On my desktop I have KVM working and one guest running, with the command line: # kvm -m 512M -net nic -net tap -hda /dev/mapper/pile-evil64 -boot c -vnc :2 -smp 2 -nographic Next I need to set up a virtual network for testing. The plan calls for four guest systems, and two virtual networks, one connected to the outside world through eth0, and the other with no gateway, just passing traffic back and forth between the VM's. All the VM's wil need to have two NICs each, one connected to each of the two virtual networks. So, having the OS automatically assign tap interfaces to guest NICs isn't going to work. I need to specify which tap goes to which virtual bridge, and I'd like that to be consistent across VM reboots. I have the bridges and several tap interfaces configured. Here's my 'brctl show' output: bridge name bridge id STP enabled interfaces br0 8000.00144fa1f17a no eth0 tap0 tap1 tap12 tap14 tap16 tap18 br1 8000.deadbeef3200 no tap11 tap13 tap15 tap17 tap9 Now I want to bring up a VM with two NICs, one attached to tap12 (bridge 0), the other on tap11 (bridge 1), but I think I've misunderstood the versious "-net" options as described in the kvm man page. It *seems* to say that the way to map a specific tap to a specific guest NIC is to say, "-net nic" followed by "-net tap,name=<name of the tap from the host OS's perspective>", and repeat that sequence for each nic to appear within the VM. So, here's the full command line I tried, based on that reading: # kvm -m 512M -net nic -net tap,name=tap11 -net nic -net tap,name=tap12 -hda /vmstore/wee -vnc :11 -cdrom /path/to/my/Windows.iso -boot d But when I try that, the host OS brings up two new tap interfaces (tap2 and tap3), the guest OS never boots (at least, nothing pops up on its console through VNC), and networking on my system completely freezes up until I kill -9 the kvm process (kill -15 is ignored) and restart br0. I tried "fd=" instead of "name=", but that looks for a file descriptor instead of a network interface name, and I didn't even know that Linux had file descriptors for network interfaces let alone how to map them to a tap. Nothing under /dev looks promising. Clearly, I am confused. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
