Product Documentation

Configure Flash Redirection on the server

Jun 18, 2013

To configure Flash Redirection on the server, use the following Citrix Policy settings:

  • Flash default behavior
  • Flash intelligent fallback
  • Flash server-side content fetching URL list
  • Flash URL compatibility list
  • Flash background color list

Set the Flash default behavior

The Citrix policy setting Flash default behavior establishes the default behavior of Flash acceleration. By default, Flash Redirection is enabled except for Windows 8 and Windows Server 2012 VDAs, where it is not supported.

To override this default behavior for individual web pages and Flash instances, use the Flash URL compatibility list setting.

Three options are available:

Option Behavior
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.

Control Flash intelligent fallback

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.

Identify websites for server-side content fetching

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 XenDesktop server provides that connection).

Note: Server-side content fetching does not support Flash applications using Real Time Messaging Protocols (RTMP); instead, server-side rendering is used, which supports HTTP and HTTPS.
To create the list of allowed URLs, add the Flash server-side content fetching URL list setting to a policy and click New to add URLs to the list. When configuring the Flash server-side content fetching URL list setting:
  • Add the URL of the Flash application, not the top-level .html page that instantiates the Flash Player.
  • Use an asterisk character at the beginning or end of the URL as a wildcard to expand your list.
  • Use a trailing wildcard to allow all child URLs, for example http://www.sitetoallow.com/*.
  • The prefixes http:// or https:// are not required, but are used if present.
Important: On the user device, be sure to enable the Enable server-side content fetching policy setting.

Specify where Flash content renders

The Flash URL compatibility list policy setting lets you specify whether Flash content from listed websites is:
  • Rendered on the user device
  • Rendered on the server
  • Blocked from rendering
When configuring the Flash URL compatibility list setting:
  • Prioritize the list, placing the most important URLs, actions, and rendering locations at the top.
  • Add sites containing Flash content that does not render correctly on the user device, specifying the Render on Server or Block option.
  • Use an asterisk character at the beginning or end of the URL as a wildcard to expand your list.
  • Use a trailing wildcard to refer to all child URLs, for example http://www.sitetoblock.com/*.
  • The prefixes http:// or https:// are not required, but are used if present.
To add the Flash URL compatibility list setting to a policy:
  1. Click New to open the Add Flash URL Compatibility list entry dialog box.
  2. Select an Action: Render on Client, Render on Server, or Block.
  3. In the URL Pattern box, type the URL of the website.
  4. Select the Flash instance you want to serve as a trigger:
    • Select Any to have the action occur any time any Flash instance connects with the listed website.
    • Select Specific and specify the Flash player ID to have the action occur only when this specific Flash instance connects with the listed website.

Enable color matching between the web page and Flash instances

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.

When configuring the Flash background color list setting:
  • For best results, consider using a color not typically used on the web page, such as black.
  • Use a trailing wildcard to enable matching in all child URLs, for example, http://www.sitetomatch.com/* FF0000.
When adding the Flash background color list setting to a policy:
  1. Click New and type the website URL followed by the appropriate 24-bit Web color hexadecimal number (for example, http://www.sitetomatch.com/ FF0000).
  2. Click the Accept button.