Even if you have two vm clones with different mac addresses, you need to tell ubuntu how exactly the machine identifies itself on the network for the two clones to get separate ip addresses.
sudo apt install -y iperf computer 1: iperf -s Computer 2:
Example update enp0s3 to match your ethernet interface update ip4 address to match an available address
from here about exit nodes and subnets IP Forwarding echo 'net.