让virtualbox虚拟机既能和主机通信，又能上网的方法

http://askubuntu.com/questions/293816/in-virtualbox-how-do-i-set-up-host-only-virtual-machines-that-can-access-the-in

8down voteaccepted

I can get the setup I want by setting up two adapters on the vm.

VirtualBox 4.2.12
Ubuntu 12.04 guest

In VirtualBox > Preferences > Network, set up a host-only network.

Mine is called vboxnet0, it is manually configured:
ip 192.168.56.1
netmask 255.255.255.0
no dhcp

Then, in the network settings for the virtual machine, set up two adapters:

Adapter 1
host only, vboxnet0

Adapter2
NAT

Boot the virtual machine and log in through the console VirtualBox provides.

Run this to see your adapters:

ls /sys/class/net

In my case the adapters were named eth1 and eth2 (and lo, the loopback interface).

Then, edit your network configuration.

sudoedit /etc/network/interfaces# The loopback network interfaceauto loiface lo inet loopback# Host-only interfaceauto eth1iface eth1 inet static        address         192.168.56.20        netmask         255.255.255.0        network         192.168.56.0        broadcast       192.168.56.255# NAT interfaceauto eth2iface eth2 inet dhcp

Note that eth1 has no default gateway specified. eth2 will get a default gateway from dhcp.