How to block websites in your office or home

Introduction

There are many different ways to block websites in your office or home, with varying levels of difficulty. Whether you're looking to stop your employees wasting time on Facebook or your kids accessing sites with adult content, these methods can help you out. I'll start with the easiest and then discuss the more complex methods.

Method 1: Router

The days of a single computer hooked up directly to a modem are in the past for most of us. Nowadays everyone has a router (usually with wireless capabilities) so they can share a single internet connection between several computers easily.

Most routers come with a website blocking feature. This is one of the simplest ways to block websites on your network. It's as simple as logging into your router and adding the sites that you'd like to block. Most routers will apply the blocks instantly without the need to restart the router. Just remember that most routers use an easy to guess default password, so be sure to change it!

	Easy to implement
	No additional cost
	No modifications required to computers on the network
	Usually each site must be individually blocked. No categories
	Can be easily bypassed with the use of web proxies

Tip

The most common way for people to bypass website blocks implemented on a small home or office router is with the use of a web proxy. Most web proxies use base64 encoding on the URL. So, for example, 'http://www.facebook.com' becomes 'aHR0cDovL3d3dy5mYWNlYm9vay5jb20='. You can use this commonality weakness to your advantage. If your router allows website blocking by keyword, you should add 'aHR0cDo' to the list. This will essentially block 99% of the free web proxies out there!

Method 2: openDNS

As part of their free, world wide, DNS service, openDNS provide a website blocking feature, allowing you to block individual sites like facebook.com or categories such as adult and social media networks.

Explanation

Although blocking sites with openDNS is quite easy to implement, it is a little more hands on than the router based blocking that we discussed above. The extra work pays off with the option to block categories of sites rather than having to know each individual domain to block.

Behind the scenes, the internet works by using IP addresses, e.g 127.0.0.1. Domain names were implemented to make it easier to remember and access a website. For example it's easier to remember a domain name like Facebook.com than the IP address 69.63.189.11.

When you surf to a domain name, like Facebook.com, your computer sends a query to a Domain Name System Server (DNS Server) which will then return the IP address of that domain, e.g 69.63.189.11. From there on, although your browser will show 'Facebook.com' in the address bar, it's really communicating with the site via it's IP address.

When someone on your network requests the IP address of a site that you've blocked, openDNS provides a false IP which leads the user to a 'blocked warning' site instead of the real site.

openDNS can only apply the settings/restrictions setup in your account if it knows your current IP address. This means that you ideally want to have a static IP address, this means that your IP address never changes. If your connection has a dynamic IP, meaning a new IP address is assigned every time your modem is restarted, I'd recommend you contact your ISP and request that you're swapped to a static IP. openDNS do offer free software for updating a dynamic IP in an openDNS network but I don't recommend this since it relies on you having the software running on a computer at all times.

How-To

This how-to assumes you're using a static IP address for your internet connection, as described above.

To use openDNS site blocking, you need to signup for a free account which will be tied to your IP address. Once logged into the openDNS site, you can add sites that you want to block or select blanket categories such as Nudity

Next you need to update your router to use the DNS servers of openDNS (208.67.222.222 and 208.67.220.220) instead of those provided by your ISP.

Once logged into the openDNS website, you can view stats via the dashboard. This will show which domains are regularly looked up, which domains it blocked and other useful information.

Tip

A great way to crack down on those trying to bypass the restrictions is to login to your openDNS control panel regularly and check the top domains in the stats section. If someone finds a way to bypass a restriction then they'll likely share it with others. You'll see any regularly visited sites in this top domains list and can review the website and decide whether it should be blocked or not.