Single network adapter limitations

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Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Single network adapter limitations

The limitations described in this topic apply only when multicast support is not enabled.

If you do not enable multicast support, you should consider installing a dedicated network adapter to achieve optimal performance and the full range of networking functionality. Although a successful cluster can be implemented with only one network adapter and without activating multicast support, this approach has two limitations:

  • Ordinary network communication among cluster hosts is not possible.

  • Network traffic intended for any individual computer within the cluster generates additional networking overhead for all computers in the cluster.

Further, if you are working from a computer that has a single network adapter that is bound to Network Load Balancing in unicast mode, you can not use Network Load Balancing Manager on this computer to configure and manage other hosts.

These limitations might not be important for many installations. If the cluster hosts are accessed only from outside the cluster (because host-to-host communication cannot take place) and noncluster communications are infrequent (for example, short nightly updates of the Web server content to individual computers in the cluster), the use of a single network adapter should be sufficient. Also, it is always possible to test and demonstrate Network Load Balancing using a single network adapter prior to installing additional network adapters for operational purposes.