The following three commands are needed to port forward from your host (“HostPort”) to a virtual machine (“GuestPort”):
$ VBoxManage setextradata "Debian" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/nginx/Protocol" TCP $ VBoxManage setextradata "Debian" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/nginx/GuestPort" 80 $ VBoxManage setextradata "Debian" "VBoxInternal/Devices/pcnet/0/LUN#0/Config/nginx/HostPort" 8080
I believe a reboot of the virtual machine (“Debian”, in this case) is required after making this change.