1NETWORKMANAGER(8)         Network management daemons         NETWORKMANAGER(8)
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NAME

6       NetworkManager - network management daemon
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SYNOPSIS

9       NetworkManager [OPTIONS...]
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DESCRIPTION

12       The NetworkManager daemon attempts to make networking configuration and
13       operation as painless and automatic as possible by managing the primary
14       network connection and other network interfaces, like Ethernet, Wi-Fi,
15       and Mobile Broadband devices. NetworkManager will connect any network
16       device when a connection for that device becomes available, unless that
17       behavior is disabled. Information about networking is exported via a
18       D-Bus interface to any interested application, providing a rich API
19       with which to inspect and control network settings and operation.
20

DISPATCHER SCRIPTS

22       NetworkManager-dispatcher service can execute scripts for the user in
23       response to network events. See NetworkManager-dispatcher(8) manual.
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OPTIONS

26       The following options are understood:
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28       --version | -V
29           Print the NetworkManager software version and exit.
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31       --help | -h
32           Print NetworkManager's available options and exit.
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34       --no-daemon | -n
35           Do not daemonize.
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37       --debug | -d
38           Do not daemonize, and direct log output to the controlling terminal
39           in addition to syslog.
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41       --pid-file | -p
42           Specify location of a PID file. The PID file is used for storing
43           PID of the running process and prevents running multiple instances.
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45       --state-file
46           Specify file for storing state of the NetworkManager persistently.
47           If not specified, the default value of
48           /var/lib/NetworkManager/NetworkManager.state is used.
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50       --config
51           Specify configuration file to set up various settings for
52           NetworkManager. If not specified, the default value of
53           /etc/NetworkManager/NetworkManager.conf is used with a fallback to
54           the older 'nm-system-settings.conf' if located in the same
55           directory. See NetworkManager.conf(5) for more information on
56           configuration file.
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58       --configure-and-quit [initrd]
59           Quit after all devices reach a stable state. The optional initrd
60           parameter enables mode, where no processes are left running after
61           NetworkManager stops, which is useful for running from an initial
62           ramdisk on rearly boot.
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64       --plugins
65           List plugins used to manage system-wide connection settings. This
66           list has preference over plugins specified in the configuration
67           file. See main.plugins setting in NetworkManager.conf(5) for
68           supported options.
69
70       --log-level
71           Sets how much information NetworkManager sends to the log
72           destination (usually syslog's "daemon" facility). By default, only
73           informational, warning, and error messages are logged. See the
74           section on logging in NetworkManager.conf(5) for more information.
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76       --log-domains
77           A comma-separated list specifying which operations are logged to
78           the log destination (usually syslog). By default, most domains are
79           logging-enabled. See the section on logging in
80           NetworkManager.conf(5) for more information.
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82       --print-config
83           Print the NetworkManager configuration to stdout and exit.
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UDEV PROPERTIES

86       udev(7) device manager is used for the network device discovery. The
87       following property influences how NetworkManager manages the devices:
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89       NM_UNMANAGED
90           If set to "1" or "true", the device is configured as unmanaged by
91           NetworkManager. Note that the user still can explicitly overrule
92           this configuration via means like nmcli device set "$DEVICE"
93           managed yes or "device*.managed=1" in NetworkManager.conf.
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SIGNALS

96       NetworkManager process handles the following signals:
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98       SIGHUP
99           The signal causes a reload of NetworkManager's configuration. Note
100           that not all configuration parameters can be changed at runtime and
101           therefore some changes may be applied only after the next restart
102           of the daemon. A SIGHUP also involves further reloading actions,
103           like doing a DNS update and restarting the DNS plugin. The latter
104           can be useful for example when using the dnsmasq plugin and
105           changing its configuration in /etc/NetworkManager/dnsmasq.d.
106           However, it also means this will shortly interrupt name resolution.
107           In the future, there may be further actions added. A SIGHUP means
108           to update NetworkManager configuration and reload everything that
109           is supported. Note that this does not reload connections from disk.
110           For that there is a D-Bus API and nmcli's reload action
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112       SIGUSR1
113           The signal forces a rewrite of DNS configuration. Contrary to
114           SIGHUP, this does not restart the DNS plugin and will not interrupt
115           name resolution. When NetworkManager is not managing DNS, the
116           signal forces a restart of operations that depend on the DNS
117           configuration (like the resolution of the system hostname via
118           reverse DNS, or the resolution of WireGuard peers); therefore, it
119           can be used to tell NetworkManager that the content of resolv.conf
120           was changed externally. In the future, further actions may be
121           added. A SIGUSR1 means to write out data like resolv.conf, or
122           refresh a cache. It is a subset of what is done for SIGHUP without
123           reloading configuration from disk.
124
125       SIGUSR2
126           The signal has no effect at the moment but is reserved for future
127           use.
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129       An alternative to a signal to reload configuration is the Reload D-Bus
130       call. It allows for more fine-grained selection of what to reload, it
131       only returns after the reload is complete, and it is guarded by
132       PolicyKit.
133

DEBUGGING

135       NetworkManager only configures your system. So when your networking
136       setup doesn't work as expected, the first step is to look at your
137       system to understand what is actually configured, and whether that is
138       correct. The second step is to find out how to tell NetworkManager to
139       do the right thing.
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141       You can for example try to ping hosts (by IP address or DNS name), look
142       at ip link show, ip address show and ip route show, and look at
143       /etc/resolv.conf for name resolution issues. Also look at the
144       connection profiles that you have configured in NetworkManager (nmcli
145       connection and nmcli connection show "$PROFILE") and the configured
146       interfaces (nmcli device).
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148       If that does not suffice, look at the logfiles of NetworkManager.
149       NetworkManager logs to syslog, so depending on your system
150       configuration you can call journalctl to get the logs. By default,
151       NetworkManager logs are not verbose and thus not very helpful for
152       investigating a problem in detail. You can change the logging level at
153       runtime with nmcli general logging level TRACE domains ALL. But usually
154       a better way is to collect full logs from the start, by configuring
155       level=TRACE in NetworkManager.conf. See NetworkManager.conf(5) manual.
156       Note that trace logs of NetworkManager are verbose and systemd-journald
157       might rate limit some lines. Possibly disable rate limiting first with
158       the RateLimitIntervalSec and RateLimitBurst options of journald (see
159       journald.conf(5) manual).
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/VAR/LIB/NETWORKMANAGER/SECRET_KEY AND /ETC/MACHINE-ID

162       The identity of a machine is important as various settings depend on
163       it. For example, ipv6.addr-gen-mode=stable and
164       ethernet.cloned-mac-address=stable generate identifiers by hashing the
165       machine's identity. See also the connection.stable-id connection
166       property which is a per-profile seed that gets hashed with the machine
167       identity for generating such addresses and identifiers.
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169       If you backup and restore a machine, the identity of the machine
170       probably should be preserved. In that case, preserve the files
171       /var/lib/NetworkManager/secret_key and /etc/machine-id. On the other
172       hand, if you clone a virtual machine, you probably want that the clone
173       has a different identity. There is already existing tooling on Linux
174       for handling /etc/machine-id (see machine-id(5)).
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176       The identity of the machine is determined by the
177       /var/lib/NetworkManager/secret_key. If such a file does not exist,
178       NetworkManager will create a file with random content. To generate a
179       new identity just delete the file and after restart a new file will be
180       created. The file should be read-only to root and contain at least 16
181       bytes that will be used to seed the various places where a stable
182       identifier is used.
183
184       Since 1.16.0, NetworkManager supports a version 2 of secret-keys. For
185       such keys /var/lib/NetworkManager/secret_key starts with ASCII "nm-v2:"
186       followed by at least 32 bytes of random data. Also, recent versions of
187       NetworkManager always create such kinds of secret-keys, when the file
188       does not yet exist. With version 2 of the secret-key, /etc/machine-id
189       is also hashed as part of the generation for addresses and identifiers.
190       The advantage is that you can keep /var/lib/NetworkManager/secret_key
191       stable, and only regenerate /etc/machine-id when cloning a VM.
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BUGS

194       Please report any bugs you find in NetworkManager at the NetworkManager
195       issue tracker[1].
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SEE ALSO

198       NetworkManager home page[2], NetworkManager.conf(5), NetworkManager-
199       dispatcher(8), NetworkManager-wait-online.service(8), nmcli(1), nmcli-
200       examples(7), nm-online(1), nm-settings(5), nm-applet(1), nm-connection-
201       editor(1), udev(7)
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NOTES

204        1. NetworkManager issue tracker
205           https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues
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207        2. NetworkManager home page
208           https://networkmanager.dev
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212NetworkManager 1.38.0                                        NETWORKMANAGER(8)
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