Skip to content

Hotspot Configuration for Trixie OS

Up

This section describes how to configure a Raspberry Pi as a standalone Wi-Fi hotspot using NetworkManager, as provided by default in Debian Trixie / Raspberry Pi OS (Trixie).

Note: This configuration is not compatible with older Bookworm-style setups that relied on dnsmasq, iptables, or /etc/network/interfaces.

Overview

NetworkManager provides built-in support for:

  • Access Point (AP) mode
  • DHCP server for hotspot clients
  • NAT (masquerading)
  • IP forwarding

No additional network services or firewall rules are required for a basic hotspot.

Naming Conventions

In the following description, replace:

  • <SSID> with the intended hotspot SSID
    e.g. RaspiCamSrv01
  • <passphrase> with the WPA2 passphrase

The NetworkManager connection ID used throughout this document is:
RaspiCamSrv

1. Create the hotspot connection

sudo nmcli con add type wifi ifname wlan0 con-name RaspiCamSrv ssid <SSID> \
  connection.autoconnect yes

2. Configure hotspot parameters

Enable Access Point mode and WPA2 security:

sudo nmcli con modify RaspiCamSrv \
  802-11-wireless.mode ap \
  802-11-wireless.band bg \
  wifi-sec.key-mgmt wpa-psk \
  wifi-sec.psk "<passphrase>"

(Optional) Lock the Wi-Fi channel for improved stability:

sudo nmcli con modify RaspiCamSrv 802-11-wireless.channel 6

sudo nmcli con modify RaspiCamSrv ipv4.method shared

This automatically enables:

  • DHCP for hotspot clients
  • NAT (masquerading)
  • IPv4 forwarding

4. Activate the hotspot

sudo nmcli con up RaspiCamSrv

NOTE: If your SSH session uses Wi-Fi, the connection will now be lost.
Reconnection will use Ethernet.

5. Verify hotspot status

Check active connections:

nmcli con show --active

Check IP address assigned to the hotspot interface:

ip addr show wlan0

You should see an address in the range assigned by NetworkManager
(e.g. 10.42.0.1/24 or similar)

6. Setup mDNS

To provide host name resolution to clients, mDNS (Multicast DNS) can be used instead of a full-fledged DNS server.

Install and enable Avahi:

sudo apt install avahi-daemon
sudo systemctl enable avahi-daemon
sudo systemctl start avahi-daemon

With Avahi, you will need to connect to the Raspberry Pi with
<hostname>.local instead of <hostname> or IP address,
where <hostname> is the name given during OS Installation

7. Test hotspot access

  1. Disconnect the Ethernet cable
  2. Power-cycle the Raspberry Pi
  3. From a mobile device:
    -- Search for the Wi-Fi network <SSID>
    -- Connect using the configured passphrase
    -- Verify internet or local access
    -- With a Ping tool, try to ping <hostname>.local