What Is a Domain Name System (DNS)?
May 15, 2024
DNS is the main index of the internet that directs traffic for queries across the web. The simplest analogy is that of a contact list on your phone: contacts are sorted by name, but then they contain specific phone numbers or addresses. At its simplest, DNS is like that for the internet. All internet servers work on Internet Protocol (IP) addresses, which mostly look like several sets of numbers separated by periods (e.g. 123.456.789.100) though other variations exist.
The domain name system was not always the default for accessing information of the web. In the early days of internet usage, a small group of individual networks managed their own naming conventions. It wasn’t until 1983 that the concept of a centralized DNS was created. When the Internet Engineering Task Force was created in 1986 to apply standard and best practices to the burgeoning platform, DNS was among its initial group of adopted guidelines.
However, the web is designed for a simple user experience with domain names we can remember, such as www.oracle.com. DNS is the system that links domain names with their proper IP addresses. When web users enter a domain name in their browser, the local internet service provider (ISP) uses DNS to identify the correct IP for the domain name, thus allowing the web user to download the desired page or asset. Further specific steps occur behind the scenes, but for the typical user, that is their experience.
Domain Name System vs. Domain Name Server
For the casual user, it can be very easy to confuse domain name system and domain name server with the acronym DNS. What is the difference? DNS properly stands for domain name system; domain name server technically is not a true term. Instead, people tend to mean nameservers, which are the local DNS servers used to resolve queries about local names. The domain name system refers to a larger, more-encompassing system for translating domain names and IP addresses as part of a multi-step process. Both the DNS process and the roles of various domain name servers are described below.
What Is Dyn?
Originally founded in 2001, Dyn grew from a student-led project to international DNS services company. Oracle acquired Dyn in 2016; since then Dyn’s DNS, web application security, email delivery services have fully integrated with Oracle Cloud Infrastructure. The result is a clear expansion in Dyn's capabilities, along with the flexibility to take advantage of Oracle Cloud's available services.
How DNS Works
While the user experience of DNS was covered above, many further steps occur outside of the user’s view. Users typically only see the steps in their web browser’s status bar, such as “contacting host” and “waiting for response.” The initial activity of the web page loading process is centered around DNS lookup and translation.
To understand how DNS works, it’s important to first learn several definitions:
- Recursive DNS resolver: A recursive DNS resolver is the DNS server that processes the initial request and connects with the higher-level authority for established domain details.
- Authoritative nameserver: Also known as a root server, these are a set of established servers that provide an authoritative list of domains.
- Top level domain: The top level domain contains the suffix of a domain name, such as .com, .org, and .net.
- Nameserver: The part of a server that contains the records of domain names and their respective IP addresses, similar to an address book.
Specifically, the uses the following steps, though a local cache on a browser or operating system can bypass some of these steps.
Initiate query by user: The web browser’s user initiates the query by typing a domain name, clicking on a hyperlink or loading a bookmark. The query is set into the internet to a recursive DNS resolver.
Resolve TLD: The resolver queries an authoritative nameserver, which generates a Top-Level Domain (TLD) response that identifies the domain’s suffix (.com, .org, etc.) and forwards the request.
Resolve nameserver: The TLD server responds with appropriate IP address of the domain’s nameserver.
Resolve IP address: With the nameserver identified, the recursive DNS resolver queries the domain’s nameserver. The nameserver responds with the proper IP address.
Data transfer: With the IP address identified, the browser can request data to be transferred for the target page and/or assets using hypertext transfer protocol (HTTP).
Commercial vs. Enterprise Needs
For most individuals or even small businesses, a commercial-level purchase of a domain name is all they will ever really need to think about. This means buying an available domain name (usually around $10-15 a year), configuring the domain name with the web host’s nameservers, and going about your business.
On an enterprise level, though, DNS has many more considerations for organizations to consider. Relying on a provider’s DNS creates various limitations. For example, this centralizes DNS, but for a company dealing with international traffic, geographic distances can slow down response times. This may be even more critical if you’re going beyond a web page and into an app that has to process queries/responses to an international userbase. This combination of physical distance and centralized DNS creates a single point of failure to generate lengthy timeouts (in terms of Internet traffic, seconds of delay is considered lengthy). An enterprise DNS setup uses a dedicated network, usually with geographically diverse locations. This creates many layers of redundancy and geographic efficiency for handling traffic, even when there is a server issue.
Security is also a concern, as unencrypted DNS communication can lead to malware and other dangerous encounters. Enterprise DNS services often have protection protocols for Distributed Denial of Service (DDoS) attacks, providing multiple layers to mitigate the impact of attack while keeping domains accessible.
Enterprise DNS Use Cases
To get a better perspective of how enterprise DNS is used, the following situations offer a closer look.
Intelligent traffic routing
Internet traffic comes with an overwhelming amount of variables from users. Location, frequency, heavy volume due to unexpected events or publicity, and many more items can cause a swell of traffic. DNS traffic management helps to balance this with intelligent systems designed to steer traffic based on location, steer traffic based on IP prefix, load balancing among hardware, and other such tools balance resources and ensure end-users have a fast and responsive experience.
Learn more about intelligent traffic routing
High availability
Every business and organization wants to maximize their uptime for their site, but some circumstances (such as an app that constantly queries a database) prioritize high availability. DNS is part of the equation that ensures high availability, and this is achieved by using a network of hardware that is balanced against failure caused by natural disasters, power outages, weather, and other uncontrollable factors. This geographically diverse network creates a strong level of redundancy to ensure services remain uninterrupted.
Learn more about high availability
DNS cache management
DNS caching is an effective tool in creating faster load/response times for end users. However, effective management of a DNS cache is necessary to ensure accuracy and protect from DNS poisoning so that private data isn’t at risk of benign exposed. Fine-tuning the DNS cache to meet an organization’s requirements is part of the greater DNS management spectrum.
Discover Oracle DNS
Oracle’s globally distributed DNS service is part of Oracle Cloud Infrastructure and delivers enterprise DNS capabilities. The result is enhanced DNS performance, resiliency, and scalability, connecting users to customers’ application as quickly as possible, from anywhere in the world.
