I work in the field of web hosting where we provide servers to host user sites.



Due to the numerous questions from both beginners and experienced users, I want to shed some light on the principles, aspects, and features of this branch of IT. I cannot guarantee a reduction in the number of questions, but it's worth sharing the knowledge.

Even if you don't use web hosting, the information provided can be informative. 

When you type a site's address (domain) into your browser, such as "dnray.com", your device sends a request to your internet provider's server. The server looks into its DNS cache, and if it cannot find the address, it accesses the root DNS server of the zone where the domain is located. The root server finds the IP address of the DNS hosting provider, which hosts the site on its servers, and transmits that information to the internet provider's server.

The internet provider then accesses the DNS of the hosting provider, receives the IP of the server hosting the site, and puts it in the database of its DNS cache. The ISP's server can then access the server of the hosting provider and retrieve the necessary data by the requested domain and transmit it back to the internet provider. The data is then transferred to the browser, which renders the website.

The DNS cache is used to unload the communication channels of the global network, but it has negative consequences. When a site is transferred to another server, a site visitor may not see it for some time because the DNS cache of their internet provider stores data about the old IP address of the site's domain name.

The speed of updating the DNS cache varies from internet service providers. On average, it takes six hours to update, but in large cities, updates occur more frequently (2-4 hours). I apologize for any confusion in translation from IT jargon to layman's terms. If you have any questions, please feel free to ask in the comments.

The domain names system is a multilevel and distributed system that stores information on each domain name on the Network. It is duplicated many times to ensure fault tolerance. In essence, it stores the domain name, the IP of the physical server where the site of the domain is located, the IP of servers of various services of the domain name, such as the mail server, and other service records.

Regarding "Different dns in the settings," I am unsure of its meaning, but I presume it refers to multiple ns servers in the domain settings. This duplication is necessary for fault tolerance, as if one ns server is unresponsive, another can take its place.

Having multiple ns servers has been a requirement for quite some time now. This is considered a necessary measure for safety and practicality. By using multiple servers, it becomes feasible to safeguard the server against unauthorized access. It's highly likely that in such instances, different dns are indeed various ns servers.

It's important to note that having several ns servers also allows for better load distribution. Additionally, if one server goes down, the other servers can take on the workload. Overall, using multiple ns servers is crucial in maintaining a resilient and secure network.

For beginners, it's advisable to introduce the concept of a hosts file. This would prevent them from purchasing domains and instead set up a web server locally, create virtual domains through hosts, and experiment with them.

However, if newcomers attempt to set up their DNS server, they may be susceptible to vulnerabilities. For instance, sending a small request can lead to a large response being sent to an unintended victim. With access to a list of improperly configured DNS servers, it's possible to carry out ddos attacks with relative ease. Therefore, it's essential to have a good understanding of DNS configuration before diving into setting up servers.

DNS cache plays a pivotal role in the efficient functioning of global network communication. When a user accesses a website, the browser first checks its local DNS cache to see if it already contains the IP address for the requested domain. If the required information is found in the cache, it eliminates the need for the browser to make a query to external DNS servers, thus saving time and reducing latency in loading the website.

Understanding DNS caching is crucial for web developers as it directly impacts website performance. By optimizing DNS configurations, developers can ensure that users' requests are directed to the closest DNS server with the necessary information already cached. This not only leads to quicker response times but also enhances overall user experience by minimizing delays in accessing web content.

In addition, effective DNS caching contributes to the optimization of the DNS infrastructure, reducing the load on global DNS servers and improving the overall reliability and speed of network communication across the internet.
It is essential to recognize the significance of DNS caching in creating and maintaining high-performance websites, ultimately contributing to seamless and efficient global network communication for users worldwide.