Configure LACP on an MLT

Important

Attach ports to an aggregator only if their system priorities are the same; otherwise, they are considered to be operating in two different switches. You can attach ports to an aggregator only if their keys are the same.

When you add a VLAN to a dynamic MLT, only the active ports of the MLT are added as port members of the VLAN. Ports configured with the same aggregation key, but not active, are not added to the VLAN. If these inactive ports become active later, the system does not automatically add them to the VLAN port member list.

You must add all inactive ports to the VLAN. If you do not add the inactive ports to the VLAN, when they become active later, hashing can result in choosing a newly active port for traffic forwarding. Because the port is not a port member of the VLAN, traffic will be dropped. When you add the VLAN to the MLT, also add the inactive aggregation ports to the VLAN. You may need to disable LACP on the inactive ports before you can add them to the VLAN. Because the ports are inactive, disabling LACP does not cause a traffic interruption.

Similarly when you remove a VLAN from a dynamic MLT, all active ports of the MLT are removed from the VLAN port member list but the inactive members are not removed. You must remove the inactive aggregation members from the VLAN.

If you later configure a port for the same aggregation, you must add this port to all VLANs that are members of the MLT.