17-4
Catalyst2950 Desktop Switch Software Configuration Guide
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Chapter17 Configuring Port-Based Traffic Control
Configuring Port Security
To disable protected port, use the no switchport protected interface configuration command.
This example shows how to configure Gigabit Ethernet interface 0/1 as a prot ec ted por t a nd veri fy the
configuration:
Switch# configure terminal
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# switchport protected
Switch(config-if)# end
Switch# show interfaces gigabitethernet0/1 switchport
Name: Gi0/1
Switchport: Enabled
<output truncated>
Protected: True
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Configuring Port Security
You can use the port security feature to restrict input to an interface by limiting and identifying MAC
addresses of the stations allowed to access the port. When you assign secure MAC addresses to a secure
port, the port does not forward packets with source addresses outside the group of defined add resses. If
you limit the number of secure MAC addresses to one and assign a singl e se cu re M AC address, th e
workstation attached to that port is assured the full bandwidth of the port.
If a port is configured as a secure port and the maximum number of secure MAC addresses is reached,
when the MAC address of a station attempting to access the port is different from any of the identified
secure MAC addresses, a security violation occurs. Also, if a station with a secure MAC address
configured or learned on one secure port attempts to access another secure port, a violation is flagg ed.
These sections include port security configuration informa tion and pr oced ure s:
•Understanding Port Security, page 17-4
•Default Port Security Configuration, page 17-6
•Port Security Configuration Guidelines, page 17-7
•Enabling and Configuring Port Security, page 17-7
•Enabling and Configuring Port Security Aging, page 17-10

Understanding Port Security

This section contains information about these topics:
•Secure MAC Addresses, page 17-5
•Security Violations, page 17-6
Step5 show interfaces interface-id switchport Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose