In this article, we will explore the inner workings of a Local DNS (Domain Name System) server and understand how it plays a crucial role in connecting our devices to websites on the internet.
What is DNS?
DNS, short for Domain Name System, is a decentralized system that converts human-readable domain names, like www.example.com, into IP addresses, which are the unique numerical addresses assigned to each device connected to the internet.
When you enter a URL into your web browser, such as www.com, your computer needs to know the corresponding IP address to establish a connection with that website. This is where DNS comes into play.
How Does DNS Work?
When you enter a URL into your web browser and hit enter, your device sends a request to a DNS server. There are two types of DNS servers: Recursive resolvers and Authoritative name servers.
Recursive Resolvers
A recursive resolver is the first link in the chain of DNS resolution. It receives the initial request from your device and starts looking for the IP address associated with the domain name you entered. If it doesn’t have the information in its cache memory, it contacts other DNS servers to find the answer.
The recursive resolver follows a hierarchical structure while searching for information. It first contacts one of thirteen root name servers distributed worldwide. These root servers provide information about top-level domains (TLDs) such as .com, .org, .net., etc.
- Example: If you entered www.com, it would contact one of these root name servers to find out which TLD server handles requests for .com domains.
The recursive resolver then contacts the TLD server responsible for handling requests for . The TLD server provides the IP address of the authoritative name server responsible for the specific domain.
- Example: In our case, it would contact the TLD server for .com domains to find out which authoritative name server has information about example.com.
Finally, the recursive resolver contacts the authoritative name server for example.com and retrieves the IP address associated with www. It stores this information in its cache memory for future use.
Authoritative Name Servers
Authoritative name servers store DNS records that contain information about specific domains. These servers are responsible for providing IP addresses associated with domain names.
When a recursive resolver contacts an authoritative name server, it provides the requested IP address, which is then passed back to your device, enabling it to establish a connection with the desired website.
The Role of a Local DNS Server
A Local DNS server, also known as a caching resolver or a DNS forwarder, exists on your local network.
When you connect to the internet, your device usually receives the IP address of your ISP’s (Internet Service Provider) DNS server automatically. However, you can configure your device or router to use a different DNS server – that’s where a Local DNS server comes in.
A Local DNS server caches recently accessed domain names and their corresponding IP addresses. So when you visit a website multiple times or other devices on your network access the same website, instead of going through the entire resolution process again and again, your local DNS server can quickly provide the required information from its cache memory.
- Example: If you visit www.com and then revisit it later, your local DNS server can provide the IP address directly without going through the recursive resolution process.
This caching mechanism not only speeds up the browsing experience but also reduces the load on the overall DNS infrastructure by minimizing redundant requests.
Conclusion
A Local DNS server acts as a middleman between your device and the internet, efficiently resolving domain names into IP addresses. It plays a crucial role in speeding up browsing, reducing network traffic, and improving overall internet performance on your local network.
Understanding how a Local DNS server works can help you optimize your network settings and choose the right DNS server for your needs. So next time you type in a URL and reach a website instantly, remember that it’s all thanks to the efficient functioning of DNS servers behind the scenes!