Product Documentation

Browser content redirection

Browser content redirection prevents the rendering of whitelisted webpages on the VDA side. This feature uses Citrix Receiver to instantiate a corresponding rendering engine on the client side, which fetches the HTTP and HTTPS content from the URL.

Note

You can specify that webpages be redirected to the VDA side (and not redirected on the client side) by using a blacklist.

This overlay web layout engine runs on the endpoint device instead of on the VDA and uses the endpoint CPU, GPU, and RAM.

Only the browser viewport is redirected. The viewport is the rectangular area in your browser where content displays. The viewport doesn’t include things like the Address Bar, Favorites Toolbar, Status Bar. Those items are in the user interface.

localized image

  1. Configure a Studio policy that specifies an Access Control List containing the URLs whitelisted for redirection or the blacklist that disables specific redirection. For the browser on the VDA to detect that the URL that the user is navigating to matches the whitelist or does not match a blacklist, a browser extension performs the comparison. The browser extension is included in the installation media and is installed automatically.
  2. If a match is found in the whitelist (for example https/www.mycompany.com/), and there is no match to a URL in the blacklist (for example https/www.mycompany.com/engineering), a virtual channel (CTXCSB) instructs Citrix Receiver that a redirection is required and relays the URL. Citrix Receiver then instantiates a local rendering engine (already present natively in the client operating system) and displays the website.
  3. Citrix Receiver then blends back the website into the virtual desktop browser content area seamlessly.

Browser viewport redirection example image

Here are scenarios of how Citrix Receiver fetches content:

  • Server fetch and server render: There is no redirection because you didn’t whitelist the site or the redirection failed. We fall back to rendering the webpage on the VDA and use Thinwire to remote the graphics. Use policies to control the fallback behavior. High CPU, RAM, and bandwidth consumption on the VDA.
  • Server fetch and client render: Citrix Receiver contacts and fetches content from the web server through the VDA using a virtual channel (CTXPFWD). This option is useful when the client doesn’t have internet access (for example, thin clients). Low CPU and RAM consumption on the VDA, but bandwidth is consumed on the ICA virtual channel.
  • Client fetch and client render: Because Citrix Receiver contacts the web server directly, it requires internet access. This scenario offloads all the network, CPU, and RAM usage from your XenApp and XenDesktop Site.

Browser viewport redirection scenarios image

Fallback mechanism:

There might be times when client redirection fails. For example, if the client machine does not have direct internet access, an error response might go back to the VDA. In such cases, the Internet Explorer browser on the VDA can then reload and render the page on the server.

You can suppress server rendering of video elements by using the existing Windows media fallback prevention policy. Set this policy to Play all content only on client or Play only client-accessible content on client. These settings block video elements from playing on the server if there are failures in client redirection. This policy takes effect only when you enable browser content redirection and the he Access Control List policy contains the URL that falls back. The URL can’t be in the blacklist policy.

System Requirements:

Windows:

  • Windows 7, 8.x, or 10 and Internet Explorer 11.
  • Citrix Receiver for Windows minimum version 4.10

Linux:

  • Citrix Receiver for Linux minimum version 13.9

XenApp and XenDesktop 7.18, 7.17, 7.16: VDA operating system: Windows 10 (minimum version 1607), Windows Server 2012 R2, Windows Server 2016 Browser on the VDA: Internet Explorer 11 and configure these options:

  • Clear Enhanced Protected Mode under: Internet Options > Advanced > Security
  • Check Enable third-party browser extensions under: Internet Options > Advanced > Browsing

Client side optimization for Citrix Receiver for Windows 4.10

HdxBrowser.exe is the overlay browser on the endpoint that is responsible for client-side rendering. To enable HdxBrowser.exe to use the GPU resources on the client, set these registry keys on the Windows endpoint.

Warning

Editing the registry incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.

\HKEY_LOCAL_MACHINE \SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_GPU_RENDERING (create if not present)

And

\HKEY_CURRENT_USER) \SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_GPU_RENDERING (create if not present)

Value name: HdxBrowser.exe Value data: 00000001 Type: DWORD

Browser content redirection