| Use LACP |
Indicates whether the aggregation supports LACP to manage the relationship between multiple switches. By using LACP, the server determines which ports are in use and can bring up alternative ports during a failure. For example, if the VSP One File server does not receive LACP messages from the primary switch within the timeout period, the server can use the ports connected to the secondary switch instead. |
| Port level Load Balancing |
One of the following load balancing schemes that is used for all ports in the aggregation.
- Normal: The server routes all traffic for a given conversation through one of the physical ports in the appropriate aggregation. The server hash and routing functions determine which packets use which physical ports of the aggregation. For example, all traffic for a particular TCP connection is routed through the same physical port unless the port drops.
- Round robin: The packets making up the traffic are routed through the ports in sequential order. For example, the first packet goes down the first port, the second packet goes down the next port and so on until all ports are used. Then the traffic starts again at the first port. This routing scheme ensures that all the ports are equally used, to provide maximum link throughput.
The disadvantage of round robin is that the clients must be able to handle out of order TCP traffic at high speed.
The LACP specification (802.3ad) requires that an implementation follow the appropriate rules to minimize out-of-order traffic and duplicated packets. Round robin load balancing directly contravenes this requirement. However, there are situations where the server hash functions cannot balance the conversations across physical ports efficiently, which results in poor link utilization and reduced throughput. In these cases, round robin load balancing can improve link utilization and improve throughput.
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