Here is a list of some DNS terms that are essential for you to know and understand. They are going to help you manage your network more easily and be familiar with the terminology. So, let’s explain a little bit more about each one of the DNS terms!
DNS
The Domain Name System, or DNS for short, is a worldwide naming database. It translates domain names to IP addresses (IPv4 and IPv6). DNS is created with several levels in hierarchical order, and it is entirely decentralized. Thanks to it, we are not required to remember long and complex numbers (IP addresses) for each website. Instead, we use the domain names.
DNS server
DNS servers are two different types – authoritative name servers and recursive name servers.
- Authoritative name servers – They store DNS zones with zone files for the domains and answer DNS queries. Examples: TLD (Top Level Domain) servers and Root servers.
- Recursive name servers – They travel and ask different servers for an answer to the DNS queries.
DNS zone
The DNS zone is a small segment of the DNS namespace. Every zone could be maintained by a separate DNS administrator. That is why the Domain Name System is decentralized. Domain and zone are not the same things. A domain could hold a single DNS zone, or it also can have several.
DNS record
A DNS record is a simple text file that indicates an instruction for a domain. There are various DNS record types that have different purposes.
For instance, one shows the IP address (A or AAAA record), another shows a service, such as an email server that receives emails (MX record), and so on.
DNS query
The DNS query is the behind-the-scenes process of obtaining different DNS records of a domain, such as searching for the IP address (A or AAAA record). Users generate DNS queries when they want to visit a particular website.
Anycast DNS
Anycast DNS is a routing mechanism that speeds the DNS resolution process. It performs by setting an identical IP address in multiple name servers placed in diverse geographical locations. As a result, when a user makes a DNS query, it is going to receive an answer from the closest and available name server.
Dynamic DNS
Dynamic DNS is implemented for automatically updating your IP address every time it changes. In the most common scenario, the Internet Service Provider (ISP) switches your IP address to a different one. The reason for that is simple. They hold extensive networks, and such action helps them for easy management. It is a great idea to implement Dynamic DNS in case you have CCTV cameras for surveillance.
DNS cache
DNS cache is a useful mechanism for storing DNS data (DNS records) of domain names that are previously queried. A lot of different devices use such cache memory mechanisms, for instance, mobiles, computers, tablets, and DNS recursive servers. The main goal of DNS cache is to reduce the needed time for resolving a domain name. Due to the implementation of such a mechanism, DNS recursive servers do not perform the entire DNS lookup process each time a specific domain name is requested.
DNS propagation
DNS propagation refers to the amount of time that is needed for your new DNS changes to spread through the entire global network – the Internet. For instance, if you modify a DNS record (A or AAAA record) and change the IP address for a particular hostname. Usually, the DNS propagation process takes a couple of hours up to 72 hours to spread the new information in each server all around the world.