Specifications

9-12
System Management Software Configuration Guide for Cisco IE 2000U and Connected Grid Switches
Chapter 9 Configuring Port-Based Traffic Control
Configuring Port Security
To return the interface to the default condition where no traffic is blocked and normal forwarding occurs
on the port, use the no switchport block {multicast | unicast} interface configuration commands.
EXAMPLE
This example shows how to block unicast and Layer 2 multicast flooding on a port:
Switch# configure terminal
Switch(config)# interface fastethernet0/1
Switch(config-if)# no shutdown
Switch(config-if)# switchport block multicast
Switch(config-if)# switchport block unicast
Switch(config-if)# end
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 addresses. If
you limit the number of secure MAC addresses to one and assign a single secure MAC address, the
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 flagged.
This section includes the following topics:
• Enabling and Configuring Port Security, page 9-12
• Enabling and Configuring Port Security Aging, page 9-16
• Port Security and Private VLANs, page 9-18
Enabling and Configuring Port Security
Follow this procedure to restrict input to an interface by limiting and identifying MAC addresses of the
stations allowed to access the port.
BEFORE YOU BEGIN
Review the “Guidelines and Limitations” section on page 9-5.
DETAILED STEPS
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the interface to configure, and enter interface configuration
mode.
Step 3
no shutdown Enable the port, if necessary. By default, UNIs and ENIs are
disabled, and NNIs are enabled.