Your link aggregation configuration is bound by the following requirements:
You must use the dladm command to configure aggregations.
An interface that has been plumbed cannot become a member of an aggregation.
All interfaces in the aggregation must run at the same speed and in full-duplex mode.
You must set the value for MAC addresses to “true” in the EEPROM parameter local-mac-address? For instructions, refer to How to Ensure That the MAC Address of an Interface Is Unique.
Certain devices do not fulfill the requirement of the IEEE 802.3ad Link Aggregation Standard to support link state notification. This support must exist in order for a port to attach to an aggregation or to detach from an aggregation. Devices that do not support link state notification can be aggregated only by using the -f option of the dladm create-aggr command. For such devices, the link state is always reported as UP. For information about the use of the -f option, see How to Create a Link Aggregation.