iwd - ArchWiki

# iwd

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- Network configuration
- Wireless network configuration
- WPA supplicant

iwd (iNet wireless daemon) is a wireless daemon for Linux written by Intel that aims to replace WPA supplicant. The core goal of the project is to optimize resource utilization by not depending on any external libraries and instead utilizing features provided by the Linux Kernel to the maximum extent possible. [1]

iwd can work in standalone mode or in combination with comprehensive network managers like ConnMan, systemd-networkd and NetworkManager.

## Installation

Install the iwd package.

## Usage

The iwd package provides the client program `iwctl`, the daemon `iwd` and the Wi-Fi monitoring tool `iwmon`.

Start/enable `iwd.service` so it can be controlled using the `iwctl` command.

### iwctl

To get an interactive prompt do:

    $ iwctl

The interactive prompt is then displayed with a prefix of `[iwd]#`.

Tip:

- In the `iwctl` prompt you can auto-complete commands and device names by hitting `Tab`.
- You can use all commands as command line arguments without entering an interactive prompt. For example: `iwctl device wlp3s0 show`.

To list all available commands:

    [iwd]# help

#### Connect to a network

First, if you do not know your wireless device name, list all wifi devices:

    [iwd]# device list

Then, to scan for networks:

    [iwd]# station device scan

You can then list all available networks:

    [iwd]# station device get-networks

Finally, to connect to a network:

    [iwd]# station device connect SSID

If a passphrase is required, you will be prompted to enter it.

Note:

- `iwd` automatically stores network passphrases in the `/var/lib/iwd` directory and uses them to auto-connect in the future. See #Optional configuration.
- To connect to a network with spaces in the SSID, the network name should be double quoted when connecting.
- iwd only supports PSK pass-phrases from 8 to 63 ASCII-encoded characters. The following error message will be given if the requirements are not met: "PMK generation failed. Ensure Crypto Engine is properly configured"

#### Disconnect from a network

To disconnect from a network:

    [iwd]# station device disconnect

#### Show device information

To display the details of a WiFi device, like MAC address, state and connected network:

    [iwd]# device device show

#### Manage known networks

To list networks you have connected to previously:

    [iwd]# known-networks list

To forget a known network:

    [iwd]# known-networks SSID forget

## WPA Enterprise

### EAP-PWD

For connecting to a EAP-PWD protected enterprice access point you need to create a file called: `essid.8021x` in the folder `/var/lib/iwd` with the following content:

    /var/lib/iwd/essid.8021x

    [Security]
    EAP-Method=PWD
    EAP-Identity=your_enterprise_email
    EAP-Password=your_password

    [Settings]
    Autoconnect=True

If you do not want autoconnect to the AP you can set the option to False and connect manually to the access point via `iwctl`. The same applies to the password, if you do not want to store it plaintext leave the option out of the file and just connect to the enterprise AP.

### EAP-PEAP

Warning: iwd is currently not secure against man-in-the-middle attacks since the certificate name is not validated. See the project's TODO file.

Like EAP-PWD, you also need to create a `essid.8021x` in the folder. Before you proceed to write the configuration file, this is also a good time to find out which CA certificate your organization uses. This is an example configuration file that uses MSCHAPv2 password authentication:

    /var/lib/iwd/essid.8021x

    [Security]
    EAP-Method=PEAP
    EAP-Identity=anonymous@realm.edu
    EAP-PEAP-CACert=/path/to/root.crt
    EAP-PEAP-Phase2-Method=MSCHAPV2
    EAP-PEAP-Phase2-Identity=johndoe@realm.edu
    EAP-PEAP-Phase2-Password=hunter2

    [Settings]
    Autoconnect=true

Tip: If you are planning on using eduroam and you are affiliated with a US-based institution, your CA is likely `Addtrust External CA Root`, as your institution probably issues certificates through Internet2's InCommon. However, you should always refer to your organization's help desk if in doubt.

### TLS Based EAP Methods on older kernels

Linux kernels older than v4.20 (e.g. linux-lts) have to be patched to connect to EAP-TLS, EAP-TTLS, and EAP-PEAP. Edit the PKGBUILD for the kernel and add the following sources

    PKGBUILD

    "iwd1.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=ab2a33c1c0b1b0a45c16746dd0101057c6d432ed"
    "iwd2.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=3a478ace6154e33009f9b01acbd4eaf7615fef0e"
    "iwd3.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=5faadff684460b7f4064f9f28db8915a56601147"
    "iwd4.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=3c7f3a6c70b47858a065b7a86313f390b083ee40"
    "iwd5.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=5362bbfdf2a8a5810d4237e4dbbf5da043e47fb6"
    "iwd6.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=5c93ce3acc010425eab01dc8e0ffb5529f3f85c1"
    "iwd7.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=ca4d545b92cf52ffe777cc7cfbaf64100dfa6e9c"
    "iwd8.patch::https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/patch/?id=f2ac228eaba9fe3f4fcf80b121eb92707afdd4de"

And add the following line to the end of the kernel config:

    config

    CONFIG_PKCS8_PRIVATE_KEY_PARSER=y

Then update the checksums of the PKGBUILD with `updpkgsums` (from pacman-contrib):

    $ updpkgsums

and build the package.

### Other cases

More example tests can be found in the test cases of the upstream repository.

## Optional configuration

This article or section needs expansion.

Reason: Mention what can be configured and how? (Discuss in Talk:Iwd#)

File `/etc/iwd/main.conf` can be used for main configuration.

By default, `iwd` stores the network configuration in `/var/lib/iwd` directory. The configuration file is named as `network.type` where network is network SSID and type is network type i.e. one of "open", "wep", "psk", "8021x". The file is used to store the encrypted `PreSharedKey` and optionally the cleartext `Passphrase` and can be created by the user without invoking `iwctl`. The file can also be used for other configuration pertaining to that network SSID.

A minimal example file to connect to a WPA2/PSK secured network with SSID "spaceship" and passphrase "test1234":

    /var/lib/iwd/spaceship.psk

    [Security]
    PreSharedKey=aafb192ce2da24d8c7805c956136f45dd612103f086034c402ed266355297295

The PreSharedKey can be calculated with wpa_passphrase (from wpa_supplicant) from the SSID and the WIFI passphrase:

    $ wpa_passphrase "spaceship" "test1234"

    network={
            ssid="spaceship"
            #psk="test1234"
            psk=aafb192ce2da24d8c7805c956136f45dd612103f086034c402ed266355297295
    }

Note: The SSID of the network is used as a filename only when it contains only alphanumeric characters or one of `- _`. If it contains any other characters, the name will instead be an `=`-character followed by the hex-encoded version of the SSID.

### Disable auto-connect for a particular network

Create / edit file `/var/lib/iwd/network.type`. Add the following section to it:

    /var/lib/iwd/spaceship.psk (for example)

    [Settings]
    Autoconnect=false

### Disable periodic scan for available networks

By default when `iwd` is in disconnected state, it periodically scans for available networks. To disable periodic scan (so as to always scan manually), create / edit file `/etc/iwd/main.conf` and add the following section to it:

    /etc/iwd/main.conf

    [Scan]
    disable_periodic_scan=true

### Enable built-in network configuration

Since version 0.19, iwd can assign IP address(es) and set up routes using a built-in DHCP client or with static configuration.

To activate iwd's network configuration feature, create/edit `/etc/iwd/main.conf` and add the following section to it:

    /etc/iwd/main.conf

    [General]
    enable_network_config=true

There is also ability to set route metric with `route_priority_offset`:

    /etc/iwd/main.conf

    [General]
    route_priority_offset=300

#### Setting static IP address in network configuration

Add the following section to `/var/lib/iwd/network.type` file. For example:

    /var/lib/iwd/spaceship.psk

    [IPv4]
    ip=192.168.1.10
    netmask=255.255.255.0
    gateway=192.168.1.1
    broadcast=192.168.1.255
    dns=192.168.1.1

#### Select DNS manager

At the moment, iwd supports two DNS managers—systemd-resolved and resolvconf.

Add the following section to `/etc/iwd/main.conf` for `systemd-resolved`:

    /etc/iwd/main.conf

    [General]
    dns_resolve_method=systemd

For `resolvconf`:

    /etc/iwd/main.conf

    [General]
    dns_resolve_method=resolvconf

### Deny console (local) user from modifying the settings

By default `iwd` D-Bus interface allows any console user to connect to `iwd` daemon and modify the settings, even if that user is not a root user.

If you do not want to allow console user to modify the settings but allow reading the status information, then create a D-Bus configuration file as follows.

    /etc/dbus-1/system.d/iwd-strict.conf

    <!-- prevent local users from changing iwd settings, but allow
         reading status information. overrides some part of
         /usr/share/dbus-1/system.d/iwd-dbus.conf. -->

    <!-- This configuration file specifies the required security policies
         for iNet Wireless Daemon to work. -->

    <!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
     "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
    <busconfig>

      <policy at_console="true">
        <deny send_destination="net.connman.iwd"/>
        <allow send_destination="net.connman.iwd" send_interface="org.freedesktop.DBus.Properties" send_member="GetAll" />
        <allow send_destination="net.connman.iwd" send_interface="org.freedesktop.DBus.Properties" send_member="Get" />
        <allow send_destination="net.connman.iwd" send_interface="org.freedesktop.DBus.ObjectManager" send_member="GetManagedObjects" />
        <allow send_destination="net.connman.iwd" send_interface="net.connman.iwd.Device" send_member="RegisterSignalLevelAgent" />
        <allow send_destination="net.connman.iwd" send_interface="net.connman.iwd.Device" send_member="UnregisterSignalLevelAgent" />
      </policy>

    </busconfig>

Tip: Remove <allow> lines above to deny reading the status information as well.

## Troubleshooting

### Connect issues after reboot

A low entropy pool can cause connection problems in particular noticeable after reboot. See Random number generation for suggestions to increase the entropy pool.

### Systemd unit fails on startup due to device not being available

Some users have reported that the provided systemd unit does not wait for the wireless device to become available. [2] Unfortunately, if iwd is started before udev renaming is done, the network device will be blocked and renaming will fail. Thus, the unit fails on startup. [3] The issue can be fixed by forcing iwd to fallback to legacy mode by adding an option to `/etc/iwd/main.conf` as follows:

    /etc/iwd/main.conf

    [General]
    use_default_interface=true

Another fix is to create a systemd unit with the following content:

    /etc/systemd/system/iwd@.service

    [Unit]
    Description=Wireless service on %I
    BindsTo=sys-subsystem-net-devices-%i.device
    After=sys-subsystem-net-devices-%i.device

    [Service]
    Type=dbus
    BusName=net.connman.iwd
    ExecStart=/usr/lib/iwd/iwd --interface %i
    LimitNPROC=1
    Restart=on-failure

Then one can enable the `iwd@device.service` unit for the specific wireless device.

Alternatively, set a proper dependency for iwd to run after systemd/udevd by creating a drop-in file as follows: [4]

The factual accuracy of this article or section is disputed.

Reason: Is "After=network-pre.target" needed? If so, is "After=systemd-udevd" even needed? This solution does not seem to work for all cases. See [5] and systemd-special(7). (Discuss in Talk:Iwd#)

    /etc/systemd/system/iwd.service.d/override.conf

    [Unit]
    After=systemd-udevd.service

If systemd-networkd is used, since both systemd-udevd/networkd play relatively well together, and both are involved, it is reasonable to start iwd after both of them:

    /etc/systemd/system/iwd.service.d/override.conf

    [Unit]
    After=systemd-udevd.service systemd-networkd.service

See FS#61367.

## See also

- Getting Started with iwd
- Network Configuration Settings
- More Examples for WPA Enterprise

Categories:

- Wireless networking
- Network configuration

Hidden categories:

- Pages or sections flagged with Template:Expansion
- Pages or sections flagged with Template:Accuracy