The easiest would be to give each VM two network interfaces. One with your internal network and another with the public network and set the IP for the interfaces if you have a Debian based VM your
/etc/network/interfaces
could look something like this
Code:
auto lo
iface lo inet loopback
# interal
auto ens18
iface ens18 inet static
address 192.168.33.21/24
bridge-ports ens18
bridge-stp off
bridge-fd 0
# public
auto ens19
iface ens19 inet static
address 212.186.XXX.XXX/24
gateway 212.186.XXX.XXX
bridge-ports ens19
bridge-stp off
bridge-fd 0