DNS – Domain Name System: What is it?
The Domain Name System, commonly known as DNS, is a fundamental internet component, yet it remains a mystery to many users. Simply put, DNS is like the internet’s phonebook, translating human-friendly domain names such as www.greencloudvps.com into IP addresses that computers use to identify each other on the network. Without DNS, browsing the web would be cumbersome, requiring us to remember complicated numerical addresses for every website we want to visit.
In this article, we will demystify DNS, explaining its importance, how it works, and its critical role in our everyday online activities. Whether you’re a beginner looking to understand the basics or a tech enthusiast seeking deeper insights, this guide will provide you with a comprehensive understanding of the DNS protocol.
What is DNS – Domain Name System?
Simply put, Domain Name System (DNS) is the phone book of the internet. It’s the system that converts website domain names (hostnames) into numerical values (IP address) so they can be found and loaded into your web browser.
This happens because machines don’t understand site names like we do. A website written as greencloudvps.com is a way for us, as humans, to remember web pages while the servers they’re stored on refer to them as numbers.
It works in the background, and it’s not something the average internet user will need to worry about much. But without it, your browser wouldn’t know where to point your web page request, and finding the information you need would be a much more arduous process.
How does it work?
When users enter a domain name into the address bar of their web browser, they will be taken to the site they want to visit. However, this seemingly instant task consists of several steps known as the DNS lookup or DNS resolution process.
Here’s an example of what the DNS resolution process is typically like to illustrate better how DNS works. You want to be taken to Greencloudvps’s website, so you enter the domain name greencloudvps.com into the web browser’s address bar. What you’re doing here is submitting a DNS request. Next, your computer will check whether it already stored a DNS entry of the domain you submitted locally. A DNS record is an IP address that matches the fully-qualified domain name.
First, your computer will search its host’s file and cache. The host file is a plain text file that maps hostnames to IP addresses in an operating system, while the cache is temporary data stored by a hardware or software component. Matching IP addresses for the DNS service are commonly found in your browser cache or internet service provider (ISP) cache.
However, if no matching IP address is found in your host file and cache, other additional steps will be added to the DNS resolution process.
Types of DNS Server
- A recursive DNS server will query other DNS servers for the answer to a given question. If it doesn’t have the answer, it will query additional servers until it finds one that does. This type of server is typically used by private users and small businesses.
- An authoritative DNS server is responsible for responding to DNS queries for a specific domain and delivering the website in response to a browser request. This type of server is typically used by large organizations and Internet service providers and will
The role of DNS in simplifying internet navigation
DNS plays a crucial role in making the internet accessible and user-friendly. Imagine if, instead of typing “www.google.com,” you had to remember and enter “172.217.16.196” every time you wanted to perform a web search. DNS abstracts these complex numerical IP addresses, allowing us to use easy-to-remember domain names.
Moreover, DNS enables:
- Scalability: By distributing the load across multiple servers, DNS ensures that no single server becomes a bottleneck, thus supporting the vast number of queries generated by billions of internet users.
- Redundancy: Multiple DNS servers provide resilience against failures, ensuring that internet services remain accessible even if some servers go down.
- Load balancing: DNS can distribute traffic across multiple servers hosting the same content, improving performance and reliability.
Still asking “What is it needed for?” The simple answer is this: Think of DNS as a cornerstone of internet infrastructure, allowing us to use the URLs and domain names that we all depend on when navigating the internet and sending emails.
Domain Name Elements
You may redirect your DNS using the different record types that make up a domain. Which to use depends on the information you’re trying to enter. You can set up A, AAAA, CNAME, SRV, NS, TXT, MX, MXE, and URL redirect records.
- An A Record directs your domain name to an individual server through its IP address. Each domain name has a primary A record, the information held within the A record controls what your domain name does when someone visits your website. An A record (Address record) allows you to associate a domain name or subdomain with an IP address (32-bit).
- An AAAA Record works similarly to an A record except it lets you direct your domain to a 128-bit Ipv6 address.
- The CNAME is used to redirect your domain or subdomain to the IP address of the destination hostname. This record identifies a domain name as an alias of another name. The benefit is, that if the IP of the destination hostname changes, you won’t need to update your DNS records because the CNAME will have the same IP.
- An MX Record is used to direct mail to the appropriate mail server. MX records must point to a hostname and never directly to an IP address.
- The NS Record lets you delegate a subdomain to a nameserver associated with the domain. This is helpful if your subdomain is hosted separately from the domain name.
Advantages and Disadvantages of DNS
DNS has lots of positive aspects and relatively few disadvantages. Most of the kinks have been worked out over the decades. Here are a few considerations:
The Advantages:
- Well-tested and well-understood by network professionals
- Works with services such as email and Active Directory
- Works on all common computer operating systems
- Work with IPv6 using AAAA records
- Many security options are available to protect the service and its resources
The Disadvantages:
- Quickly becomes complex in large, distributed networks
- Administrators must deliberately take steps to secure it
Learning how to troubleshoot DNS is essential. If you can identify and diagnose name-resolution issues and then take appropriate steps to correct them, you can address common network problems quickly. Tools such as nslookup, dig, and host allow you to generate name resolution queries to test DNS.
DNS operates in nearly every network, making your skill and experience with it a benefit at any organization.
In summary
Understanding DNS (Domain Name System) is crucial for navigating the internet effectively and ensuring secure, efficient access to web services. By following these guidelines, users and administrators can ensure robust DNS configurations, enhancing both the performance and security of their internet experience.