Debian to Router

Transform a Debian PC or Raspberry Pi into a fully functional Wi-Fi router with DHCP, DNS, and NAT capabilities.

Features

• Automatic interface detection: Finds Wi-Fi adapters supporting AP mode and connected Ethernet interfaces
• Complete router functionality: Hostapd (access point), dnsmasq (DHCP/DNS), iptables (NAT/forwarding)
• Persistent or temporary mode: Choose between one-time setup or automatic startup on boot
• Systemd service integration: Single service manages all components in correct order
• Resource optimization: Optional TTY-only mode to disable GUI and save resources
• Easy cleanup: Remove all configurations and restore original state

Requirements

• Debian/Ubuntu/Raspberry Pi OS (systemd-based)
• Root privileges
• Ethernet connection with internet access (WAN)
• Wi-Fi adapter supporting AP mode (nl80211 driver)
• NetworkManager installed

Check Wi-Fi AP support

iw list | grep -A 10 "Supported interface modes"
# Look for "AP" in the output

Installation

# Clone repository
git clone https://github.com/StenguyzCSGO/Debian-to-router.git
cd Debian-to-router

# Make executable
chmod +x router.sh

# Run as root
sudo ./router.sh

Usage

Interactive Setup

The script will prompt you for:

1. Wi-Fi network name (SSID): Your access point name
2. Password: Minimum 8 characters, WPA2-PSK encryption
3. Persistent mode: Enable automatic startup on boot
4. TTY mode (if persistent): Disable graphical interface to save resources

Post-Installation

After successful setup, the script is installed as:

sudo router-mode

Monitor services:

systemctl status router-mode.service
systemctl status hostapd dnsmasq
journalctl -u router-mode -f

Remove Configuration

sudo router-mode
# Answer 'y' to cleanup prompt

This removes all configurations, restores NetworkManager control, resets iptables, and re-enables GUI if disabled.

Default Configuration

Setting	Value
LAN Gateway	192.168.50.1
LAN Subnet	192.168.50.0/24
DHCP Range	192.168.50.50 - 192.168.50.150
DNS Servers	1.1.1.1, 8.8.8.8
Wi-Fi Channel	7 (2.4 GHz)
Encryption	WPA2-PSK

How It Works

Persistent Mode (Systemd Service)

1. Script copies itself to /usr/local/sbin/router-mode
2. Creates router-mode.service systemd unit
3. Service starts after network and NetworkManager
4. Configuration saved to /etc/router-mode/config
5. On boot: loads config, detects interfaces, starts hostapd/dnsmasq

Network Configuration

• Wi-Fi interface configured with static IP (192.168.50.1/24)
• NetworkManager releases control of Wi-Fi interface
• IPv4 forwarding enabled via sysctl
• NAT configured with iptables MASQUERADE
• Hostapd creates WPA2 access point
• Dnsmasq provides DHCP and DNS forwarding

File Locations

/usr/local/sbin/router-mode              # Installed script
/etc/router-mode/config                  # Saved configuration
/etc/systemd/system/router-mode.service  # Systemd service
/etc/hostapd/hostapd.conf                # Access point config
/etc/dnsmasq.d/router.conf               # DHCP/DNS config
/etc/NetworkManager/conf.d/ROUTER_MODE.conf
/etc/network/interfaces.d/ROUTER_MODE.conf
/etc/sysctl.d/99-router-ipforward.conf

TTY Mode (Console Only)

When enabled, the system boots to text console (TTY) instead of graphical interface:

Switch between TTY consoles:

• Ctrl+Alt+F1 to F6: Access TTY1-6
• Alt+F1 to F6: Switch TTY (when already in console)

Temporarily start GUI:

sudo systemctl start gdm3  # or lightdm/sddm

Permanently re-enable GUI:

sudo systemctl set-default graphical.target
sudo reboot

Troubleshooting

Service won't start:

journalctl -u router-mode -n 50
systemctl status hostapd --no-pager

Wi-Fi adapter not detected:

iw list  # Check AP mode support
nmcli device  # Verify interface detection

No internet on connected devices:

# Check NAT rules
sudo iptables -t nat -L -n -v

# Check IP forwarding
cat /proc/sys/net/ipv4/ip_forward  # Should be 1

# Verify WAN interface has internet
ping -I eth0 8.8.8.8

Interface blocked:

rfkill list
rfkill unblock wifi

Security Notes

• Use strong WPA2 passwords (minimum 8 characters)
• Configuration file /etc/router-mode/config is chmod 600 (root only)
• Consider firewall rules for production deployments
• Default configuration accepts all forwarded traffic (adjust iptables for restrictions)

Advanced Configuration

Edit /etc/hostapd/hostapd.conf for:

• Channel selection (channel=7)
• Wi-Fi band (hw_mode=g for 2.4GHz, hw_mode=a for 5GHz)
• Country code (country_code=US)
• Hidden SSID (ignore_broadcast_ssid=1)

Edit /etc/dnsmasq.d/router.conf for:

• DHCP lease time (12h)
• DNS servers (server=1.1.1.1)
• Static IP assignments
• Custom domain name

Restart services after changes:

sudo systemctl restart router-mode.service

License

MIT License - See LICENSE file for details

Contributing

Pull requests welcome. For major changes, please open an issue first.