Core Issue
Cisco routers may be configured at different logging levels for each type of logging. If the level is set too low, certain messages are not displayed.
Resolution
If certain log messages are not displayed, perform these steps:
- Determine the logging level by issuing the show logging command. This is a sample command output:
router#show log
Syslog logging: enabled (0 messages dropped, 1 messages rate-limited, 0
flushes, 0 overruns, xml disabled)
Console logging: level debugging, 499 messages logged, xml disabled
Monitor logging: level debugging, 173 messages logged, xml disabled
Buffer logging: level debugging, 499 messages logged, xml disabled
Logging Exception size (4096 bytes)
Count and timestamp logging messages: disabled
Trap logging: level informational, 24 message lines logged
The above example indicates the logging for the console, monitor, and buffer are set to the debugging level, but trap logging is set to the informational level. Because the debugging level is the highest level, more messages are logged at the debugging level than are logged at the informational level.
Trap logging is used for sending log messages to an external syslog server. Therefore, in this case, some log messages which are seen on the console (Console logging), during a Telnet session (Monitor logging), or on the internal buffer through the show logging command (Buffer logging), are not seen on the syslog server.
- In order to change the logging level, issue one of these global configuration logging commands:
For example, to set the logging level to debugging for trap logging, this would be the command:
router#config t
router(config)#logging trap debugging
router(config)#^Z (ctrl z to exit)
router#write mem
The router should now send all log messages to the syslog server.
For more information on the logging commands and levels, refer to the Logging command documentation section of Troubleshooting and Fault Management Commands.
