Purpose
Command or Action
switch# interface ethernet 1/1
switch(config-if)#
Prevents the flooding of unknown multicast or unicast
packets on the specified interface.
[
no
]
switchport block
{
multicast
|
unicast
}
Example:
Step 3
Use the
no
form of this command to resume normal
forwarding on the port.
switch(config-if)# switchport block unicast
Displays the switchport blocking configuration.
(Optional)
show interface
[
ethernet slot
/
port
|
port-channel number
]
switchport
Step 4
Example:
switch(config-if)# show interface ethernet 1/1
switchport
Copies the running configuration to the startup
configuration.
(Optional)
copy running-config startup-config
Example:
Step 5
switch(config-if)# copy running-config
startup-config
Verifying the Switchport Blocking Configuration
To display switchport blocking configuration information, perform one of the following tasks:
Purpose
Command
Displays the switchport blocking
configuration for all interfaces.
show interface switchport
Displays the switchport blocking
configuration for the specified
interface.
show interface
{
ethernet slot
/
port
|
port-channel number
}
switchport
Displays the switchport blocking
configuration in the running
configuration.
show running-config interface
[
ethernet slot
/
port
|
port-channel
number
]
Configuration Example for Switchport Blocking
The following example shows how to block multicast and unicast flooding on Ethernet interface 1/2 and how
to verify the configuration:
switch#
configure terminal
switch(config)#
interface ethernet 1/2
switch(config-if)#
switchport block multicast
switch(config-if)#
switchport block unicast
switch(config-if)#
show running-config interface ethernet 1/2
!Command: show running-config interface Ethernet1/2
!Time: Wed Apr 15 16:25:48 2015
Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.x
451
Configuring Switchport Blocking
Verifying the Switchport Blocking Configuration