Nextcloud Port Forwarding: TCP/UDP, AIO & CGNAT Fix

Ensure your Docker container maps host port 80 and 443. If using a reverse proxy (Caddy, Nginx Proxy Manager, or Traefik), bind Nextcloud internally and forward 80/443 directly to the proxy container. For deep syntax rules, see our Docker Port Forwarding Guide.

services:
  nextcloud:
    image: nextcloud:latest
    container_name: nextcloud-server
    restart: unless-stopped
    ports:
      - "80:80"       # Web (HTTP) - TCP
      - "443:443"     # Web (HTTPS TLS) - TCP
    environment:
      - OVERWRITEPROTOCOL=https
    volumes:
      - nextcloud_data:/var/www/html
volumes:
  nextcloud_data:

Even with correct router port forwarding, Nextcloud rejects external requests unless your public domain is explicitly declared in config/config.php. Add your DDNS hostname or custom domain:

'trusted_domains' => 
array (
  0 => '192.168.1.100',
  1 => 'cloud.yourdomain.com',
  2 => '203.0.113.50',
),
'overwrite.cli.url' => 'https://cloud.yourdomain.com',
'overwriteprotocol' => 'https',

Step 1: Access the FRITZ!Box Dashboard

Open your browser and navigate to http://fritz.box (or 192.168.178.1). Enter your FRITZ!Box administrator password.

Step 2: Add Device for Port Sharing (Gerät für Freigabe hinzufügen)

Go to Internet → Permit Access (Freigaben) → Port Sharing (Portfreigaben). Click Add Device for Sharing (Gerät für Freigabe hinzufügen). Select your Nextcloud server from the device dropdown list and verify that "Always assign this network device the same IPv4 address" is checked.

Step 3: Create HTTP & HTTPS Port Sharings

Scroll down to Port Sharings (Portfreigaben) and click New Sharing (Neue Freigabe):

• Rule 1 (HTTPS): Application: HTTPS-Server | Protocol: TCP | Port to device: 443 | Port shared externally: 443.
• Rule 2 (HTTP): Application: HTTP-Server | Protocol: TCP | Port to device: 80 | Port shared externally: 80.
• Rule 3 (Talk): Application: Custom (Andere Anwendung) | Protocol: UDP | Port to device: 3478 | Port shared externally: 3478.

Step 4: Enable Independent Port Sharing (Selbstständige Portfreigaben)

If using Nextcloud Talk with dynamic UPnP/PCP negotiation, check "Permit independent port sharing for this device". Click Apply (Übernehmen) to save. For additional FRITZ!OS troubleshooting, refer to our FRITZ!Box Port Forwarding Guide.