A new approach is proposed to offload of link aggregation from a host to a HBA in SRIOV mode. The HBA first creates one or more link aggregation offload engines each having one or more physical ports and to establish a first link between a VM running on the host and one of the link aggregation offload engines for network data transmission with the VM. Once a data packet is received from the VM over the first link, the link aggregation offload engine chooses a first physical port based on its link aggregation method and establish a second link with the chosen first physical port to transmit the packet out of the HBA. If the second link fails, the link aggregation offload engine then chooses a second physical ports and establish a third link with the chosen second physical port to transmit the packet out of the HBA device instead.