The legacy and second generation versions of Flash Redirection are independent solutions and run in separate virtual channels.
For the latest updates to HDX Flash Compatibility, refer to CTX136588.
To configure Flash Redirection on the server, use the following Citrix Policy settings:
The Citrix policy setting Flash default behavior establishes the default behavior of Flash acceleration. By default, Flash Redirection is enabled.
To override this default behavior for individual web pages and Flash instances, use the Flash URL compatibility list setting.
Three options are available:
|Block Flash player||Flash Redirection and server-side rendering are not used. The user cannot view any Flash content.|
|Disable Flash acceleration||Flash Redirection is not used. The user can view server-side rendered Flash content if a version of Adobe Flash Player for Windows Internet Explorer compatible with the content is installed on the server.|
|Enable Flash acceleration||Flash Redirection is used; this is the default.
Important: This option requires that the Enable HDX MediaStream Flash Redirection on the user device Group Policy Objects policy setting is enabled on the user device.
Flash intelligent fallback is enabled by default, to detect instances of small Flash movies (such as those frequently used to play advertisements) and to render them on the server instead of redirecting them for rendering on the user device.
Flash intelligent fallback does not cause any interruption or failure in the loading of the web page or the Flash application.
To redirect all instances of Flash content for rendering on the user device, disable the Flash intelligent fallback policy setting.
By default, Flash Redirection downloads Flash content to the user device, where it is played. The Flash server-side content fetching URL list policy setting allows you to specify websites whose Flash content can instead be downloaded to the server and then transferred to the user device for rendering. This setting works with the Enable server-side content fetching setting on the user device and is primarily intended for use with Intranet sites and internal Flash applications. It also works with most Internet sites and can be used when the user device does not have direct access to the Internet (for example, when the XenApp or XenDesktop server provides that connection).
To improve the appearance of the web page when using Flash Redirection, use the Flash background color list policy setting. This enables you to match the colors of web pages and Flash instances.
To use Flash Redirection, install Citrix Receiver and the Adobe Flash Player on the user device. No further configuration is required on the user device. However, you can change the default settings using Group Policy Objects as described in this section.
The following illustration indicates how the Flash Redirection is handled for various network types.
By default, Flash Redirection downloads Adobe Flash content to the user device, where it is played. Enabling server-side content fetching causes the Flash content to download to the server and then be sent to the user device. Unless there is an overriding policy (such as a site blocked through the Flash URL compatibility list policy setting), the Flash content plays on the user device.
|Disabled||Disables server-side content fetching, overriding the Flash server-side content fetching URL list setting on the server. Server-side content fetching fallback is also disabled.|
|Enabled||Enables server-side content fetching for web pages and Flash applications identified in the Flash server-side content fetching URL list. Server-side content fetching fallback is available, but Flash content is not cached.|
|Enabled (persistent caching)||Enables server-side content fetching for web pages and Flash applications identified in the Flash server-side content fetching URL list. Server-side content fetching fallback is available. Content obtained through server-side fetching is cached on the user device and stored from session to session.|
|Enabled (temporary caching)||Enables server-side content fetching for web pages and Flash applications identified in the Flash server-side content fetching URL list. Server-side content fetching fallback is available. Content obtained through server-side fetching is cached on the user device and deleted at the end of the session.|
Enabling server-side content fetching requires settings on both the client device and the server:
You can redirect an attempt to obtain Flash content using the URL rewriting rules for client-side content fetching setting, which is a second generation Flash Redirection feature. When configuring this feature, you provide two URL patterns using Perl regular expressions. If the user device attempts to fetch content from a website matching the first pattern (the URL match pattern), it is redirected to the website specified by the second pattern (the rewritten URL format).
You can use this setting to compensate for content delivery networks (CDN). Some websites delivering Flash content use CDN redirection to enable the user to obtain the content from the nearest of a group of servers containing the same content. When using the Flash Redirection client-side content fetching feature, the Flash content is requested from the user device, while the rest of the web page on which the Flash content resides is requested by the server. If CDN is in use, the server request is redirected to the closest server, and the user device request follows to the same location. Note that this may not be the location closest to the user device; depending on distance, there could be a noticeable delay between the loading of the web page and the playing of the Flash content.