Introduction
The internet is a vast network of interconnected devices, each identified by a unique IP address. To make these addresses more human-friendly, we use domain names like www.netflix.com. But how does your computer know which IP address corresponds to that domain name? This is where DNS resolution and caching come into play.
The Role of the Web Browser
When you enter a URL in your web browser, it initiates a process to translate that domain name into an IP address. This process starts with the browser checking various caches for this information.
Checking the Caches
The browser first checks its own cache to see if it has a record of the IP address for the domain. If it doesn’t find it there, it checks the operating system’s cache, then the network’s cache, and finally the ISP’s cache. If the IP address is found in any of these caches, the webpage is loaded.
DNS Resolution
If the IP address is not found in any of the caches, the browser initiates a DNS resolution process. This involves a three-way handshake with the Root Server. The Root Server has a directory of all top-level domains (like .com, .in, .org, etc.) and can direct the browser to the server that holds the IP address information for the specific domain.
Conclusion
Understanding the process of DNS resolution and caching is crucial for anyone working with web technologies. It not only helps in troubleshooting network issues but also in optimizing web performance. By caching IP addresses, browsers can load webpages faster, providing a better user experience.