How the intrusion log operates

When the switch detects an intrusion attempt on a port, it enters a record of this event in the Intrusion Log. No further intrusion attempts on that port will appear in the Log until you acknowledge the earlier intrusion event by resetting the alert flag.

The Intrusion Log lists the 20 most recently detected security violation attempts, regardless of whether the alert flags for these attempts have been reset. This gives you a history of past intrusion attempts. Thus, for example, if there is an intrusion alert for port A1 and the Intrusion Log shows two or more entries for port 1, only the most recent entry has not been acknowledged (by resetting the alert flag). The other entries give you a history of past intrusions detected on port A1.

Multiple intrusion log entries for the same port

switch(config)# show port-security intrusion-log
 Status and Counters - Intrusion Log

 Port  MAC Address     Date / Time
 ----- ------------- --------------------------
 1     080009-e93d4f   03/07/11 21:09:34
 1     080009-e93d4f   03/07/11 10:18:43

The log shows the most recent intrusion at the top of the listing. You cannot delete Intrusion Log entries (unless you reset the switch to its factory-default configuration). Instead, if the log is filled when the switch detects a new intrusion, the oldest entry is dropped off the listing and the newest entry appears at the top of the listing.