Chapter 39. Introduction to NetworkManager Debugging
Increasing the log levels for all or certain domains helps to log more details of the operations NetworkManager performs. Administrators can use this information to troubleshoot problems. NetworkManager provides different levels and domains to produce logging information. The
/etc/NetworkManager/NetworkManager.conf file is the main configuration file for NetworkManager. The logs are stored in the journal.
This section provides information on enabling debug logging for NetworkManager and using different logging levels and domains to configure the amount of logging details.
39.1. Debugging levels and domains
You can use the
domains parameters to manage the debugging for NetworkManager. The level defines the verbosity level, whereas the domains define the category of the messages to record the logs with given severity (
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Does not log any messages about NetworkManager
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Logs only critical errors
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Logs warnings that can reflect the operation
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Logs various informational messages that are useful for tracking state and operations
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Enables verbose logging for debugging purposes
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Enables more verbose logging than the
Note that subsequent levels log all messages from earlier levels. For example, setting the log level to
INFO also logs messages contained in the
WARN log level.
For details on
domains, refer to the
39.2. Setting the NetworkManager log level
By default, all the log domains are set to record the
INFO log level. Disable rate-limiting before collecting debug logs. With rate-limiting,
systemd-journald drops messages if there are too many of them in a short time. This can occur when the log level is
This procedure disables rate-limiting and enables recording debug logs for the all (ALL) domains.
To disable rate-limiting, edit the
/etc/systemd/journald.conffile, uncomment the
RateLimitBurstparameter in the
[Journal]section, and set its value as
systemctl restart systemd-journald
/etc/NetworkManager/conf.d/95-nm-debug.conffile with the following content:
domainsparameter can contain multiple comma-separated
Restart the NetworkManager service.
systemctl restart NetworkManager
39.3. Temporarily setting log levels at run time using nmcli
You can change the log level at run time using
nmcli. However, Red Hat recommends to enable debugging using configuration files and restart NetworkManager. Updating debugging
domains using the
.conf file helps to debug boot issues and captures all the logs from the initial state.
Optional: Display the current logging settings:
nmcli general loggingLEVEL DOMAINS INFO PLATFORM,RFKILL,ETHER,WIFI,BT,MB,DHCP4,DHCP6,PPP,WIFI_SCAN,IP4,IP6,A UTOIP4,DNS,VPN,SHARING,SUPPLICANT,AGENTS,SETTINGS,SUSPEND,CORE,DEVICE,OLPC, WIMAX,INFINIBAND,FIREWALL,ADSL,BOND,VLAN,BRIDGE,DBUS_PROPS,TEAM,CONCHECK,DC B,DISPATCH
To modify the logging level and domains, use the following options:
To set the log level for all domains to the same
nmcli general logging level LEVEL domains ALL
To change the level for specific domains, enter:
nmcli general logging level LEVEL domains DOMAINS
Note that updating the logging level using this command disables logging for all the other domains.
To change the level of specific domains and preserve the level of all other domains, enter:
nmcli general logging level KEEP domains DOMAIN:LEVEL,DOMAIN:LEVEL
39.4. Viewing NetworkManager logs
You can view the NetworkManager logs for troubleshooting.
To view the logs, enter:
journalctl -u NetworkManager -b