How to Add a Porn Filter to Your Home Network

Written by franzro | Published 2021/09/23
Tech Story Tags: home-network-security | dns | opendns | family-shield | how-to-add-nsfw-filter-network | security | how-to-block-adult-content | block-nsfw-content-at-home

TLDRConfigure most home networks to filter out porn, malware and other unwanted content for free. All you need to do is configure your home Wifi router to use a family-friendly DNS server called ‘OpenDNS Family Shield’. Two DNS servers from OpenDNS will check every request they get and will block requests to inappropriate sites. The instructions below explain how to set up your router to point to a family friendly DNS server. If you have trouble getting this right, you can try the ‘The Ultimate Guide to Changing Your DNS Server’.via the TL;DR App

If you have children you may have worried about how easy it is for them to come across hard-core porn on the internet. If this worries you and you want to do something about it, here is a completely free and easy way you can configure most home networks to filter out porn, along with malware and other unwanted content. 

How it works

Every time you go to a website, like cnn.com, for example, your browser needs to find the unique IP address that belongs to that website (when I wrote this article cnn.com, for example, had an IP address of 151.101.1.67). The human-readable address (cnn.com) only exists to make life easier for us people. The computers on the Internet all use IP addresses to communicate with each other. There are special servers on the Internet called Domain name Servers (DNS) that ‘know’ about all websites on the Internet and exist for the sole purpose of translating website addresses to IP addresses. 
When you type an address into your browser, the browser first asks your computer, then your Wifi router, and then your Internet Service Provider (in that order) for a DNS server it should use to translate the website address to an IP address. It will use the first one it gets back and asks that DNS server to provide it with the IP address for the website you are trying to visit. The browser then uses the IP address to fetch the webpage from the webserver. 
Two DNS servers from OpenDNS will check every request they get and will block requests to inappropriate sites. So, when the browser requests an IP address from one of these DNS servers, the family friendly DNS server checks if the website is a porn site and, if it does, returns the IP address of its error page instead of the actual IP address of the website. So, to make sure porn sites cannot be viewed on a home network, all we need to do is configure the Wifi router to use the OpenDNS servers. 
The instructions below explain how to set up your router to point to a family-friendly DNS server. 

Setup Instructions

To set this up, all you need to do is configure your home Wifi router to use a family-friendly DNS server from OpenDNS called ‘OpenDNS Family Shield’. Here are the three simple steps you need to follow to implement this:
  1. Browse to your router and log in
  2. Find the DNS configuration setting and enter the following two DNS servers
    208.67.222.123
    and
    208.67.220.123
  3. Save and reboot your router
Unfortunately, this is not always as straightforward as it was on my router. If you have trouble getting this right, you can try the ‘The Ultimate Guide to Changing Your DNS Server’ linked below. 

Some caveats

  1. Most, but not all routers allow for a DNS configuration. If yours does not you can still set the OpenDNS up on every computer your children use. If you want to do this, use the ‘The Ultimate Guide to Changing Your DNS Server’ linked below.
  2. If your children are tech-savvy enough to know how to set their device up to use a specific DNS server, they can bypass the router DNS altogether. Then a DNS filter set up on the router will not work, but then, I assume, no technical solution will be able to stop them from viewing pornography if that is what they want to do. 
  3. Mobile data bypasses your router altogether and goes straight to a cellphone tower. If your children switch their devices to mobile data, they can get access to any site the cellphone providers DNS allows. Some mobile providers allow you to set up a family filter option on the account. You may need to check with the provider if yours does. 
  4. This filter method will also not work if you use a VPN. VPN’s use their own DNS servers and unless your VPN provider has a DNS with a family filter, this will not work for you. However, a VPN is a simple way to get around this setup in case you want specific computers on your network to get around the filter. 

Talk to your children

The reality is that no filtering is 100% and most children will come across porn at some stage. This is why I recommend that you talk with your children about it, regardless of whether you set up this filter or not. There are many resources on this topic on the web and I included just a few of them below. 

References

This article was also published here.

Written by franzro | Product Design, Usability and UX, Frontend Development
Published by HackerNoon on 2021/09/23