12/12/2023
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What Is DNS?

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Contents

  1. Introduction
  2. How DNS Works
  3. DNS Technology Scheme
  4. DNS Server Operation
  5. What is a DNS Zone?
  6. Geo-DNS
  7. Attacks on DNS Servers and Methods of Protection
  8. Conclusion

Introduction

DNS, or Domain Name System, is a technology that enables browsers to locate a domain by its name using DNS servers. Let's delve into what DNS is in reality and how DNS servers work.

How DNS Works

The Domain Name System (DNS) is a fundamental technology of the Internet environment responsible for storing and processing domain address data. This tool facilitates the transformation of domain names into IP addresses. IP addresses enable the location of sites, servers, and other devices. Thus, the DNS system serves as a kind of "phone book" that stores a database of domain names and their corresponding addresses.

The operation of DNS technology is facilitated by a DNS server. This can be either hardware or software that grants access to the domain name system, stores data regarding the mapping of specific IP addresses to their corresponding domains, and also caches data in the form of IP addresses and the corresponding domains of other DNS servers. It does not function in virtual zones but is implemented on specific physical devices. All domain data is stored in record format on computers equipped with the appropriate software.

DNS Technology Scheme

What Is DNS?

The user enters the domain name into the browser, and the resolver contacts the DNS server. Subsequently, the server sends the data to the user's browser. The browser uses the IP address to render the web resource.

These are basic DNS technology functions:

  • Storage and management of distributed data.
  • Caching of data to accelerate information loading.
  • Reservation — multiple logically and physically isolated DNS servers store and process information about the same nodes.

DNS Server Operation

When a user enters a website address in their browser, a query is initiated. This query is then forwarded to a Domain Name System (DNS) server. The primary function of the DNS server is to find a match between the provided domain name and its corresponding IP address. Here is the workflow:

  1. User Query

    When you type a website address (e.g., www.example.com) in your browser and hit enter, your browser sends a request, known as a query, to a DNS server.

  2. DNS Resolution

    The DNS server checks if it already knows the corresponding IP address for the website. If not, it goes through a step-by-step process, starting with root servers, then moving to top-level domain servers, until it finds the authoritative server for the specific website.

  3. IP Retrieval and Display

    Once the DNS server identifies the IP address, it sends it back to your browser. Your browser can then use this IP address to connect to the web server hosting the website, retrieve the necessary data, and display the site on your screen.

What Is a DNS Zone?

A DNS zone is a segment of the DNS namespace managed either by a group of servers or a single server. It exclusively contains DNS records for a specific domain. Each record related to a domain is located within a designated DNS zone. The type of zone can vary based on the nature of the domain's requirements.

Geo-DNS

Geo-DNS is a service that employs additional servers to distribute traffic based on the geographical location of requests. This optimization of traffic routing enhances the performance of domains through geographic considerations.

Geo-DNS becomes essential for websites situated in one region but garnering popularity in another. For instance, if a site is physically located in the European zone but has a significant user base in the USA, frequent requests from American users might experience slower loading times. This delay occurs because the nearest DNS server is situated in Europe. To address this issue and improve speed, the owner of the resource should take specific actions, such as hosting the site directly in the USA.

Attacks on DNS Servers and Methods of Protection

Attacks on DNS servers pose a significant threat, leading to a loss of functionality and the potential compromise of information.

In the case of DNS spoofing, a type of cyberattack, malicious actors manipulate DNS records, replacing legitimate IP addresses with fraudulent ones. Consequently, users may unintentionally land on the attackers' resources instead of their intended destinations.

DDoS attacks can render DNS servers inaccessible, impacting not only users' access but also the resources hosted behind these servers. Website owners can face severe disruptions.

To safeguard against such attacks, it is crucial to implement robust security measures such as DNSSEC, BIG, and DANE protections, along with the following best practices:

  • Regularly update the software for DNS servers to patch vulnerabilities.
  • Implement spoofing protection measures to detect and prevent malicious manipulations.
  • Control access to DNS servers, restricting it to authorized administrators within the network.
  • Prohibit dynamic updating of DNS zones to prevent unauthorized modifications.
  • Conduct regular scans of DNS servers to identify and address potential issues.
  • Disable recursive query processing to reduce the risk of exploitation.
  • Utilize a traffic filtering service with automatic activation to counteract attacks promptly.
  • Choose reputable service providers, such as 3HCloud, for enhanced security.

By combining these protective measures, organizations can significantly reduce the risk of DNS-related attacks and fortify the security of their online infrastructure.

Conclusion

DNS is a system for associating domain names with their corresponding IP addresses. DNS servers facilitate the storage of data on the IP addresses associated with specific domains, enable caching for efficient data retrieval, and swiftly provide information to users upon request. Servers located in different locations increase page loading speed and user loyalty to the resource.


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