17-10
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 17 Configuring Flex Links and the MAC Address-Table Move Update Feature
Configuring Flex Links and MAC Address-Table Move Update
This example shows how to configure the preemption mode as forced for a backup interface pair and to
verify the configuration:
Switch#
configure terminal
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
Switch#
show interface switchport backup detail
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet0/21 GigabitEthernet0/2 Active Up/Backup Standby
Interface Pair : Gi0/1, Gi0/2
Preemption Mode : forced
Preemption Delay : 50 seconds
Bandwidth : 100000 Kbit (Gi0/1), 100000 Kbit (Gi0/2)
Mac Address Move Update Vlan : auto
Configuring VLAN Load Balancing on Flex Links
Beginning in privileged EXEC mode, follow these steps to configure VLAN load balancing on Flex
Links:
In the following example, VLANs 1 to 50, 60, and 100 to 120 are configured on the switch:
Switch(config)#
interface gigabitEthernet 0/6
Switch(config-if)#
switchport backup interface gigabitEthernet 0/8 prefer vlan 60,100-120
When both interfaces are up, gigabitethernet port 0/8 forwards traffic for VLANs 60 and 100 to 120 and
gigabitethernet port 0/6 forwards traffic for VLANs 1 to 50.
Switch# show
interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet0/6 GigabitEthernet0/8 Active Up/Backup Standby
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 26.
Step 3
switchport backup interface interface-id prefer vlan
vlan-range
Configure a physical Layer 2 interface (or port channel)
as part of a Flex Links pair with the interface, and specify
the VLANs carried on the interface. The VLAN ID range
is 1 to 4094.
Step 4
end
Return to privileged EXEC mode.
Step 5
show interfaces [interface-id] switchport backup
Verify the configuration.
Step 6
copy running-config startup config
(Optional) Save your entries in the switch startup
configuration file.