Which term best describes a firewall located at the boundary between the internal network and the Internet?

• A. Border
• B. Internal
• C. Perimeter
• D. Edge

Answer: (C)

The concept here is the terminology for a firewall placed at the boundary between the trusted internal network and the Internet. This sits at the outer edge of the network and functions as the first line of defense, enforcing policies on traffic crossing the boundary. Perimeter is the standard label for this role in security architecture, signaling the outer protective boundary of the network. While border is sometimes used in other contexts, it’s less precise for this specific function; edge is too generic and can refer to any device at the network’s edge, not necessarily the boundary firewall; internal describes something inside the network, not at the boundary.