19-8
Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
OL-8915-03
Chapter 19 Configuring Flex Links and the MAC Address-Table Move Update Feature
Configuring Flex Links and MAC Address-Table Move Update
In this 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, Gi0/8 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 Backup Interface State
------------------------------------------------------------------------
GigabitEthernet0/6 GigabitEthernet0/8 Active Up/Backup Standby
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 Gi0/6 goes down, Gi0/8 carries
all VLANs of the Flex Link pair.
Switch#
show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet0/6 GigabitEthernet0/8 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 Gi0/6 comes up, VLANs preferred on this interface are blocked on the peer interface Gi0/8 and
forwarded on Gi0/6.
Switch#
show interfaces switchport backup
Switch Backup Interface Pairs:
Active Interface Backup Interface State
------------------------------------------------------------------------
GigabitEthernet0/6 GigabitEthernet0/8 Active Up/Backup Standby
Vlans Preferred on Active Interface: 1-50
Vlans Preferred on Backup Interface: 60, 100-120
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.
Command
Purpose
