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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 23 Configuring Flex Links and the MAC Address-Table Move Update Feature Configuring Flex Links and MAC Address-Table Move Update
To disable a Flex Link backup interface, use the no switchport backup interface interface-id interface
configuration command.
This example shows how to configure an interface with a backup interface and to verify the
configuration:
Switch# configure terminal
Switch(conf)# interface gigabitethernet1/0/1
Switch(conf-if)# switchport backup interface gigabitethernet1/0/2
Switch(conf-if)# end
Switch# show interface switchport backup
Switch Backup Interface Pairs:
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet1/0/1 GigabitEthernet1/0/2 Active Up/Backup Standby
Beginning in privileged EXEC mode, follow these steps to configure a preemption scheme for a pair of
Flex Links:
Step 4 end Return to privileged EXEC mode.
Step 5 show interface [interface-id] switchport backup Verify the configuration.
Step 6 copy running-config startup config (Optional) Save your entries in the switch startup
configuration file.
Command Purpose
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface interface-id Specify the interface, and enter interface configuration
mode. The interface can be a physical Layer 2 interface or
a port channel (logical interface). The port-channel range
is 1 to 48.
Step 3 switchport backup interface interface-id Configure a physical Layer 2 interface (or port channel)
as part of a Flex Links pair with the interface. When one
link is forwarding traffic, the other interface is in standby
mode.
Step 4 switchport backup interface interface-id preemption
mode [forced | bandwidth | off]
Configure a preemption mechanism and delay for a Flex
Link interface pair. You can configure the preemption as:
Forced—the active interface always preempts the
backup.
Bandwidth—the interface with the higher bandwidth
always acts as the active interface.
Off—no preemption happens from active to backup.
Step 5 switchport backup interface interface-id preemption
delay delay-time Configure the time delay until a port preempts another
port.
Note Setting a delay time only works with forced and
bandwidth modes.
Step 6 end Return to privileged EXEC mode.