Raspberry Pi – Useful Network Utility + DNS Blocker

Over the Holidays, I get a little free time to get back into the entertainment side of computers and electronics. Last week, I noticed some websites starting to load slower than normal. I jumped into the firewall logs and noticed the advertisements were doing massive DNS queries. Some websites were making 50-200 connections every second in an attempt to load as much click through and advertisement as possible. I took all of the DNS names from my firewall log, ran my quick DNS Lookup Powershell Script to lookup all of the possible IP addresses hidden behind that DNS name, then blocked all of it in my firewall. These few websites forced me to block a few Class C subnets and forty-five single IPs. After this firewall config update, pages loaded instantly again. This is a lot of work to do every few months to keep up with the changing advertisement landscape.
I know a lot of pay-for appliances exist for the enterprise to block advertisements and “bad sites” but I never gave it much thought to research the raspberry Pi offerings. I needed something quick, automatic, and very low cost + low power.

My bro @EuroBrew told me about this software for the Raspberry Pi called “Pi-Hole” — Website here https://pi-hole.net/
After installing it, I am impressed. The web-based Admin GUI is great. You can edit, add or remove items to your black+white list on the fly. It even has fancy graphs to show you how many items were blocked. Pi-Hole was running for two minutes and with a few seconds of Facebook Traffic from the wife, it had already started to show some big numbers. Summary: You don’t know what you accessing until you see how much is blocked.

The Dashboard:


Even though you are accessing a single website, it’s amazing how many other sites are accessed without you even noticing. Again, within that two minutes of activity, thinking that facebook would be the top site accessed, here are the top URLs.


Now, let me help you get this installed in your home lab!

Here are my quick steps to get this going:
1 – Download the updated version of Raspbian — I recommend the lite version https://www.raspberrypi.org/downloads/raspbian/
2 – Use their website if you need assistance to get a clean Raspberry Pie setup.
— Use an image tool to image your SD Card
— Boot up your RasbPi with the new image and configure the Timezone + Keyboard.
—- It is important to make sure your “|” key works…. UK version of the keyboard has issues so change it to US.
—- You can do this with the “sudo raspi-config” command + menu system.
3 – Now configure your RaspPi with a static IP. The Pi-Hole installer will help you with that but its way faster to do it now.
— You edit the /etc/dhcpcd.conf file with “sudo nano /etc/dhcpcd.conf” and change the static settings for your eth0 interface.
4 – Now you can run the pi-hole installer with “curl -L https://install.pi-hole.net | bash”
— Capital L and vertical line is a must for that command.
— This will fail if DNS isn’t working so check your network settings with an ifconfig if you are having issues.
5 – When the installer is complete, it will give you a Password to write down….. Don’t forget to do this!
— You can also change the password after the installed is finished with command “pihole -a -p mynewpassword123”
6- From a browser, go to your new Pi-Hole install via http://x.x.x.x/admin and configure it.
— Click Login on the left window.
—- From here you have access to Settings where you can correct any missed settings, or change your Temperature Units from Celsius to Fahrenheit.

Now, update your PC, Wireless, router settings to use your RaspPi as your DNS server and you are done.
You can go into great detail to add additional blocks so hit the google search box for that.