Oleg Goldshmidt wrote:
It is, indeed, worth a try.
If you do, I am curious whether it works or not, so a summary will be
appreciated.
Me it'll take some time until I get to try it. If Daniel tries it,
please do report.
Switching is fine, as long as they are only layer 2 aware. So long
as you actually have two actual physical network cards, there is no
reason for the packet not to go out. A layer 3 switch might notice
the short path, but a layer 2 switch should work fine.
Unless VM0 sends an ARP inquiring about the destination IP,
This ARP is sent to a physical NIC.
VM1
dutifully replies with its MAC (all through the hypervisor's virtual
switch),
No, as far as the machine is concerned, the sending out of an ARP
through VM1 and receiving it through VM0 are two separate events. Unless
it is layer 3 aware, there is no reason for it to know that the ARP
received through a physical Ethernet device originated in our machine.
then VM0 stack forms a frame with VM1's MAC as destination.
Of course it does. I find it hard to believe that a VM would form a
switch between two separate physical interfaces. In fact, VMs work extra
hard to make sure that you can INCREASE the number of physical layers
you have, no decrease it.
The frame, from VM0's point of view, goes out of its *virtual* NIC,
and then gets L2-switched locally by the virtual switch without going
out of any physical interface.
Who gave the VM the right to assume that VM1 and VM0 are layer 2
connected? If it does that, switch VM software - it's a bug.
Shachar
--
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com
_______________________________________________
Linux-il mailing list
[email protected]
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
