LAG configuration guidelines

Aggregation member interface restrictions

  • If any features in the following list are configured on the interface, you cannot assign an interface to a Layer 2 aggregation group:
    • MAC authentication

    • Port security

    • 802.1X

  • Do not assign a reflector port for port mirroring to an aggregation group.

Requirements for adding interfaces

Keep in mind the following requirements when adding interfaces to a LAG:

  • The product supports 256 LAG interfaces with a maximum of eight physical interfaces per LAG.

  • After the maximum limit of members is reached in a LAG, an additional port cannot be added to the aggregation group. If a port belongs to a card type with a different speed than the other aggregation members, the port can still be added to the aggregation group. If dynamic LAG is enabled, any port member with a speed different than other aggregation members is blocked or ineligible from the same aggregation group. Any operational keys/attributes or configuration changes might affect the aggregation states of the member ports.

  • The nondefaults configuration on an interface is removed automatically when the interface is added to a link aggregation. For example: Assume that you remove a member interface from an existing LAG and add it to another LAG. The software removes the nondefault configurations on the interface when it is added to the new LAG.

Configuration consistency requirements

  • Configure at least one active mode aggregation in two devices.

  • For a successful static aggregation, make sure the ports at both ends of each link are in the same aggregation state.

  • For a successful dynamic aggregation, make sure the peer ports of the ports aggregated at one end are also aggregated, and that one of the ends is configured as "active". The two ends can automatically negotiate the aggregation state of each member port.

Removing interfaces

  • Deleting an aggregate interface also deletes its aggregation group and causes all member ports to leave the aggregation group.

  • When a member interface is removed from a LAG, the interface becomes disabled.

Disabling an interface

When an interface LAG is disabled with the shutdown command, all its members also become operationally down.