Setting up Wi-Fi

Tip

• There is nothing more reliable than wired Ethernet, so it's better to use it. Wi-Fi with the steel case (on PiKVM V3 and V4) results in poor performance. But who are we to stop you... :)
• Devices based on Raspberry Pi Zero 2 W does not support 5GHz Wi-Fi.

The following describes how to setup a Wi-Fi connection. We recommend to do this while having a display and keyboard or a serial console connected directly to the Raspberry Pi as you will loose network connectivity once you connect to a Wi-Fi. Alternatively you can connect to the PiKVM via SSH. The built-in Web Terminal (available through the browser) should also work.

Take a look at the easiest way

This guide describes how to manually set up a Wi-Fi. An easier way is to use On-boot config. It is also mandatory for Zero 2 W board.

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Setting up Wi-Fi manually

1. Make filesystem writable using the rw command.

2. Create the Wi-Fi settings file /etc/systemd/network/wlan0.network with the following content:

   [Match]
   Name=wlan0
   
   [Network]
   DHCP=yes
   DNSSEC=no
   
   [DHCP]
   ClientIdentifier=mac
   RouteMetric=50
   

3. Set network ESSID and password:

   [root@pikvm ~]# wpa_passphrase 'MyNetwork' 'P@assw0rd' > /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
   [root@pikvm ~]# chmod 640 /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
   

   PiKVM V3, PiKVM V4, and DIY builds based on Raspberry Pi 4 include experimental support for connecting to WPA3 networks. To connect to a WPA3 network, you need to make sure your PiKVM is up-to-date, and edit the /etc/wpa_supplicant/wpa_supplicant-wlan0.conf file after creating it:

   1. uncomment the plain-text psk= line, and comment/remove the hashed psk= line;
   2. add options key_mgmt=SAE and ieee80211w=2 before the closing } line;
   3. finally, add a global option sae_pwe=2 before the network={ line.

   For instance, if your /etc/wpa_supplicant/wpa_supplicant-wlan0.conf looks like this:

   network={
     ssid="MyNetwork"
     #psk="P@assw0rd"
     psk=4134d31e95e6387761d485796310894b1ac5e9bb86b3b96e0dd3473cea440014
   }
   

   You need to change it as follows:

   sae_pwe=2
   
   network={
     ssid="MyNetwork"
     psk="P@assw0rd"
     #psk=4134d31e95e6387761d485796310894b1ac5e9bb86b3b96e0dd3473cea440014
     key_mgmt=SAE
     ieee80211w=2
   }
   

   Connecting to mixed WPA2/3 networks in WPA2 mode (older devices)

   Add options key_mgmt=WPA-PSK-SHA256 WPA-PSK and ieee80211w=1 to /etc/wpa_supplicant/wpa_supplicant-wlan0.conf inside the network={ block.

   This enables WPA2 PMF (protected management frame) support, which is often necessary to connect to WPA2/3 mixed mode networks.

   Using Wi-Fi with hidden ESSID

   Add global option scan_ssid=1 to /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

   Using 5GHz Wi-Fi in the USA

   Add global option country=US to /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

   Block 2 GHz or 5 GHz

   Add option bssid=xx:xx:xx:xx:xx:xx to /etc/wpa_supplicant/wpa_supplicant-wlan0.conf inside the network={ block.

   Here, xx:xx:xx:xx:xx:xx is the MAC address of the specific 2 GHz or 5 GHz AP that you want to allow. All other APs in this network will be blocked.

4. Enable the wpa_supplicant@wlan0 service:

[root@pikvm ~]# systemctl enable wpa_supplicant@wlan0.service

1. Make filesystem read-only again using ro command

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Multiple Wi-Fi networks

You can configure PiKVM to connect to one of several known Wi-Fi networks. To do this, just simply add the configuration of these networks. Pay attention to the symbol >>, it is used to append at the end of configuration, while a single > will overwrite the entire configuration.

1. Make the filesystem writeble with rw command.

2. Add some new networks:

   [root@pikvm ~]# wpa_passphrase 'Wifi1' 'P@assw0rd' >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
   [root@pikvm ~]# wpa_passphrase 'Wifi2' 'P@assw0rd' >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
   [root@pikvm ~]# wpa_passphrase 'Wifi3' 'P@assw0rd' >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
   

   If any of those networks enable or require WPA3, edit your wpa_supplicant-wlan0.conf as described above, making changes to relevant network={...} blocks.

3. Restart the service: systemctl restart wpa_supplicant@wlan0.service.

4. Make the filesystem read-only again using ro command

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Antenna on PiKVM V4

PiKVM V4 has a robust metal case that protects your device from physical damage and electromagnetic interference. This also means that an external antenna must be used for Wi-Fi. We recommend the official Antenna Kit for Raspberry Pi.

To install the antenna, fix it in the round hole in the back side of the PiKVM, and plug the wire to the connector on the Compute Module 4.

Next, to activate the antenna, add line dtparam=ant2 to the /boot/config.txt file on PiKVM, and perform reboot.

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Useful console commands

• iwconfig - Manipulate the basic wireless parameters.
• iwlist - Allow's you to initiate scanning and list frequencies, bit-rates, encryption keys, etc.
• iwspy - Displays per node link quality.
• iwpriv - Allow's you to manipulate the Wireless Extensions specific to a driver (private).

Some examples

[root@pikvm ~]# iw dev wlan0 scan | egrep "signal:|SSID:" | sed -e "s/\tsignal: //" -e "s/\tSSID: //" | awk '{ORS = (NR % 2 == 0)? "\n" : " "; print}' | sort

[root@pikvm ~]# iwlist wlan0 scan | egrep "Cell|ESSID|Signal|Rates"

[root@pikvm ~]# iwlist wlan0 scan

[root@pikvm ~]# iw wlan0 info

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Additional resources

• Arch Linux Wiki for systemd-networkd