s1 h2 h1 nat_app.py cpu-veth-0 cpu-veth-1, port 11 port 1 00:aa:bb:00:00:04 10.0.0.1 port 2 00:aa:bb:00:00:05 192.168.0.1 00:04:00:00:00:10 10.0.0.10 00:05:00:00:00:10 192.168.0.10 Internal External