The Function of DNS in Web Browsing
When you use your web browser and you put in a website address like www.technomixt.com, you might think the browser sends a request directly to the site. In reality, there is an intricate machine effortlessly and completely hidden from you—Domain Name System (DNS). DNS provided an important service that allows faster, simpler and more user-friendly internet browsing. In fact, DNS is sometimes referred to as the "phonebook of the internet!"
What is DNS?
DNS stands for Domain Name System and is a hierarchical decentralized naming system for computers, services, or any resource connected to the internet or a private network. DNS translates user-friendly domain names (like google.com) into machine-readable IP (Internet Protocol) addresses (like 142.250.190.14). Computers communicate in numbers while we, humans communicate and remember through words. In this case DNS bridges that gap.
Without DNS, we would have to remember directory strings of numbers (IP addresses) for each website we visit—it would be unfathomable!
What Is the Process of DNS?
There are a number of steps that takes place when DNS resolution occurs:
1. User Input
When you enter a website URL into your browser, you activate a DNS query.
2. DNS Resolver
The DNS query goes to a DNS resolver (usually operated by your ISP) that will find the correct IP address.
3. Recursive Query
If the resolver does not already have the IP address cached, it will contact other DNS servers in order:
- Root DNS servers - The first step of the process that will point the query to the correct top-level domain (TLD) server.
- TLD servers - For domains, like .com, .org, or .net.
- Authoritative DNS servers - The authoritative DNS servers that make the final mapping between the domain name and the IP address.
4. Result Back to Browser
The server that resolves the domain name returns the IP address back to your browser. Your browser will then connect to the correct associated server and map out the website.
All of this occurs in milliseconds, speeding up efficient movement through browsing for the user.
Why is DNS important?
User Convenience: Rather than memorizing long IP addresses, users can simply type in easy to remember names like amazon.com.
Scalability: There are billions of websites, and the DNS can accommodate a very large amount of growth.
Redundancy and Speed: DNS is storing records in cache for already executed lookups, meaning users aren't repeating lookups too consistently, and this makes for a faster web experience.
Flexibility: Thanks to DNS we can change the IP address of a website without changing the domain name.
What about potential security with DNS?
While DNS is incredibly important, nothing is without risks:
DNS Spoofing (Cache Poisoning): DNS resolver is fooled into giving a false IP address causing the user to be redirected to malicious website.
DDoS Attacks: Disruption of websites by causing overload on DNS servers.
User Data: DNS queries are traditionally unencrypted, meaning that anyone can look over a user's shoulder.
As a response to some of these issues, newer protocols have been developed like DNSSEC (DNS Security Extensions) or DoH (DNS over HTTPS) that add addition layers of security.
DNS is one of the pillars of the internet. It is a translator, changing easy-to-remember domain names and in a numerical form (IP address), which computers can communicate with each other. The internet would be chaotic and unusable without DNS. As the web matures into a more secure and efficient internet, DNS will also change to more effectively deliver safe and easy experiences for users around the world.