There is a problem with Virtualbox network host-only interface since it is loopback interface and Windows manage it in a diffrent way.
Easy way to solve this is to open 'regedit'. Search for 'HKLM:\system\CurrentControlSet\control\class{4D36E972-E325-11CE-BFC1-08002BE10318}'. There is plenty of interfaces. Simply look one named 'VirtualBox Host-Only Ethernet Adapter'. Then add new DWORD(32) key named '*NdisDeviceType' and value '1' (hex). Reboot.
I don't know if there is a need to add standard fw rules like host port 9000 allow for all, since i had it already.