English
Back to glossary

DNS

What is DNS?

Every device associated with the Internet has a one-of-a-kind IP address that different machines use to discover that particular gadget. In that sense, DNS servers get rid of the requirement for people to retain IP locations! Basically, instead of memorizing an IP number, all you have to do is remember a simple IP address like google.com.

How Does it Work?

The entire DNS process includes changing a hostname (for example, www.example.com) into a PC-friendly IP address, (for example, 192.147.1.1). An IP address is given to every device connected with the Internet. When a user wants to stack a site page, the word form of the IP address needs to be converted into numbers - and that’s exactly what the DNS does. 

Types of DNS servers

The following are the different types of DNS servers:

  • DNS Resolver
  • DNS Root Server
  • Authoritative Name Server

Types of DNS queries

The following are the different types of DNS queries

  • Recursive
  • Iterative
  • Non-recursive

Types of DNS Record Types

Commonly used record types

  • A (Host address)
  • AAAA (IPv6 host address)
  • ALIAS (Auto resolved alias)
  • CNAME (Canonical name for an alias)
  • MX (Mail eXchange)
  • NS (Name Server)
  • PTR (Pointer)
  • SOA (Start Of Authority)
  • SRV (location of service)
  • TXT (Descriptive text)


Less commonly used record types:

  • AFSDB (AFS DataBase location)
  • ATMA (Asynchronous Transfer Mode address)
  • CAA (Certification Authority Authorization)
  • CERT (Certificate / CRL)
  • DHCID (DHCP Information)
  • DNAME (Non-Terminal DNS Name Redirection)
  • HINFO (Host information)
  • ISDN (ISDN address)
  • LOC (Location information)
  • MB, MG, MINFO, MR (mailbox records)
  • NAPTR (Naming Authority Pointer)
  • NSAP (NSAP address)
  • RP (Responsible Person)
  • RT (Route through)
  • TLSA (Transport Layer Security Authentication)
  • X25 (X.25 PSDN address)

 

Advantages of DNS

The advantages of DNS include that:

  1. They link a new IP address to the host’s IP address changes.
  2. The DNS makes domain names easier to remember than an actual IP address
  3. They allow organizations to create a domain name hierarchy


Disadvantages of DNS

When it comes to disadvantages, there are, in fact, many disadvantages to DNS! Firstly, the domain name registry can only be controlled by ICANN. This goes against the idea of net neutrality - an ideal that is becoming more and more important to web developers worldwide. 

Secondly, DNS makes it very easy for hackers to do their job! This is because DNS queries do not indicate who initiated them, and that’s why the server-side can only see the IP address. Why is that a problem? When IP addresses can easily be manipulated by hackers!

 

Final Words

The DNS works great in terms of simplifying the whole IP address resolution process. However, it is not a perfect process by any means and can, in fact, be manipulated in plenty of ways!