Cisco Nexus 5000 Series Command Reference Release 4.0(1a)N2(1) (OL-16599-01, March 2009)

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Cisco Nexus 5000 Series Command Reference
OL-16599-01
Chapter 2 Ethernet Commands
switchport block
switchport block
To prevent the unknown multicast or unicast packets from being forwarded, use the switchport block
interface configuration command. To allow the unknown multicast or unicast packets to be forwarded,
use the no form of this command.
switchport block {multicast | unicast}
no switchport block {multicast | unicast}
Syntax Description
Command Default Unknown multicast and unicast traffic are not blocked. All traffic with unknown MAC addresses is sent
to all ports.
Command Modes Interface configuration mode
Command History
Usage Guidelines You can block the unknown multicast or unicast traffic on the switch ports.
Blocking the unknown multicast or unicast traffic is not automatically enabled on the switch ports; you
must explicitly configure it.
Examples This example shows how to block the unknown multicast traffic on an interface:
switch# configure terminal
switch(config)# interface ethernet 1/1
switch(config-if)# switchport block multicast
Related Commands
multicast Specifies that the unknown multicast traffic should be blocked.
unicast Specifies that the unknown unicast traffic should be blocked.
Release Modification
4.0(0)N1(1a) This command was introduced.
Command Description
show interface
switchport
Displays the switch port information for a specified interface or all
interfaces.