This chapter covers
- Real-time logging to the console and VTY lines
- Storing log messages locally and on a Syslog server
- The Syslog message format
- Syslog severity levels
Syslog is a standard for message logging in computers and is CCNA exam topic 4.5: Describe the use of syslog features including facilities and severity levels. Like SNMP, the topic of the previous chapter, Syslog provides mechanisms to collect information about devices and monitor network health.
Although they do have their similarities, there are significant differences between SNMP and Syslog, and for that reason, most networks make use of both protocols. SNMP is like a network health report, proactively polling devices at regular intervals to gather mostly (but not exclusively) quantitative metrics—numerical statistics like traffic rates, CPU utilization, error rates, etc. SNMP is also often used for event-based alerting using Trap and Inform messages.