MikroTik DNS Switcher

A simple web app for self-hosting enthusiasts who want to selectively enable Pi-hole (or other DNS servers) on a per-device basis through their MikroTik router.

Why This Exists

Like many self-hosters, I love Pi-hole for blocking ads on smart TVs and IoT devices where browser ad-blockers can't help. But running it network-wide breaks things unexpectedly and causes family complaints.

The solution: Make Pi-hole opt-in per device instead of network-wide.

• Default: Everyone uses normal DNS (ISP, Google, Cloudflare, whatever)
• When needed: Toggle Pi-hole on for specific devices that benefit from it
• Smart TVs: Always use Pi-hole (they're ad-spam machines anyway)
• Your devices: Switch Pi-hole on/off as needed
• Quick fixes: Temporarily disable Pi-hole when troubleshooting

It works by tweaking DHCP lease entries on your MikroTik router via the API, so each device can have its own DNS settings.

Quick Start

Docker (Recommended)

git clone https://github.com/DanielHreben/mikrotik-dns-switcher.git
cd mikrotik-dns-switcher

# Configure environment
cp .env.example .env
nano .env  # Edit with your MikroTik details

# Start
docker-compose up -d

Open http://localhost:3000 or http://your-server-ip:3000

nginx-proxy (Optional)

For nginx-proxy deployments with automatic reverse proxy:

# Add VIRTUAL_HOST to your .env
echo "VIRTUAL_HOST=dns-switcher.yourdomain.com" >> .env

# Use the nginx-proxy compose file
docker-compose -f docker-compose.nginx-proxy.yml up -d

Environment Variables

Edit .env with your setup:

MIKROTIK_HOST=192.168.88.1        # Your router's IP
MIKROTIK_USERNAME=admin           # Router username  
MIKROTIK_PASSWORD=your-password   # Router password
CUSTOM_DNS=192.168.1.100          # Your Pi-hole IP (or 8.8.8.8)

MikroTik Setup

Enable API on your router:

/ip service enable api
/ip service set api port=8728

Development

# Clone and install
git clone https://github.com/DanielHreben/mikrotik-dns-switcher.git
cd mikrotik-dns-switcher
yarn install

# Configure and run
cp .env.example .env
nano .env
yarn start

API Testing

You can manage specific devices by adding the X-Real-IP header:

curl -H "X-Real-IP: 192.168.1.100" http://localhost:3000/api/dns

API

Method	Endpoint	Description
GET	/api/dns	Check DNS status
PUT	/api/dns	Switch to custom DNS
DELETE	/api/dns	Reset to default DNS

Troubleshooting

• Can't connect to MikroTik: Check IP/credentials, ensure API is enabled
• DNS changes not sticking: Try disconnecting/reconnecting WiFi, some devices cache DNS
• Check logs: docker-compose logs -f

About

Built this for my own home network and figured others might find it useful. Just a hobby project - feel free to fork it or send PRs if you find bugs!

Apache License 2.0 - do whatever you want with it.