FPCNLBCluster object

Applies to: desktop apps only

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 (available only in Forefront TMG Enterprise 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.

Ff825597.bkbutton(en-us,VS.85).png Click here to see the Forefront TMG object hierarchy.


The FPCNLBCluster object has these types of members:

  • Methods
  • Properties


The FPCNLBCluster object has these methods.

Method Description

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



The FPCNLBCluster object has these properties.

Property Access type 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.


Minimum supported client

Windows Vista, None supported

Minimum supported server

Windows Server 2008 R2, Windows Server 2008 with SP2 (64-bit only)


Forefront Threat Management Gateway (TMG) 2010



See also

COM Objects



Build date: 7/12/2010