Protected Port Configuration Guidelines; Configuring A Protected Port; Configuring Port Blocking; Default Port Blocking Configuration - Cisco Catalyst 3750 Software Configuration Manual

Chapter 18 Configuring Port-Based Traffic Control

Protected Port Configuration Guidelines

You can configure protected ports on a physical interface (for example, Gigabit Ethernet1/0/1) 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.

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 an interface 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.

Default Port Blocking Configuration

The default is to not block flooding of unknown multicast and unicast traffic out of a port, but to flood
these packets to all ports.
78-15870-01
Purpose
Enter global configuration mode.
Enter interface configuration mode, and enter the type and
number of the interface to configure, for example
gigabitethernet1/0/1.
Configure the interface to be a protected port.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3750 Metro Switch Software Configuration Guide

Configuring Port Blocking

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