Cisco routers, switches, PIX and ASA firewalls prioritize log messages into 8 levels (0-7), as shown below:
Level Level Name Description
0 Emergencies System is unusable
1 Alerts Immediate action needed
2 Critical Critical conditions
3 Errors Error conditions
4 Warnings Warning conditions
5 Notifications Informational messages
6 Informational Normal but significant conditions
7 Debugging Debugging messages
When you enable logging for a specific level, all logs of that severity and greater (numerically less) will be logged. In this case we can see that logging level of 3 (as seen by the 3 in "LINK-3-UPDOWN") and level 5 (as seen by the 5 in "LINEPROTO-5-UPDOWN") are shown, which means that logging level 5 must have been configured. As shown by the table, logging level 5 is Notifications.
Incorrect Answers:
A: Alerts is logging level 1, and all levels 5 and below (more severe) are being logged.
B: Critical is logging level 2, and all levels 5 and below are being logged.
C: Errors is logging level 3, and all levels 5 and below are being logged.