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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Configuring System Message Logging
This chapter describes how to configure system message logging on the Catalyst 3750-X or 3560-X
switch. Unless otherwise noted, the term switch refers to a Catalyst 3750-X or 3560-X standalone switch
and to a Catalyst 3750-X switch stack.
Note For complete syntax and usage information for the commands used in this chapter, see the Cisco IOS
Configuration Fundamentals Command Reference, Release 12.2.
Understanding System Message Logging, page 34-1
Configuring System Message Logging, page 34-2
Displaying the Logging Configuration, page 34-14
Caution Logging messages to the console at a high rate can cause high CPU utilization and adversely affect how
the switch operates.

Understanding System Message Logging

By default, a switch sends the output from system messages and debug 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 hostname-n, where 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.
Note 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 Catalyst 3750-X switches, messages appear on the active consoles after the process that
generated them has finished. On Catalyst 3560-X switches, messages appear on the console after the
process that generated them has finished.