Cisco Catalyst 4500 Series Software Configuration Guide

64-2
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 64 Port Unicast and Multicast Flood Blocking
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.
Note Starting with Cisco IOS Release 12.2(52)SG, only IPV4 and IPv6 unknown multicast traffic flooding is
blocked; Layer 2 unknown multicast flooding is not. This behavior stems from a fix for the following
problem: when you configure blocking of unknown multicast flooding on a port, broadcast traffic to the
port is also blocked.
To disable the flooding of multicast and unicast packets to an interface, perform this task:
This example shows how to block unicast and multicast flooding on a GigabitEthernet interface1/1 and
how to verify the configuration:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet1/1
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
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(config)# interface interface-id
Enters interface configuration mode and enter the type and
number of the switch port interface (for example,
GigabitEthernet 1/1).
Step 3
Switch(config-if)# switchport block
multicast
Blocks unknown multicast forwarding to the port.
Step 4
Switch(config-if)# switchport block unicast
Blocks unknown unicast forwarding to the port.
Step 5
Switch(config)# end
Returns to privileged EXEC mode.
Step 6
Switch#
show interface interface-id
switchport
Verifies your entry.
Step 7
Switch# copy running-config startup-config
(Optional) Saves your entries in the configuration file.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E