NetworkManager - ArchWiki

# NetworkManager

Related articles

- Network configuration
- Wireless network configuration
- Category:Network configuration

NetworkManager is a program for providing detection and configuration for systems to automatically connect to network. NetworkManager's functionality can be useful for both wireless and wired networks. For wireless networks, NetworkManager prefers known wireless networks and has the ability to switch to the most reliable network. NetworkManager-aware applications can switch from online and offline mode. NetworkManager also prefers wired connections over wireless ones, has support for modem connections and certain types of VPN. NetworkManager was originally developed by Red Hat and now is hosted by the GNOME project.

Warning: By default, Wi-Fi passwords are stored in clear text. See section #Encrypted Wi-Fi passwords

## Installation

NetworkManager can be installed with the package networkmanager. The package does not include the tray applet nm-applet which is part of the network-manager-applet. It has functionality for basic DHCP support. For full featured DHCP and if you require IPv6 support, dhclient integrates it.

Note: You must ensure that no other service that wants to configure the network is running; in fact, multiple networking services will conflict. You can find a list of the currently running services with `systemctl --type=service` and then stop them. See #Configuration to enable the NetworkManager service.

### VPN support

NetworkManager VPN support is based on a plug-in system. If you need VPN support via NetworkManager, you have to install one of the following packages:

- networkmanager-openconnect
- networkmanager-openvpn
- networkmanager-pptp
- networkmanager-vpnc
- networkmanager-l2tpAUR
- networkmanager-strongswanAUR

Warning: VPN support is unstable, check the daemon processes options set via the GUI correctly and double-check with each package release.[1]

### PPPoE / DSL support

Install rp-pppoe for PPPoE / DSL connection support.

## Front-ends

To configure and have easy access to NetworkManager, most users will want to install an applet. This GUI front-end usually resides in the system tray (or notification area) and allows network selection and configuration of NetworkManager. Various desktop environments have their own applet. Otherwise you can use #nm-applet.

### GNOME

GNOME has a built-in tool, accessible from the Network settings.

### KDE Plasma

Install the plasma-nm package.

### nm-applet

network-manager-applet is a GTK+ 3 front-end which works under Xorg environments with a systray.

To store connection secrets install and configure GNOME/Keyring.

Be aware that after enabling the tick-box option `Make available to other users` for a connection, NetworkManager stores the password in plain-text, though the respective file is accessible only to root (or other users via `nm-applet`). See #Encrypted Wi-Fi passwords.

In order to run `nm-applet` without a systray, you can use trayer or stalonetray. For example, you can add a script like this one in your path:

    nmgui

    #!/bin/sh
    nm-applet    2>&1 > /dev/null &
    stalonetray  2>&1 > /dev/null
    killall nm-applet

When you close the stalonetray window, it closes `nm-applet` too, so no extra memory is used once you are done with network settings.

#### Xfce

While network-manager-applet works in Xfce, in order to see notifications, including error messages, `nm-applet` needs an implementation of the FreeDesktop.org Desktop notifications. In the xfce panel settings the applet is named "Notification Area" which might be misleading to some users especially in different translation. To enable notifications install xfce4-notifyd, a package that provides an implementation for the specification. To add a password prompt for new wifi networks install a service that implements org.freedesktop.secrets like gnome-keyring.

Without such a notification daemon, `nm-applet` outputs the following errors to stdout/stderr:

    (nm-applet:24209): libnotify-WARNING **: Failed to connect to proxy
    ** (nm-applet:24209): WARNING **: get_all_cb: couldn't retrieve
    system settings properties: (25) Launch helper exited with unknown
    return code 1.
    ** (nm-applet:24209): WARNING **: fetch_connections_done: error
    fetching connections: (25) Launch helper exited with unknown return
    code 1.
    ** (nm-applet:24209): WARNING **: Failed to register as an agent:
    (25) Launch helper exited with unknown return code 1

`nm-applet` will still work fine, though, but without notifications.

Should the applet not appear, install the xfce4-indicator-pluginAUR package. [2]

#### Openbox

To work properly in Openbox, the GNOME applet requires the xfce4-notifyd notification daemon for the same reason as in XFCE and the gnome-icon-theme package to be able to display the applet in the systray.

`nm-applet` installs the autostart file at `/etc/xdg/autostart/nm-applet.desktop`. If you have issues with it (e.g. `nm-applet` is started twice or is not started at all), see Openbox#autostart or [3] for solution.

### Command line

The following applications can be useful for configuring and managing networks without X.

#### nmcli

A command line frontend, nmcli, is included with networkmanager.

For usage information, see nmcli(1). Examples:

- To connect to a wifi network:

      nmcli dev wifi connect <name> password <password>

- To connect to a wifi on the `wlan1` wifi interface:

      nmcli dev wifi connect <name> password <password> iface wlan1 [profile name]

- To disconnect an interface:

      nmcli dev disconnect iface eth0

- To reconnect an interface marked as disconnected:

      nmcli con up uuid <uuid>

- To get a list of UUIDs:

      nmcli con show

- To see a list of network devices and their state:

      nmcli dev

- To turn off wifi:

      nmcli r wifi off

#### nmtui

A curses based graphical frontend, nmtui, is included with networkmanager.

For usage information, see nmtui(1).

#### nmcli-dmenu

Alternatively there is networkmanager-dmenu-gitAUR which is a small script to manage NetworkManager connections with dmenu instead of `nm-applet`. It provides all essential features such as connect to existing NetworkManager wifi or wired connections, connect to new wifi connections, requests passphrase if required, connect to existing VPN connections, enable/disable networking, launch nm-connection-editor GUI.

## Configuration

NetworkManager will require some additional steps to be able run properly. Make sure you have configured `/etc/hosts` as described in Network configuration#Set the hostname section.

### Enable NetworkManager

NetworkManager is controlled via `NetworkManager.service`. Once the NetworkManager daemon is started, it will automatically connect to any available "system connections" that have already been configured. Any "user connections" or unconfigured connections will need nmcli or an applet to configure and connect.

NetworkManager has a global configuration file at `/etc/NetworkManager/NetworkManager.conf`. Usually no configuration needs to be done to the global defaults.

### Enable NetworkManager Wait Online

If you have services which fail if they are started before the network is up, you may use `NetworkManager-wait-online.service` in addition to `NetworkManager.service`. This is, however, rarely necessary because most networked daemons start up okay, even if the network has not been configured yet.

In some cases, the service will still fail to start successfully on boot due to the timeout setting in `/usr/lib/systemd/system/NetworkManager-wait-online.service` being too short. Change the default timeout from 30 to a higher value.

### Set up PolicyKit permissions

See General troubleshooting#Session permissions for setting up a working session.

With a working session, you have several options for granting the necessary privileges to NetworkManager:

- Option 1. Run a Polkit authentication agent when you log in, such as `/usr/lib/polkit-gnome/polkit-gnome-authentication-agent-1` (part of polkit-gnome). You will be prompted for your password whenever you add or remove a network connection.
- Option 2. Add yourself to the `wheel` group. You will not have to enter your password, but your user account may be granted other permissions as well, such as the ability to use sudo without entering the root password.
- Option 3. Add yourself to the `network` group and create the following file:

    /etc/polkit-1/rules.d/50-org.freedesktop.NetworkManager.rules

    polkit.addRule(function(action, subject) {
      if (action.id.indexOf("org.freedesktop.NetworkManager.") == 0 && subject.isInGroup("network")) {
        return polkit.Result.YES;
      }
    });

  All users in the `network` group will be able to add and remove networks without a password. This will not work under systemd if you do not have an active session with systemd-logind.

### Network services with NetworkManager dispatcher

There are quite a few network services that you will not want running until NetworkManager brings up an interface. Good examples are NTPd and network filesystem mounts of various types (e.g. netfs). NetworkManager has the ability to start these services when you connect to a network and stop them when you disconnect. To activate the feature you need to start the `NetworkManager-dispatcher.service`.

Once the feature is active, scripts can be added to the `/etc/NetworkManager/dispatcher.d` directory. These scripts must be owned by root, otherwise the dispatcher will not execute them. For added security, set group ownership to root as well:

    # chown root:root scriptname

Also, the script must have write permission for owner only, otherwise the dispatcher will not execute them:

    # chmod 755 scriptname

The scripts will be run in alphabetical order at connection time, and in reverse alphabetical order at disconnect time. They receive two arguments: the name of the interface (e.g. `eth0`) and the status (up or down for interfaces and vpn-up or vpn-down for vpn connections). To ensure what order they come up in, it is common to use numerical characters prior to the name of the script (e.g. `10_portmap` or `30_netfs` (which ensures that the portmapper is up before NFS mounts are attempted).

Warning: If you connect to foreign or public networks, be aware of what services you are starting and what servers you expect to be available for them to connect to. You could make a security hole by starting the wrong services while connected to a public network

#### Avoiding the dispatcher timeout

If the above is working, then this section is not relevant. However, there is a general problem related to running dispatcher scripts which take longer to be executed. Initially an internal timeout of three seconds only was used. If the called script did not complete in time, it was killed. Later the timeout was extended to about 20 seconds (see the Bugtracker for more information). If the timeout still creates the problem, a work around may be to modify the dispatcher service file `/usr/lib/systemd/system/NetworkManager-dispatcher.service` to remain active after exit:

    /etc/systemd/system/NetworkManager-dispatcher.service

    .include /usr/lib/systemd/system/NetworkManager-dispatcher.service
    [Service]
    RemainAfterExit=yes

Now start and enable the modified `NetworkManager-dispatcher` service.

Warning: Adding the `RemainAfterExit` line to it will prevent the dispatcher from closing. Unfortunately, the dispatcher has to close before it can run your scripts again. With it the dispatcher will not time out but it also will not close, which means that the scripts will only run once per boot. Therefore, do not add the line unless the timeout is definitely causing a problem.

#### Start OpenNTPD

Install the networkmanager-dispatcher-openntpd package.

#### Mount remote folder with sshfs

As the script is run in a very restrictive environment, you have to export `SSH_AUTH_SOCK` in order to connect to your SSH agent. There are different ways to accomplish this, see this message for more information. The example below works with GNOME Keyring, and will ask you for the password if not unlocked already. In case NetworkManager connects automatically on login, it is likely gnome-keyring has not yet started and the export will fail (hence the sleep). The `UUID` to match can be found with the command `nmcli con status` or `nmcli con list`.

    #!/bin/sh
    USER='username'
    REMOTE='user@host:/remote/path'
    LOCAL='/local/path'

    interface=$1 status=$2
    if [ "$CONNECTION_UUID" = "uuid" ]; then
      case $status in
        up)
          export SSH_AUTH_SOCK=$(find /tmp -maxdepth 1 -type s -user "$USER" -name 'ssh')
          su "$USER" -c "sshfs $REMOTE $LOCAL"
          ;;
        down)
          fusermount -u "$LOCAL"
          ;;
      esac
    fi

#### Use dispatcher to automatically toggle Wi-Fi depending on LAN cable being plugged in

The idea is to only turn Wi-Fi on when the LAN cable is unplugged (for example when detaching from a laptop dock), and for Wi-Fi to be automatically disabled, once a LAN cable is plugged in again.

Create the following dispatcher script (Source), replacing `LAN_interface` with yours.

    /etc/NetworkManager/dispatcher.d/wlan_auto_toggle.sh

    #!/bin/sh

    if [ "$1" = "LAN_interface" ]; then
        case "$2" in
            up)
                nmcli radio wifi off
                ;;
            down)
                nmcli radio wifi on
                ;;
        esac
    fi

Note: You can get a list of interfaces using nmcli. The ethernet (LAN) interfaces start with `en`, e.g. `enp0s5`

#### Use dispatcher to connect to a VPN after a network connection is established

In this example we want to connect automatically to a previously defined VPN connection after connecting to a specific Wi-Fi network. First thing to do is to create the dispatcher script that defines what to do after we are connected to the network.

  1. Create the dispatcher script:

    /etc/NetworkManager/dispatcher.d/vpn-up

    #!/bin/sh
    VPN_NAME="name of VPN connection defined in NetworkManager"
    ESSID="Wi-Fi network ESSID (not connection name)"

    interface=$1 status=$2
    case $status in
      up|vpn-down)
        if iwgetid | grep -qs ":\"$ESSID\""; then
          nmcli con up id "$VPN_NAME"
        fi
        ;;
      down)
        if iwgetid | grep -qs ":\"$ESSID\""; then
          if nmcli con show --active | grep "$VPN_NAME"; then
            nmcli con down id "$VPN_NAME"
          fi
        fi
        ;;
    esac

If you would like to attempt to automatically connect to VPN for all Wi-Fi networks, you can use the following definition of the ESSID: `ESSID=$(iwgetid -r)`. Remember to set the script's permissions accordingly.

If you require and tick the `nm-applet` option to Make the VPN connection available to all users, trying to connect may still fail and NetworkManager will complain about 'no valid VPN secrets', because of the way VPN secrets are stored, which brings us to step 2:

  2. Either edit the VPN connection configuration file to make NetworkManager store the secrets by itself rather than inside a keyring that will be inaccessible for root: open up `/etc/NetworkManager/system-connections/name of your VPN connection` and change the `password-flags` and `secret-flags` from `1` to `0`.

Alternatively put the password directly in the configuration file adding the section `vpn-secrets`:

     [vpn]
     ....
     password-flags=0

     [vpn-secrets]
     password=your_password

Note: It may now be necessary to re-open the NetworkManager connection editor and save the VPN passwords/secrets again.

#### Use dispatcher to handle mounting of CIFS shares

Some CIFS shares are only available on certain networks or locations (e.g. at home). You can use the dispatcher to only mount CIFS shares that are present at your current location.

The following script will check if we connected to a specific network and mount shares accordingly:

    /etc/NetworkManager/dispatcher.d/mount_cifs

    #!/bin/bash
    if [ "$2" = "up" ]; then
      if [ "$CONNECTION_UUID" = "uuid" ]; then
        mount /your/mount/point &
        # add more shares as needed
      fi
    fi

Note: You can get a list of uuids using nmcli.

The following script will unmount all CIFS before a disconnect from a specific network:

    /etc/NetworkManager/dispatcher.d/pre-down.d/mount_cifs

    #!/bin/bash
    umount -a -l -t cifs

Note: Make sure this script is located in the pre-down.d subdirectory as shown above, otherwise it will unmount all shares on any connection state change.
Note: Ever since NetworkManager 0.9.8, the 'pre-down' and 'down' actions are not executed on shutdown or restart, so the above script will only work if you manually disconnect from the network. See this bug report for more info.

As before, do not forget to set the script permissions accordingly.

See also NFS#NetworkManager dispatcher for another example script that parses `/etc/fstab` mounts during dispatcher actions.

### Proxy settings

NetworkManager does not directly handle proxy settings, but if you are using GNOME or KDE, you could use proxydriver wich handles proxy settings using NetworkManager's informations. proxydriver is found in the package proxydriverAUR.

In order for proxydriver to be able to change the proxy settings, you would need to execute this command, as part of the GNOME startup process (System -> Preferences -> Startup Applications):

    xhost +si:localuser:your_username

See: Proxy settings.

### Disable NetworkManager

It might not be obvious, but the service automatically starts through dbus. To completely disable it you can mask the services `NetworkManager` and `NetworkManager-dispatcher`.

### Checking connectivity

This article or section is out of date.

Reason: connectivity checking is enabled by default through `/usr/lib/NetworkManager/conf.d/20-connectivity.conf` (Discuss in Talk:NetworkManager#)

The factual accuracy of this article or section is disputed.

Reason: "the desktop manager" might handle captive portals, but this is mostly done through capnet-assistAUR (Discuss in Talk:NetworkManager#)

This article or section needs expansion.

Reason: This section could also tell, how you could configure your own webserver/or an alternative URL to enable this (Discuss in Talk:NetworkManager#)

NetworkManager can try to reach a page on Internet when connecting to a network. For those behind a captive portal, the desktop manager can automatically open a window asking for credentials. To enable this feature, uncomment the connectivity section in `/etc/NetworkManager/NetworkManager.conf`.

## Testing

NetworkManager applets are designed to load upon login so no further configuration should be necessary for most users. If you have already disabled your previous network settings and disconnected from your network, you can now test if NetworkManager will work. The first step is to start `NetworkManager.service`.

Some applets will provide you with a `.desktop` file so that the NetworkManager applet can be loaded through the application menu. If it does not, you are going to either have to discover the command to use or logout and login again to start the applet. Once the applet is started, it will likely begin polling network connections with for auto-configuration with a DHCP server.

To start the GNOME applet in non-xdg-compliant window managers like awesome:

    nm-applet --sm-disable &

For static IP addresses, you will have to configure NetworkManager to understand them. The process usually involves right-clicking the applet and selecting something like 'Edit Connections'.

## Troubleshooting

### No prompt for password of secured Wi-Fi networks

When trying to connect to a secured Wi-Fi network, no prompt for a password is shown and no connection is established. This happens when no keyring package is installed. An easy solution is to install gnome-keyring. If you want the passwords to be stored in encrypted form, follow GNOME Keyring to set up the gnome-keyring-daemon.

### No traffic via PPTP tunnel

PPTP connection logins successfully; you see a ppp0 interface with the correct VPN IP address, but you cannot even ping the remote IP address. It is due to lack of MPPE (Microsoft Point-to-Point Encryption) support in stock Arch pppd. It is recommended to first try with the stock Arch ppp as it may work as intended.

To solve the problem it should be sufficient to install the ppp-mppeAUR[broken link: archived in aur-mirror] package.

See also WPA2 Enterprise#MS-CHAPv2.

### Network management disabled

When NetworkManager shuts down but the pid (state) file is not removed, you will see a `Network management disabled` message. If this happens, remove the file manually:

    # rm /var/lib/NetworkManager/NetworkManager.state

### Problems with internal DHCP client

If you have problems with getting an IP address using the internal DHCP client, consider dhclient as DHCP client.

After installation, update the NetworkManager config file:

    /etc/NetworkManager/NetworkManager.conf

    dhcp=dhclient

This workaround might solve problems in big wireless networks like eduroam.

### Customizing resolv.conf

See the main page: resolv.conf. If you use dhclient, you may try the networkmanager-dispatch-resolvAUR[broken link: archived in aur-mirror] package.

### DHCP problems with dhclient

If you have problems with getting an IP address via DHCP, try to add the following to your `/etc/dhclient.conf`:

     interface "eth0" {
       send dhcp-client-identifier 01:aa:bb:cc:dd:ee:ff;
     }

Where `aa:bb:cc:dd:ee:ff` is the MAC address of this NIC. The MAC address can be found using the `ip link show interface` command from the iproute2 package.

### Hostname problems

NetworkManager utilizes dhclient in default and falls back to its internal DHCP funtionality, if the former is not installed. To make dhclient forward the hostname requires to set a non-default option, dhcpcd forwards the hostname by default.

First, check which DHCP client is used (dhclient in this example):

    # journalctl -b | egrep "dhc"

    ...
    Nov 17 21:03:20 zenbook dhclient[2949]: Nov 17 21:03:20 zenbook dhclient[2949]: Bound to *:546
    Nov 17 21:03:20 zenbook dhclient[2949]: Listening on Socket/wlan0
    Nov 17 21:03:20 zenbook dhclient[2949]: Sending on   Socket/wlan0
    Nov 17 21:03:20 zenbook dhclient[2949]: XMT: Info-Request on wlan0, interval 1020ms.
    Nov 17 21:03:20 zenbook dhclient[2949]: RCV: Reply message on wlan0 from fe80::126f:3fff:fe0c:2dc.

#### Configure dhclient to push the hostname to the DHCP server

Copy the example configuration file:

    # cp /usr/share/dhclient/dhclient.conf.example /etc/dhclient.conf

Take a look at the file - there will only really be one line we want to keep and dhclient will use it's defaults (as it has been using if you did not have this file) for the other options. This is the important line:

    /etc/dhclient.conf

    send host-name = pick-first-value(gethostname(), "ISC-dhclient");

Force an IP address renewal by your favorite means, and you should now see your hostname on your DHCP server.

IPv6 push host name:

    # cp /usr/share/dhclient/dhclient.conf.example /etc/dhclient6.conf

    /etc/dhclient6.conf

    send fqdn.fqdn = pick-first-value(gethostname(), "ISC-dhclient");

#### Configure NetworkManager to use a specific DHCP client

If you want to explicitly set the DHCP client used by NetworkManager, it can be set in the global configuration:

    /etc/NetworkManager/NetworkManager.conf

    dhcp=internal

The alternative `dhcp=dhclient` is used per default, if this option is not set.

Then restart `NetworkManager.service`.

Note: Support for dhcpcd has been disabled in networkmanager-1.0.0-2 (2015-02-14).

### Missing default route

On at least one KDE4 system, no default route was created when establishing wireless connections with NetworkManager. Changing the route settings of the wireless connection to remove the default selection "Use only for resources on this connection" solved the issue.

### 3G modem not detected

See USB 3G Modem#Network Manager.

### Switching off WLAN on laptops

Sometimes NetworkManager will not work when you disable your Wi-Fi adapter with a switch on your laptop and try to enable it again afterwards. This is often a problem with rfkill. Install the rfkill package and use:

    $ watch -n1 rfkill list all

to check if the driver notifies rfkill about the wireless adapter's status. If one identifier stays blocked after you switch on the adapter you could try to manually unblock it with (where X is the number of the identifier provided by the above output):

    # rfkill event unblock X

### Static IP address settings revert to DHCP

Due to an unresolved bug, when changing default connections to a static IP address, `nm-applet` may not properly store the configuration change, and will revert to automatic DHCP.

To work around this issue you have to edit the default connection (e.g. "Auto eth0") in `nm-applet`, change the connection name (e.g. "my eth0"), uncheck the "Available to all users" checkbox, change your static IP address settings as desired, and click Apply. This will save a new connection with the given name.

Next, you will want to make the default connection not connect automatically. To do so, run `nm-connection-editor` (not as root). In the connection editor, edit the default connection (e.g. "Auto eth0") and uncheck "Connect automatically". Click Apply and close the connection editor.

### Cannot edit connections as normal user

See #Set up PolicyKit permissions.

### Forget hidden wireless network

Since hidden networks are not displayed in the selection list of the Wireless view, they cannot be forgotten (removed) with the GUI. You can delete one with the following command:

    # rm /etc/NetworkManager/system-connections/SSID

This works for any other connection.

### VPN not working in GNOME

When setting up OpenConnect or vpnc connections in NetworkManager while using GNOME, you will sometimes never see the dialog box pop up and the following error appears in `/var/log/errors.log`:

    localhost NetworkManager[399]: <error> [1361719690.10506] [nm-vpn-connection.c:1405] get_secrets_cb(): Failed to request VPN secrets #3: (6) No agents were available for this request.

This is caused by the GNOME NM Applet expecting dialog scripts to be at `/usr/lib/gnome-shell`, when NetworkManager's packages put them in `/usr/lib/networkmanager`. As a "temporary" fix (this bug has been around for a while now), make the following symlink(s):

- For OpenConnect: `ln -s /usr/lib/networkmanager/nm-openconnect-auth-dialog /usr/lib/gnome-shell/`
- For VPNC (i.e. Cisco VPN): `ln -s /usr/lib/networkmanager/nm-vpnc-auth-dialog /usr/lib/gnome-shell/`

This may need to be done for any other NM VPN plugins as well, but these are the two most common.

### Unable to connect to visible European wireless networks

WLAN chips are shipped with a default regulatory domain. If your access point does not operate within these limitations, you will not be able to connect to the network. Fixing this is easy:

1. Install crda
2. Uncomment the correct Country Code in `/etc/conf.d/wireless-regdom`
3. Reboot the system, because the setting is only read on boot

### Automatic connect to VPN on boot is not working

The problem occurs when the system (i.e. NetworkManager running as the root user) tries to establish a VPN connection, but the password is not accessible because it is stored in the Gnome keyring of a particular user.

A solution is to keep the password to your VPN in plaintext, as described in step (2.) of #Use dispatcher to connect to a VPN after a network connection is established.

You do not need to use the dispatcher described in step (1.) to auto-connect anymore, if you use the new "auto-connect VPN" option from the `nm-applet` GUI.

### Systemd Bottleneck

Over time the log files (`/var/log/journal`) can become very large. This can have a big impact on boot performance when using NetworkManager, see: Systemd#Boot time increasing over time.

### Regular network disconnects, latency and lost packets (WiFi)

NetworkManager does a scan every 2 minutes.

Some WiFi drivers have issues when scanning for base stations whilst connected/associated. Symptoms include VPN disconnects/reconnects and lost packets, web pages failing to load and then refresh fine.

Running `journalctl -f` will indicate that this is taking place, messages like the following will be contained in the logs at regular intervals.

    NetworkManager[410]: <info>  (wlp3s0): roamed from BSSID 00:14:48:11:20:CF (my-wifi-name) to (none) ((none))

There is a patched version of NetworkManager which should prevent this type of scanning: networkmanager-noscanAUR.

Alternatively, if roaming is not important, the periodic scanning behavior can be disabled by locking the BSSID of the access point in the WiFi connection profile.

## Tips and tricks

### Encrypted Wi-Fi passwords

By default, NetworkManager stores passwords in clear text in the connection files at `/etc/NetworkManager/system-connections/`. To print the stored passwords, use the following command:

    # grep -H '^psk=' /etc/NetworkManager/system-connections/*

The passwords are accessible to the root user in the filesystem and to users with access to settings via the GUI (e.g. `nm-applet`).

If it is preferable to save the passwords in encrypted form in a keyring instead of clear text. The downside of using a keyring is that the connections have to be set up for each user.

#### Using Gnome-Keyring

The keyring daemon has to be started and the keyring needs to be unlocked for the following to work.

Furthermore, NetworkManager needs to be configured not to store the password for all users. Using GNOME `nm-applet`, run `nm-connection-editor` from a terminal, select a network connection, click `Edit`, select the `Wifi-Security` tab and click on the right icon of password and check `Store the password only for this user`.

#### Using KDE Wallet

This article or section is out of date.

Reason: plasma-nm has a different interface. (Discuss in Talk:NetworkManager#)

Using KDE's kdeplasma-applets-plasma-nm[broken link: archived in aur-mirror], click the applet, click on the top right `Settings` icon, double click on a network connection, in the `General settings` tab, untick `all users may connect to this network`. If the option is ticked, the passwords will still be stored in clear text, even if a keyring daemon is running.

If the option was selected previously and you un-tick it, you may have to use the `reset` option first to make the password disappear from the file. Alternatively, delete the connection first and set it up again.

### Sharing internet connection over Wi-Fi

You can share your internet connection (e.g. 3G or wired) with a few clicks using nm. You will need a supported Wi-Fi card (Cards based on Atheros AR9xx or at least AR5xx are probably best choice). Please note that a firewall may interfere with internet sharing.

#### Ad-hoc

This article or section needs language, wiki syntax or style improvements.

Reason: "I think so"... (Discuss in Talk:NetworkManager#)

- Install the dnsmasq package to be able to actually share the connection.
- Custom `dnsmasq.conf` may interfere with NetworkManager (not sure about this, but I think so).
- Click on applet and choose "Create new wireless network".
- Follow wizard (if using WEP, be sure to use 5 or 13 character long password, different lengths will fail).
- Settings will remain stored for the next time you need it.

#### Real AP

Support of infrastructure mode (which is needed by Android phones as they intentionally do not support ad-hoc) is added by NetworkManager as of late 2012.

See Fedora's wiki.

### Sharing internet connection over Ethernet

Scenario: your device has internet connection over wi-fi and you want to share the internet connection to other devices over ethernet.

Requirements:

- Install the dnsmasq package to be able to actually share the connection.
- Your internet connected device and the other devices are connected over a suitable ethernet cable (this usually means a cross over cable or a switch in between).
- Internet sharing is not blocked by a firewall.

Steps:

- Run `nm-connection-editor` from terminal.
- Add a new ethernet connection.
- Give it some sensible name. For example "Shared Internet"
- Go to "IPv4 Settings".
- For "Method:" select "Shared to other computers".
- Save

Now you should have a new option "Shared Internet" under the Wired connections in NetworkManager.

### Checking if networking is up inside a cron job or script

Some cron jobs require networking to be up to succeed. You may wish to avoid running these jobs when the network is down. To accomplish this, add an if test for networking that queries NetworkManager's nm-tool and checks the state of networking. The test shown here succeeds if any interface is up, and fails if they are all down. This is convenient for laptops that might be hardwired, might be on wireless, or might be off the network.

    if [ $(nm-tool|grep State|cut -f2 -d' ') == "connected" ]; then
        #Whatever you want to do if the network is online
    else
        #Whatever you want to do if the network is offline - note, this and the else above are optional
    fi

This useful for a `cron.hourly` script that runs fpupdate for the F-Prot virus scanner signature update, as an example. Another way it might be useful, with a little modification, is to differentiate between networks using various parts of the output from nm-tool; for example, since the active wireless network is denoted with an asterisk, you could grep for the network name and then grep for a literal asterisk.

### Connect to network with secret on boot

By default, NetworkManager will not connect to networks requiring a secret automatically on boot. This is because it locks such connections to the user who makes it by default, only connecting after they have logged in. To change this, do the following:

1. Right click on the `nm-applet` icon in your panel and select Edit Connections and open the Wireless tab
2. Select the connection you want to work with and click the Edit button
3. Check the boxes “Connect Automatically” and “Available to all users”

Log out and log back in to complete.

### Automatically unlock keyring after login

NetworkManager requires access to the login keyring to connect to networks requiring a secret. Under most circumstances, this keyring is unlocked automatically at login, but if it isn't, and NetworkManager isn't connecting on login, you can try the following.

#### GNOME

Note: The following method is dated and known not to work on at least one machine!

- In `/etc/pam.d/gdm` (or your corresponding daemon in `/etc/pam.d`), add these lines at the end of the "auth" and "session" blocks if they do not exist already:

     auth            optional        pam_gnome_keyring.so
     session         optional        pam_gnome_keyring.so  auto_start

- In `/etc/pam.d/passwd`, use this line for the 'password' block:

     password    optional    pam_gnome_keyring.so

  Next time you log in, you should be asked if you want the password to be unlocked automatically on login.

#### SLiM login manager

See SLiM#Gnome Keyring.

#### Troubleshooting

While you may type both values at connection time, kdeplasma-applets-plasma-nm[broken link: archived in aur-mirror] 0.9.3.2-1 and above are capable of retrieving OpenConnect username and password directly from KWallet.

Open "KDE Wallet Manager" and look up your OpenConnect VPN connection under "Network Management|Maps". Click "Show values" and enter your credentials in key "VpnSecrets" in this form (replace username and password accordingly):

    form:main:username%SEP%username%SEP%form:main:password%SEP%password

Next time you connect, username and password should appear in the "VPN secrets" dialog box.

### Ignore specific devices

Sometimes it may be desired that NetworkManager ignores specific devices and does not try to configure addresses and routes for them.You can quickly and easily ignore devices by MAC or interface-name by using the following in `/etc/NetworkManager/NetworkManager.conf`:

    [keyfile]
    unmanaged-devices=mac:00:22:68:1c:59:b1;mac:00:1E:65:30:D1:C4;interface-name:eth0

After you have put this in, restart NetworkManager, and you should be able to configure interfaces without NetworkManager altering what you have set.

### Enable DNS Caching

See dnsmasq#NetworkManager to enable the plugin that allows DNS caching using dnsmasq.

### Configuring MAC Address Randomization

As of version 1.4.0, NetworkManager supports two types MAC Address Randomization: randomization during scanning, and stable randomization. Both modes can be configured by modifying `/etc/NetworkManager/NetworkManager.conf`.

Randomization during Wi-Fi scanning is enabled by default starting on version 1.2.0, and it can be disabled by adding the following lines to `/etc/NetworkManager/NetworkManager.conf`:

    [device]
    wifi.scan-rand-mac-address=no

Tip: Disabling MAC address randomization may be needed for stable connection, see e.g. [4].

In contrast, stable randomization generates a different MAC address for each different connection. This is specially useful when, for example, a portal remembers your login status based on your MAC address. To enable this mode, you can use the option

    [connection]
    wifi.cloned-mac-address=random

or

    [connection]
    ethernet.cloned-mac-address=random

You can read more about it here

### Enable IPv6 Privacy Extensions

See IPv6#NetworkManager

## See also

- NetworkManager for Administrators Part 1

Category:

- Network configuration

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