Cisco catalyst 3750 Command Reference Manual page 602

show interfaces
This is an example of output from the show interfaces switchport backup command. In this example,
VLANs 1 to 50, 60, and 100 to 120 are configured on the switch:
Switch(config)#interface gigabitEthernet 2/0/6
Switch(config-if)#switchport backup interface gigabitEthernet 2/0/8 prefer vlan 60,100-120
When both interfaces are up, Gi2/0/8 forwards traffic for VLANs 60, 100 to 120, and Gi2/0/6 forwards
traffic for VLANs 1 to 50.
Switch#show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Down/Backup Up
Vlans on Interface Gi 2/0/6: 1-50
Vlans on Interface Gi 2/0/8: 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 Gi2/0/6 goes down, Gi2/0/8 carries
all VLANs of the Flex Link pair.
Switch#show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Down/Backup Up
Vlans on Interface Gi 2/0/6:
Vlans on Interface Gi 2/0/8: 1-50, 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 Gi2/0/6 comes up, then VLANs preferred on this interface are blocked on the peer interface
Gi2/0/8 and forwarded on Gi2/0/6.
Switch#show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface
------------------------------------------------------------------------
GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Down/Backup Up
Vlans on Interface Gi 2/0/6: 1-50
Vlans on Interface Gi 2/0/8: 60, 100-120
This is an example of output from the show interfaces interface-id pruning command:
Switch# show interfaces gigibitethernet1/0/2 pruning
Port
This is an example of output from the show interfaces interface-id trunk command. It displays trunking
information for the port.
Switch# show interfaces gigabitethernet1/0/1 trunk
Port
Gi1/0/1
Port
Gi1/0/1
Catalyst 3750 Switch Command Reference
2-572
Backup Interface
Backup Interface
Backup Interface
Vlans pruned for lack of request by neighbor
Mode Encapsulation
auto negotiate
Vlans allowed on trunk
1-4094
Chapter 2 Catalyst 3750 Switch Cisco IOS Commands
State
State
State
Status Native vlan
trunking 1
OL-8552-07