Microsoft Internet Security and Acceleration Server 2000

FPCLAT Collection

The FPCLAT collection represents the Local Address Table (LAT) of the ISA array. FPCLAT holds a collection of FPCLATEntry objects, each representing one entry in the table. The LAT is a table of all internal IP address ranges used by the internal network behind the ISA server. ISA Server uses the LAT to control the way computers on the internal network communicate with external networks.

The LAT is maintained centrally at the ISA Server computer. Firewall clients automatically download and receive LAT updates at preset intervals. When a Firewall client requests an object, the client checks the LAT. If an IP address request is in the LAT, then the Firewall client requests the object directly. If the IP address request is not in the LAT, the client asks the ISA Server computer to request the object on its behalf.

Secure network address translation (SecureNAT) clients do not have a local copy of the LAT. Therefore, when a SecureNAT client requests an object, the request is sent through ISA Server. If the request is to an external IP address, then ISA Server makes the request on behalf of the client.

This collection is a property of the FPCNetworkConfiguration object.

Click here to see the ISA object hierarchy.

Note to C++ Programmers

This collection implements the IFPCLAT interface.

Note  When you've made and saved changes to the LAT that will affect whether a Network Interface Card (NIC) is external or internal, the Firewall and Web proxy (w3proxy) services must be restarted for your change to take effect. To stop and restart the services, use the FPCArray.SendRestartNotification method.


The following table lists the methods of the FPCLAT collection.

Method Description
Add Creates a new entry in the LAT and returns a reference to it.
AddFromAllCards Adds to the LAT all the ranges accessible through all network interface cards (NICs) of a specific server, according to the Windows 2000 routing table.
AddFromSelectedAdapters Adds to the LAT containing all the ranges accessible through the selected network interface cards of a specific server according to the Windows 2000 routing table.
AddPrivateRanges Adds the private ranges 10.x.x.x, 192.168.x.x. and 172.16.x.x - 172.31.x.x to the LAT.
Clear Clears the LAT. All entries are removed.
IsIpInternal Returns a Boolean value that specifies whether an IP address is internal.
Item Retrieves the given FPCLATEntry object from the collection.
Refresh Reads the object's configuration information from persistent storage, discarding any changes to the configuration that were not saved.
Remove Removes a LAT entry object from the collection.
Save Saves the collection's configuration to persistent storage.


The following table lists the properties of the FPCLAT collection.

Property Description
Count Gets the number of LAT entries in the collection.
VendorParametersSets Gets a reference to an object for storing and loading of custom data into the FPCLAT collection's storage.


  Windows NT/2000: Requires Windows 2000.
  Version: Requires ISA Server 2000.
  Header: Msfpccom.idl.