DNS filtering is a computer security technique used to regulate what types of online content can be accessed by users. It works by redirecting incoming network traffic such as web requests away from malicious websites and other dangerous sources.
At a basic level, DNS filtering involves comparing data sent from the user’s device against a database of site names, IP addresses and domain names which are either allowed or blocked. When a DNS request is made, the filter searches the database to see if it matches an allowed or blocked entry. If the entry is allowed to pass through, the filter will send the correct IP address of the requested domain name back to the user, allowing them to access the requested website.
DNS filtering can also be used to block malicious websites by using artificial intelligence (AI) and machine learning algorithms to identify and block malicious sites before they become active in the DNS system. This is known as ‘real-time’ DNS filtering and can be used to block websites that are known to contain malware, adware, spyware, or other malicious content.
DNS filtering is most commonly used by organizations to ensure that their employees are not accessing inappropriate websites or engaging in unacceptable activities while using organization computers and networks. It is also used by parents to protect their children from accessing inappropriate content online.
DNS filtering can also be used to improve online network performance, by blocking unwanted network traffic. This technique is also used by ISPs and governments to censor and block certain types of content.
While DNS filtering provides a useful tool for protecting users and networks from malicious actors, it is not perfect. DNS filtering can lead to false positive results which block sites even though they are not malicious. This can lead to legitimate traffic being blocked while malicious traffic gets through. As such, DNS filtering should be used in conjunction with other computer security measures.
