Server load balancer (SLB) provides traffic load distribution functionality for this release of the switch firmware. Load distribution can be performed at layer 2 or layer 3 of the networking protocol stack. This release provides support for only load distribution at layer 3.
When used at layer 3, LBGs consist of server members identified by layer 3 protocol (IP) addresses. Server members are next hop targets of a targeted equal cost multiple path (ECMP) route. The LBG is identified by a Virtual IP address prefix (VIP) which is used to represent a virtual server. From the clients' point of view, the virtual server is a highly available server entity with expandable resource. Load distribution is performed through the routing hash function of the switch. Load distribution policies are based on the contents of the L3/4 packet header. Failover is supported at the server member's level. A failed member within an LBG is replaced by another server member that is part of the same group. Health check is performed by the switch through an ICMP ping.
Refer to the Sun Ethernet Fabric Operating System SLB Administration Guide for more information about this feature.