Host network disconnect on VM startup/shutdown => Fixed in SVN

[Legorol]

Host: Windows 7 x64
Guest: variety of Windows versions, e.g. Windows 8.1 Enterprise
Network: Bridged mode to host's Realtek PCIe Gigabit Ethernet

Very often when I start up or shut down a VM that has bridged mode networking, the host(!) network briefly disconnects for 20-30 seconds. Seems to happen only when there is no other VM running and so the VM is the first one I'm starting, or the last one I'm shutting down. The issue may be related to the new NDIS6 driver entering/exiting bypass mode.

The issue also often occurs when closing the VM's window on the host, e.g. by pressing the close (X) icon in the top-right corner of the VM window. Host network disconnects before the "Close Virtual Machine" dialog shows up, and also after a button is pressed in the dialog. Presumably because while the dialog is showing, the VM is suspended.

The temporary disconnect interrupts all network activity, e.g. file downloads, Skype call etc.

As evidence of the host network disconnect, here is an example of a continuous ping on the host to the local router during a VM start up:

Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
No resources.
No resources.
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No resources.
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64
Reply from 192.168.0.1: bytes=32 time<1ms TTL=64

This issue was first reported during the version 5 beta and more information is available in this thread: ​https://forums.virtualbox.org/viewtopic.php?f=15&t=66927

[Legorol]

Log of a complete session from start up to shut down

[Legorol]

As a workaround, for now I switched to using the legacy NDIS5 bridged network driver. As per page 34 of the User Manual, I installed VirtualBox with

VirtualBox.exe -msiparams NETWORKTYPE=NDIS5

This seems to eliminate the problem.

[Aleksey Ilyushin]

Could you try this test build? It no longer restarts the filter driver when virtual machine gets paused or activated.

[Legorol]

The test build seems to do it, I haven't encountered the issue yet since installing it. I made sure that when installing the test build, it is the NDIS6 driver that gets installed/used.

[Frank Mehnert]

Fix is part of VBox 5.0.4.