Cisco 2975 - Catalyst LAN Base Switch, Software Configuration Manual

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23-11
Catalyst 2975 Switch Software Configuration Guide
OL-19720-02
Chapter 23 Configuring Port-Based Traffic Control
Configuring Port Security
•
restrict—When the number of secure MAC addresses reaches the maximum limit allowed on the
port, packets with unknown source addresses are dropped until you remove a sufficient number of
secure MAC addresses to drop below the maximum value or increase the number of maximum
allowable addresses. In this mode, you are notified that a security violation has occurred. An SNMP
trap is sent, a syslog message is logged, and the violation counter increments.
• shutdown—A port security violation causes the interface to become error-disabled and to shut down
immediately, and the port LED turns off. 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 shut
down interface configuration commands. This is the default mode.
•
shutdown vlan—Use to set the security violation mode per-VLAN. In this mode, the VLAN is error
disabled instead of the entire port when a violation occurs
Table 23-1 shows the violation mode and the actions taken when you configure an interface for port
security.
Default Port Security Configuration
Table 23-2 shows the default port security configuration for an interface.
Table 23-1 Security Violation Mode Actions
Violation Mode
Traffic is
forwarded
1
1. Packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses.
Sends SNMP
trap Sends syslog
message Displays error
message
2
2. The switch returns an error message if you manually configure an address that would cause a security violation.
Violation
counter
increments
Shuts down port
protect No No No No No No
restrict No Yes Yes No Yes No
shutdown No No No No Yes Yes
shutdown vlan No No Yes No Yes No
3
3. Shuts down only the VLAN on which the violation occurred.
Table 23-2 Default Port Security Configuration
Feature Default Setting
Port security Disabled on a port.
Sticky address learning Disabled.
Maximum number of secure
MAC addresses per port 1
Violation mode Shutdown. The port shuts down when the maximum number of
secure MAC addresses is exceeded.
Port security aging Disabled. Aging time is 0.
Static aging is disabled.
Type is absolute.