Wifi SystemdNetworkd
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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 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.