GAV: Question on HTTP Byte-Range requests with Gateway Anti-Virus.
The SonicWall Gateway Anti-Virus (GAV) by default suppresses the use of HTTP Byte-Range requests to prevent the sectional retrieval and reassembly of potentially malicious content. This is done by terminating the connection and thus preventing the user from receiving the malicious payload. By enabling this option you will override this setting. The option is located in the Security Services > Gateway Anti-Virus page under Configure Gateway AV Settings window. To enable or disable this option, cick the check-box under Enable HTTP Byte-Range requests with Gateway AV in the Configure Gateway AV Settings window.
There have been some known-instances where not enabling the Byte-Range requests with Gateway AV will prevent Microsoft BITS transfer from occuring (Microsoft updates, one-to-click, Windows 8 Store updates, etc..). Microsoft BITS is used for background updates with Microsoft applications. The technology "chunks" the download in order to download in the background. It is recommended to enable this feature if experencing failed downloads with Microsoft products.