How to connect a virtual machine to a virtual mikrotik?

Question

virtual box

In virtualbox raised two virtual machines
1. RouterOS with two network adapters.
2. Ubuntu with one network adapter.
In the settings of the machine with Mikrotik, I specified the network bridge and selected the interface. On the Mikrotik itself, dhcp-client hung up on the ether1 interface. Everything works, Mikrotik goes online. How to connect virtual machine with ubuntu to mikrotik's ether2 interface? It is necessary that the virtual machine go to the Internet through Mikrotik, and not through the host machine.

Answer 1

Specify the desired Microta interface as the default gateway for Ubuntu.
Of course, the devices must be on the same network.

Answer 2

Just push the second RouterOS interface and the Ubuntu interface into the same Internal network, make them addressable, on Ubuntu, set the gateway to the RouterOS address from this network and it will work.