Tracing levels determine how much information about a module should be
stored in the trace buffer or file.
The table below shows all of the trace levels that are available and
provides descriptions of what types of messages are displayed with each tracing
level.
Table 1. Tracing Levels and Descriptions
|
Trace Level
|
Level Number
|
Description
|
|
Emergency
|
0
|
The message is regarding an issue that makes the system
unusable.
|
|
Alert
|
1
|
The message is regarding an action that must be taken
immediately.
|
|
Critical
|
2
|
The message is regarding a critical condition. This is the
default setting.
|
|
Error
|
3
|
The message is regarding a system error.
|
|
Warning
|
4
|
The message is regarding a system warning
|
|
Notice
|
5
|
The message is regarding a significant issue, but the router is
still working normally.
|
|
Informational
|
6
|
The message is useful for informational purposes only.
|
|
Debug
|
7
|
The message provides debug-level output.
|
|
Verbose
|
8
|
All possible tracing messages are sent.
|
|
Noise
|
-
|
All possible trace messages for the module are logged.
The noise level is always equal to the highest possible tracing
level. Even if a future enhancement to tracing introduces a higher tracing
level, the noise level will become equal to the level of that new enhancement.
|
Trace level settings are leveled, meaning that every setting will
contain all messages from the lower setting plus the messages from its own
setting. For instance, setting the trace level to 3(error) ensures that the
trace file will contain all output for the 0 (emergencies), 1 (alerts), 2
(critical), and 3 (error) settings. Setting the trace level to 4 (warning) will
ensure that all trace output for the specific module will be included in that
trace file.
The default tracing level for every module on the router is notice.
All trace levels are not user-configurable. Specifically, the alert,
critical, and notice tracing levels cannot be set by users. If you wish to
trace these messages, set the trace level to a higher level that will collect
these messages.
When setting trace levels, it is also important to remember that the
setting is not done in a configuration mode, so trace level settings are
returned to their defaults after every router reload.
Caution |
Setting tracing of a module to the debug level or higher can have a
negative performance impact. Setting tracing to this level or higher should be
done with discretion.
|
Caution |
Setting a large number of modules to high tracing levels can severely
degrade performance. If a high level of tracing is needed in a specific
context, it is almost always preferable to set a single module on a higher
tracing level rather than setting multiple modules to high tracing levels.
|
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