I have tried what you suggested (breaking the bridge on the host, and giving the host tap 192.168.5.1 and the guest eth0 192.168.5.2 and tried pinging one from the other. I get 100% packet loss. This points to QEMU's tap networking as far as I can see. I have tried uninstalling the 64 bit version and installing the 32bit tap adapter (and bridging it) from openvpn 2.3.6-I601 but that didn't seem to make any difference.
I tried using a very old qemu (0.11.1) with qemu manager and the 32bit tap adapter and bridge set up (using the same disk image but specifying intel E1000 netcard for the vm) and that works. so some time between 0.11.1 and 2.0 tap networking has got broken. I can spend some more time trying stuff out if you have any suggestions. There must be some people actually using the windows host qemu and tap somewhere! :-) (I don't have any problems running with a linux host and tap bridged network - well a few errors, but it (networking) seems to work anyway) -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1404278 Title: tap connections not working on windows host Status in QEMU: New Bug description: using latest qemu 2.2.0 64bit for windows host (installed from qemu-w64-setup-20141210.exe obtained from http://qemu.weilnetz.de/w64/ ),OpenVPN 2.6.3-I601 64bit tap adapter named tap01 and calling qemu using the following. qemu-system-x86_64.exe -m 512 -net nic -net tap,ifname=tap01 -hda "c:\\data\\images\\test.img" where the image contains a slackware 14.0 64bit install. The tap is bridged with the real network adapter and the bridge is given an ip of 10.1.1.41 (which works as the ip for the windows host). The tap adapter (in network connections) shows connected when the qemu vm is running. inside the vm, the network is given an ip of 10.1.1.143 (the netmask and default gateway are the same for the virtual and real pc). fault. The vm cannot see the rest of the local network or visa-versa. This used to work in early (0.9 32bit) versions of qemu. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1404278/+subscriptions
