The Domain Name System (DNS) is the Internet version of the Yellow Pages. In the good old days, business addresses you needed were looked up in the yellow pages. The DNS is exactly the same. However, you don’t really have to look up: your computer connected to the Internet will do it for you. This way your computer knows where to find Google or DMTwebhsoting.com.
In order for two computers in an IP network to be able to communicate with each other, the protocol stipulates that they need an IP address. Think of an IP address as a street address – in order for a computer to “find” another, it needs to know the number of the other computer. Since most people are better at remembering names (e.g. www.DMTwebhosting.com ) – than numbers (140.169.32.000), they need a program that computers can use to translate names into IP addresses.
The program for translating names into numbers and vice versa is called “DNS” or Domain Name System. A computer that runs DNS is called a “DNS server”. Without DNS, we would have to remember the IP address of every server we want to connect to – what a fun.
This is how DNS works
DNS is such an integral part of the internet, and it’s important to understand how it works.
Think of DNS as a phone book, but instead of associating people’s names with their addresses, the phone book assigns computer names to IP addresses. Each link is referred to as a “DNS record”.
There are countless computers on the Internet, so it makes no sense to put all the records together in one big book. Instead, the DNS is organized into smaller books or domains. Domains can be very large so that they are further divided into smaller books, so-called “zones”. All books are not stored on a single DNS server – that would be impractical.
Instead, there are many DNS servers that store all of the DNS records for the Internet. Any computer that wants to know a number or name can ask its DNS server, and its DNS server knows how to query – or query – other DNS servers when it needs a record. When a DNS server queries other DNS servers, it performs an “upstream” query. Queries for a domain can be “upstream” until they lead back to the responsible server of the domain or to the “authoritative name server”.
An authoritative name server is a place where administrators manage server names and IP addresses for their domains. Whenever a DNS administrator wants to add, change, or delete a server name or IP address, he makes a change to his authoritative DNS server (sometimes referred to as the “master DNS server”). There are also “slave” DNS servers. Copies of the DNS entries for their zones and domains are located on these DNS servers.
The four DNS servers that load a website
- DNS recurser: The DNS recurser is the server that responds to a DNS request and asks another DNS server for the address or has already saved the website’s IP address.
- Root name server: A root name server is the name server for the root zone. He responds to direct requests and can return a list of authoritative name servers for the corresponding top-level domain.
- TLD name server: The top-level domain server (TLD) is one of the high-level DNS servers on the Internet. When you search for www.DMTwebhosting.com, the first answer is a TLD server for “.com”. Then DNS searches for “DMTwebhosting“.
- Authoritative name server: The authoritative name server is the end station of a DNS query. The DNS entry for the request is on the authoritative name server.
Types of DNS services
There are two types of DNS services on the Internet. Each of these services handles DNS queries differently depending on the function.
- Recursive DNS resolver: A recursive DNS resolver is the DNS server that responds to the DNS query and searches for the authoritative name server or a cached DNS result for the requested name.
Authoritative DNS server: An authoritative DNS server stores the DNS request. So if you ask an authoritative DNS server for one of its IP addresses, it doesn’t have to ask another server. The authoritative name server is the last resort for these names and IP addresses.
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