DNS cache – Definition

Definition of DNS cache

DNS cache is a temporary cache memory that DNS resolvers and other devices utilize to store information. The memory stores the DNS records that were first applied to the searched domain names. The IP addresses (IPv4 or IPv6) of domain names, information about their email server, their services, authentication and verification data, and more are all stored in these records. All of the data will be saved in the DNS cache. However, as previously stated, it will only be for a short time, as determined by the TTL (Time to Live) value issued to each DNS record.

When someone tries to access a website, caching inhibits redundancy. As a result, the time it takes to go to the website is reduced. In addition, the cache may provide the IP address if the device you’re using recently visited the page it’s trying to access. The webpage request can be completed without engaging the DNS server in this fashion.

As a result, the DNS cache speeds up the DNS search procedure that would usually be required to connect a domain name to an IP address. This speeds up the process of going to the website.

The way it functions

A DNS Cache works by temporarily saving the answers of DNS queries or other FQDNs, from previously visited web pages in a local file for speedier retrieval. DNS records do not often change. In that fact, most Operating Systems such as Linux, Windows, etc., activate DNS caching by default. Why? Because it facilitates and improves web surfing speed. How? By storing the information (DNS cache) about the visited websites. And if you visited before dnsitsec.com, and now you want to reaccess it due to DNS cache, it will be faster. 

How to delete DNS cache?

  • On Windows

Start Windows PowerShell or the Command Prompt. Then run ipconfig /flushdns into the command prompt. First, a confirmation message must be received. After that, the Domain Name System cache is deleted.

  • On macOS

Locate the Terminal if you’re an Apple user. Then, at the command prompt, copy and paste the following syntax:

sudo killall -HUP mDNSResponder

Then insert your password and press Enter. Cache flushing for the Domain Name System is now free!

  • On Linux

If you are a Linux client and want to delete your Domain Name System cache, you must first find and open the Terminal. Then, type the following command:

sudo systemd-resolve –flush-caches

After that, type your password and hit Enter. You’re all set!


To sum up, a DNS cache is helpful for achieving a faster and more efficient DNS resolution. So, you should be aware of it and how it works. And if you need to delete it, just follow the steps above. Good luck!