IPMP and link aggregation are different technologies available in the appliance to achieve improved network performance as well as maintain network availability. In general, you deploy link aggregation to obtain better network performance, while you use IPMP to ensure high availability. The two technologies complement each other and can be deployed together to provide the combined benefits of network performance and availability.
In link aggregations, incoming traffic is spread over the multiple links that comprise the aggregation. Thus, networking performance is enhanced as more NICs are installed to add links to the aggregation. IPMP's traffic uses the IPMP interface's data addresses as they are bound to the available active interfaces. If, for example, all the data traffic is flowing between only two IP addresses but not necessarily over the same connection, then adding more NICs will not improve performance with IPMP because only two IP addresses remain usable.
Performance can be affected by the number of VNICs/VLANs configured on a datalink for a given device, as well as by using a VLAN ID. Configuring multiple VNICs over a given device may impact the performance of all datalinks over that device by up to five percent, even when VNICs are not in use. If more than eight VNICs/VLANs are configured over a given datalink, performance may degrade significantly. Also, if a datalink uses a VLAN ID, all datalink performance for that device may be impacted by an additional five percent.