I'm trying to set up a virtual network as described here. These are my steps:
ifup eth0 # uses DHCP brctl addbr br0 ifconfig br0 up 192.168.0.1 kvm ... -device e1000,netdev=tap0 -netdev type=tap,id=tap0,sccript=/etc/qemu-ifup
where qemu-ifup does
ifconfig tap0 0.0.0.0 promisc up brctl addif br0 tap0
And finally, inside the vm,
ifconfig eth0 192.168.0.2 route add default gw 192.168.0.1
This allows me to ping 192.168.0.1 and 10.42.42.127 (the host's IPs) from inside the guest, and the guest from inside the host.
However, I cannot ping a guest from inside another guest, nor any other IP outside the host (10.42.42.1, or 188.8.131.52, for example).
How should I set this up?