What is DNS (Domain Name System)
What is DNS?
DNS, an abbreviation of the Domain Name System, makes your Internet browsing without much trouble. The DNS functions as an interpreter between humans, who talk words, and computers, who “talk numbers”. These numbers are functionally similar to telephone numbers and are known as IP addresses. Domain Name System or DNS is a central part of the Internet. We use it to translate numbers that computers understand like 22.214.171.124 (IPv4) or newer IP addresses such as 2a00:1450:4007:805:0:0:0:2004 (IPv6) to something we can read, for example, bieneit.de.
This translation is called a DNS lookup
How DNS works?
When you type in your web browser a website domain (bieneit.de), your device needs the IP (126.96.36.199) to actually go there. It gets it by sending a query to a DNS server – a special kind of server that has a database of IP addresses and their associated hostnames. This communication look like this:
- Your device:“What is the IP address of bieneit.de?”
- DNS server:“It’s 188.8.131.52”
- Your deviceaccesses bieneit.de.
- You use your favorite search engine without ever thinking of the inner-workings of the internet.
If only it were that simple. Your query “What is the IP address of bieneit.de?” actually goes through multiple DNS servers before coming back to you with an answer. Imagine that the internet is a colossal virtual highway system. To visit a website, you have to get in a car and drive to your destination without any map or GPS. You would get lost at the first crossroads you hit – but that’s where DNS saves the day. Like a traffic officer, the DNS server directs you towards the next crossroads, where another DNS server directs you to the next crossroads until you reach your final destination.
Eventually, you will be led to an authoritative nameserver that provides the IP address you’re looking for.
Types of DNS Servers
There are several types of DNS Servers that help us perform a DNS lookup:
- Authoritative nameserver
This server holds the records for specific domain names. Like IP addresses and more. This type of nameserver is often run by hosting companies holding the websites themselves or by domain registrars.
- DNS recursive resolver
A server that is often managed by our ISPs, wireless carriers or third-party providers like Google, OpenDNS, and Cloudflare with its new service. The user usually has to set up a computer to use a third-party provider. The client asks this server for the IP address. This server does not hold the IP address so it has to ask other servers. When it gets an answer, the client gets the IP address of the site (or an error if the address could not be found).
- Root nameserver
These nameservers hold information about TLDs. They know where to look for information on sites that are under some TLD as .me, .com, .org etc. There are 13 sets of these root servers. They are called “A Root”, “B Root”, all the way to “M Root”. These name servers are all operated by different operators like Verisign, Cogent Communications, Netnod, University of Maryland etc.
- TLD nameserver
These nameservers hold the information about servers that hold specific domain name information or Authoritative nameservers. These are often called NS records. There are multiple companies and organizations that operate these nameservers. For example, Afilias for .me, .org etc., and Verisign for .com, .net etc.
DNS records act as instructions for the DNS server, so it knows which domain names each IP address is associated with. DNS records contain a lot of different syntax and commands for how the server should respond to the request. Some of the most common forms DNS records are:
- A record
This record holds the IPv4 of the domain name.
- AAAA record
This record holds the IPv6 (just a newer type of an IP address) of the domain name.
- MX record
This record lists email exchange servers that are to be used with the domain.
- TXT record
A catch-all record. It is intended to provide textual information about the domain name to external services. CNAME record: Canonical name. Used to redirect one domain to another.
What Are Name Servers?
If you have your own Internet domain you need to know that the name servers are the portion of your DNS records that enable people to use your domain name to access your site, rather than your complex IP address. Your name servers are an aspect of your registrar, and the purpose is to point your domain to the place where your site is being hosted. Changing your name servers allows you to change your web host without having to move your domain to a new registrar. Name servers can also be referred to as DNS servers, which can lead to some confusion of the two terms.
At the end, you need to know that research has shown that the first quarter of 2018 closed with approximately 333.8 million domain name registrations across all top-level domains (TLDs), an increase of approximately 1.4 million domain name registrations, or 0.4 percent, compared to the fourth quarter of 2017. Domain name registrations have grown by approximately 3.2 million, or 1.0 percent, year over year.
The path from the domain name to the IP address look like this