New year, new flat, and new home infrastructure. With so many machines connected to the network, I want to try again a home DNS server so that I don't need to remember all the IPs in my LAN. That is my goal, and if it serves as a base for further browsing experience improvement, then welcome.
In this article I intend to setup a DNSMasq minimally for my network.
I've been collecting few Raspberry Pi that have some spare use, mostly try ups of systems before I go serious in DigitalOcean, or I surrender and buy a Synology to do confident NAS. Anyhow, I have a network of around 15 devices and a DNS starts to be necessary as I really don't want to remember all their IPs.
Last iteration was a PiHole over a Raspberry Pi 3B+. It was a great project that ran ok-ish in that machine but suffered from my annoying Vodafone router, which wouldn't let me set up stuff and therefor I couldn't make my own DNS server to be delivered with the DHCP config to the machines, plus some issues due to the tricky setup. Unstable internet connection and miserable overall experience, I won't go that route again. But while fighting with the PiHole I got to know DNSMasq and had the whole time the idea that with it should suffice.
This time I want it simple: the lowest Raspberry Pi I have around and DNSMasq, and let's see.
Let's leave this clear: I just want one step further than a
/etc/hosts file in every machine. I want that the DHCP server in my router delivers my local name server address, which will resolve the names for the machines in my local network and the rest just upstream as usual. And has to be children level easy to maintain and set up.
I am explicitly not going for a sink hole, or a DNS cache, or any other of the benefits that DNSs have and that I will explore later on.
I have all other Raspberries scheduled with future plans, so I can only use this Raspberry 2B+. As you can see in the specs, it is only 100 Mb Ethernet, and I have my concern if it will endure correctly in a local network environment, but I guess that the load for name resolving should not be that huge. That will be something I will study.
Well, in internet are plenty of tutorials and set-by-step how-tos on how to get a working RPi. I won't go deep here, but just for the record:
In your own computer, download the Raspberry Pi Imager
Insert your Micro-SD card
Choose the Raspberry Pi OS Lite (32-bit) and the location of your Micro-SD card.
I would recommend to press the Settings button (the round gear) and adjust some of the settings there, as I intend to do it headless. Follow this nice tutorial, and don't forget to set up the SSH access!
Write the Micro-SD card
Plug it into the Raspberry
Connect the power and wait some minutes
Go to your router's network section to see the Raspberry getting connected and with what IP. If you don't have that, you can always run the following shell command (Mac and Linux). Just replace the
$INTERFACE with the name of the interface you use to connect to the network (like
$ sudo arp-scan --interface="$INTERFACE" --localnet
SSH to your machine and finish the installation by firing the
raspi-config and by setting a static IP, using
dhcpcd in my case (this is important, you want a static address for your DNS server, right?)
Reboot, and there you go.
So we have the RPi up and running, we SSH into it and we're ready to go. From the several options that we have, I chose DNSMasq as I discovered it in the past and I can only see benefits:
Update the system. In my case took a while:
$ sudo apt update
$ sudo apt upgrade
Install the DNSMasq package
$ sudo apt install dnsmasq
Done, DNSMasq is in our system
The configuration of the server is done by editing the file in
Make a backup of the config file
$ cp /etc/dnsmasq.conf ~/dnsmasq.conf.backup
Edit the configuration file
$ sudo nano /etc/dnsmasq.conf
bogus-priv parameter. They prevent packets with malformed domain names and packets with private IP addresses from leaving the network.
domain= parameter, and set a value for it, for example:
domain=local. This way all local machines defined in the
/etc/hosts will acquire a domain suffix, in the example the host
alderaan.local, which has some further advantages.
resolv-file= parameter and place the following value
resolv-file=/etc/resolv.dnsmasq.conf. This is telling where to find a file where we have set up the upstream nameservers. We go there in a second.
ctrl + o and exit with
ctrl + x
Now we create the file with the upstream servers:
Open nano with a new file, that is the name we used in the previous point 5.
$ sudo nano /etc/resolv.dnsmasq.conf
We add one line like the following per name server (where
[ip] is the name server IP we want to set up):
In my case, I added the following:
The 2 first ones are the primary and secondary DNSs from Cloudflare, and the 2 last ones are the primary and secondary DNSs from Quad9. You can choose yours from this article (nice explanation, BTW).
ctrl + o and exit with
ctrl + x
And now comes the goal achievement: to set up the dictionary that tailors the names and the IPs of the local machines. This is no more than just setting up the
/etc/hosts file in the DNS server machine, and it will be picked up and used. So simple.
Make a backup of the file
$ cp /etc/hosts ~/hosts.backup
Edit the file
$ sudo nano /etc/hosts
Add all the name / IP pairs that define the machines in the network. Here's my whole file at this point:
::1 localhost ip6-localhost ip6-loopback
ctrl + o and exit with
ctrl + x
Now the only thing left is to restart the DNSMasq server for the changes to take effect:
$ sudo service dnsmasq restart
We can also check the status of the server by running:
$ sudo service dnsmasq status
Here we have 2 main options:
For the local machines that are set up with static IPs, the only option is to do the first point. As I have all the RPi machines set up with
dhcpcd I have to go one by one and change the
/etc/dhcpcd.conf where I have defined the
static domain_name_servers parameter to point to
192.168.0.231 (My DNS server's IP)
For the local machines that read from DHCP, which are the majority (laptops, phones, tablets, ...) I only need to go to the router and tell that he has to distribute another IP for the DNS server.
At this point, all the infrastructure is prepared. The new clients in the network will request to the DCHP the network config and will receive the new DNS local server. Just remember the DHCP clients that are currently connected to the network, they need to refresh the network parameters.
While the previous PiHole approach kept me working for several days, this approach was done during a closing day moment in the bed with the laptop in my lap and working straight away. All actions get summarized here:
Really really simple 😊
After executing all these actions, I realized that maybe I was a bit over complicating the nameserver set up for the upstream: wanting to keep it simple, we can even have it set up in the
dnsmasq.conf. It would reduce the files to only one, but still make sense to me to have it externalized (but then we could also externalize other parameters too)
I remember tunning up a bit the DNS server in the PiHole and there are other parameters I'd love to try. Also there are plenty of articles (like this one) suggesting approaches here and there, that are interesting to consider. Will happen soon 😊