What is 'guest' here? As far as I know, the VM does not have an IP on the lan.

I mean, you need to be able to use your VM Manager tool to find out what is the IP/hostname of your guest.

A Default VirtualBox configuration does not allow direct host-> guest access, it's on some hidden VB-only NAT. You need to change the Network Interface type to Bridged or Host-only or something else to have access to the VM.

I haven't done it for some time, but in my memory it was neither a problem on OSX nor on Linux with VBox. Maybe try Vagrant? I don't remember, sorry. But ask around and you should find a super easy way to make this happen.