DNS, short for Domain Name System, is defined as a directory of IP addresses used to map and identify computers and other networked devices so they can reach different websites on the internet. This article explains how DNS works, its continued importance in a connected world, and the different types of DNS servers.Â
Table of Contents
DNS, short for Domain Name System, is a directory of IP addresses used to map and identify computers and other networked devices so they can reach different websites on the internet.Â
Using DNS, a nomenclature database, domain names are identified and transformed into Internet Protocol (IP) addresses. Domain Name System is the Internet’s telephone directory. People use domain names like espn.com or thenewyorktimes.com to access information online.
Through IP addresses, web browsers may communicate with each other. DNS transforms domain names to IP addresses to allow users to load Internet resources. A computer’s IP address to find a website is mapped to that website’s name by the Domain Name System. Each internet-connected device has a distinct IP address those other computers can use to find the device.
Domain Name System servers eliminate the need for users to memorize IP addresses such as 192.168.1.1 (in IPv4) or more complex alphanumeric IP addresses such as 2400: cb00:2048: 1:c629: d7a2 (in IPv6).13 authoritative name servers, also referred to as â€œroot servers,â€ the database name servers that supported the DNS root zone are part of the open, worldwide network of the DNS system.
When a root server, also referred to as a DNS root nameserver, receives a DNS query including a domain name (such as www.thousandeyes.com), it forwards it to a top-level domain (TLD) nameserver depending on the TLD of the domain, such as .com, .net, and.org.
When a request in the root zone is made for a DNS record, it instantly responds with a list of authoritative TLD name servers for the appropriate TLD that may respond to the first DNS lookup request. Stanford Research Institute’s Elizabeth Feinler kept a master list of all internet-connected computers during the 1970s and the early 1980s. She was tasked with matching IP addresses and domain names.
Given the explosive expansion of the internet, it was clear that this was unsustainable, so Paul Mockapetris created DNS in 1983. This automated, scalable system managed domain name to IP address translation. Maintaining all those names in one directory would be challenging, given that there are currently several million registered domains.
The directory is distributed globally, much like the internet itself, using domain name servers that regularly exchange information to provide updates and remove duplications. Increasing performance is another justification for developing a distributed system. The implication is that a domain could have many IP addresses.
During the DNS resolution process, a hostname, like www.example.com, is translated to an IP address that computers can comprehend (such as 192.168.1.1). Every device has a distinct IP ID, which is necessary for identification in the same way a street location is required to identify a particular home. When a user asks a web page to load, there must be a translation between what they put into the browser (example.com) and the computer address necessary to locate the example.com site.
DNS servers change domain names and URLs to IP IDs that machines may use. They convert the information a person types into a browser into data that a computer can use to discover a webpage. DNS resolution is the name given to this process of translation and lookup. The DNS is set up in a hierarchy.
An initial DNS query is sent for an IP address to a recursive resolver. A root server that has data on country domains and top-level domains is the first place this search leads. The DNS system directs the request to the closest root server because root servers are dispersed throughout the globe.
A top-level domain server, which houses data for the second-level domain, receives the request once it has reached the appropriate root server. The DNS client device sends the request to a domain nameserver, which checks for the IP address and delivers it back to access the relevant website.
When a user inputs a domain name into a browser, DNS servers transform the request into an IP address and determine the server to which the user will connect. These are known as query requests. In a typical DNS query, the user’s entered URL must pass through four servers before the IP address is returned.
The computer will query another server on the computer network if the data is not already stored locally. Like a PC, recursive DNS servers have a local cache. Many ISPs use the same recursive DNS servers. Therefore, a popular domain name can already be in its cache. If the site has been cached, the inquiry will end here, and the visitor will view the page.
If the necessary data is not already cached, a recursive DNS server will look elsewhere. The query then moves on to the subsequent authoritative DNS server in the chain. The search will continue until a domain-specific nameserver is located. The records for these authoritative name servers’ respective domain names must be kept on file by these name servers.
For instance, someone may contact the authorized name server for liquidweb.com’s address record to determine its IP address. A recursive DNS server receives the record for liquidweb.com from the authoritative name servers. The data is then stored in the local cache of the device. The recursive server will be responsible for another inquiry that requests the liquidweb.com record.Â
A time-to-live value, which indicates when a record will expire, is present in every DNS record. After some time has elapsed, the recursive DNS server will seek an updated version of the records. Your computer receives a record from the recursive DNS server after it receives the data.
The record is then kept on our machine in the local cache. It passes our browser the IP address it has read from the DNS record. After establishing a connection with the web server connected to the A records IP, the web browser will display the website. The lookup procedure usually takes only a few milliseconds from beginning to end.
DNS server classification typically follows this nomenclature:
1. Primary server
There is only one primary server per domain, and each domain needs to have one. Primary servers, which are authoritative for the domains they serve, are where all domain changes are made. The primary server must be used for all administrative tasks in the zone, such as creating subdomains within the zone or other similar administrative tasks.
Additionally, one must use the primary server for any zone-related adjustments as well as any adjustments or additions to RRs in the zone files. Except when Active Directory services and Microsoft DNS Server are integrated, each zone has a single primary server.
2. Authoritative server
Other name servers in the DNS query it. It caches the information other name servers send back in return. For data that has been cached, authoritative servers aren’t authoritative. Recursive DNS nameservers ask authoritative DNS nameservers for information about individual websites’ whereabouts.
These responses include crucial data for each domain, such as IP addresses. An authoritative DNS server provides two critical functions regardless of the area it serves. It begins by storing IPs and domain names. It also responds to inquiries via a recursive DNS server about the IP address that corresponds to a domain name.
3. Secondary server
Since they simply collect information from the primary server and serve as a backup, secondary DNS servers are also called slave servers. The central server in Microsoft’s DNS Server software is the Master Server. DNS servers on secondary servers serve as backups.
Secondary servers can access the primary server’s zone files through a zone transfer. There can be as many secondary servers as required to offer load balancing, fault tolerance, and traffic reduction for any particular zone. Furthermore, a single DNS server can function as a secondary server for several zones.
4. Caching server
Caching DNS servers execute requests, cache the responses, and provide the results to the requesting client rather than maintaining zone files as other secondary servers. The fundamental distinction between caching servers and other secondary servers is while other secondary servers keep track of zone files, caching servers don’t.Â
Caching servers retain data from other name servers for a specific time frame, as set by the authoritative name server. They offer a local cache of looked-up names. No domain considers them to be authoritative. Administrative costs are cheaper for them. They lessen the zone’s overhead related to the secondary server.
5. Root servers
The root DNS servers are in charge of TLD. They maintain information on TLD zones and sit atop the DNS structure. It will connect domain and IP addresses and serve as the primary interface between internet users and content. The functioning of the root name server is overseen by ICANN (Internet Corporation for Assigned Names and Numbers).
There are more than 13 workstations in the root nameserver system, even though only 13 root nameservers exist. There are 13 types of root nameservers, but each one is duplicated globally and uses Anycast routing to deliver quick responses.
6. Non-authoritative name servers
Non-authoritative servers don’t manage this specific DNS zone. They utilize iterative or recursive DNS requests to gather information about particular zones. The zone’s source files are not present on non-authoritative name servers. They have a domain-specific cache file built using the results of all previous DNS lookups.
A DNS server’s response to a DNS query for which the original file is missing is a non-authoritative answer. For instance, when one asks Google’s open DNS server 126.96.36.199 to respond to their DNS records query for the domain tecadmin.net, it doesn’t return the domain’s original zone files.
7. Forwarding servers
Forwarding servers forward requests to another DNS server. They serve as the main hub for all off-site DNS requests. Off-site queries were centralized by them. Off-site inquiries will first pass through forwarding servers. They will cut down on duplicate off-site requests. There’s no extra setup required for forwarding servers.
All off-site DNS queries are directed at forwarding servers, a type of primary or secondary server. All queries from outside the site must pass via the server designated as the forwarding server. A rich cache of data is built upon forwarding servers, which are used to consolidate off-site queries.
Although they can resolve names locally in the router or PC, resolver servers are not authoritative DNS servers. Resolvers are servers that receive DNS queries from internet browsers and other apps. The resolver is in charge of finding the IP address relevant to the hostname after receiving it.
Users might run the resolver with the LAN, an Internet Service Provider (ISP), a mobile operator, a Wifi connection, or other third parties. It is instantly resolved if the hostname is in the resolver’s local database or the OS system’s caches on the local device.
There is a good reason why DNS has become a staple for internet operations, along with standards like TCP (Transmission Control Protocol) and technologies such as LTE (Long-Term Evolution). Some of its key benefits include:itÂ
1. Supporting our growing reliance on the internet
Most of the time, DNS is the sole system that enables internet browsing. As the web grows into a more prevalent component of society, it is more important than ever that DNS servers be updated. The internet wouldn’t be possible without them. We cannot function without the internet because it has become such a crucial part of daily life for individuals and businesses.
By keeping track of all IP addresses, DNS facilitates internet usage. Websites make up the entirety of the internet, and a DNS server is required to load each one.
2. Eliminating the need to memorize IP addresses
A clever way to translate domain or subdomain names to IP addresses is using DNS servers. Imagine how it would feel to be forced to remember the IP addresses for every website a person typically visits regularly, such as Twitter, Facebook, Google, etc. It would undoubtedly be terrible.
Its system also makes it simple for search engines to archive and categorize data. When the name is provided to the search engines, all domains are transformed into IP addresses. Consequently, it is no longer necessary to remember the IP IDs for each website one often accesses.Â
3. Increasing security
DNS servers are crucial to securing your connections at home or a particular business. Security-focused DNS servers typically make sure that attempts to attack a person’s server environment are stopped before access to your machines. It’s crucial to remember that the word used is enhanced, nevertheless.
This implies that you must take additional network security precautions to safeguard your data, mainly if your company is large and has a high volume of sensitive data. Using DNS servers, a person may design the Domain Name System protocol, specify specific data structures in detail, and exchange data.
4. Providing compatibility with search engines
A search engine allows users to find any website. The search engine functions rapidly since it is not required to trace the IP addresses of the websites. For connection and communication accessibility, the systems and DNS convert the domain name to its IP address. They merely need to keep in mind the URLs of online pages.
The website’s name is referenced on every page. If you have a website at facebook.com, facebook.com/pages is a subdomain of that same website. The connection between domain names and their web pages is simple for search engines to recall.
5. Speeding up internet connections
High connection speeds are a fundamental aspect of several of these servers, and people and businesses that utilize Domain Name System servers may be able to benefit from them. There is high-speed internet access for DNS servers. They respond quickly to requests, and it takes them only a second to locate the IP address.
The request is sent to the closest Domain Name System server if any DNS server cannot discover the IP address. On the internet, there are a large number of connected DNS servers. They only have to find the IP address quickly.Â
6. Being versatile and simple
A DNS server is not only straightforward to use but also adaptable. Further, configuring them is simple. The website’s nameservers are all that you need to keep in mind. The hosting providers take care of all other duties in the background.Â
Website IP addresses may shift for a variety of reasons. To use this knowledge effectively, users must also stay current. It may take a lot of work to complete this. However, the Domain Name System makes this easier by regularly updating IP addresses, saving users from having to make significant efforts.
7. Enabling load balancing
New queries are sent to the closest Domain Name System server if any DNS server receives many requests. That implies that the servers handle load balancing. You can specify the technical features of the database service using DNS. It is a protected web-based interface that enables the users to be the masters of their domains.
It may describe the DNS protocol, the exact definition of the datatypes and frameworks, and the DNS data communication exchanges. To create, update, and manage one or more domain names, users simply need to log into the SafeDNS program.
Domain Name System or DNS is among the foundational systems powering the world wide web today. As we progress into IPv6 and eventually new versions of the internet, DNS servers will help connect computers with an infinite number of websites without remembering any IP address. Organizations should know the meaning of DNS and how it works to strengthen and protect this system against cyber threats targeting networks.Â
Did this article help you understand the working of the Domain Name System (DNS)? Tell us on FacebookOpens a new window , TwitterOpens a new window , and LinkedInOpens a new window . We’d love to hear from you!Â Â