802.3ad mode

Bonding mode 4 (802.3ad), also known as LACP (Link Aggregation Control Protocol) mode, is used for load balancing and fault tolerance. The IEEE 802.3ad specification allows the grouping of Ethernet interfaces at the physical layer to form a single link layer interface. If a bonding interface is set to this mode, it requires that all the slave devices operate at the same speed and are duplex. In this way, the network can benefit from the aggregated bandwidth of all the slaves, and if one of the slaves is down, the whole network will not be affected.