An air-gapped network is characterized by...

• A. It is connected to the internet at all times for updates.
• B. It uses wireless connections to external networks.
• C. It relies on VPN tunnels to remote sites.
• D. It is physically isolated with no external connectivity, used for highly sensitive or legacy systems.

Answer: (D)

An air-gapped network is defined by complete physical isolation from external networks, with no external connectivity at all. That means there’s no direct or indirect path to the Internet or other networks, which is exactly what the description of being physically isolated with no external connectivity, used for highly sensitive or legacy systems, conveys. The other scenarios introduce some form of external access—whether it’s Internet access for updates, wireless links to external networks, or VPN connections to remote sites—which would break the isolation that defines an air gap. In practice, any updates or data transfers to an air-gapped system are done only through tightly controlled, offline methods, not via continuous network connections.