Espero que isso responda à sua pergunta:
Inherent in all teaming technologies is network-connection fault tolerance or AFT. In order for AFT to work, at least two network connections must be present and have links in the same network. These two network connections indicate to the system whether or not they have network connectivity using several different mechanisms. Briefly, these mechanisms are as follows:
Probe Packets — the teamed adapters send and receive probe packets to determine the presence or state of each adapter in the team.
Activity-Based Tolerance — when probe packets are not used, or do not reach their destination, selection of a Primary (or active) Adapter is made by sensing activity on the link.
Link-Based Tolerance — when neither probe packets nor activitybased tolerance are available or successful, link-based tolerance is used to check the links of the teamed adapters to select a Primary Adapter.
(mais detalhes começam na página 6)