Quando você escolhe uma rede com ponte no Virtualbox, isso será reconhecido como se estivesse diretamente conectado à interface. Isso é explicado aqui:
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.
Você pode encontrar mais informações sobre redes em ponte com o Virtualbox no link