Advanced Network Setup

For the captive portal to work correctly, the operating system must act as an access point and provide basic network services (DHCP and DNS).

1. Install Requirements

sudo apt update
sudo apt install hostapd dnsmasq

2. Network Interface Configuration

Assign a static IP to the WiFi hotspot interface:

sudo ip addr add 192.168.10.1/24 dev wlx1cbfce41183a
sudo ip link set wlx1cbfce41183a up

3. hostapd Configuration (Access Point)

Create or edit /etc/hostapd/hostapd.conf:

interface=wlx1cbfce41183a
driver=nl80211
ssid=My_WiFi_Network
hw_mode=g
channel=6
auth_algs=1
wmm_enabled=0
macaddr_acl=0
ignore_broadcast_ssid=0

To enable it, edit /etc/default/hostapd:

DAEMON_CONF="/etc/hostapd/hostapd.conf"

4. dnsmasq Configuration (DHCP and DNS)

Edit /etc/dnsmasq.conf:

interface=wlx1cbfce41183a
bind-interfaces
dhcp-range=192.168.10.10,192.168.10.100,255.255.255.0,12h
dhcp-option=3,192.168.10.1
dhcp-option=6,192.168.10.1,8.8.8.8
server=8.8.8.8

5. Start Services

sudo systemctl unmask hostapd
sudo systemctl enable hostapd
sudo systemctl restart hostapd

sudo systemctl enable dnsmasq
sudo systemctl restart dnsmasq

6. Common Troubleshooting

• Interface “Busy”: Configure NetworkManager to ignore the WiFi interface by adding to /etc/NetworkManager/conf.d/99-catsplash.conf:

  [keyfile]
  unmanaged-devices=interface-name:wlx1cbfce41183a

• DNS not responding: Check that port 53 is not blocked by systemd-resolved or another service.