Specifications

CHAPTER 5
Implementing High Availability
Syslog
Cisco devices produce system logging (or syslog) messages that can be output to the device console, VTY connection,
system buffer, or remote syslog server. If sent to a syslog server, messages are sent on UDP port 514. You are probably
familiar with the syslog message %SYS-5-CONFIG_I: Configured from console by console, for instance. A syslog
message always starts with the percent sign and has the following format:
%FACILTY-SUBFACILITY-SEVERITY-MNEMONIC: message text
Each portion of a syslog message has a specific meaning:
n FACILITY-SUBFACILITY: This tells the protocol, module, or process that generated the message. Some examples
are SYS for the operating system, OSPF, IF for an interface, and IP.
n SEVERITY: A number from 0 to 7 designating the importance of the action reported. The levels are:
n Emergency: 0
n Alert: 1
n Critical: 2
n Error: 3
n Warning: 4
n Notice: 5
n Informational: 6
n Debugging: 7
n MNEMONIC: A code that identifies the action reported.
n A plain-text description of the event that triggered the syslog message.
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CCNP SWITCH 642-813 Quick Reference by Denise Donohue