VMware should publish more blogs like this one on Beacon Probing:

Beaconing is a software solution for detecting link failures downstream from the physical switch.ESX provides a simple and elegant teaming solution. All uplinks connected to a vswitch are assumed to connect to the same physical network (same broadcast domain) so they are all equivalent. Users can configure a list of active and standby uplinks for traffic to go out of the ESX host. If a link fails, the adapter driver detects it and marks the uplink as failed and stops using this uplink. Existing traffic will fail over to a standby uplink or redistributed to the remaining team members.

Read the full article here…