As a nice little lockdown project I decided to up our home network security game a bit. And it was a good excuse to finally buy a Raspberry Pi. I’ve fancied one for years, but always worried it’d end up buried in a drawer not getting used.
I’ve been using Steven Black’s blocking scripts (https://github.com/StevenBlack/hosts)on my Mac for ages now, and they do cut down the amount of annoying ads and other distractions that cover the internet these days. Seemed rude to not have the same protection running on all the hosts in the house. I am just running the lists that block know advertising sites and malicious site. There are also lists to block adults sites, gambling sites and others if you want to restrict what your network can be used for.
But maintaining the lists across multiple machines would be a complete pain. The iOS devices don’t let you do it for a start, and some machines I’m not allowed to play with, like C’s work laptop.
Enter Pi-Hole which is basically a DNS server that implements Steven’s host lists at a network level. A DNS server is what turns Domain Names like stuart-moore.com into the IP Addresses that the internet actually runs on, which in this case would be 18.104.22.168
Pi-Hole works by stepping in between your hosts and the normal DNS, and if a request is made to a ‘bad’ domain then it will answer the request with the address 0.0.0.0 rather than forwarding it on for the real answer. Your browser will ignore this address and it’ll be like your request just fell into a black hole
It has a very simple, almost automated (almost!), install which will get you up and running pretty quickly. Steven’s various host lists can be selected, and you can add you own or from other sources as well
Installation and Hardware
There’s a lot of good PiHole installation documents out there so I’m not going to repeat them here. The one I used was the official one here is the one I followed
Hardware wise I ordered myself a Raspberry Pi 4 2GB kit from The Pi Hut. Came with almost everything I needed, the only extra bits I added were a heatsink and a Cat 5 cable as shamefully I don’t have any lying around the house now it’s all Wifi
2GB seemed plenty enough to run PiHole and some VPN stuff I wanted to use (more details on that in another post), and it saved a few sheckles.
The install went really easily and soon I have my own DNS server running on a fixed IP address. During the install I’d selected to have all external DNS queries relayed to Cloudflare’s DNS servers (22.214.171.124) via an encrypted channel, so no chance of them being sniffed. An extra layer of security there.
Now to make it really useful I had to get that address out to all of the devices on the network. This is where PlusNet comes in
Configuring it with PlusNet
We have a nice simple router that came with out PlusNet fibre. Years ago I used to have custom firmware and things, but having a bit of an SLA with C we went to something simple and easy that I wasn’t likely to break at an inopportune moment.
Unfortunately the PlusNet router doesn’t give you very much control over the networking settings. To make configuring all the devices (and any new ones) easy I wanted to push the new DNS IP address out via DHCP so they’d pick it up automatically.
While the PlusNet router gives you a few options to alter a very small number of configuration values, the DNS server address isn’t one of them. Turns out this has been a know issue with these PlusNet routers for a while, with a long running thread on the PlusNet forums complaining about it
So that option was out, but…..
The solution to the PlusNet problem
Luckily PiHole comes with a solution to this. It has it’s very own DHCP server built in! So all I had to do was to configure that. It’s very simple to do.
Once you installed Pi-Hole it provides you with a nice Web admin interface to configure it with. Under Settings you can find the DHCP opion:
All you need to provide is the range of IPs you want you devices to be on. Keeping it on the 192.168.1.x range makes it easier with the PlusNet router as they’ll all be on the same subnet.
2 things to note in my screen shot:
- A 1 hour lease is really short. I’ve set mine like that while I’m experimenting
- The PlusNet router gateway is 192.168.254, use that one. Mine is different due to my VPN setup
You can only have 1 DHCP server on a network or the clients get confused over which one to get their configuaration. Now that we have an alternative to the PlusNet DHCP server we need to disable DHCP on the PlusNet router
To disable it
login to you PlusNet router by going to http://192.168.1.254
Click on the ‘Advanced Settings’ button
Login using the password from the back of your PlusNet router
Continue to Advanced Settings
Select ‘Home Network’
Select ‘IP Addresses’
You should now be at a screen that look like this:
Tick No next to ‘DHCP Server Enable’. Then click on apply at the bottom right, confirm you’re sure, and you’re all done.
Your little Raspberry Pi and PiHole are now controlling your DNS and your DHCP settings for everything on your home network.
PiHole so far
I’ve only had mine in for a little less than a week, and we appear to be blocking about 8-10% of DNS queries atm. Which is a solid amount of web queries that we’re not having to transfer over the network, so things are feeling a bit speedier than before.
Also seeing fewer pop ups coming through, and some sites are much more readable without the inserted images and videos getting in the way.
Looking at the load averages on my little Pi, it seems to be coping with all this with it’s feet up. So there’s plenty of room to add some more bits and pieces onto it. I’ve already added an outbound VPN connection for our outgoing traffic and there’ll be more coming along as well
Adding the Pi-Hole was a simple and easy way to block out annoying internet adverts and potential malicious sites for every device on our network. If we had children then I’d definitely be using some of the stricter lists to keep an lid on what they could stumble across.
It would have been simpler if the PlusNet router allowed you to alter a few more settings, but disabling it only takes a few clicks through simple admin interfaces to sort out.