Protected Port Configuration Guidelines; Configuring A Protected Port; Configuring Port Blocking - Cisco Catalyst 3120 Software Manual

Configuring Port Blocking

Protected Port Configuration Guidelines

You can configure protected ports on a physical interface (for example, Gigabit Ethernet port 1) or an
EtherChannel group (for example, port-channel 5). When you enable protected ports for a port channel,
it is enabled for all ports in the port-channel group.
Do not configure a private-VLAN port as a protected port. Do not configure a protected port as a
private-VLAN port. A private-VLAN isolated port does not forward traffic to other isolated ports or
community ports. For more information about private VLANs, see
VLANs."

Configuring a Protected Port

Beginning in privileged EXEC mode, follow these steps to define a port as a protected port:
Command
Step 1 configure terminal
Step 2 interface interface-id
Step 3 switchport protected
Step 4
end
Step 5 show interfaces interface-id switchport
Step 6 copy running-config startup-config
To disable protected port, use the no switchport protected interface configuration command.
This example shows how to configure a port as a protected port:
Switch# configure terminal
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# switchport protected
Switch(config-if)# end
Configuring Port Blocking
By default, the switch floods packets with unknown destination MAC addresses out of all ports. If
unknown unicast and multicast traffic is forwarded to a protected port, there could be security issues. To
prevent unknown unicast or multicast traffic from being forwarded from one port to another, you can
block a port (protected or nonprotected) from flooding unknown unicast or multicast packets to other
ports.
These sections contain this configuration information:
•
•
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
25-6
Default Port Blocking Configuration, page 25-7
Blocking Flooded Traffic on an Interface, page 25-7
Chapter 25
Purpose
Enter global configuration mode.
Specify the interface to be configured, and enter interface
configuration mode.
Configure the interface to be a protected port.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Configuring Port-Based Traffic Control
Chapter 15, "Configuring Private
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