Beth Kon wrote:
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.
It's actually not okay. You're creating a bridge with two tap devices
on the bridge that happen to be connected in qemu by a vlan. If one tap
device receives a packet, qemu is going to forward that packet to the
other tap device, which will in turn send the packet to the bridge which
in turn sends it to the first tap device.
Resulting in an infinite networking loop.
Regards,
Anthony Liguori
