Virtual Box DHCP Server not working

I installed a mini Ubuntu Linux guest, however the host-only network interface could not get appropriate ip address from dhcp server

$ VBoxManage  list dhcpservers
NetworkName:    HostInterfaceNetworking-vboxnet0
IP:             192.168.56.100
NetworkMask:    255.255.255.0
lowerIPAddress: 192.168.56.101
upperIPAddress: 192.168.56.254
Enabled:        No

It looks the dhcp server is not enabled, alought it looks enabled from GUI

$ VBoxManage dhcpserver modify --netname HostInterfaceNetworking-vboxnet0 --enable
$ VBoxManage  list dhcpservers
NetworkName:    HostInterfaceNetworking-vboxnet0
IP:             192.168.56.100
NetworkMask:    255.255.255.0
lowerIPAddress: 192.168.56.101
upperIPAddress: 192.168.56.254
Enabled:        Yes

Remember to reboot VirtualBox, otherwise it does not work (at least in my setup)

ubuntu netplan

new ubuntu release uses netplan to configure interface.

Add the last two lines to enable the interface enp0s8

pandy@ubuntu:~$ cat /etc/netplan/01-netcfg.yaml
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    enp0s3:
      dhcp4: yes
    enp0s8:
      dhcp4: yes