Configuring Vlan Load Balancing On Flex Links - Cisco Catalyst 2960 Software Configuration Manual

Chapter 19 Configuring Flex Links and the MAC Address-Table Move Update Feature
Catalyst 2960 switch:
Switch# show interfaces 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:
Command
Step 1 configure terminal
Step 2 interface interface-id
Step 3 switchport backup interface interface-id prefer vlan
vlan-range
Step 4 end
Step 5 show interfaces [interface-id] switchport backup
Step 6 copy running-config startup config
To disable the VLAN load balancing feature, use the no switchport backup interface interface-id
prefer vlan vlan-range interface configuration command.
In the following example, VLANs 1 to 50, 60, and 100 to 120 are configured on the switch:
Catalyst 2960-S switch:
Switch(config)#interface gigabitethernet 2/0/6
Switch(config-if)#switchport backup interface gigabitethernet 2/0/8 prefer vlan 60,100-120
Catalyst 2960 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, Gi2/0/8 forwards traffic for VLANs 60 and 100 to 120, and Gi0/6 forwards
traffic for VLANs 1 to 50.
Switch#show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet2/0/6
OL-26520-01
Configuring Flex Links and the MAC Address-Table Move Update
Purpose
Enter global configuration mode.
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.
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.
Return to privileged EXEC mode.
Verify the configuration.
(Optional) Save your entries in the switch startup
configuration file.
Backup Interface
GigabitEthernet2/0/8
Catalyst 2960 and 2960-S Switches Software Configuration Guide, Release 15.0(1)SE
State
Active Up/Backup Up
19-11