The use of virtual machines is becoming increasingly popular, and in this short article we want to show you how network modes work, giving you the opportunity to consider how you can better manage connections according to your needs.
Virtual Machines are connected to virtual network adapters, presented to the guest OS by the Hypervisor. Among the possible options to choose from, we have on one side BM, and on the other a series of further possibilities, such as NAT, host-only and internal.
Bridged Mode represents the most direct way to connect a Virtual Machine to the network. In fact, in this mode, the VM is “connected” directly to the same network to which the system hosting it is physically connected.
If there is an active DHCP system on this network, then the VM will be assigned an IP address. In this way, in the eyes of other hosts within the network, it will appear as a generic machine with its own IP and MAC addresses.
Network Address Translation (NAT) is used to allow the Guest Virtual Machine to access external networks. The IP address configured on the host’s physical interface is used, but host and guest are not yet able to communicate with each other.
This mode is not intended to connect the virtual machine to the host’s network. Instead, a private internal network is created in which the VM is placed. The Host and the Guest VM can communicate together, but the VM cannot “talk” to the outside world.
This mode, like host-only, is not intended to connect the virtual machine to the host’s network. In this case, the Guest VM is isolated and cannot talk to the Host or the outside world, but can talk to other VMs, if they are connected to the same internal network.
For a deeper insight
Now that we’ve seen a brief overview of networking modes for Virtual Machines, if you want to delve deeper into the topic and better understand how to configure your systems, I refer you to these two articles, regarding the two most widely used virtualization systems: