

OK

DNS - Uncheck IPv6

Configuring forward lookup zone

Expand Server Node

Right Click on Forward Lookup Zones

New Zone

DNS - Opening New Zone Wizard

New Zone wizard will appear. Give Next. Now you have to select the zone type.  

What is a zone? What are its types?

A zone is an entity that stores the records (information) about the objects that it manages. A record consists of a domain and its corresponding IP address. There are three types of zones. 

• Primary Zone:  You can add and alter resource records in a primary zone.

• Secondary Zone: It contains read-only records obtained from a primary DNS zone.

• Stub Zone:  Stub zone in Microsoft server 2008 is a specialized version of a secondary zone. A stub zone contains only those resource records that are necessary to identify the authoritative DNS server for that zone. 

As we are creating a new zone for the first time, hence select primary zone.

DNS - Zone Type

Keep the option Store the Zone in Active Directory checked and give next.

Next is Zone replication scope.

Zone Replication Scope	Description
All DNS servers in the Active Directory forest	Replicates zone data to all DNS servers running on domain controllers in the Active Directory forest. Usually, this is the broadest scope of replication.
All DNS servers in the Active Directory domain	Replicates zone data to all DNS servers running on domain controllers in the Active Directory domain. This option is the default setting for Active Directory-integrated DNS zone replication in the Windows Server 2003 family.
All domain controllers in the Active Directory domain	Replicates zone data to all domain controllers in the Active Directory domain. If you want Windows 2000 DNS servers to load an Active Directory zone, this setting must be selected for that zone.

We will keep the default and give next. 

Provide the zone name. e.g. ciots.com

Select - Allow both nonsecure and secure dynamic updates and give next and finish.

An entry will be created for ciots.com in the forward lookup zones.

Select ciots.com, right click on it and select New Host. A host is used to resolve an IP address to a device in a domain. The device can be a computer, printer etc. 

DNS - Adding a new Host

The New Host window will appear.

Now consider for the domain ciots.com we have the FTP server at location 192.168.1.12 for which we have to create the DNS forward lookup entry. 

Enter name ftp and provide the IP address as 192.168.1.12

DNS - Configuring new host

Finally click on Add Host. With this we have completed forward lookup entry.

Video Tutorial Creating a DNS Forward Lookup Zone

Configuring reverse lookup zone


Right click on Reverse Lookup Zones and Select New Zone. The settings will be nearly same as the configuration settings of forward lookup zone.

Select IPv4 Reverse Lookup Zone – Next
Enter Network ID as 192.168.1 – Next
Allow both nonsecure and secure dynamic updates – Next – Finish

Right Click on the node created and select New Pointer (PTR)

DNS - Adding new PTR

Enter host IP address: 192.168.1.12

Host name: browse and select ftp.ciots.com

OK

Now we will use the nslookup command to verify these entries.

Verify Forward Lookup entry

In the command prompt, enter nslookup ftp.ciots.com , this will give the associated IP address.

Verify Reverse Lookup entry

In the command prompt, enter nslookup 192.168.1.12 , this will give the associated host name.

DNS - nslookup command

Video Tutorial Creating a New Reverse Lookup Zone