Verifying where flash content is rendered (Client or Server)
If the flash is rendered on the client, once the user is able to login to the machine they can then open a 32-bit version of Internet Explorer and browse to a Flash site such as YouTube. When a video starts playing and they try and move the windowed Internet Explorer the Flash section should move almost independently (Not in sync) to the main window and then snap into place as the thin client window receives redraw instructions from Citrix. Another way is to take a screen shot or print screen for the Internet Explorer with flash content loaded, when the flash content is rendering in the client, the screen shot will only show the black ground for the flash section as if the flash is not loaded.This will verify the Flash redirection section of the policy.
If the flash is rendered on the server (HVD), the flash section in the Internet explorer will move in sync with the Internet explorer window, and if you take a screen shot, the flash content is also get captured in the screen shot
Verifying server-side or client-side fetching
To verify the server side content fetching a networking tool such as tcpdump or wireshark will allow you to see if there are packets going from the thin client. You can find the TCPDump add-on in this post for installing on the 6215 client, To run this just use the command ‘tcpdump’ as root and it will show all network traffic. To see only HTTP traffic you can use the filter / command ‘tcpdump tcp port 80’. This will show if the thin client is trying to make a connection to YouTube or a similar Flash hosting site. If Flash redirection with client side rendering and server side fetching is in place then you should see no HTTP traffic while playing the Flash video.
If you are unable to use packet capture tools then blocking access to the particular Flash hosting site from the switch / router the thin client is connected to should suffice, the user should still be able to see the Flash content with the block in place.
1. Citrix HDX user policies settings control the behaviour of the flash redirection. These policies settings can be deployed and applied via either Citrix Dekstop Studio or Active Directory Group Policy Object. Ensure these two approaches of deploying settings do not clash with each other.
2. Flash Redirection measures the round trip latency between the server and user device the first time an individual browser or browser tab accesses an embedded Flash Player. This measurement includes both the latency of the network connection and any other latency in the data path. If the latency is determined to be within an acceptable threshold, Flash Redirection is used to render Flash content on the user device. If the latency is above this threshold, the Flash content rendering fallback to server side. The default threshold setting is 30 milliseconds
To change the default threshold settings, edit the Flash Redirection policy and add "Flash latency threshold" setting to the policy and specify the value to be above 30 milliseconds e.g 100
3. Enable Flash event logging to allow Flash events to be recorded in the Windows application event log. On computers running Windows 7 or Windows Vista, a Flash Redirection-specific log appears in the Applications and Services Log node. And you can check out the event logs in HVD to find out why a certain flash instance is not behaving as what you expected.
4. If you experienced audio break up issue when having graphic movement in HVD, check and verify the flash content is rendering on the client, not on the server. It is also good to check if the USB headset device is redirected to HVD by checking the HVD Win OS device manager to see if the usb headset is recognized by HVD. 6215 thin client should control the USB device locally for audio playback, and hence the USB headset should not needed to be redirected to HVD.
5. Ensure the flash player installed on HVD and on thin client are on the same major version (e.g 11.x), and compatible with each other.