This is how I got host networking for VirtualBox and have it setup to use bridging on FedoraCore 6 host. This allows for two way traffic between the host and the guest. You will need bridge-utils and uml-utilities.
The first step is to configure the host with a bridge and a tap device. With this only the bridge will get an IP address and not the ethX nor the tapX device.
I am using dhcp to assign the IP addresses so the basic commands on the host are as below and can be put in the rc.local file for it to come up on boot:
# VirtualBox Bridging
# load the tun module
modprobe tun
# Create a tap device with permission for the user running vbox
tunctl -t tap0 -u {user}
chmod 666 /dev/net/tun
# Bring up ethX and tapX in promiscuous mode
ifconfig eth0 0.0.0.0 promisc
ifconfig tap0 0.0.0.0 promisc
# Create a new bridge and add the interfaces to the bridge.
brctl addbr br0
brctl addif br0 eth0
brctl addif br0 tap0
# Give the bridge a dhcp address.
dhclient br0You should now be able to use host networking in VirtualBox, just change "attached to" to "host interface" and add the interface name of "tap0" in your networking settings for the guest.
Notes:
If you're using a firewall on your host, make sure to turn it off when testing network setup.
I have had success with using APF as firewall which seems compatible with bridging.
