It is possible to
configure system message logging on the
switch also supports Smart Logging to capture
packet flows based on configured triggers.
Logging messages to the console at a high rate can cause high
CPU utilization and adversely affect how the
By default, a
switch sends the output from system messages
privileged EXEC commands to a logging process.
Stack members can
trigger system messages. A stack member that generates a system message appends
its hostname in the form of
n is a
switch number from 1 to 9, and redirects the
output to the logging process on the stack master. Though the stack master is a
stack member, it does
not append its
hostname to system messages.
The logging process
controls the distribution of logging messages to various destinations, such as
the logging buffer, terminal lines, or a UNIX syslog server, depending on your
configuration. The process also sends messages to the console.
The syslog format
is compatible with 4.3 BSD UNIX.
When the logging
process is disabled, messages are sent only to the console. The messages are
sent as they are generated, so message and debug output are interspersed with
prompts or output from other commands. On the
switches, messages appear on the active
consoles after the process that generated them has finished.
You can set the
severity level of the messages to control the type of messages displayed on the
consoles and each of the destinations. You can time-stamp log messages or set
the syslog source address to enhance real-time debugging and management.
You can access logged
system messages by using the
switch command-line interface (CLI) or by
saving them to a properly configured syslog server. The
switch software saves syslog messages in an
internal buffer on a standalone
switch, and in the case of a
switch stack, on the stack master. If a
switch or the stack master fails, the log is
lost unless you had saved it to flash memory.
You can remotely
monitor system messages by viewing the logs on a syslog server or by accessing
switch through Telnet, through the console
port, or through the Ethernet management port. In a
switch stack, all stack member consoles
provide the same console output.