Cisco IE-4000 Software Configuration Manual page 385

Configuring FlexLinks and the MAC Address-Table Move Update
How to Configure the FlexLinks and MAC Address-Table Move Update

Neither of the links can be a port that belongs to an EtherChannel. However, you can configure two port channels
(EtherChannel logical interfaces) as FlexLinks, and you can configure a port channel and a physical interface as
FlexLinks, with either the port channel or the physical interface as the active link.

A backup link does not have to be the same type (Gigabit Ethernet, or port channel) as the active link. However, you
should configure both FlexLinks with similar characteristics so that there are no loops or changes in behavior if the
standby link begins to forward traffic.

STP is disabled on FlexLinks ports. A FlexLinks port does not participate in STP, even if the VLANs present on the
port are configured for STP. When STP is not enabled, be sure that there are no loops in the configured topology.
Once the FlexLinks configurations are removed, STP is reenabled on the ports.
Follow these guidelines to configure VLAN load balancing on the FlexLinks feature:

For FlexLinks VLAN load balancing, you must choose the preferred VLANs on the backup interface.

You cannot configure a preemption mechanism and VLAN load balancing for the same FlexLinks pair.
Follow these guidelines to configure the MAC address-table move update feature:

You can enable and configure this feature on the access switch to send the MAC address-table move updates.

You can enable and configure this feature on the uplink switches to receive the MAC address-table move updates.
How to Configure the FlexLinks and MAC Address-Table Move
Update
Configuring FlexLinks
Command
1. configure terminal
2. interface interface-id
3. switchport backup interface interface-id
4. end
Purpose
Enters global configuration mode.
Specifies the interface, and enters 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 10.
Configures a physical Layer 2 interface (or port channel)
as part of a FlexLinks pair with the interface. When one
link is forwarding traffic, the other interface is in standby
mode.
Returns to privileged EXEC mode.
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