Which device is described as 'Device used to segment LANs to balance network traffic and to provide data filtering for security purposes'?

• A. Interface card
• B. Hub
• C. Router
• D. Switch

Answer: (C)

Segmenting LANs and applying security filtering is a function of a router. A router operates at the network layer and divides a larger local area into separate subnets, directing traffic between those subnets based on IP routing decisions. This separation helps balance network load by choosing efficient paths and prevents broadcast traffic from flooding other segments. Routers also enforce security through access control lists and firewall features, filtering traffic as it moves between networks.

In contrast, an interface card is just a device’s connection point to a network; a hub simply repeats signals to all ports, keeping a single shared collision and broadcast domain; a switch confines traffic to the destination port within a LAN and, while capable of some segmentation with VLANs and ACLs, does not inherently manage inter-network traffic or provide broad security filtering at the network boundary in the same way a router does.