Reference Guide

22 Preparing Your Systems for Clustering
Assigning Static IP Addresses to Cluster Resources and Components
NOTE: WSFC supports configuring cluster IP address resources to obtain
IP address from a DHCP server in addition to through static entries. It is
recommended that you use static IP addresses.
A static IP address is an Internet address that a network administrator assigns
exclusively to a system or a resource. The address assignment remains in
effect until it is changed by the network administrator.
The IP address assignments for the cluster’s public LAN segments depend on
the environment’s configuration. Configurations running the Windows
operating system require static IP addresses assigned to hardware and
software applications in the cluster, as listed in Table 2-1.
Table 2-1. Applications and Hardware Requiring IP Address Assignments
Application/Hardware Description
Cluster IP address The cluster IP address is used for cluster management and
must correspond to the cluster name. Because each server
has at least two network adapters, the minimum number of
static IP addresses required for a cluster configuration is five
(one for each network adapter and one for the cluster).
Additional IP addresses are required when WSFC is
configured with application programs that require IP
addresses, such as file sharing.
Cluster-aware
applications running
on the cluster
These applications include Microsoft SQL Server Enterprise
Edition, Microsoft Exchange Server, and Internet
Information Server (IIS). For example, SQL Server
Enterprise Edition requires at least one static IP address for
the virtual server as SQL Server does not use the cluster's IP
address. Also, each IIS Virtual Root or IIS Server instance
configured for failover needs a unique static IP address.