Content types

Applies To: Forefront Threat Management Gateway (TMG)

The content types rule element allows you to apply another layer of security to your access rules by limiting the rule application to specific types of content, based on the Multipurpose Internet Mail Extensions (MIME) type and file name extension.

Content type settings apply only to HTTP and tunneled FTP traffic which passes through Forefront TMG.

When a client requests HTTP content, Forefront TMG sends the request to the Web server. When the Web server returns the object, Forefront TMG checks the object's MIME type or its file name extension, depending on the header information returned by the Web server. Forefront TMG determines if a rule applies to a content type that includes the requested file name extension, and processes the rule accordingly.

When a client requests FTP content, Forefront TMG checks the file name extension of the requested object. Forefront TMG determines if a rule applies to a content type that includes the requested file name extension, and processes the rule accordingly.

Preconfigured Content Types

Forefront TMG is preconfigured with the following content types that can be used in access rules. Preconfigured content types cannot be modified or deleted. Custom content types can be added in the Toolbox in the Firewall Policy node.

Content Type Description

Application

Used to control access to content containing applications, such as executables, dynamic-link libraries (DLL), .ole, and .vbs files.

Application Data Files

Used to control access to content containing data for applications, such as Perfmon, Help, and .wmf files.

Audio

Used to control access to content containing audio files, such as MP3 and WAV files.

Compressed Files

Used to control access to content including compressed files, such as .z and .zip files.

Documents

Used to control access to documents, such as text, Adobe PDF, and XML documents.

HTML Documents

Used to control access to content containing HTML documents, such as .xsl and .htm files.

Images

Used to control access to content containing images, such as Windows Bitmap, JPEG, and GIF files.

Macro Documents

Used to control access to documents that may contain macros, such as Microsoft Office Word and Microsoft Office Excel®.

Text

Used to control access to content containing text files, such as .txt and plain text files.

Video

Used to control access to content containing video files, such as .AVI, QuickTime, and MPEG files.

VRML

Used to control access to content containing VRML files, such as .flr and .wrl files.