Kai Schaetzl wrote: > Ross S. W. Walker wrote on Tue, 1 Apr 2008 10:16:38 -0400: > > > dnsmasq is going to filter out the incoming dhcp requests as it acts as a > > dhcp server itself. Try disabling dnsmasq, or move your VMs off of virbr0 > > onto xenbr0. > > I wrote dnsmasq is killed then ;-) I started service libvirtd and then > killed dnsmasq and made sure it wasn't running. Then I tried. And the > virbr0 is not used anyway. However, something that libvirtd does seems to > switch on some extra forwarding that helps the broadcast packet to travel > from peth0 to eth0 which otherwise it would only do if it had an IP address > target. I have now stopped libvirtd as well and it still works, even for a > VM that I start after that (which means I can rule arp table out as its MAC > address was unknown). And iptables does not show any forwarding rules once > I stop libvirtd. The NAT stays active stopping libvirtd, but I killed it > with iptables. Still it works. So, there must be something that switches > this on. I'm sure if I reboot the host the problem is back. Yeah, I would use xenbr0 (or eth0 in 3.2 parlance) as the bridge if you plan on using an external DHCP server and avoid the whole NAT and dnsmasq mess. I would probably use virbr0 as a nice virtual network only service, remove forwarding and NAT on it and keep it for internal traffic only. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.