virtualbox.org

After migrating from VBox 3.2.12 to 4.0, my paravirtualized network interfaces (at least in Windows Guests) stopeed working reliably. Light network usage (like pinging a host) works, but as soon as I'm trying to do anything useful over the network like copying files from a Windows Guest, the network in the guest stops working (disconnect).

The problem only occurs in the following combination of settings:

• The problem only occurs with VirtualBox 4.0.0. Switching back to VirtualBox 3.2.12 solves the problem.
• The problem only occurs when using a recent virtio network driver (either version following this Link). Using the older Qumranet virtio driver from here works fine.
• The problem only occurs with a bridged connection to the host's network. Changing the NIC's attachment from bridged to NAT "solves" the problem.

My environment is as follows:

• The host is running Ubuntu 10.04 LTS (Lucid) AMD64 running on a Core2 Quad Q9400 CPU
• The host is connected to a GBit ethernet with a Marvell 88E8001 Gigabit Ethernet Controller using the "skge" kernel module
• VirtualBox is Version 4.0.0 with the VirtualBox 4.0 Oracle VM VirtualBox Extension Pack installed
• Windows guests experiencing the problem are fully patched Windows XP SP3 and Windows 7 (both 32bit)

Any idea what I could do to solve this?

Please open bug report in bugzilla.

Thanks for the link

I'll retest with 4.0.2 and if it's not solved create a bug report.