What is DNS (Domain Name System)

DNS is the fundamental component of internet services, which is used for resolving ip address of a specific url such and www.sonicvision.in. DNS act as directory for internet which help computers, network devices and users to locate each other in the internet world.

When you enter a domain name in a web browser, the browser uses DNS to find the corresponding IP address of the server hosting that website. The DNS process involves several steps, including querying authoritative DNS servers, caching, and resolving the domain to an IP address.

DNS Zones

A DNS zone essentially represents a specific part of the overall DNS namespace. It's a unit of administration, and each zone is hosted on a DNS server. This server is entrusted with maintaining the resource records associated with the zone and responding to DNS queries pertaining to that particular segment of the namespace.

For instance, envision a scenario where you want to resolve the domain www.sonicvision.in to its corresponding IP address. The DNS server that holds authoritative control over this specific translation process is said to host the sonicvision.in zone. Within this zone, you'd find the necessary resource records, like the A record associating the domain with its IP address.

Type of DNS Zones

• Primary Zone

• Secondary Zone

• Stub Zone

• Reverse lookup zone

Primary zones

A DNS server that hosts a primary zone serves as the primary repository of information for that specific zone. It stores the relevant zone data either in a local file or within Active Directory Domain Services (AD DS). When it comes to tasks such as creating, modifying, or removing resource records, the primary zone is the authoritative source. On the other hand, secondary zones function as read-only replicas of primary zones. They contain copies of the data from primary zones and do not permit direct modifications to the zone content.

Upon deploying Active Directory, an associated DNS zone linked to your organization's AD DS domain name is automatically generated. By default, this AD DS DNS zone undergoes replication to any other domain controller functioning as a DNS server within the domain. Additionally, there's the option to configure Active Directory Integrated DNS zones for replication across all domain controllers within an AD DS forest or specific domain controllers within a particular AD DS domain partition.

Secondary zone

A secondary zone functions as a read-only replica of a primary zone. In the case where a DNS server hosts a secondary zone, it acts as a secondary source for information concerning that particular zone. The data for this zone on the server is obtained from another remote DNS server computer, which serves as the primary host for the zone. To stay current, this DNS server must have network connectivity to the remote server, which provides updates about the zone.

Because a secondary zone is essentially a duplicate of a primary zone hosted elsewhere, it doesn't have the capability to be stored in Active Directory Domain Services (AD DS) as an Active Directory Integrated zone.

Stub zone

A stub zone exclusively holds details about the authoritative name servers for a specific zone. The DNS server hosting this zone retrieves its information from another DNS server that serves as the primary host for the zone. To accomplish this, the DNS server must be able to connect to the remote DNS server over the network to obtain and copy the authoritative name server information associated with the zone.

Reverse lookup zones

In the majority of Domain Name System (DNS) lookups, clients commonly execute a forward lookup. This type of search relies on the DNS name of another computer, as stored in a host (A) resource record. The query anticipates an IP address as the resource data for the response provided.

DNS additionally facilitates a reverse lookup procedure wherein clients utilize a known IP address to retrieve a computer name associated with that address. This reverse lookup is essentially a inquiry like, "Could you provide the DNS name corresponding to the computer utilizing the IP address 192.168.10.20?"