Comment 113 for bug 997978

I got the same issue, but my host OS is RHEL 6.3 (2.6.32-220.el6.x86_64), the qemu-kvm version is 0.12.1.2 , and my guest base image is Ubuntu 12.4 LTS.
My problem is:
After I enable the libvirt_use_virtio_for_bridges = true in the nova.conf, the new instance can not get ip address and the gateway can not be added in the router table.

The router table like this:

--before enable virtio
~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.17.33.8 0.0.0.0 UG 100 0 0 eth0
172.17.32.0 0.0.0.0 255.255.252.0 U 0 0 0 eth0

--after enable virtio
~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.17.32.1 0.0.0.0 UG 100 0 0 eth0
172.17.32.0 0.0.0.0 255.255.252.0 U 0 0 0 eth0

Here is the dnsmasq process on my host server:
root 32034 32033 0 Oct12 ? 00:00:00 /usr/sbin/dnsmasq --strict-order --bind-interfaces --conf-file= --domain=novalocal --pid-file=/var/lib/nova/networks/nova-br100.pid --listen-address=172.17.33.8 --except-interface=lo --dhcp-range=172.17.33.3,static,120s --dhcp-lease-max=256 --dhcp-hostsfile=/var/lib/nova/networks/nova-br100.conf --dhcp-script=/usr/bin/nova-dhcpbridge --leasefile-ro

Soren,
Your solution are only for ubuntu host and should install the ppa on the host machine, right?
Is there any solution or workaround for RHEL?