1.安装bridge-utils
sudo pacman -Sy bridge-utils
2.安装uml_utilities
sudo pacman -Sy uml_utilities
3.sudo modprobe tun，并将tun添加到/etc/rc.conf中去
4.sudo chmod 0666 /dev/net/tun
5.sudo tunctl -t tap0 -u  "your user name"
6.sudo ifconfig eth0 0.0.0.0 promisc
   sudo ifconfig tap0 0.0.0.0 promisc
7.sudo brctl addbr br0
8.brctl addif br0 eth0
9.brctl addif br0 tap0 #将tap0加入网桥
10.ifconfig tap0 up #激活tap0
11.sudo dhcpcd -t 30 -h "your user name" br0&
12.设置vbox中使用主机接口，名称为tap0即可