Re: [Qemu-devel] accidental mistyping of command line kills networking

[Beth Kon <eak@us.ibm.com>]

Beth Kon wrote:
> I accidentally entered a command line as follows:
>
> /usr/bin/qemu-kvm -drive 
> file=/scratch/images/beth/windows/win2k3_32_R2.dat.10G.img,if=ide -m 
> 2048 -boot cd -net nic,model=rtl8139 -net tap,script=/etc/qemu-ifup 
> -vnc :12 -usbdevice tablet -monitor stdio -net nic,model=e1000 -net 
> tap,script=/etc/qemu-ifup
>
> and the machine's networking broke, requiring a network restart to get 
> it back in order. The second -net tap,script=/etc/qemu-ifup causes the 
> problem.
>
> /var/log/messages shows
> tap0: received packet with  own address as source address
>
> I don't have time at the moment to look into what's going wrong.  Just 
> wanted to make people aware.
>
> Beth Kon
>
>
A clarification... this command line is ok. But as it happens, windows 
datacenter does not have a driver for rtl8139. So somehow, this 
driverless adapter in windows is effectively causing an "extra" tap 
device to be specified on the qemu command line, wreaking havoc with the 
networking on the host.