Cisco Catalyst 3550 Series User Manual

21-7
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 21 Configuring Port-Based Traffic Control
Configuring Port Blocking
To return the interface to the default condition where no traffic is blocked, use the no switchport block
{multicast | unicast} interface configuration commands.
This example shows how to block unicast and multicast flooding on Gigabit Ethernet interface 0/1 and
verify the configuration:
Switch# configure terminal
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# switchport block multicast
Switch(config-if)# switchport block unicast
Switch(config-if)# end
Switch# show interfaces gigabitethernet0/1 switchport
Name: Gi0/1
Switchport: Enabled
<output truncated>
Protected: True
Unknown unicast blocked: enabled
Unknown multicast blocked: enabled
Resuming Normal Forwarding on a Port
Beginning in privileged EXEC mode, follow these steps to resume normal forwarding on a port:
Step 6
show interfaces interface-id switchport Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the type and number of the physical interface to configure, for
example gigabitethernet0/1, and enter interface configuration mode.
Step 3
no switchport block multicast Enable unknown multicast flooding to the port.
Step 4
no switchport block unicast Enable unknown unicast flooding to the port.
Step 5
end Return to privileged EXEC mode
Step 6
show interfaces interface-id switchport Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.

Cisco Catalyst 3550 Series Specifications

General

Brand	Cisco
Model	Catalyst 3550 Series
Category	Network Router
Language	English