virtualbox.org

I am running virtual box to anonymize my activity. I am not doing anything illegal, but I prefer the privacy of not being tracked.

On the virtual box system, I connect to a VPN to have a unique IP address. I use "bridged adapter" for the network settings, as this was the only setting that worked with my VPN. However, I am concerned because I have read that, when using bridged, all traffic passes from the virtual system to the internet via the host system. I am concerned that my host machine's MAC may be passed on from any traffic originated by my virtual machine.

The research I've done has not been fruitful in answering my question because I am not familiar with the language enough to know exactly what is being said. So I'm hoping someone can answer this question here for me:

I access a website from my virtual machine while on a bridged network. Will the MAC address of my host machine be passed on/visible to that website?

jenn23 wrote:However, I am concerned because I have read that, when using bridged, all traffic passes from the virtual system to the internet via the host system.

Well of course it does. At some point the comms must travel though a physical NIC, and your host provides that. Guest comms are however spoofed using the guests MAC address, so anything on the other end of the cable thinks that your end has two PCs on a switch.

In any case it really would not matter. Once you send data (which always happens) your location is registered.

Thank you both for your replies.

mpack wrote:Well of course it does. At some point the comms must travel though a physical NIC, and your host provides that. Guest comms are however spoofed using the guests MAC address, so anything on the other end of the cable thinks that your end has two PCs on a switch.

So what you are saying is that anything on the other end (e.g., a website that I send information to) can identify my particular NIC? And thus if I visit that same website from both the host and guest, that website would be able to identify that host and guest are related because they both have the same NIC?

Perryg wrote:In any case it really would not matter. Once you send data (which always happens) your location is registered.

What do you mean by this? Thus far my VPN has been sufficient for spoofing my location. I am not concerned about my IP address, only my MAC address (or other hardware information that would make it obvious that the two machines are related).

I do have a friend who uses Virtual Box on NAT and uses SSH/OpenVPN to tunnel. This works for him (i.e., he has been doing it for years and has never had any problems). Could he potentially have problems if the site decided to look at the NIC? Or is there something different about NAT vs bridged that makes NAT a better option?

NAT is certainly different. All machines behind a NAT have private IP addresses (which cannot be routed through the Internet). All traffic to the Internet uses the NAT device's public IP (and hence the NAT device's MAC address).

To be clear on what will be visible from internet :
- Your public IP is known to ANY Internet device being involved with your packet.
- Your LAN router will know the MACs of your machines.
- The first internet router (your ISP's) will know the MAC of your internet router.
- Any other router will know the MAC of the previous router before him.
The MAC of your physical NIC on your computer or on your VM will NOT be visible outside of the switched network they are connected on.
MAC are meant to stay within a single broadcast network and used only to know the actual next device involved into layer 3 networking. Only IPs are global and meant to know the final host.

So it actually doesn't matter what you use : NAT, Host-only, bridged... nothing will ever see your MAC expect your own router.
On the other hand, if you want to hide your IP, only the use of a VPN, SSH tunneling, SOCKS/HTTP (properly configured) proxy will hide that.