my working pi-hole & fritzbox setup

in linux, dns, pi-hole, fritzbox, note-to-self

As a note to myself, I write this post so that I never have to scrape this info from old threads and hallucinating LLMs again.

Required Hardware

• short micro-usb cable
• short cat5 ethernet cable (optional)
• Raspberry Pi 1/2 or Zero 2 W, optionally with ethernet adapter
• a working 8gb+ micro sd card, micro-to-full-size adapter if you are using Raspberry Pi 1

SD Card Setup

• download LATEST rpi-imager x86_64 AppImage - never use rpi-imager from os software repo
• chmod a+x <imager-binary> -> sudo ./<imager-binary>
• choose Raspberry Pi OS Lite:
  • scroll down
  • Raspberry Pi OS (other)
  • Raspberry Pi OS Lite (32-bit)
• set up the image
  • enable and set up wifi if you use it
  • enable remote access (ssh) with password
• flash image

First boot and fixed IP-Address and SSH Setup

• plug the ethernet cable into your Raspberry Pi and into your fritzbox
• plug the micro-usb cable into your Raspberry Pi then into the USB-A port of your fritzbox
• wait 1-2 minutes
• Log in to your fritzbox
• click Heimnetz -> Netzwerk
• find your Raspberry Pi (look for the name you gave it during image creation)
• click the pencil-icon in the table
• click Heimnetz-Tab of the detail view
• set IPv4-Adresse to something you like
  • I use 2 since it is lower than the default lower bound of the default fritzbox dhcp lease range (20)
• tick IPv4-Adresse dauerhaft zuweisen
• click Übernehmen and confirm any popups

At this point my fritzbox 7583 reliably crashes out and reboots. Nevermind, all settings are saved and your wifi/internet will be back after about 2 minutes.

Now, reboot your Raspberry Pi using ssh-password-login and the original ip-address or just pull the usb and connect it again

OS Setup & pi-hole Installation

locally, edit ~/.ssh/config and add:

Host pihole ph
  Hostname 192.168.178.2
  user pi

Change hostname to the IP you assigned in fritzbox ui and user to the username set during image creation, then save the file and run ssh-copy-id pihole.

Now, connect to your pi-hole host, then run sudo raspi-config, go to Advanced Options, select A1 Expand Filesystem. Confirm, reboot, wait.

Log in again, install pi-hole as described here.

Note the password that is displayed on the final view of the installer and follow the link displayed there to open the pi-hole web interface.

Fritzbox Setup

• Log in to your fritzbox
• click Heimnetz -> Netzwerk
• select Netzwerkeinstellungen Tab of detail view
• scroll down to Erweiterte Netzwerkeinstellungen
• click the button labelled Erweiterte Netzwerkeinstellungen
• select IPv4 Tab of detail view
• in the DHCP section enter the IP-Address of your pi-hole host in Lokaler DNS-Server
  • ⚠️ it is possible that Lokaler DNS-Server is completely empty. If so, write it down so you can revert to the empty value if you ever choose to.
• confirm
• confirm using required fritzbox 2FA option
  • I use random button on the device
• now, reboot or reconnect your devices and you should begin to see traffic in the pi-hole web interface

You're done - your pi-hole is working and every device on your network should use it!

RESETTING / REVERTING

If you want to stop using pi-hole, follow the steps above but enter the original value as Lokaler DNS-Server or leave it blank if it was blank/empty before!

Important note

The name and location of every button, tab and input I mention in this post may change at any time or can be different on your fritzbox model. The general concepts are the same, regardless of the button placement/label.

Extra stuff

This is strictly optional but it's what i want from my setup!

Disabling web interface password

I don't care for a password on my pihole web interface, so I run sudo pihole setpassword and hit return to turn it off.

enabling logrotate

logrotate will keep your logs small and limited to a few days. Run sudo cp /etc/.pihole/advanced/Templates/logrotate /etc/pihole/, then edit the copied file (sudo nano /etc/pihole/logrotate) to change the logrotate settings for pi-hole, FTL and webserver logs.

keeping query log short

To keep the database small and fast, edit the pihole.toml: sudo nano /etc/pihole/pihole.toml and change maxDBdays to a small value.