Logging on Cisco IOS Devices
Share this page:Logging is one of the things the Network Engineers are not really fond of, but you need to really understand why and how it needs to be used, for two reasons:
1. Not to miss a major event on a Device.
2. Not to get “overflown” by different events while “playing around” in a CLI.
Lets start with the Logging of a remote IP, or locally (in a FILE):
(config)#logging x.y.z.w
7 is DEBUGGING, so LOG EVERYTHING 0-7:
(config)#logging file flash:syslog 7
emergencies System is unusable (severity=0)
alerts Immediate action needed (severity=1)
critical Critical conditions (severity=2)
errors Error conditions (severity=3)
warnings Warning conditions (severity=4)
notifications Normal but significant conditions (severity=5)
informational Informational messages (severity=6)
debugging Debugging messages (severity=7)
Set the SEVERITY level:
(config)#logging trap 4 <- FROM WARNING-4 (INCLUDING 4) TO MORE CRITICAL (ALERT-1, CRITICAL-2, ERROR-3)
Add SEQUENCE numbers:
(config)#service sequence-numbers <- “SERVICE” command IS FOR SYSTEM GENERAL SETTINGS
Add/Remove TIMESTAMPS
(config)#no service timestamps debug
(config)#no service timestamps log
Set the LOGGING messages to be saved in Local:
(config)#logging facility local4
Specific (more GRANULAR) logging settings can be configured on the Interface Level:
(config-if)#logging event ?
bundle-status BUNDLE/UNBUNDLE messages
link-status UPDOWN and CHANGE messages
nfas-status NFAS D-channel status messages
power-inline-status Inline power messages
spanning-tree Spanning-tree Interface events
status Spanning-tree state change messages
subif-link-status Sub-interface UPDOWN and CHANGE messages
trunk-status TRUNK status messages