NAME

       NetworkManager - network management daemon

SYNOPSIS

       NetworkManager [OPTIONS...]

DESCRIPTION

       The NetworkManager daemon attempts to make networking configuration and operation as
       painless and automatic as possible by managing the primary network connection and other
       network interfaces, like Ethernet, WiFi, and Mobile Broadband devices. NetworkManager will
       connect any network device when a connection for that device becomes available, unless
       that behavior is disabled. Information about networking is exported via a D-Bus interface
       to any interested application, providing a rich API with which to inspect and control
       network settings and operation.

DISPATCHER SCRIPTS

       NetworkManager will execute scripts in the /etc/NetworkManager/dispatcher.d directory or
       subdirectories in alphabetical order in response to network events. Each script should be
       a regular executable file owned by root. Furthermore, it must not be writable by group or
       other, and not setuid.

       Each script receives two arguments, the first being the interface name of the device an
       operation just happened on, and second the action. For device actions, the interface is
       the name of the kernel interface suitable for IP configuration. Thus it is either
       VPN_IP_IFACE, DEVICE_IP_IFACE, or DEVICE_IFACE, as applicable. For the hostname and
       connectivity-change actions it is always "none".

       The actions are:

       pre-up
           The interface is connected to the network but is not yet fully activated. Scripts
           acting on this event must be placed or symlinked into the
           /etc/NetworkManager/dispatcher.d/pre-up.d directory, and NetworkManager will wait for
           script execution to complete before indicating to applications that the interface is
           fully activated.

       up
           The interface has been activated.

       pre-down
           The interface will be deactivated but has not yet been disconnected from the network.
           Scripts acting on this event must be placed or symlinked into the
           /etc/NetworkManager/dispatcher.d/pre-down.d directory, and NetworkManager will wait
           for script execution to complete before disconnecting the interface from its network.
           Note that this event is not emitted for forced disconnections, like when carrier is
           lost or a wireless signal fades. It is only emitted when there is an opportunity to
           cleanly handle a network disconnection event.

       down
           The interface has been deactivated.

       vpn-pre-up
           The VPN is connected to the network but is not yet fully activated. Scripts acting on
           this event must be placed or symlinked into the
           /etc/NetworkManager/dispatcher.d/pre-up.d directory, and NetworkManager will wait for
           script execution to complete before indicating to applications that the VPN is fully
           activated.

       vpn-up
           A VPN connection has been activated.

       vpn-pre-down
           The VPN will be deactivated but has not yet been disconnected from the network.
           Scripts acting on this event must be placed or symlinked into the
           /etc/NetworkManager/dispatcher.d/pre-down.d directory, and NetworkManager will wait
           for script execution to complete before disconnecting the VPN from its network. Note
           that this event is not emitted for forced disconnections, like when the VPN terminates
           unexpectedly or general connectivity is lost. It is only emitted when there is an
           opportunity to cleanly handle a VPN disconnection event.

       vpn-down
           A VPN connection has been deactivated.

       hostname
           The system hostname has been updated. Use gethostname(2) to retrieve it. The interface
           name (first argument) is empty and no environment variable is set for this action.

       dhcp4-change
           The DHCPv4 lease has changed (renewed, rebound, etc).

       dhcp6-change
           The DHCPv6 lease has changed (renewed, rebound, etc).

       connectivity-change
           The network connectivity state has changed (no connectivity, went online, etc).

       The environment contains more information about the interface and the connection. The
       following variables are available for the use in the dispatcher scripts:

       CONNECTION_UUID
           The UUID of the connection profile.

       CONNECTION_ID
           The name (ID) of the connection profile.

       CONNECTION_DBUS_PATH
           The NetworkManager D-Bus path of the connection.

       CONNECTION_FILENAME
           The backing file name of the connection profile (if any).

       CONNECTION_EXTERNAL
           If "1", this indicates that the connection describes a network configuration created
           outside of NetworkManager.

       DEVICE_IFACE
           The interface name of the control interface of the device. Depending on the device
           type, this differs from DEVICE_IP_IFACE. For example for ADSL devices, this could be
           'atm0' or for WWAN devices it might be 'ttyUSB0'.

       DEVICE_IP_IFACE
           The IP interface name of the device. This is the network interface on which IP
           addresses and routes will be configured.

       IP4_ADDRESS_N
           The IPv4 address in the format "address/prefix gateway", where N is a number from 0 to
           (# IPv4 addresses - 1). gateway item in this variable is deprecated, use IP4_GATEWAY
           instead.

       IP4_NUM_ADDRESSES
           The variable contains the number of IPv4 addresses the script may expect.

       IP4_GATEWAY
           The gateway IPv4 address in traditional numbers-and-dots notation.

       IP4_ROUTE_N
           The IPv4 route in the format "address/prefix next-hop metric", where N is a number
           from 0 to (# IPv4 routes - 1).

       IP4_NUM_ROUTES
           The variable contains the number of IPv4 routes the script may expect.

       IP4_NAMESERVERS
           The variable contains a space-separated list of the DNS servers.

       IP4_DOMAINS
           The variable contains a space-separated list of the search domains.

       DHCP4_<dhcp-option-name>
           If the connection used DHCP for address configuration, the received DHCP configuration
           is passed in the environment using standard DHCP option names, prefixed with "DHCP4_",
           like "DHCP4_HOST_NAME=foobar".

       IP6_<name> and DHCP6_<name>
           The same variables as for IPv4 are available for IPv6, but the prefixes are IP6_ and
           DHCP6_ instead.

       CONNECTIVITY_STATE
           The network connectivity state, which can take the values defined by the
           NMConnectivityState type, from the org.freedesktop.NetworkManager D-Bus API: unknown,
           none, portal, limited or full. Note: this variable will only be set for
           connectivity-change actions.

       In case of VPN, VPN_IP_IFACE is set, and IP4_*, IP6_* variables with VPN prefix are
       exported too, like VPN_IP4_ADDRESS_0, VPN_IP4_NUM_ADDRESSES.

       Dispatcher scripts are run one at a time, but asynchronously from the main NetworkManager
       process, and will be killed if they run for too long. If your script might take
       arbitrarily long to complete, you should spawn a child process and have the parent return
       immediately. Scripts that are symbolic links pointing inside the
       /etc/NetworkManager/dispatcher.d/no-wait.d/ directory are run immediately, without waiting
       for the termination of previous scripts, and in parallel. Also beware that once a script
       is queued, it will always be run, even if a later event renders it obsolete. (Eg, if an
       interface goes up, and then back down again quickly, it is possible that one or more "up"
       scripts will be run after the interface has gone down.)

OPTIONS

       The following options are understood:

       --version | -V
           Print the NetworkManager software version and exit.

       --help | -h
           Print NetworkManager's available options and exit.

       --no-daemon | -n
           Do not daemonize.

       --debug | -d
           Do not daemonize, and direct log output to the controlling terminal in addition to
           syslog.

       --pid-file | -p
           Specify location of a PID file. The PID file is used for storing PID of the running
           process and prevents running multiple instances.

       --state-file
           Specify file for storing state of the NetworkManager persistently. If not specified,
           the default value of /var/lib/NetworkManager/NetworkManager.state is used.

       --config
           Specify configuration file to set up various settings for NetworkManager. If not
           specified, the default value of /etc/NetworkManager/NetworkManager.conf is used with a
           fallback to the older 'nm-system-settings.conf' if located in the same directory. See
           NetworkManager.conf(5) for more information on configuration file.

       --plugins
           List plugins used to manage system-wide connection settings. This list has preference
           over plugins specified in the configuration file. Currently supported plugins are:
           keyfile, ifcfg-rh, ifcfg-suse, ifupdown.

       --log-level
           Sets how much information NetworkManager sends to the log destination (usually
           syslog's "daemon" facility). By default, only informational, warning, and error
           messages are logged. See the section on logging in NetworkManager.conf(5) for more
           information.

       --log-domains
           A comma-separated list specifying which operations are logged to the log destination
           (usually syslog). By default, most domains are logging-enabled. See the section on
           logging in NetworkManager.conf(5) for more information.

       --print-config
           Print the NetworkManager configuration to stdout and exit.

UDEV PROPERTIES

       udev(7) device manager is used for the network device discovery. The following property
       influences how NetworkManager manages the devices:

       NM_UNMANAGED
           No default connection will be created and automatic activation will not be attempted
           when this property of a device is set to a true value ("1" or "true"). You will still
           be able to attach a connection to the device manually or observe externally added
           configuration such as addresses or routes.

           Create an udev rule that sets this property to prevent NetworkManager from interfering
           with virtual Ethernet device interfaces that are managed by virtualization tools.

SIGNALS

       NetworkManager process handles the following signals:

       SIGHUP
           The signal causes a reload of NetworkManager's configuration. Note that not all
           configuration parameters can be changed at runtime and therefore some changes may be
           applied only after the next restart of the daemon. A SIGHUP also involves further
           reloading actions, like doing a DNS update and restarting the DNS plugin. The latter
           can be useful for example when using the dnsmasq plugin and changing its configuration
           in /etc/NetworkManager/dnsmasq.d. However, it also means this will shortly interrupt
           name resolution. In the future, there may be further actions added. A SIGHUP means to
           update NetworkManager configuration and reload everything that is supported. Note that
           this does not reload connections from disk. For that there is a D-Bus API and nmcli's
           reload action

       SIGUSR1
           The signal forces a rewrite of DNS configuration. Contrary to SIGHUP, this does not
           restart the DNS plugin and will not interrupt name resolution. In the future, further
           actions may be added. A SIGUSR1 means to write out data like resolv.conf, or refresh a
           cache. It is a subset of what is done for SIGHUP without reloading configuration from
           disk.

       SIGUSR2
           The signal has no effect at the moment but is reserved for future use.

       An alternative to a signal to reload configuration is the Reload D-Bus call. It allows for
       more fine-grained selection of what to reload, it only returns after the reload is
       complete, and it is guarded by PolicyKit.

DEBUGGING

       The following environment variables are supported to help debugging. When used in
       conjunction with the --no-daemon option (thus echoing PPP and DHCP helper output to
       stdout) these can quickly help pinpoint the source of connection issues. Also see the
       --log-level and --log-domains to enable debug logging inside NetworkManager itself.

       NM_PPP_DEBUG: When set to anything, causes NetworkManager to turn on PPP debugging in
       pppd, which logs all PPP and PPTP frames and client/server exchanges.

BUGS

       Please report any bugs you find in NetworkManager at the NetworkManager bug tracker[1].

SEE ALSO

       NetworkManager home page[2], NetworkManager.conf(5), nmcli(1), nmcli-examples(7), nm-
       online(1), nm-settings(5), nm-applet(1), nm-connection-editor(1), udev(7)

NOTES

        1. NetworkManager bug tracker
           https://bugzilla.gnome.org/enter_bug.cgi?product=NetworkManager

        2. NetworkManager home page
           https://wiki.gnome.org/Projects/NetworkManager