Understanding How Unicast Flood Blocking Works - Cisco WS-C6506 Software Manual

Configuring Unicast Flood Blocking
This chapter describes how to configure unicast flood blocking on the Catalyst 6500 series switches.
For complete syntax and usage information for the commands that are used in this chapter, refer to the
Note
Catalyst 6500 Series Switch Command Reference publication.
This chapter consists of these sections:
•
•
•

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.
If you are configuring unicast flood blocking on a secure port, see
Note
Security."
OL-8978-04
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
C H A P T E R
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
45
Chapter 38, "Configuring Port
45-1