What this NAT networking interview question tests
This is an easy conceptual question about network address translation—a foundational topic in systems and infrastructure roles at trading firms and tech companies. It tests whether you understand how private and public IP address spaces interact, and the practical mechanisms that enable many internal devices to communicate with the outside world through a single gateway.
To answer questions in this area, candidates should be able to distinguish between different NAT configurations and explain how each one handles the mapping between internal addresses and the shared external address. The question rewards clarity on the mechanism itself, not memorization of acronyms.
- Private vs. public IP address spaces
- Stateful translation and connection tracking
- Port rewriting and address multiplexing