The static multimode interface group implementation in Data ONTAP is in compliance with IEEE 802.3ad (static). Any switch that supports aggregates, but does not have control packet exchange for configuring an aggregate, can be used with static multimode interface groups.
Static multimode interface groups do not comply with IEEE 802.3ad (dynamic), also known as Link Aggregation Control Protocol (LACP). LACP is equivalent to Port Aggregation Protocol (PAgP), the proprietary link aggregation protocol from Cisco.
This logical aggregation of interfaces allows for multiple individual connections to be distributed among the interfaces in the interface group. Each connection or session uses one interface within the interface group and has a reduced likelihood of sharing that single interface with other connections. This effectively allows for greater aggregate throughput, although each individual connection is limited to the maximum throughput available in a single port.
When you use the round-robin load balancing scheme, all sessions are distributed across available links on a packet-by-packet basis and are not bound to a particular interface from the interface group.
For more information about this scheme, see the Round-robin load balancing.
If a port fails or is unplugged in a static multimode interface group, the traffic that was traversing that failed link is automatically redistributed to one of the remaining interfaces. If the failed or disconnected port is restored to service, traffic is automatically redistributed among all active interfaces, including the newly restored interface.
The switch is configured so that all ports to which links of an interface group are connected are part of a single logical port. Some switches might not support link aggregation of ports configured for jumbo frames. For more information, see your switch vendor's documentation.
The following figure is an example of a static multimode interface group. Interfaces e0, e1, e2, and e3 are part of the MultiTrunk1 multimode interface group. All four interfaces in the MultiTrunk1 multimode interface group are active.
Several technologies exist that enable traffic in a single aggregated link to be distributed across multiple physical switches. The technologies used to enable this capability vary among networking products. Static multimode interface groups in Data ONTAP conform to the IEEE 802.3 standards. If a particular multiple switch link aggregation technology is stated to interoperate or conform to the IEEE 802.3 standards, it should operate with Data ONTAP.
The IEEE 802.3 standard states that the transmitting device in an aggregated link determines the physical interface for transmission. Therefore, Data ONTAP is only responsible for distributing outbound traffic and cannot control how inbound frames arrive. If you want to manage or control the transmission of inbound traffic on an aggregated link, it must be modified on the directly connected network device.