# WebDAV External Access Troubleshooting Guide

## Problem
WebDAV works on intranet but fails from external networks with "Connection refused" error.

## Common Causes and Solutions

### 1. Service Bound to Localhost Only

**Symptom:** Service only listens on `127.0.0.1` or `::1` instead of all interfaces.

**Solution:**
- **Apache:** Change `Listen 127.0.0.1:5006` to `Listen 0.0.0.0:5006` or `Listen *:5006`
- **Nginx:** Change `listen 127.0.0.1:5006;` to `listen 0.0.0.0:5006;` or `listen *:5006;`
- **Other services:** Ensure binding to `0.0.0.0` or `*` instead of `localhost`/`127.0.0.1`

**Check:**
```bash
netstat -tuln | grep 5006
# or
ss -tuln | grep 5006
```

If you see `127.0.0.1:5006` or `::1:5006`, the service is only accessible locally.

### 2. Firewall Blocking Port 5006

**Solution:**

**UFW (Ubuntu/Debian):**
```bash
sudo ufw allow 5006/tcp
sudo ufw reload
```

**firewalld (CentOS/RHEL):**
```bash
sudo firewall-cmd --permanent --add-port=5006/tcp
sudo firewall-cmd --reload
```

**iptables:**
```bash
sudo iptables -A INPUT -p tcp --dport 5006 -j ACCEPT
sudo iptables-save
```

### 3. Router Port Forwarding Not Configured

**Solution:**
1. Access your router's admin panel
2. Navigate to Port Forwarding / Virtual Server settings
3. Add rule:
   - **External Port:** 5006
   - **Internal IP:** Your NAS IP address (e.g., 192.168.1.100)
   - **Internal Port:** 5006
   - **Protocol:** TCP
4. Save and apply changes

### 4. Router Firewall Blocking Incoming Connections

**Solution:**
- Check router firewall settings
- Ensure port 5006 is allowed for incoming connections
- Some routers have separate WAN firewall rules

### 5. ISP Blocking Port 5006

**Solution:**
- Some ISPs block certain ports
- Try a different external port (e.g., 5007, 8080)
- Update port forwarding to use the new port

### 6. Service Not Running or Crashed

**Check service status:**
```bash
# For systemd services
systemctl status webdav
# or
systemctl status apache2
# or
systemctl status nginx

# Check if process is running
ps aux | grep -i webdav
```

**Restart service:**
```bash
sudo systemctl restart webdav
# or
sudo systemctl restart apache2
# or
sudo systemctl restart nginx
```

### 7. NAS-Specific Configuration

**Synology NAS:**
1. Control Panel → External Access → Router Configuration
2. Enable port forwarding for port 5006
3. Control Panel → Security → Firewall
4. Ensure port 5006 is allowed

**QNAP NAS:**
1. Network & Virtual Switch → Port Forwarding
2. Add rule for port 5006
3. Security → Firewall → Allow port 5006

**Other NAS:**
- Check NAS admin panel for port forwarding/firewall settings
- Ensure WebDAV service is enabled and configured for external access

## Diagnostic Steps

1. **Run the diagnostic script:**
   ```bash
   chmod +x diagnose_webdav.sh
   sudo ./diagnose_webdav.sh
   ```

2. **Test local connection:**
   ```bash
   curl -k -X PROPFIND https://localhost:5006
   # or
   curl -k -X PROPFIND https://127.0.0.1:5006
   ```

3. **Test from internal network:**
   ```bash
   curl -k -X PROPFIND https://<NAS_INTERNAL_IP>:5006
   ```

4. **Test from external network:**
   ```bash
   curl -k -X PROPFIND https://jimmygan.myds.me:5006
   ```

5. **Check if port is reachable externally:**
   ```bash
   # From external network
   telnet jimmygan.myds.me 5006
   # or
   nc -zv jimmygan.myds.me 5006
   ```

## Quick Fix Checklist

- [ ] Service is bound to `0.0.0.0:5006` (not `127.0.0.1:5006`)
- [ ] Firewall allows port 5006
- [ ] Router port forwarding configured (External 5006 → Internal NAS IP:5006)
- [ ] Router firewall allows incoming connections on port 5006
- [ ] WebDAV service is running
- [ ] Tested local connection (works)
- [ ] Tested internal network connection (works)
- [ ] External connection still fails → Check ISP/port blocking

## Additional Notes

- **DDNS:** Your domain `jimmygan.myds.me` appears to be a DDNS service. Ensure it's properly configured and pointing to your current external IP.
- **HTTPS:** Since you're using HTTPS, ensure SSL certificate is valid and the service is configured for SSL/TLS.
- **IPv6:** The error shows IPv6 connection attempts. If your router/NAS doesn't support IPv6 properly, you may need to disable IPv6 or configure it separately.