19-10
Catalyst 2960 and 2960-S Switch Software Configuration Guide
OL-8603-09
Chapter 19 Configuring Flex Links and the MAC Address-Table Move Update Feature
Configuring Flex Links and the MAC Address-Table Move Update
Beginning in privileged EXEC mode, follow these steps to configure a preemption scheme for a pair of
Flex Links:
To remove a preemption scheme, use the no switchport backup interface interface-id preemption
mode interface configuration command. To reset the delay time to the default, use the no switchport
backup interface interface-id preemption delay interface configuration command.
This example shows how to configure the preemption mode as forced for a backup interface pair and to
verify the configuration:
Catalyst 2960-S switch:
Switch# configure terminal
Catalyst 2960 switch:
Switch(conf)# interface gigabitethernet0/1
Switch(conf-if)#switchport backup interface gigabitethernet0/2 preemption mode forced
Switch(conf-if)#switchport backup interface gigabitethernet0/2 preemption delay 50
Switch(conf-if)# end
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 6.
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.
Step 7 show interfaces [interface-id] switchport backup Verify the configuration.
Step 8 copy running-config startup config (Optional) Save your entries in the switch startup
configuration file.