Logging Configuration
With the Logging Configuration page, you can:
The switch generates log messages of different severity levels when the configuration
changes and when certain network or switch events occur. You can display log information
about switch activity on the management console. You can also write it to a buffer, file,
or the UNIX syslog facility.
Console logging occurs on a terminal or PC connected to the console port.
To enable console logging:
- In the Console Logging area, select the Enable Console Logging
checkbox.
- From the Logging Level drop-down list, select a severity level (the amount of detail to
be logged).
Before you set this option, review the severity
level descriptions.
- Click Apply.
Buffer logging occurs in a buffer in Flash memory. The buffer maintains the information
on a first-in, first-out basis.
To enable buffer logging:
- In the Buffer Logging area, select the Enable Buffer Logging checkbox.
- From the Logging Level drop-down list, select a severity level (the amount of detail to
be logged).
Before you set this option, review the severity
level descriptions.
- In the Buffer Size field, enter the size of the buffer in bytes.
The amount of space allocated to the buffer depends on available memory. The default
buffer size is 4096 bytes. The recommended buffer size setting is 32 KB. If the buffer
capacity is not adequate, you can increase its size. If the buffer is using up too much
memory and you are seeing memory allocation failed (MALLOC FAILED) messages on the
console, then you can make it smaller.
- Click Apply.
Note: You can display the buffer by clicking Show Buffer.
You can clear the buffer contents by clicking Clear Buffer.
A log file is maintained on an external server or in Flash memory. In the switch fails,
it writes information about the failure to this file before functionality is lost.
To enable file logging:
- In the File Logging field, select the Enable File Logging checkbox.
- From the Logging Level drop-down list, select a severity level (the amount of detail to
be logged).
Before you set this option, review the severity
level descriptions.
- In the Log File Name field, enter a TFTP URL and the filename or the appropriate XMODEM
command or flash: filename.
- In the Min File Size and Max File Size fields, enter a minimum and maximum file size in
bytes.
The minimum file size is 1024 bytes; the maximum file size is from 4096 to 64 KB for
switches with 8 MB of DRAM.
The minimum file size is the trimmed file size; trimming prevents it from exceeding the
maximum size. You should set these values based on the amount of available memory, and you
should restrict the maximum file size to prevent the Flash file system from becoming very
close to full. When the Flash file system is close to full, logging slows, which could
degrade performance in other areas.
- Click Apply.
You can use the UNIX syslog facility to process log information. Log information is
sent to the UNIX host where it is managed according to the facility established on the
host.
To set up the syslog facility:
- In the Syslog Status area in the New Host field, enter the IP address of the UNIX host
that receives the log information.
- Click <<Add<<.
- From the Logging Level drop-down list, select a severity level (the amount of detail to
be logged).
Before you set this option, review the severity
level descriptions.
The logging level applies to all hosts in the Current Hosts list.
- From the Facility drop-down list, select a facility to handle the log data.
The facility applies to all hosts in the Current Hosts list.
- Click Apply.
Note: You can also remove a syslog host by selecting it in the Current
Hosts list and clicking Remove.
When you select a severity level, the switch logs all syslog messages of that level and
above. For example, if you select critical, the switch logs error
messages for critical, alerts, and emergencies. The default severity level to log is
errors.
In all cases, the severity level defines the amount of detail to be logged:
| Severity |
Description |
| emergencies |
The switch is at risk of failing. |
| alerts |
A condition exists that should be immediately corrected. |
| critical |
A critical condition exists, such as a hard device error. |
| errors |
Error messages. |
| warnings |
Warning messages. |
| notifications |
Conditions that are not errors but could require special handling. |
| informational |
Informational messages. |
| debugging |
Messages only used for debugging. |