NIC teaming is the grouping of two or more physical network interface cards (NICs) into a single logical NIC, for the purpose of achieving either or both of the following ends:
Network fault tolerance
High availability is maximized by binding two or more physical NICs to a logical NIC. If a NIC fails, the network connection continues through another NIC.
Network traffic load balancing
Balancing the network traffic load on a server enhances the functionality of the server and the network. The traffic is distributed amongst the members of a NIC team so that the traffic is routed on all of the teamed connections.
While NIC teaming is possible for a number of different media types, the primary focus of the NIC teaming feature in IP Manager is Ethernet-media devices. In addition, for load balancing, the following conditions are assumed:
The teamed connections terminate on the same remote device.
The remote device is configured with an EtherChannel or an equivalent port-trunking protocol.
A teamed NIC can have as many as eight NICs.
In the IP Manager, NIC teaming support is applicable specifically to device specific discovery and occurs at three different points which are IP Availability Manager initialization, oid2Type configuration, and Discovery probes.
In a team of two or more NICs, the secondary NIC assumes the primary or active role, if the primary NIC fails. Failover will not occur unless the primary NIC is specified. The NIC with the highest supported speed is chosen as the primary NIC. If more than one NIC runs at the highest supported speed, the last of these NICs added to the team becomes the primary. The NIC teaming functionality provides network access redundancy monitoring.
NIC teaming discovery is enabled by default in the tpmgr-param.conf file (EnableTeamedNICDiscovery =TRUE). Discovery of Interfaces on Hosts is impacted due to support for NIC teaming discovery (for devices having OID .220.127.116.11.4.1.318.104.22.168.1.*).
Upon discovery of the device (host) that is configured for NIC teaming, a redundancy group NetworkAdapterRedundancyGroup is created in the IP Manager. If the NetworkAdapterRedundancyGroup (NARG) is not created, either the EnableTeamedNICDiscovery flag is set to FALSE or the Host may be of a different vendor type other than Broadcom, Intel, or HP.Note:
The VMware Smart Assurance IP Manager Reference Guide provides more information on NIC teaming including attributes, root cause problems, and events for the NetworkAdapterRedundancyGroup.