Bridge-mode networking and virtual network adapters

Question

Say I have physical network adapter eth0 on my host machine and VirtualBox virtual machine with bridged network. Host and virtual machine have different IP addresses in the same network.

I can easily ping this virtual machine from my local network. But I can't understand how is this possible. ARP broadcast request is sent to all physical network cards. On the host with my virtual machine ARP request is duplicated to virtual network adapter (because it's bridged). Virtual machine responses with ARP reply containing its MAC. But virtual adapter's MAC address differs from real physical network's MAC address.

How IP packet eventually reaches virtual adapter ?

Answer 1

When you choose for bridged network in Virtualbox, this will be recognized as if it's directly connected to the interface. This is explained here:

With bridged networking, VirtualBox uses a device driver on your host system that filters data from your physical network adapter. This driver is therefore called a "net filter" driver. This allows VirtualBox to intercept data from the physical network and inject data into it, effectively creating a new network interface in software. When a guest is using such a new software interface, it looks to the host system as though the guest were physically connected to the interface using a network cable: the host can send data to the guest through that interface and receive data from it.

You can find more about bridged networking with Virtualbox at http://www.virtualbox.org/manual/ch06.html#network_bridged