Security Violations - Cisco 2950 - Catalyst Switch Configuration Manual

Configuring Port Security

Security Violations

It is a security violation when one of these situations occurs:
•
•
You can configure the interface for one of three violation modes, based on the action to be taken if a
violation occurs:
•
•
•
Table 22-1
security.
Table 22-1 Security Violation Mode Actions
Traffic is
Violation Mode forwarded
protect No
restrict No
shutdown No
1. Packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses.
2. The switch will return an error message if you manually configure an address that would cause a security violation.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
22-8
The maximum number of secure MAC addresses have been added to the address table, and a station
whose MAC address is not in the address table attempts to access the interface.
An address learned or configured on one secure interface is seen on another secure interface in the
same VLAN.
protect—When the number of secure MAC addresses reaches the limit allowed on the port, packets
with unknown source addresses are dropped until you remove a sufficient number of secure MAC
addresses or increase the number of maximum allowable addresses. You are not notified that a
security violation has occurred.
restrict—When the number of secure MAC addresses reaches the limit allowed on the port, packets
with unknown source addresses are dropped until you remove a sufficient number of secure MAC
addresses or increase the number of maximum allowable addresses. In this mode, you are notified
that a security violation has occurred. Specifically, an SNMP trap is sent, a syslog message is
logged, and the violation counter increments.
shutdown—In this mode, a port security violation causes the interface to immediately become
error-disabled, and turns off the port LED. It also sends an SNMP trap, logs a syslog message, and
increments the violation counter. When a secure port is in the error-disabled state, you can bring it
out of this state by entering the errdisable recovery cause psecure-violation global configuration
command, or you can manually re-enable it by entering the shutdown and no shutdown interface
configuration commands. This is the default mode.
shows the violation mode and the actions taken when you configure an interface for port
Sends SNMP
1
trap
No
Yes
Yes
Sends syslog Displays error
message message
No No
Yes No
Yes No
Chapter 22 Configuring Port-Based Traffic Control
Violation
counter
2
increments
No
Yes
Yes
Shuts down port
No
No
Yes
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