In SLB-L2, an LBG consists of switch port members. Load distribution is performed through the LAG hash function of the switch. Load distribution policies are based on the contents of the L2/3/4 packet header. Failover is supported at the level of the switch port members. Depending on the fail-over method chosen, a failed member within an LBG is replaced by another switch port or by a group of switch ports within the LBG. Link-level connectivity between the switch port and the server is monitored by a health check mechanism.