Oracle VirtualBox allows you to choose between different networking modes for the network adapter used in the VM. Here is the list of available options:
- Not attached: In this mode, VirtualBox reports to the guest that a network card is present, but that there is no connection – it’s like an Ethernet cable that is not connected to the network card.
- Network Address Translation (NAT): This is the default networking mode, and it requires no configuration on either the host or the guest VM. This is great if you just want to browse the web within the guest.
- Host-only: In this mode, the guest VMs can interact with each other as well as with the host, but they cannot talk to the outside world. In this mode, a virtual interface is created on the host, which provides connectivity across the guest VM and the host.
- Bridged networking: This networking mode helps you to set up routing between the guest and the rest of the network. This is for more advanced networking needs such as network simulations and running servers in a guest. It does so by using a virtual network interface, which filters data from the physical network adapter, so that the guest and the host can talk to each other, and also with other VMs on the network and in the outside world.
- Internal networking. This mode is similar to a bridged network mode when it comes to communicating with the other VMs on the same host, but it is more secure and does not let you communicate with an external network.
There are two sub-modes of Internal Networking:
- UDP tunnel: This sub-mode helps to interconnect guest VMs running on different physical hosts directly and transparently over the existing network infrastructure.
- VDE (Virtual Distributed Ethernet) networking: This mode helps to connect to a Virtual Distributed Ethernet switch on a Linux or a FreeBSD host. To enable this mode VirtualBox needs compilation because this feature does not come by default with VirtualBox.