Pi-hole Network DNS

A Raspberry Pi running Pi-hole as the DNS server for my home network, filtering ads and trackers for every device before queries ever leave the LAN. It's the first service in my homelab and the one that taught me the most about DNS, DHCP, and troubleshooting infrastructure you actually depend on every day.

• Part of: my_home_lab
• Portfolio: uploadtigris.github.io

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What it does

Pi-hole is a DNS sinkhole: it sits between every device on the network and the upstream resolvers, answering queries for ad/tracker domains with a dead end and forwarding everything else on. One box, configured once, cleans up browsing for every phone, laptop, and TV on the network — no per-device client needed.

• Network-wide ad and tracker blocking at the DNS layer
• Upstream resolution via Cloudflare (1.1.1.1), with Google (8.8.8.8 / 8.8.4.4) as fallback
• Block lists: StevenBlack's Unified Hosts list plus HaGeZi's Pro list (~170k+ additional domains)
• Query logging and the Pi-hole admin dashboard for visibility into what's being asked for

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Hardware & software

Device	Raspberry Pi 2 Model B
OS	Debian Trixie (32-bit), headless
Connection	Wired Ethernet to the router for stability
Addressing	Static IP so every client can rely on it as DNS

Full step-by-step build (imaging the SD card, enabling SSH, installing Pi-hole, setting the static IP, and pointing the router at it) is written up here: Pi-hole Setup Guide →

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How it fits the network

Pi-hole now lives in the Servers VLAN (October 2026). pfSense hands out its address as the DNS server on the Mgmt, Trusted, IoT and Servers networks, and the firewall forces Trusted and IoT through it by blocking DNS to anywhere else. Guest uses its own pfSense gateway for DNS and never touches Pi-hole. See network-segmentation-ids.

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Troubleshooting write-ups

Running DNS for the whole house means when Pi-hole breaks, the internet "breaks" for everyone — which makes it a great teacher. Two real failures I diagnosed and wrote up as I went:

1. The DNS server that quietly stopped resolving. After a restart, the Pi came up on a new DHCP address instead of holding its static IP, which broke DNS network-wide — the tell was exactly one query per hour showing up in the logs. I tracked it down, pinned the address properly, and wrote up the fix. → LinkedIn write-up

2. The "404" that turned out to be a corrupted install. The admin console started returning a 404 and apt upgrade threw package errors. I power-cycled, confirmed the Pi was reachable with arp -a, forced a filesystem check (sudo touch /forcefsck), and worked through apt --fix-broken install and dpkg --configure -a. The root cause was a corrupted Pi-hole install, not a dying SD card, so reinstalling from the official script brought it back — no reflash needed. → LinkedIn write-up

Both are examples of how I document every fix: what broke, how I found it, what I changed, and what I'd watch next time.

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What's in this repo

Path	What it holds
README.md	What it does and how it fits the network
docs/01_setup-guide.md	Full build: SD card, SSH, install, static IP, router DNS
docs/02_reinstall-after-power-outage.md	Rebuilding the Pi after a power outage
images/	Screenshots

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Everyday commands

# Find the Pi on the network (ping sweep, no port scan)
sudo nmap -sn 192.168.1.0/24

# Update Pi-hole
pihole -up

# Live-tail the DNS query log
pihole -t

# Set / reset the admin password
sudo pihole setpassword

Admin dashboard: http://<pi-hole-ip>/admin

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Skills this project exercises

DNS · DHCP & static addressing · nmap · arp · SSH · Raspberry Pi · Linux (Debian) administration · troubleshooting & documentation