The effects of using Autodetect setting on cluster network interface card

If you use a multiple speed Ethernet network adapter for cluster communications and configure the adapter to "autosense" the network speed, the adapter may cause problems within the cluster.

The "autosense" mode of some 10/100 Ethernet adapters may automatically detect the speed of the connected network. However, during the detection process, packets cannot be handled by the adapter and must be queued. Some adapters may inadvertently trigger the autodetection process to reoccur intermittently. As a result, communications are queued and communication delayed. Delays of this nature may cause cluster nodes not to receive critical packets in a timely fashion and may cause premature failover of cluster resources.

For best results, manually configure the adapter for the network speed to avoid potential negative performance effects and unnecessary failovers in the cluster. For network adapters that do not support manual settings, follow the card manufacturer's specifications.