DNS Content Filtering: Everything You Need To Know

  • Posted on: 3 January 2017
  • By: admin

All of us must have encountered DNS content filtering one time or another, whether we know it or not. While surfing the net, you must have come across messages telling you that the website you are trying to access is blocked or that access to a particular website is denied. These messages appear due to the DNS filtering being enabled on your network.

To understand what DNS content filtering is you must be familiar with the term DNS first. DNS (Domain Name System) is an integral part of the internet which is responsible for mapping the web address you enter in your browser (like google.com) to its corresponding IP address ( The systems on net communicate with the help of these IP addresses only.

DNS filtering allows you to block some of these IP addresses, thus, making them inaccessible to the users on that network. It monitors the websites we are visiting and looks for any objectionable content in it. This objectionable content could be user specific, varying from pornography, viruses and spyware, religiously or politically controversial topics etc. Once it finds that the incoming web page contains any of these objectionable materials, it immediately blocks and reports it.

Now, the first question which arises in your mind is who needs DNS filtering and why do they need it? DNS filtering finds its use at many places from organizations and corporations to small homes. They all require it for one reason or another.
The corporations need DNS filtering to ensure DNS protection. It weeds out harmful sites containing viruses and spyware which may compromise their network security. They also need it to block online pornography and other video streaming sites like youtube which eat a great chunk from their bandwidth.

DNS filtering also enables parents in blocking pornographic contents at home. It is also a common practice in schools and academic places to install DNS filtering solution, where access to certain websites which are distracting in nature like facebook or twitter or the pornographic content is denied.

Now that you know who needs DNS filtering and why it is important, you should know how it is implemented. There are various different techniques for DNS filtering from which you may choose the one which fits your requirements.

• Blacklists – These are the lists which contain a directory of sites which you don’t want to be accessed. Generally, sites containing viruses, spyware or some other malware are marked under this list.
• Category based filtering – In this type of filtering, you can block websites belonging to certain categories. These categories can be predefined such as video streaming or social networking sites or can be customized as per your requirements.
• Keyword filters – This would allow you to block websites containing some particular keywords. This is particularly helpful in blocking websites which may have radical contents (especially religious or political) not suitable for your work environment.
• Time-based filters – As the name suggests it uses a timer for DNS filtering. The filters can be imposed during the certain period of time and relaxed after that. It results in better utilization of bandwidth as the timer can be turned on during the desired period and then switched off as per your convenience.

Having a DNS content filtering solution ensures DNS protection for your network. It protects your network from viruses and other malicious programs, thus, ensuring a safe and secure work environment. Having DNS filtering at homes and schools prevents children from getting distracted and guarantees their overall growth.

Now that you everything about DNS filtering, you may be tempted to go for a DNS filtering solution. But before, that you must get acquainted with the features you are looking for in it. Not every other DNS filtering solution is suitable for you and, mind you, there are a whole lot of them out there. So first, you must assess your needs and requirements and then look for the most suitable solution.