Security+ Question of the Week: Confining Communications to a Subnet

The correct answer is A.

The task of confining sensitive communications to a specific subnet can be accomplished by manipulating the access tables of a router. A subnet is a layer 3 network segmentation, thus a layer 2 switch does not manage subnet communications. An IDS is a monitor of communications, not a manager of communications. A firewall is used to filter traffic between network segments, i.e. subnets, but it can also manipulate traffic at other layers and even perform content inspection. A firewall’s foundation is a router, thus router is the more specific correct answer.