VIP Property of the IFPCEENLBCluster Interface

The VIP property gets the virtual IP address of the Network Load Balancing (NLB) cluster.

	BSTR* pbstrVIP



Pointer to a BSTR that is set on return to a string value specifying the virtual IP address of the NLB cluster.

Return Value

This property method returns S_OK if the call is successful; otherwise, it returns an error code.

[Visual Basic]
Property VIP As String

Property Value

String that specifies the virtual IP address of the NLB cluster.


This property is read-only. Its default value is an empty string. The virtual IP address of the NLB cluster can be modified by calling the SetVIPAndMask method or by importing the value of this property from a saved configuration.

Note  If you programmatically change the primary virtual IP address of an NLB cluster by importing this setting from a stored configuration when one or more additional virtual IP addresses are configured in the AdditionalVIPs property, IP address conflicts between array members are inevitable.

Forefront TMG requires every network adapter in an NLB cluster to have a dedicated IP address and a virtual IP address. When the virtual IP address of an NLB cluster is configured in Forefront TMG, Forefront TMG integration with NLB sets this IP address as the second IP address of all the network adapters attached to the applicable network in the array. Forefront TMG also sets the first IP address in the TCP/IP properties of these network adapters as the dedicated IP address provided it is not equal to the IP address specified in the VIP property.

The DNS name of the array, which is the DNSName property of the FPCArray object, can be mapped in the DNS zone files used by clients to the virtual IP addresses of all the NLB clusters that are configured in the array followed by the default IP addresses of the array members. When an NLB cluster is enabled, clients in the applicable network that send requests to the DNS name of the array would use its virtual IP address because it is the first available IP address to which the DNS name is resolved. When the cluster is disabled, clients would use the first available dedicated IP address.

For SecureNAT clients sending requests that are not handled by the Forefront TMG Web proxy to an NLB cluster, the default gateway should be set to the virtual IP address of the cluster.


Client Requires Windows Vista or Windows XP.
Server Requires Windows Server 2008.
Version Requires Forefront Threat Management Gateway (TMG).

Declared in Msfpccom.idl.


Requires Msfpccom.dll.

See Also


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Build date: 11/30/2009

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