[Qemu-devel] Re: Qemu port on Windows to support tun/tap

[Alexander E. Patrakov]

Ming-Ching Tiew wrote:

> 
>> I started it this way :-
>>
>> qemu.exe -L .\bios -nics 1  -tap tap0801 -m 8 -boot a -fda linux.img
>> -enable-audio -localtime
>>
>> Is the name "tap0801" correct ?
> 
> OK I got it partially working now. Looks like the name is not the "device
> driver" name, but rather, the arbitrary network interface name assigned
> during the installation, which is normally it the form of "Local Area
> Connection x". I renamed and matched it accordingly, then the above works.
> I could now ping between the guest OS and host OS.
> 
> But still there are other problems, such as :-
> 
> 1. If I start up second instance of guest OS, it will not join the
> network. Looks like
>    somewhere there is a limitation on single open.
> 
> 2. And I can't have multiple network cards within one guest OS using the
>    tap devices.
> 
> Anyway, I view this as the current limitation of the software. Until
> changes made to improving it, I will have to live with this limitation.

When you try to use multiple instances of qemu on tun/tap network, you must
make sure that each virtual machine gets its own MAC address.

qemu -macaddr 52:54:00:12:34:56 ....
qemu -macaddr 52:54:00:12:34:57 ....

Here 52:54:00 is Realtek and 12:34:56 is what you can change.

-- 
Alexander E. Patrakov