Network Requirements for Geographically Dispersed Clusters

  • Article

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

The following network requirements pertain to all server clusters, but are particularly important with regard to geographically dispersed clusters:

  • All nodes must be on the same subnet. The nodes in the cluster can be on different physical networks, but the private and public network connections between cluster nodes must appear as a single, nonrouted Local Area Network (LAN). You can do this by creating virtual LANs (VLANs).

  • Each VLAN must fail independently of all other cluster networks. The reason for this rule is the same as for regular LANs — to avoid a single point of failure.

  • The roundtrip communication latency between any pair of nodes cannot exceed 500 milliseconds. If communication latency exceeds this limit, the Cluster service assumes the node has failed and will potentially fail over resources.