Building a Pi-hole with Raspberry Pi for Enhanced Home Network Security

Why DNS Is the Most Overlooked Security Layer in Your Home Network

Every time you open a browser, launch an app, or your smart TV phones home, your device starts with a DNS query — a request to translate a domain name into an IP address. By default, those queries travel in plaintext to your ISP’s DNS servers. Your ISP can log every domain you visit, advertisers can track your browsing patterns, and a compromised DNS response can redirect you to a malicious server without you ever knowing.

Pi-hole fixes this at the network level. It runs on a small device inside your home network and acts as a local DNS resolver. Every device on your network — phones, laptops, smart TVs, IoT gadgets — sends its DNS queries to Pi-hole first. Pi-hole checks those queries against curated blocklists and drops any requests to known ad networks, trackers, or malicious domains before a connection is ever established.

The result is network-wide protection without installing anything on individual devices, and dramatically reduced ad and telemetry traffic across your entire household.

How DNS Sinkholing Works

Browser-based ad blockers work by removing elements from a webpage after it loads. Pi-hole is fundamentally different — it works at the DNS layer, which means blocked connections are never initiated in the first place. When a device asks for a tracking domain, Pi-hole responds with a non-routable IP address (0.0.0.0) and the connection dies immediately.

Because the blocked connection never reaches the ad or tracking server, you also save bandwidth and reduce page load times. Malvertising scripts — malicious code embedded in ad networks — can’t execute if they can’t load.

Hardware Options

Pi-hole is lightweight enough to run on almost anything that can run Linux. You don’t need dedicated hardware, though it helps for reliability.

Minimum requirements:

• RAM: 512 MB (1 GB or more recommended for large blocklists or busy networks)
• Storage: 8 GB MicroSD (Class 10 or better), or an SSD for more reliable long-term operation
• Network: Wired Ethernet preferred for a device acting as your DNS server

Step-by-Step Deployment

1. Prepare the Operating System

If you’re using a Raspberry Pi, start with Raspberry Pi OS Lite (64-bit). Use the Raspberry Pi Imager to flash it, and take advantage of the advanced options to configure a custom user account, enable SSH, and set up SSH key authentication before you even boot the device.

Assign a static IP address. A DNS server that changes its IP address will break your entire network. The cleanest approach is to configure a DHCP reservation on your router using the Pi’s MAC address. If you prefer to configure it on the device itself, edit the network configuration:

# Static IP configuration for eth0 (legacy dhcpcd method)
interface eth0
static ip_address=192.168.1.50/24
static routers=192.168.1.1
static domain_name_servers=127.0.0.1

For systems using NetworkManager or systemd-networkd, refer to your distro’s documentation for the equivalent static IP configuration.

2. Install Pi-hole

The official installer is a shell script. Many guides tell you to pipe it directly into bash from a URL — don’t do that blindly. Download it first, check what it does, then run it:

# Download the installer locally
curl -sSL https://install.pi-hole.net -o basic-install.sh

# Inspect it before running
less basic-install.sh

# Run the installer
sudo bash basic-install.sh

During the interactive setup:

• Interface: Select your active network interface (eth0 for wired Ethernet).
• Upstream DNS: Choose a privacy-respecting upstream resolver. Quad9 (9.9.9.9 / 149.112.112.112) offers built-in malicious domain blocking. Cloudflare (1.1.1.1) is fast and privacy-focused. You’ll replace this with Unbound later if you want full recursive resolution.
• Web Interface: Enable it — the dashboard is genuinely useful for monitoring and managing blocklists.
• Query Logging: Turn this on. Being able to see DNS queries in real time is invaluable for spotting compromised devices or misconfigured apps.

After installation, Pi-hole will display an admin password. Copy it immediately, then set a custom one:

# Pi-hole v5 and earlier
pihole -a -p

# Pi-hole v6+
pihole setpassword

Advanced Security Configurations

1. Local Recursive Resolution with Unbound

Even with Pi-hole filtering your traffic, forwarding queries to a public resolver like Cloudflare or Google means those companies log every domain your network requests. Unbound eliminates that data leak entirely.

Instead of forwarding to a commercial resolver, Unbound contacts the root DNS servers directly and resolves domain names by walking down the DNS hierarchy itself — no third party involved.

Install Unbound:

sudo apt update && sudo apt install unbound -y

Create the Pi-hole configuration file:

sudo nano /etc/unbound/unbound.conf.d/pi-hole.conf

Paste the following hardened configuration:

server:
    verbosity: 1
    interface: 127.0.0.1
    port: 5335
    do-ip4: yes
    do-udp: yes
    do-tcp: yes
    do-ip6: no

    # Root hints file for bootstrapping recursive resolution
    root-hints: "/var/lib/unbound/root.hints"

    # DNSSEC validation
    auto-trust-anchor-file: "/var/lib/unbound/root.key"

    # Buffer and cache sizing
    so-rcvbuf: 4m
    so-sndbuf: 4m
    msg-cache-size: 64m
    rrset-cache-size: 128m
    infra-cache-numhosts: 10000

    # Security hardening
    harden-glue: yes
    harden-dnssec-stripped: yes
    use-caps-for-id: no
    edns-buffer-size: 1232
    prefetch: yes
    num-threads: 1

    # Block private IP responses from public DNS (DNS rebinding protection)
    private-address: 192.168.0.0/16
    private-address: 169.254.0.0/16
    private-address: 172.16.0.0/12
    private-address: 10.0.0.0/8

Restart Unbound:

sudo service unbound restart

Point Pi-hole at Unbound: In the Pi-hole Admin Console, go to Settings > DNS, remove any public upstream resolvers, and enable Custom 1 (IPv4). Enter 127.0.0.1#5335 and save. Pi-hole will now forward non-blocked queries to your local Unbound instance rather than a commercial resolver.

2. Curated Threat Intelligence Blocklists

Pi-hole ships with a default blocklist focused on advertising domains. To extend coverage to malware, command-and-control infrastructure, and IoT telemetry, add curated blocklists from the security community.

Firebog’s Curated Lists is the most widely used collection. Lists highlighted in green are vetted to cause the fewest false positives for normal browsing.

To add a list:

1. Open the Pi-hole Admin Console and go to Adlists (or Group Management > Adlists in newer versions).
2. Paste the list URL and click Add.
3. Update the blocklist database:

   pihole -g
   

Update your blocklists regularly. Threat intelligence feeds track active phishing and malware campaigns, and stale lists miss new infrastructure.

3. Blocking Smart TV and IoT Telemetry with Regex

Modern smart devices are aggressive about phoning home. You can write custom regular expressions in Pi-hole to block entire families of tracking domains rather than adding entries one by one.

In the web panel, go to Domains, select the RegEx filter tab, and add patterns like these:

# Samsung Smart TV telemetry
^(.+[_.-])?samsungcloudplatform\.com$

# LG smart ad tracking
^(.+[_.-])?ad\.lgsmartad\.com$

# Windows diagnostic telemetry
^(.+[_.-])?telemetry\.microsoft\.com$

Adjust based on the devices on your network. The query log will show you exactly which domains your devices are trying to reach, making it straightforward to identify new telemetry patterns.

Configuring Your Router

Pi-hole only blocks traffic from devices that use it as their DNS server. The most effective way to ensure every device on your network goes through Pi-hole is to configure your router to hand out the Pi-hole’s IP address as the DNS server via DHCP.

1. Log into your router’s admin panel (usually 192.168.1.1 or 192.168.0.1).
2. Find the DHCP settings for your LAN — not the WAN DNS settings.
3. Set DNS 1 to Pi-hole’s static IP (e.g., 192.168.1.50).
4. Do not add a public fallback DNS. If you set a secondary like 8.8.8.8, client operating systems will round-robin between both servers and a significant portion of your queries will bypass Pi-hole entirely. For redundancy, run a second Pi-hole instance instead.
5. Renew leases on connected devices by restarting them or toggling airplane mode on mobile devices. On Windows, run ipconfig /flushdns.

Maintenance and Troubleshooting

Monitor the query log. The Query Log in the web interface shows DNS requests in real time. If a site stops loading after you set up Pi-hole, check for red entries — those are blocked domains. If you identify a false positive, whitelist the specific domain rather than disabling the entire blocklist.

Secure remote access to the admin interface. Never expose Pi-hole’s web port to the internet. If you need to manage it from outside your home network, install Tailscale or WireGuard on the Raspberry Pi and connect via VPN. You’ll also get the benefit of Pi-hole’s DNS filtering while you’re away from home.

Useful CLI commands:

# Check Pi-hole status
pihole status

# Generate a diagnostic debug log
pihole -d

# Restart the DNS service
pihole restartdns

# Update Pi-hole itself
pihole -up

Wrapping Up

Pi-hole is one of the most effective privacy and security improvements you can make to a home network, and it requires zero changes on individual devices. Once it’s running, every phone, laptop, and IoT gadget benefits automatically.

Pair it with Unbound for fully private recursive resolution, add curated threat intelligence blocklists, and block telemetry domains with regex rules — and you’ve built a genuine security layer, not just an ad blocker.

Before anything breaks your setup: Use the Teleporter tool in Settings > Teleporter to export your configuration and blocklists. SD cards fail, and being able to restore your Pi-hole in minutes rather than hours is worth the two minutes it takes to make a backup.