The ‘DNS server’ goes by many names like ‘name server’ or a ‘domain name system server.’ It is a computer server that maintains a database of hostnames and their corresponding IP addresses and which, in most cases, resolves or translates hostnames to the requested IP addresses. The uses of DNS differ as they communicate with one another using unique protocols and employ specialized software.
In this article, we will examine the fundamentals of DNS servers, their uses, and why they are crucial to the workings of the internet.
Uses of DNS
Simply put, you need a DNS server because it simplifies daily routines— internet use. The Domain Name System server is a go-between for people and computers.
It is worth noting that computers, mobile devices, and other internet gadgets use numbers. These numbers are also known as IP addresses and play a critical role in the workings of the internet. For example, when we go online, we type in domain names instead of their numeric addresses, and the DNS server helps with that translation.
An example of how the DNS works are Google. You simply type “google.com” in the search area when accessing Google. Inputting the IP address of Google would be difficult for users since it is easier to master phrases and words than numbers.
Without a domain name system (DNS) server, we would have to memorize the IP addresses of every website we want to visit.
Security of the DNS server
Cybercriminals have exploited several security holes in the DNS over the years. For example, DNS spoofing (DNS poisoning) is a prevalent threat involving sending false data to Recursive DNS servers.
Often, the malicious data will cause users’ requests to be forwarded to an imposter DNS server. That is, the requests are often redirected to a sham domain. These fraudsters use this approach to get critical information about internet users.
Furthermore, hackers try to deceive people into thinking their fake website is legitimate by using deceptive headlines. For example, sometimes they change one letter in the domain name to another that seems similar, such as changing the letter l to the number 1. There is a considerable possibility of falling prey to a phishing attempt if the user fails to recognize the difference.
DNSSEC is the most effective method to increase DNS security and decrease vulnerability to DNS spoofing. Also, it is used to add a cryptographic signature to DNS records.
DNS server and internet performance
DNS data (such as A records and IP addresses) obtained from DNS queries can be stored in the DNS cache of recursive DNS servers for a limited time. In this way, when requests for the same IP address arrive, the servers can respond quickly. This is why caching DNS data is so helpful.
The DNS resolution process occurs once by the local DNS server, regardless of whether many users simultaneously request access to the same website. The DNS cache then uses this information to respond to the remaining requests.
Furthermore, the TTL (Time-To-Live) number determines how long the DNS data will remain valid. It is up to the administrators to determine the TTL. The value could be different depending on the preference.
Increasing the TTL can reduce the burden on the Authoritative DNS servers. However, a shorter TTL will always result in more precise outcomes.
DNS Caching
DNS caching seeks to shorten the time it takes to receive a response to a DNS query. Caching enables DNS to deliver the same information to clients faster the next time they query it by storing initial responses to requests closer to the clients.
There are several places where DNS data can be cached. Typical examples include the following:
Browser
Most browsers, including Apple Safari, Google Chrome, and Mozilla Firefox, automatically cache DNS information for a predetermined period. Therefore, before the request leaves the computer for a local DNS resolver server, the browser is the first cache examined when a DNS request is made.
Operating system
Stub resolvers, incorporated into many operating systems, cache DNS information and respond to queries before they are routed to an external server. Often, the OS is questioned after the browser or other querying tool.
Recursive resolver
Resolvers may skip DNS resolution steps if they already have part of the records required to respond. For instance, the resolver can bypass the root server and directly query the TLD server if it only has A and no NS records.