Promiscuous mode and host OS network performance...

[ecsnl]

Hello,

While testing Virtualbox on systems connected to the same switch and internet connection (over the same router) I noticed something which I can not trace at all.

One 4 computers (put together myself) the internet connections in some cases crawls to a complete hold. The host OS is Windows 7 or the guest OS in Virtualbox is
eComStation (OEM version of OS/2) Under Windows the mail client stops working (time out messages from Thunderbird they can not reach my IMAP server).
Threw-put on the Firefox and Internet Explorer goes down to a few kilobyte a seconds.

These systems have a Quad core Intel CPU and 4 GB of RAM or more.
They have an Nvidia or Realtek chipset gigabit chipsets.
The computers that have this problem still have plenty of RAM free and the CPU load is low...

I have been reading on the internet to try and find more information about promiscuous mode that Virtualbox uses.

The weird thing is in the same testlab we have HP Desktop machines running with 2 core Intel CPU's and less RAM
also running the same version of Virtualbox and the internet connection under Windows does not have these weird slow downs.
These machine however all have Intel network cards.

From what I can tell if I remove the Virtual box driver for NIC support the internet threw put problems seem to go away on
the home build computers.

Do some NIC chipsets/NIC drivers not implement promiscuous mode correctly or less efficient ?!

Thanks,

Roderick

[BillG]

On the evidence you provide, I would suspect it was a problem with the NIC driver in the host OS. Some of these just don't work well with VirtualBox. The fact that the HP machines with Intel NICs work OK would tend to confirm this.

See if you can find a later version of the Win 7 driver for the NIC card you are using. If there is nothing on Windows update, look on the manufacturer's website.