Cisco Gigabit Ethernet Switch Module for HP BladeSystem p-Class Command Reference Guide

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Cisco Gigabit Ethernet Switch Module for the HP p-Class Blade System Command Reference Guide
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Chapter 2 CGESM Switch Cisco IOS Commands
switchport backup interface
switchport backup interface
Use the switchport backup interface interface configuration command on a Layer 2 interface to
configure Flex Links, a pair of interfaces that provide backup to each other. Use the no form of this
command to remove the Flex Links configuration.
switchport backup interface {interface-id} [mmu primary vlan vlan-id | preemption {delay
delay-time | mode {bandwidth | forced | off}}]
no switchport backup interface {interface-id} [mmu primary vlan | preemption {delay | mode}]
Syntax Description
Defaults The default is to have no Flex Links defined.
Preemption mode is off. No preemption occurs.
Preemption delay is set to 35 seconds.
Command Modes Interface configuration
Command History
Usage Guidelines With Flex Links configured, one link acts as the primary interface and forwards traffic, while the other
interface is in standby mode, ready to begin forwarding traffic if the primary link shuts down. The
interface being configured is referred to as the active link; the specified interface is identified as the
backup link. The feature provides an alternative to the Spanning Tree Protocol (STP), allowing users to
turn off STP and still retain basic link redundancy.
• This command is available only for Layer 2 interfaces.
• You can configure only one Flex Link backup link for any active link, and it must be a different
interface from the active interface.
• An interface can belong to only one Flex Link pair. An interface can be a backup link for only one
active link. An active link cannot belong to another Flex Link pair.
interface-id Specify that the Layer 2 interface to act as a backup link to the interface
being configured. The interface can be a physical interface or port channel.
The port-channel range is 1 to 48.
mmu Configure the MAC move update (MMU) for a backup interface pair.
primary vlan vlan-id The VLAN ID of the private-VLAN primary VLAN; valid range is 1 to 4094.
preemption Configure a preemption scheme for a backup interface pair.
mode Specifies a preemption mode as bandwidth, forced, or off.
bandwidth (Optional) Specify that the interface with the higher available bandwidth
always preempts the backup.
forced (Optional) Specify that the interface always preempts the backup.
off (Optional) Specify that no preemption occurs from backup to active.
delay delay-time (Optional) Specify a preemption delay; the valid values are 1 to 300 seconds.