KVM, network & bridging

[TheCoop]

So, I'm trying to set up kvm and bridged networking. My host has a wireless connection to my router, which uses dhcp. I've set up a bridge network device, and linked the wireless network adapter and tap0 to it. From a null network config:

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wpa_supplicant ... wlan0
tunctl -u <user> -t tap0

brctl addbr br0
brctl addif br0 wlan0
brctl addif br0 tap0
ifconfig tap0 up 0.0.0.0 promisc
ifconfig wlan0 promisc

dhcpcd br0 (successfully gets an ip address)

kvm -net nic,macaddr=72:7d:39:89:4a:e1 -net tap,ifname=tap0,script=no,downscript=no -hda gentoo.img -cdrom install-amd64-minimal-2008.0.iso -boot d

But dhcpcd within the guest doesn't receive any response from the dhcp server on the wireless router. What am I missing, or how can I help diagnose the issue?

[Abraxas]

I'm pretty sure bridging does not work with wireless interfaces.

[ianw1974]

Yep, you can't really bridge with wireless. What you need to do is create a tap interface and just just assign a route on the main host system:

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route add -host x.x.x.x dev tap0

where x.x.x.x is the IP of your guest. The guest will use the tap device for it's network connection. The kernels proxy ARP feature should/will ensure the routing will go back and to, and the guest machine should be able to ping all physical machines on your network.

[epsilon72]

Hello,
I was able to use comments in this thread in conjunction with this page to get networking to work with a virtual machine.

The only problem is .... having it set up this way kills network for my actual computer (i.e., it only works inside the vm until I restart eth0).

Is there any way to prevent this?