The Domain Name System (DNS) is the phonebook of the internet. It is a hierarchical and distributed naming system that translates human-readable domain names into machine-readable IP addresses. This allows us to easily access websites by typing in their domain names, rather than having to remember their IP addresses.
For example, instead of having to remember the IP address 192.0.2.1, we can simply type in www.webstax.com.au and our browsers will automatically translate that domain name into the IP address.
DNS works by using a distributed network of servers. When a user types in a domain name, their computer first sends a query to a DNS resolver. The DNS resolver then queries a DNS server, which looks up the domain name in its database. If the domain name is found, the DNS server returns the IP address of the website to the DNS resolver. The DNS resolver then returns the IP address to the user’s computer, which then uses the IP address to connect to the website.
DNS is a critical part of the internet infrastructure. Without DNS, it would be much more difficult to access websites. We would have to remember long and complicated IP addresses, and it would be much more difficult for computers to find websites.
How DNS works in detail
The DNS system is hierarchical. This means that there are different levels of DNS servers, each of which is responsible for a different part of the domain name space.
The top-level domain (TLD) servers are the root servers. There are only 13 root servers in the world, and they are responsible for storing the mapping between TLDs and their respective top-level domain name servers.
The top-level domain name servers are responsible for storing the mapping between domain names and IP addresses. These servers are organised into zones, and each zone is responsible for a different part of the domain name space.
When a user types in a domain name, their computer first sends a query to a DNS resolver. The DNS resolver then queries a root server. The root server returns the IP address of the top-level domain name server for the domain name in question.
The DNS resolver then queries the top-level domain name server, which returns the IP address of the domain name server for the domain name.
The DNS resolver then queries the domain name server, which returns the IP address of the website.
DNS security
DNS is a critical part of the internet infrastructure, and as such, it is a target for cyberattacks. Some common DNS attacks include:
DNS spoofing: This is a type of attack where the attacker sends fake DNS responses to a user’s computer. This can redirect the user to a malicious website.
DNS cache poisoning: This is a type of attack where the attacker corrupts the DNS cache on a user’s computer. This can redirect the user to a malicious website.
DNS hijacking: This is a type of attack where the attacker takes control of a DNS server. This can allow the attacker to redirect users to malicious websites.
There are a number of things that can be done to protect against DNS attacks, including:
Using a secure DNS provider
Using a firewall
Keeping your operating system and software up to date
Being careful about what websites you visit
Conclusion
DNS is a critical part of the internet infrastructure. It allows us to easily access websites by typing in their domain names, rather than having to remember their IP addresses. DNS is also a target for cyberattacks, so it is important to take steps to protect yourself from these attacks.
I hope this blog post has helped you understand what DNS is and how it works. If you have any questions, please feel free to get in touch to find out more.