In SQL Server 6.5 Enterprise Edition, the wizard does not work if you have existing IP addresses in the same resource group. However, it is possible to add TCP/IP addresses after the SQL Server failover group has been configured, and SQL Server 6.5 does service client request over all TCP/IP addresses. This behavior is unintentional, has not been tested, and is not supported.
In SQL Server 7.0 Enterprise Edition, the Cluster Wizard only allows one TCP/IP address. If you set up another TCP/IP address resource in the same resource group as the virtual SQL Server server, that TCP/IP address is ignored.
SQL Server 7.0 Enterprise Edition listens only on the first IP address in the resource group. The logic used on the server is:
IF (NOT a virtual server on cluster)
Listen on all IP addresses on the machine
ELSE
Listen on only the first IP address within the resource group
: A stand-alone SQL Server does listen to and answer client request on all TCP/IP addresses available on the computer. Hence, you should not plan on upgrading from a single SQL Server to a clustered virtual SQL Server if you rely on this feature.