What is DNS?
Last Updated: February 9th, 2023 4 min read Severs Australia
The Domain Name System (DNS) is a hierarchical system for naming devices connected to a network like the internet. Its primary use is to associate human-readable domain names with the numerical Internet Protocol (IP) addresses needed to identify devices to underlying network protocols. This functionality thus serves as a distributed directory service that’s now an essential component of the internet. The DNS can affect a network server in several ways, including browsing speed and email addresses.
An IP address is a set of numbers that uniquely identifies each device on the internet. The fourth version (IPv4) is currently the most widely used, which consists of four eight-bit numbers separated by periods. These IP addresses, therefore, have the form x.x.x.x, where each x is a number between 0 and 255 inclusively. Version six (IPv6) of the IP uses eight groups of four-digit hexadecimal numbers separated by colons. The IPv6 format is thus x:x:x:x:x:x:x:x, where each x is a four-digit hexadecimal number. IPv4 and IPv6 addresses will be used concurrently for the foreseeable future since the two protocols can’t directly communicate with each other.
IP addresses may be static or dynamic. A static address never changes, so it can be tracked more easily than a dynamic address and is, therefore, less secure. An Internet Service Provider (ISP) can assign addresses dynamically by using a pool of addresses for a group of devices, allowing the address for each device to change periodically.
Users who want to view a website typically enter a DNS name into their address bar rather than an IP address. This name is then transmitted as a DNS query to the ISP’s DNS server, which attempts to resolve the DNS name into an IP address. If the attempt is successful, the server sends the IP address back to the user’s computer as an authoritative answer so it can connect to the website.
If the resolution attempt is unsuccessful, the DNS server checks its cache for a record of previous DNS queries for that IP address. If this attempt is successful, the server will send the IP address back as a non-authoritative answer to indicate that the IP address was supplied by a third party rather than the DNS server itself. If the DNS server is still unable to resolve the DNS name, it will use its root hint files to obtain the IP address of other authoritative servers.
The time needed to answer a DNS query can affect the time needed to display a website on your computer, although DNS doesn’t directly affect your download speed. Choosing the best DNS server for your router can reduce DNS query time, which typically involves the use of specialized software.
You’ll need to update your router’s DNS settings once you’ve determined the DNS server you want to use. This procedure generally involves going to your router’s administration page and selecting the advanced settings to display the DNS server addresses the router is currently using. Record the existing addresses before replacing them with the new addresses, and test the new addresses to determine if they improve your browsing speed.
DNS uses a mail exchanger (MX) record that can improve email functions. The MX record specifies the servers that will accept email messages on behalf of the recipient’s domain and assigns a preference value to each server. This prioritised list of mail servers determines how the Simple Mail Transfer Protocol (SMTP) will route the email message. Modifying the MX record can, therefore, minimize the number of “hops” that SMTP needs to make before delivering your message to the end recipient.