How does VirtualBox's new Network Adapter drivers affect the computer?

Question

I am using a PC, and just trying the latest VirtualBox and Ubuntu 2011.10, and while installing VirtualBox, it actually installed Network Adapter drivers 3 times, and warned "during installation your network traffic might be affected".

Will the replaced Network Adapter drivers affect my computer in any way? It is not the manufacture's drivers, so it might not be totally the same.

Is it to channel the in and out traffic into the Virtual PC?

Also, what if Windows 7 Update actually install a new network adapter driver and replace the VirtualBox driver? Won't that affect the running of VirtualBox?

Answer 1

The drivers that it installs allows for Bridged Mode network, meaning that the same physical network adapter can be used by the VM as well as by the host, as opposed to NAT mode. It also installs a Host Only network adapter that allows the host to communicate with the VMs on a separate network.

If you are not using a VM-only network, you can safely disable the VirtualBox Host-Only Network adapter in Network and Sharing Settings -> Change Adapter Settings

VirtualBox also supports a paravirtualized network adapter, which requires the installation of a driver within the guest, but provides better performance. From Chapter 6 of the manual:

The "Paravirtualized network adapter (virtio-net)" is special. If you select this, then VirtualBox does not virtualize common networking hardware (that is supported by common guest operating systems out of the box). Instead, VirtualBox then expects a special software interface for virtualized environments to be provided by the guest, thus avoiding the complexity of emulating networking hardware and improving network performance. Starting with version 3.1, VirtualBox provides support for the industry-standard "virtio" networking drivers, which are part of the open-source KVM project.

Answer 2

This drivers give the ability of the virtual machine software to communicate with internet or your local area connection the way you configure it. And yes if the windows changes the driver that came with the virtual machine software it may affect the way it works. And there is some performance penalty but on modern machine you won't notice it.