This feature allows users to configure L2 subinterfaces on MLAG interfaces. L2 subinterfaces are not supported on the MLAG peer-link.

In order to achieve split horizon and prevent double-delivery of packets in an MLAG setup, egress ACLs are installed on all active MLAG interfaces so that BUM traffic received on the MLAG peer-link cannot get forwarded out any MLAG interfaces. When only one half of an MLAG interface is active, this egress ACL is removed to allow BUM traffic from the peer-link to be forwarded out MLAG interfaces.