Wifi SystemdNetworkd
DART-MX95 Overview
The DART-MX95 supports the following WiFi modules:
| Module | Chipset | Features | Network Interface(s) |
|---|---|---|---|
| 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
To set your network's SSID and password:
# wpa_passphrase <SSID> <PASSWORD> >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
Enable Wi-Fi interface:
# networkctl up wlan0
Restart the services:
# systemctl restart systemd-networkd.service # systemctl restart wpa_supplicant@wlan0.service
Wait a few seconds and then check if wlan0 is up and has an assigned IP:
# ifconfig wlan0
Check if the gateway and the DNS server are reachable:
# ping -I wlan0 192.168.1.1 # ping -I wlan0 8.8.8.8
To make the Wi-Fi connection permanent, enable the wpa_supplicant service:
# systemctl enable wpa_supplicant@wlan0.service
If wlan0 fails to connect, the following commands may be helpful for debugging:
# journalctl -u wpa_supplicant@wlan0.service # journalctl -u systemd-networkd.service # wpa_cli
Configuring WiFi Access Point with Hostapd
hostapd is a versatile option for setting up a WiFi access point. It offers more options and flexibility compared to other tools.
For instance, hostapd can even enable the creation of a WiFi 6 access point.
udhcpd is a suitable option for providing DHCP services alongside hostapd. It's a lightweight DHCP server that can be easily integrated with hostapd.
The following steps describe how to create an access point using hostapd and udhcpd.
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 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.
Testing WiFi throughput
Establish connection to WiFi network and use iperf3 tool on target and another host:
iperf3 server (on Target/Host):
# iperf3 -s
iperf3 client (on Host/Target):
Run UDP test for 30 seconds # iperf3 -c <IP_ADDRESS_OF_IPERF_SERVER> -t 30 -u -b 0
Run TCP test for 30 seconds # iperf3 -c <IP_ADDRESS_OF_IPERF_SERVER> -t 30
Note on DART-MX95 WiFi Initialization
WiFi is initialized by /etc/wifi/variscite-wifi. During initialization, the Linux device tree model property is read from /proc/device-tree/model and is used to determine the Variscite SOM model and configure the SoM GPIO pins.
Therefore, customers who choose to modify the Linux device tree model property should only append to the string provided by Variscite.