You will also need to know the IP address range that your version of VirtualBox uses for its "Host only" network type. Check the network configuration of the host system on Mac OS there's an interface called "vboxnet0". At the time of writing, the default on Mac OS is 192.168.56.1. On linux, you don't have need to create "vboxnet0" but the default IP address range is on VirtualBox. It's on file -> Settings -> Network and then add a host only network. It will also have 192.168.56.1 (at this time)as default IP address range.