Wireless networking

Wireless networking

NixOS' uses wpa_supplicant for wireless networking. This article describes how to configure NixOS to use wpa_supplicant and to connect to a variety of wireless networks.

Configuration

To enable wireless networking add the following attribute to your configuration.nix and reconfigure your system.

networking.wireless.enable = true;

You should already have set networking.hostName and it might be mandatory for wireless networking to have this set. (Is this true?)

It might also be a good idea to enable a firewall by setting networking.firewall.enable = true;. (Explain pros and cons.)

Prerequisites

Before proceeding make sure to check whether your wireless network card has properly been recognized. You can check this by issuing iwconfig and you should see a wireless extension being reported for wlan0.

Scan for wireless networks

To scan for wireless networks in range you can use the following command.

iwlist wlan0 scan

Wirless networks

Configuration of wireless networks is being done in /etc/wpa_supplicant.conf. This file is readable and writable by root only so make sure to have root privileges before editing. Since this file contains plain passwords for wireless networks you shouldn't attempt to make this file readable by any other account than root.

The file /etc/wpa_supplicant.conf contains a lot of configuration and documentation already. However, these are sensible default values which should work in most cases. As of now don't touch them unless something isn't working as expected or you know what you are doing.

To the end of the file you can describe the wireless networks you want to connect to. In most cases you only need to specify a essid and a passphrase. To add a wireless network called mynetwork with passphrase mysecretpass add the following contents to the end of the file /etc/wpa_supplicant.conf.

network={
  ssid="mynetwork"
  psk="mysecretpassphrase"
}

You now should reconfigure your system again and wpa_supplicant should take care of automatically getting you connected as soon as you are in range for any of the networks specified in /etc/wpa_supplicant.conf.

You don't need the human-readable passphrase stored in /etc/wpa_supplicant.conf:

wpa_passphrase 'mynetwork' 'mysecretpassphrase' | grep -v '#psk="' >> /etc/wpa_supplicant.conf

This will append to /etc/wpa_supplicant.conf something like this:

network={
       ssid="mynetwork"
       psk=d2b1d5f68ef2c2b04a89361f0722e65a1591de6d82b979d03fabf501c4356589
}

Insecure wireless networks

To connect to a wireless network named insecureNetwork which isn't secured by a passphrase use the following configuration.

network={
 ssid="insecureNetwork"
 key_mgmt=NONE
}