Chromecast Problems while VirtualBox NDIS6 Bridged Networking Driver is enabled

[pgn-1111]

Hi,

I've got problems with Chromecast
- not finding devices at all
- OR sometimes finding and classifying video devices as audio

I've tried to nail down this problem to its root cause since months and didn't find the cause. Tried updating Win10 Pro x64 from 1703 to 1903. From 1903 to 1909. No luck. Tried updating VirtualBox from 5.2.x to the current version. No luck. Tried to disable Windows Firewall, tried to disable AV software, no luck. I've found a reproducer now.

On VirtualBox 6.1.6 and Windows 10 Pro x64 1903
(also can be reproduced other 5.x, 6.x VirtualBox builds and/or Win10 1909, so I suspect a generic problem):
- Go to Windows Network Adapter settings -> Click your LAN connection -> Enable "VirtualBox NDIS6 Bridged Networking Driver", Click OK.

Now Google Chrome will have trouble to find Chromecast devices to stream to. Surprisingly, it sometimes find them and then presents an immediate error when trying to cast the desktop. The same can be reproduced with VLC media player. It sometimes does not detect Chromecast devices, sometimes it detects them and only streams audio. (There are no network limits... double checked! So it's caused by the vbox filter driver.)

Workaround:
- Go to Windows Network Adapter settings -> Click your LAN connection -> Disable "VirtualBox NDIS6 Bridged Networking Driver", Click OK.

Now, Google Chrome and VLC both start detecting Chromecasts fine again some seconds after clicking OK to apply the setting. Streaming works rock-solid on first attempt now.

Please file a bug and fix the filter driver. So I must not turn it on every time I'd like to use VirtualBox and turn it off when I need Chromecast to work.

Fyi: Chromecast uses Multicast mDns in its recent implementation in the current Google Chrome version. The Problem with the VBox Filter driver is *maybe* related to multicast data. Because I didn't have this problem when Google Chrome (v58.x?!) used the legacy media route implementation (years ago).

Thank you.

Screenshots:

[scottgus1]

Please file a bug and fix the filter driver.

You can do this in the Bugtracker, as you know the situation better than we do. Put a link to this topic, and post the vbox.log for a guest where this problem happens.