Blocking Flooded Traffic On An Interface - Cisco 4500M Software Manual

Configuring Port Blocking

Blocking Flooded Traffic on an Interface

Note The interface can be a physical interface (for example, GigabitEthernet 1/1) or an EtherChannel
group (such as port-channel 5). When you block multicast or unicast traffic for a port channel, it is
blocked on all ports in the port channel group.
To disable the flooding of multicast and unicast packets to an interface, perform this task:
Command
Step 1
Switch# configure terminal
Step 2
Switch(config)# interface interface-id
Step 3
Switch(config-if)# switchport block
multicast
Step 4
Switch(config-if)# switchport block unicast
Step 5
Switch(config)# end
Step 6
Switch#
show interface interface-id switchport
Step 7
Switch# copy running-config startup-config
This example shows how to block unicast and multicast flooding on a GigabitEthernet interface 0/1 and
how to 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 interface gigabitethernet1/1 switchport
Name: Gi1/3
Switchport: Enabled
<output truncated>
Port Protected: On
Unknown Unicast Traffic: Not Allowed
Unknown Multicast Traffic: Not Allowed
Broadcast Suppression Level: 100
Multicast Suppression Level: 100
Unicast Suppression Level: 100
Software Configuration Guide—Release 12.2(25)EW
37-2
Chapter 37
Purpose
Enters global configuration mode.
Enters interface configuration mode and enter the type and
number of the switchport interface (for example,
GigabitEthernet 1/1).
Blocks unknown multicast forwarding to the port.
Blocks unknown unicast forwarding to the port.
Returns to privileged EXEC mode.
Verifies your entry.
(Optional) Saves your entries in the configuration file.
Port Unicast and Multicast Flood Blocking
OL-6696-01