FPCNLBCluster Object

The FPCNLBCluster object represents a Network Load Balancing (NLB) cluster for a network and provides access to the configuration settings of the NLB cluster through its properties (not available in Forefront TMG Medium Business Edition).

When NLB integration is enabled in an array through the NLBIntegrationEnabled property of the array, the array member network adpaters that are attached to the same network can be configured as an NLB cluster on the applicable network by setting the properties of the FPCNLBCluster object for the network. Note that an NLB cluster cannot be created for the following predefined array-level networks: Local Host, Quarantined VPN Clients, and VPN Clients.

Forefront TMG requires every network adapter in an NLB cluster to have a dedicated IP and a virtual IP address. When the virtual IP address of an NLB cluster is configured in Forefront TMG, NLB integration 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 default IP address provided it is not equal to the IP address specified in the VIP property.

NLB clusters dynamically distribute the flow of incoming TCP and UDP traffic among the cluster nodes according to a set of traffic-handling rules.

This object is accessed through the NLBCluster property of the FPCNetwork object.

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The FPCNLBCluster object defines the following method.

Method Description


Sets the virtual IP address and its mask for the Network Load Balancing (NLB) cluster.


The FPCNLBCluster object defines the following properties.

Property Description


Gets an FPCIPAddresses collection that contains the additional virtual IP addresses of the Network Load Balancing (NLB) cluster.


Gets the subnet mask for the virtual IP address of the Network Load Balancing (NLB) cluster.


Gets or sets a Boolean value that indicates whether Network Load Balancing (NLB) is enabled on the network.


Gets or sets a value from the FpcNLBOperationMode enumerated type that specifies the mode in which Network Load Balancing (NLB) operates.


Gets the virtual IP address of the Network Load Balancing (NLB) cluster.

Interfaces for C++ Programming

This object implements the IFPCEENLBCluster and IFPCNLBCluster2 interfaces.


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

Declared in Msfpccom.idl.

See Also

COM Objects

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Build date: 11/30/2009

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