NIC teaming functionality provides network access redundancy and allows for rapid convergence when a failure occurs. NIC teaming is the process of grouping together several physical NICs (Network Interface Cards) into one single logical NIC, which can be used for network fault tolerance and/or transmission load balancing. In a team of two or more NICs, the secondary NIC assumes the primary or active role, if the primary NIC fails. However, failover will not occur unless the primary NIC is specified.
NIC teaming has two purposes:
Fault Tolerance: By binding more than one physical NIC to a logical NIC, high availability is maximized. Even if one NIC fails, the network connection does not cease and continues to operate on other NICs.
Load Balancing: Balancing the network traffic load on a server can enhance the functionality of the server and the network. Load balancing within a network interconnect controller (NIC) team enables distributing traffic amongst the members of the NIC team so that traffic is routed among all available paths. In most scenarios of Load Balancing, it is required that teamed connections usually terminate on the same remote device and that the device has an Etherchannel (or equivalent protocol) configured.