Explanation and definition of DNS cache
A DNS cache is a temporary cache memory used by DNS resolvers and other devices to store data. The DNS records that were initially applied to the domain names that were searched are kept in memory. These records contain information such as domain names’ IP addresses (IPv4 or IPv6), details about their email servers, services, authentication, verification information, and more. The DNS cache will save all of the data. However, as previously said, it will only last briefly because each DNS record has a TTL (Time to Live) value.
It is significant to notice that the DNS cache will momentarily contain all of the records for the different domain names. This is because the administrator sets the TTL (Time to Live) value, which determines how long it will last.
Users’ DNS queries can get faster responses thanks to this method, which also aids in effective resource optimization.
Does DNS cache provide any advantages?
- It defends your authoritative DNS servers against DDoS attacks and lessens the load on your authoritative servers because it stores DNS responses.
- By letting you connect to the closest node, it expedites access.
- It helps you save money by lowering bandwidth usage if you have an on-premises Domain Name System.
- Furthermore, it enables you to access the service in case an error in the authoritative domain names happens before the cached DNS records run out of validity. Failures lose less time as a result of this.
What should you beware of?
Yes, the DNS cache is so valuable, but it’s not secure. That’s why thieves were able to develop a way to abuse it. They insert false data (IP addresses and domain names) and carry out an attack known as DNS poisoning (DNS spoofing). Such incorrect DNS information (DNS records) directs consumers to a website that looks just like the original one but is actually run by the criminal. Therefore, it is crucial to understand that routinely clearing it could stop such malicious assaults.
When should I clear the DNS cache?
The so-called DNS Propagation period begins when you update your domain’s DNS records and point them to a new server. Unfortunately, the DNS cache on your PC is practically out of date while the process is still running.
As a result, even though your website is accessible to everyone else, you can have DNS problems on it. This data will be refreshed by flushing it on your computer, which will ultimately shorten the DNS propagation time.
A DNS poisoning or spoofing attack is another reason to flush your DNS cache. Hackers inject a fake DNS record into the Domain Name System cache resource records during DNS poisoning attacks. They can use this tactic to drive you to phony websites, where they can trick you into giving them personal information or infect your computer with malware.
How to clean (flush) the DNS cache on your browser?
There are various methods for clearing it. Your OS and the browser you use will determine this.
- Google Chrome (on Edge or Opera works similarly)
If you are using Google Chrome, copy this text – chrome://net-internals/#dns. Paste it into your address bar and press Enter. Locate Host resolver cache and select Clear Host Cache on the load page. You are now successfully flush it.
So, if you are using Safari, go to Preferences and then click on Advanced. So, now you need to find the Show Develop menu in the menu bar. There, find Develop and then Empty Caches. Now you need to restart your browser, and you are done.
The DNS cache is an effective instrument for speeding up and improving the DNS resolution process. As a result, the user’s device and the network (all of its involved servers) save time, effort, and resources. Furthermore, follow the instructions for your browser if you need to flush it for any of the reasons above.
Everyone appreciates its usefulness, even the web’s shady side. However, don’t forget to safeguard the security of the DNS cache because it can be misused for illegal activities.