Cisco WS-C6506 User Manual

CHAPTER
45-1
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
45
Configuring Unicast Flood Blocking
This chapter describes how to configure unicast flood blocking on the Catalyst 6500 series switches.
Note For complete syntax and usage information for the commands that are used in this chapter, refer to the
Catalyst 6500 Series Switch Command Reference publication.
This chapter consists of these sections:
• Understanding How Unicast Flood Blocking Works, page 45-1
• Unicast Flood Blocking Configuration Guidelines, page 45-2
• Configuring Unicast Flood Blocking on the Switch, page 45-2
Understanding How Unicast Flood Blocking Works
You can enable unicast flood blocking on any Ethernet port on a per-port basis. Unicast flood blocking
provides you the option to drop the unicast flood packets on an Ethernet port that has only one host that
is connected to the port. All the Ethernet ports on a switch are configured to allow unicast flooding;
unicast flood blocking allows you to drop the unicast flood packets before they reach the port.
Caution You must have a static CAM entry that is associated with the Ethernet port before you enable unicast
flood blocking. If you do not have a static CAM entry that is associated with the port, you will lose
network connectivity if you enable unicast flood blocking. You can verify that a static CAM entry exists
by entering the show cam static command.
Note If you are configuring unicast flood blocking on a secure port, see Chapter 38, “Configuring Port
Security.”

Cisco WS-C6506 Specifications

General

Model	WS-C6506
Product Type	Switch
Number of Slots	6
Operating System	Cisco IOS
Product Series	Catalyst 6500
Ports	Depends on modules installed
Management	CLI, SNMP, Web