Chapter 40. 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.
40.1. Debugging levels and domains
You can use the levels
and 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 (level
).
Log levels | Description |
---|---|
| Does not log any messages about NetworkManager |
| Logs only critical errors |
| Logs warnings that can reflect the operation |
| Logs various informational messages that are useful for tracking state and operations |
| Enables verbose logging for debugging purposes |
|
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 ERR
and WARN
log level.
Additional resources
-
For details on
domains
, refer to theNetworkManager.conf(5)
man page.
40.2. 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 TRACE
.
This procedure disables rate-limiting and enables recording debug logs for the all (ALL) domains.
Procedure
To disable rate-limiting, edit the
/etc/systemd/journald.conf
file, uncomment theRateLimitBurst
parameter in the[Journal]
section, and set its value as0
:RateLimitBurst=0
Restart the
systemd-journald
service.#
systemctl restart systemd-journald
Create the
/etc/NetworkManager/conf.d/95-nm-debug.conf
file with the following content:[logging] domains=ALL:DEBUG
The
domains
parameter can contain multiple comma-separateddomain:level
pairs.Restart the NetworkManager service.
#
systemctl restart NetworkManager
40.3. 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 levels
and domains
using the .conf
file helps to debug boot issues and captures all the logs from the initial state.
Procedure
Optional: Display the current logging settings:
#
nmcli general logging
LEVEL 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,DISPATCHTo modify the logging level and domains, use the following options:
To set the log level for all domains to the same
LEVEL
, enter:#
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
40.4. Viewing NetworkManager logs
You can view the NetworkManager logs for troubleshooting.
Procedure
To view the logs, enter:
#
journalctl -u NetworkManager -b
Additional resources
-
The
NetworkManager.conf(5)
man page -
The
journalctl
man page