Note: If you are not sure about Syslog, please read our Syslog tutorial.
Question 1
Question 2
Explanation
Usually no action is required when a route flaps so it generates the notification syslog level message (level 5).
Question 3
Explanation
If you used to configure a Cisco device then maybe you saw this notice level message:
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down |
Number 5 in the above message represents for the Notification Level (Normal, but significant, conditions exist).