Can a host with a public address initiate a connection to a host with a
private NAT address?
<hr>

If a host has an IP address of 10.0.1.1/24 and a default NAT gateway of 
10.0.1.254, and the host 10.0.1.1 sends a ping to the host 131.94.1.1 on 
the public Internet, what will the source IP of the ping be when it arrives
at 131.94.1.1?
<hr>

Does a box working as a NAT router need to keep record of the state 
of each connection that passes through it?
<hr>