Configuring and Monitoring Port Security
Reading Intrusion Alerts and Resetting Alert Flags
11-36
•
Because the Port Status screen (figure 11-13 on page 11-35) does
not indicate an intrusion for port A1, the alert flag for the intru
sion on port A1 has already been reset.
•
Since the switch can show only one uncleared intrusion per port,
the alert flag for the older intrusion for port A3 in this example
has also been previously reset.
(The intrusion log holds up to 20 intrusion records and deletes an
intrusion record only when the log becomes full and a new intrusion
is subsequently detected.)
Note also that the "prior to" text in the record for the earliest intrusion
means that a switch reset occurred at the indicated time and that the
intrusion occurred prior to the reset.
3. To acknowledge the most recent intrusion entry on port A3 and enable
the switch to enter a subsequently detected intrusion on this port, type
(for
[R]
Reset alert flags
on two or more ports, this step resets the alert flags for all such ports.)
If you then re-display the port status screen, you will see that the Intrusion
Alert entry for port A3 has changed to "
Intrusion Alert flag has been acknowledged (reset) is that the Intrusion Alert
column in the port status display no longer shows "
the intrusion occurred (port A3 in this example). (Because the Intrusion Log
provides a history of the last 20 intrusions detected by the switch, resetting
the alert flags does not change its content. Thus, displaying the Intrusion Log
again will result in the same display as in figure 11-14, above.)
CLI: Checking for Intrusions, Listing Intrusion Alerts,
and Resetting Alert Flags
The following commands display port status, including whether there are
intrusion alerts for any port(s), list the last 20 intrusions, and either reset the
alert flag on all ports or for a specific port for which an intrusion was detected.
(The record of the intrusion remains in the log. For more information, refer
to "Operating Notes for Port Security" on page 11-40.)
Syntax: show interfaces brief
List intrusion alert status (and other port status informa-
tion)'.
show port-security intrusion-log
List intrusion log content.
). (Note that if there are unacknowledged intrusions
". That is, your evidence that the
No
" for the port on which
Yes