DNS - Domain Name Server - Part 1

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When we open our browser and start to enter www.google.com or www.youtube.com and the page appears and we start search something and watching videos on that browser. Do you ever think about how this browser can understand the word www.google.com since we already know that our internet world uses IP addresses to communicate? 

We call this www.google.com or any other website name as the domain name and usually, we call it URL (Uniform Resource Locator - the link to access the website).

For easy understanding, we as humans also have a unique number which is our IC Number, let's say we don't have a name and use our IC number as our identification identity. How many people can remember other people's IC numbers? That's why we have the name for easy to remember and we have an IC number for our identity identification.

Same as the domain, the existing domain name usually comes with a unique IP address. For example, when we ping www.google.com and the result will show the unique IP address 78.83.4.159.

How does this domain have the IP address? To be more specific actually, the IP address is come first before the domain name. This means we need to have the static IP address and we can point to our domain name. This is done by Domain Name Server or DNS.


DNS is created to make human easy to remember the website name and if we are using the IP address to access our website is going to be very troublesome. maybe we can remember 1 or 10 website IP addresses but if we have a lot of IP addresses is going to be difficult for humans to remember. That is why we use the name of a network interface instead of an IP address. 

The relationship between the name of a computer and an IP address is defined in the Domain Name System (DNS) database. The DNS database is distributed worldwide. The DNS database contains individual records that are called Resource Records (RR). Individual parts of the DNS database called zones are placed on particular name servers. DNS is a worldwide distributed database.

DNS uses both UDP and TCP protocols for the transport of its queries/answers. It uses port 53 for both protocols (i.e., ports 53/UDP and 53/TCP). Common queries such as the translation of a name to an IP address and vice versa are performed by UDP protocol. Queries transporting zone transfer data occur between the primary and secondary name servers and are transported by TCP protocol. 

DNS translates human queries into numbers using a system known as IPv4 or IPv6. With IPv4, the numbers are 32-bit integers that are expressed in decimal notation.IPv6, which was created to address concerns about the internet running out of IPv4 addresses, uses 128-bit-sized numbers, compared to 32-bit numbers with IPv4. There are 340 trillion possible IPv6 addresses.

Resources.

  • https://developers.google.com/speed/public-dns/docs/using
  • https://ns1.com/resources/dns-protocol#:~:text=What%20is%20the%20DNS%20Protocol,instead%20of%20numeric%20IP%20addresses.
  • https://docs.oracle.com/en-us/iaas/Content/ContEng/Tasks/contengconfiguringdnsserver.htm

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