Auto-LAG Configuration Guidelines Follow these guidelines when configuring the auto-LAG feature. • When auto-LAG is enabled globally and on the port interface, and if you do not want the port interface to become a member of the auto EtherChannel, disable the auto-LAG on the port interface. • A port interface will not bundle to an auto EtherChannel when it is already a member of a manual EtherChannel. To allow it to bundle with the auto EtherChannel, first unbundle the manual EtherChannel on the port interface. • When auto-LAG is enabled and auto EtherChannel is created, you can create multiple EtherChannels manually with the same partner device.
But by default, the port tries to create auto EtherChannel with the partner device. • The auto-LAG is supported only on Layer 2 EtherChannel. It is not supported on Layer 3 interface and Layer 3 EtherChannel. • The auto-LAG is supported on cross-stack EtherChannel. How to Configure EtherChannels After you configure an EtherChannel, configuration changes applied to the port-channel interface apply to all the physical ports assigned to the port-channel interface, and configuration changes that are applied to the physical port affect only the port where you apply the configuration.
When bundling physical ports into an EtherChannel, configurine settings on the EtherChannel itself, rather than directly on its member ports. The following sections provide various configuration information for EtherChannels: Configuring Layer 2 EtherChannels Configure Layer 2 EtherChannels by assigning ports to a channel group with the channel-group command in interface configuration mode. This command automatically creates the port-channel logical interface. Procedure Configuring EtherChannels Auto-LAG Configuration Guidelines Command or Action Purpose Step 1 enable Example: Device> enable Enables privileged EXEC mode. Enter your password if prompted. Step 2 configure terminal Example:
Device# configure terminal Enters global configuration mode. Step 3 interface interface-id Example: Device(config)# interface gigabitethernet 1/0/1 Specifies a physical port, and enters interface configuration mode. Valid interfaces are physical ports. Configuring EtherChannels 13