Accès au réseau avec vbox 5.0.2

Hi, I followed installing yunohost via virtualbox but at the end of the installation I can not access the network … I do not ping my box and my IP address is not set yet the system is configured in dHCP mode in the interface file, as if the system was not on the network. the icon virtualbox tells me that the cable is connected. I am in access bridge and the installation is made without problem, for cons I turn on vbox 5.0.2