If you own or plan to start an online business, congrats! You got an ambitious and exciting mission that only the bravest and smartest can comply with. But, to make it, there’s an inevitable step: you must conquer the DNS world first!
Start your ninja training now, understanding some of its basic DNS terms.
Domain Name System (DNS).
The first on the list of our DNS terms, of course is the Domain Name System. It is the great solution to make the use of the Internet as easy as it’s now. It’s a very helpful database that translates domain names into their corresponding IP addresses to be found and loaded.
Before finding a host was done through its IP address, a numerical string like 22.214.171.124 (IPv4) or 1580:cb11:2045:1::c530:d6a1 (IPv6).
Numbers are great and easy for machines to communicate and execute their processes, but this was not too simple for humans. Imagine memorizing the IP address of every website you want to visit! Therefore, this system was created for hosts to have catchy names, easy for humans to remember, like example.com.
The second one in our list of DNS terms is the domain name. It is a line of text for mapping an IP address. It’s used for accessing websites by typing easy and memorable names instead of their corresponding numerical addresses, called IP addresses. You type example.com, instead of 1580:cb11:2045:1::c530:d6a1.
Fully Qualified Domain Name (FQDN) explained.
An IP address is a line of numbers, divided by periods, used to identify websites, computers, and routers. Every IP address is unique, and it’s mathematically created and allocated by IANA, the Internet Assigned Numbers Authority.
IP addresses hold location information vital for finding and identifying machines. Besides, they are needed for devices to communicate and exchange information on a network.
A DNS query, also known as a DNS request, is a petition of DNS information that a user sends to a DNS server via his or her device and browser. The most common DNS query is the one you send every time you want to visit a website. You type a domain name, and a DNS query to get the associated IP address of such domain is sent to a DNS server. Without this information, the website can’t be loaded for the user.
The DNS records are simple text files hosted on the authoritative name server and have instructions about the domain like its IP address, the services that a host uses, records for authentication purposes, and more.
An example of one is the A record that connects the domain name and its IPv4 address.
Authoritative name server.
An authoritative name server is the type of server that holds all the DNS records of a domain name and other web resources. Once a DNS query has been sent, a process to get the necessary IP address for loading a domain name starts. And an authoritative name server is the last server that participates in such a process. It’s the one that will deliver the A record that contains the IP address.
A recursive server has a searcher vocation. Every time a DNS query is sent from a user’s device, this server will take it, and it will start a searching process in which it will query different servers until it gets the DNS data needed to answer such query. When it looks for the associated IP address of a domain name, its goal is to reach the authoritative name server, to finally obtain the A record that contains that IP address.
Recursive servers can cache the results of their searches for a period of time defined by the TTL (time-to-live) of every DNS record. If the information queried is not saved in its cache anymore, it has to do the whole searching process again by querying other servers.
DNS has its own and very specific rules and processes. However, if you want to survive and successfully complete your mission, this is a good starting point! Success, DNS ninja!