Sample Filters

Sample application filters developed by using the ISA Server SDK are provided in the Samples\application_filters directory on the ISA CD-ROM in the SDK directory. These are provided to demonstrate coding techniques for creating application filters. The samples are briefly described in the following text. For more information regarding each filter, see the ReadMe file provided with each sample.

Note to C++ Programmers  The samples work only if compiled using Visual C++ 6.0 (Service Pack 3 or higher) with Active Template Library (ATL) 3.0.

CL.EXE, LINK.EXE, and other command-line tools require you to set certain environment variables properly. These include PATH, which must point to the \bin subdirectory of your Visual C++ installation, LIB, which must point to \lib, and INCLUDE, which must point to \include.

When you install Visual C++, Setup creates a batch file, VCVARS32.BAT, that contains commands to modify the PATH, LIB, and INCLUDE environment variables. If these variables haven't been set properly, run VCVARS32.BAT before you compile at the command prompt. VCVARS32.BAT is located in the \bin subdirectory. Note that you do not need to run VCVARS32.BAT if you are compiling your program inside the development environment.

For more information, see MSDN.

In addition to the samples, several filters are provided as part of ISA. These application filters may also be of interest to filter developers. The filters include:

• An FTP filter that works with Firewall service and SecureNAT clients.
• An H.323 protocol filter that works with Firewall service and SecureNAT clients.
• An HTTP Redirector filter.
• A streaming media filter.
• An SMTP filter.
• An RPC filter.
• A SOCKS 4.3 filter.

For a general understanding of the filter development process, see Developing Application Filters. For a detailed example of the filter-development procedure, see How to Create an Application Filter.