Revision as of 21:45, 21 October 2024

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Wireless

DART-MX95 Overview

The DART-MX95 supports the following WiFi modules:

Module	Chipset	Features	Network Interface(s)
Sterling LWB	Cypress CYW4343W	802.11 b/g/n	wlan0
Sterling LWB5	Cypress CYW43353	802.11 ac/a/b/g/n,	wlan0
Murata LBEE5PL2DL	NXP IW611	802.11 a/ac/ax/b/g/n	wlan0, uap0, wfd0
Murata LBES5PL2EL	NXP IW612	802.11 a/ac/ax/b/g/n, 802.15.4	wlan0, uap0, wfd0

This guide demonstrates how to configure WiFi using systemd-networkd. It is important to use the correct network interface for the module assembled on your DART-MX95.

Managing WiFi using systemd-networkd

systemd-networkd is a system daemon that manages network configurations. It detects and configures network devices as they appear.
systemd-networkd's functionality can be useful for both wireless and wired networks.
This guide describes how to use systemd-networkd to configure wireless networks.

Enabling and disabling WiFi

To enable WiFi run

# networkctl up wlan0

To disable WiFi run

# networkctl down wlan0

Configuring WiFi Client

Scanning for available WiFi APs

If WiFi is enabled you can get the list of available APs by running

# iw dev wlan0 scan | grep SSID

Connecting to a protected WiFi network

Create /etc/systemd/network/80-wifi-station.network as following:

# cp /lib/systemd/network/80-wifi-station.network.example /etc/systemd/network/80-wifi-station.network

Append the following content to /etc/systemd/network/80-wifi-station.network:

"[DHCPv4]
"RouteMetric=9"
"[IPv6AcceptRA]"
"RouteMetric=9"

Create /etc/wpa_supplicant/wpa_supplicant-wlan0.conf with the following content:

"ctrl_interface=/var/run/wpa_supplicant"
"eapol_version=1"
"ap_scan=1"
"fast_reauth=1"
wpa_passphrase <SSID> <password>

Restart the services

# systemctl restart systemd-networkd.service
# systemctl restart wpa_supplicant@wlan0.service

Wait a few seconds and than make sure wlan0 is up and connected to the AP

# ifconfig wlan0

Configuring WiFi access point with hostapd

hostapd is a versatile tool for setting up a WiFi access point and generally offers more options and flexibility compared to NetworkManager.
For instance, hostapd enables the creation of a WiFi 6 access point, which is not currently possible with NetworkManager.
udhcpd is a suitable option for providing DHCP services alongside hostapd. It's a lightweight DHCP server that can be easily integrated with hostapd.

Create /etc/hostapd.conf

The next step is to create /etc/hostapd.conf. The following table shows how to configure 802.11bgn, 802.11ac, and 802.11ax access points:

Wi-Fi 2.4GHz (802.11bgn)
/etc/hostapd.conf

Wi-Fi 5 (802.11ac)
/etc/hostapd.conf

Wi-Fi 6 (802.11ax)
/etc/hostapd.conf

# /etc/hostapd.conf for 2.4 GHz (802.11b/g/n)
# AP Net Interface
interface=uap0

# 2.4 GHz
hw_mode=g

# Enable 802.11n (Wi-Fi 4) standard
ieee80211n=1
wmm_enabled=1

# Demo was run in the US
country_code=US

# Our SSID
ssid=Var_AP_2G

# Automatically select the best channel
# Notes about the LWB/LWB5 modules:
#  - For AP+STA, the channel must match the STA channel
#  - The LWB does not support auto channel selection.
#    We recommend using channel 1
channel=0

# /etc/hostapd.conf for Wi-Fi 5 (802.11ac)
# AP Net Interface
interface=uap0

# 5 GHz
hw_mode=a

# Enable 802.11ac (Wi-Fi 5) standard
ieee80211ac=1
wmm_enabled=1

# Demo was run in the US
country_code=US

# Our SSID
ssid=Var_AP_Wifi5

# Automatically select the best channel
# Notes about the LWB/LWB5 modules:
#  - For AP+STA, the channel must match the STA channel
#  - The LWB5 does not support auto channel selection.
#    For LWB5, we recommend using channel 36.
channel=0

# /etc/hostapd.conf for Wi-Fi 6 (802.11ax)
# AP Net Interface
interface=uap0

# 5 GHz
hw_mode=a

# Enable 802.11ax (Wi-Fi 6) standard
ieee80211ax=1
wmm_enabled=1

# Demo was run in the US
country_code=US
                                                       
# Our SSID
ssid=Var_AP_Wifi6

# Automatically select the best channel
channel=0

Add the Control interface directory and group to /etc/hostapd.conf:

# Control interface directory and group
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

Note: When copying the text above, your file may contain zero width spaces at the end of each line (appearing as `^^k` in nano or hex `e2 80 8b` in hexdump). This will cause hostapd to fail. You can fix it by running:

# sed 's/\xe2\x80\x8b//g' /etc/hostapd.conf > /etc/hostapd_cleaned.conf && mv /etc/hostapd_cleaned.conf /etc/hostapd.conf

Configure DHCP server

# Sample udhcpd configuration file (/etc/udhcpd.conf)
# The start and end of the IP lease block
start 192.168.5.20 #default: 192.168.0.20
end 192.168.5.25 #default: 192.168.0.254
# The interface that udhcpd will use
interface uap0 #default: eth0
#Example
opt dns 8.8.8.8 8.8.4.4 # public google dns servers
option subnet 255.255.255.0
opt router 192.168.5.1
option lease 864000 # 10 days of seconds

Then, assign uap0 an ip and start hostapd and udhcpd:

ifconfig uap0 192.168.5.1
sleep 1
systemctl restart hostapd
sleep 1
udhcpd /etc/udhcpd.conf

At this point, devices can connect and dhcp an ip address using the access point on uap0.

Optionally configure NAT between uap0 and eth0:

# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
# iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# iptables -A FORWARD -i uap0 -o eth0 -j ACCEPT

and allow ip forwarding:

echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

Now, devices connecting to the access point on uap0 will have network access through eth0.

Wifi SystemdNetworkd: Difference between revisions