Cisco IE-3000-8TC Command Reference Manual page 587

Chapter 2 IE 3000 Switch Cisco IOS Commands
The following example shows how to configure preferred VLANs:
Switch(config)# interface gigabitethernet 1/2
Switch(config-if)# switchport backup interface gigabitethernet 1/1 prefer vlan 60,100-120
You can verify your setting by entering the show interfaces switchport backup privileged EXEC
command.
In the following example, VLANs 60, and 100 to 120 are configured on the switch:
Switch(config)# interface gigabitEthernet 1/2
Switch(config-if)# switchport backup interface gigabitEthernet 1/1 prefer vlan 60,100-120
When both interfaces are up, Gi1/2 forwards traffic for VLANs 1 to 50, and Gi1/1 forwards traffic for
VLANs 60 and 100 to 120.
Switch# show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet1/2 GigabitEthernet1/1 Active Up/Backup Up
Vlans Preferred on Active Interface: 1-50
Vlans Preferred on Backup Interface: 60, 100-120
When a Flex Link interface goes down (LINK_DOWN), VLANs preferred on this interface are moved
to the peer interface of the Flex Link pair. In this example, if interface Gi1/2 goes down, Gi1/1 carries
all VLANs of the Flex Link pair.
Switch# show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet1/2 GigabitEthernet1/1 Active Down/Backup Up
Vlans Preferred on Active Interface: 1-50
Vlans Preferred on Backup Interface: 60, 100-120
When a Flex Link interface comes up, VLANs preferred on this interface are blocked on the peer
interface and moved to the forwarding state on the interface that has just come up. In this example, if
interface Gi1/2 comes up, VLANs preferred on this interface are blocked on the peer interface Gi1/1 and
forwarded on Gi1/2.
Switch# show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet1/2 GigabitEthernet1/1 Active Up/Backup Up
Vlans Preferred on Active Interface: 1-50
Vlans Preferred on Backup Interface: 60, 100-120
The following example shows how to configure multicast fast-convergence on interface Gi1/1:
Switch# configure terminal
Switch(config)# interface gigabitEthernet 1/1
Switch(config-if)# switchport backup interface gigabitEthernet 1/2 multicast
fast-convergence
Switch(config-if)# end
OL-13019-01
Backup Interface
Backup Interface
Backup Interface
switchport backup interface
State
State
State
Cisco IE 3000 Switch Command Reference
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