Setting Up Pi-hole with DHCP and Static IP on a Debian Mac Mini

Goal

Transform an old Mac Mini into a dedicated Pi-hole server with full DNS and DHCP control. Ensure the system has a static IPv4 address to avoid losing connectivity on reboot or DHCP lease issues.

Environment

• Mac Mini (Intel) running Debian 12
• Pi-hole installed via curl method
• AT&T BGW320 router
• Pi-hole to serve DNS and DHCP

Install Pi-hole

curl -sSL https://install.pi-hole.net | bash

Selected options during guided setup:

• Interface: enp1s0f0
• IPv4 only (initially)
• Upstream DNS: OpenDNS + Cloudflare
• Enabled web UI and logging

Enable DHCP in Pi-hole

1. Log into http://pi.hole/admin
2. Go to Settings → DHCP
3. Enable DHCP server
4. Set range: 192.168.1.100 to 192.168.1.150
5. Gateway: 192.168.1.254

Disabled DHCP on the AT&T BGW320 router as much as allowed.

Bug Encountered: No IPv4 After Reboot

After rebooting the Mac Mini, Pi-hole failed to serve DNS. ip a showed only a 169.254.x.x address (self-assigned).

Diagnosis:

• Cause: Debian minimal install didn’t have dhcpcd
• Static IP config wasn’t applying
• DHCP fallback failed because Pi-hole was its own DHCP server

Fix: Install DHCP Client and Static IP Config

Step 1: Install dhcpcd

sudo apt update
sudo apt install dhcpcd5

Step 2: Edit /etc/dhcpcd.conf

At the bottom of the file:

interface enp1s0f0
static ip_address=192.168.1.78/24
static routers=192.168.1.254
static domain_name_servers=127.0.0.1

Step 3: Mistake I Made

Originally wrote:

static routers=192.168.1.254/24

This failed silently. Removing /24 fixed it.

Step 4: Restart DHCP Client

sudo systemctl enable dhcpcd
sudo systemctl restart dhcpcd

Confirmed Working

After reboot:

ip a

Showed:

inet 192.168.1.78/24 scope global enp1s0f0

Also confirmed:

nslookup google.com 192.168.1.78

Resolved correctly through Pi-hole.

Lessons Learned

• Always double-check interface names with ip a
• dhcpcd is not always installed by default on Debian minimal
• Syntax errors in dhcpcd.conf won’t necessarily throw errors — always verify with ip a
• Setting up DNS + DHCP on the same box is reliable with proper ordering and config

Written by Brian, for future reference and anyone troubleshooting Pi-hole static IPs on Debian.