Which device forwards traffic between subnets by inspecting IP addresses and operates at layer 3 of the OSI model?

The device that forwards traffic between subnets by inspecting IP addresses and operates at layer 3 of the OSI model is the router. Routers are specifically designed to direct packets of data from one network to another by examining the destination IP address in the packet header. This IP address inspection enables routers to determine the best path for forwarding the traffic, ensuring that data reaches its intended subnet.

Working at layer 3, the network layer of the OSI model, routers utilize network addressing and routing protocols to make forwarding decisions across different networks or subnets. This capability is fundamental to the structure of the Internet and local area networks, as it allows for the interconnection of diverse networks.

In contrast, firewalls primarily focus on filtering traffic based on security rules and do not generally route between subnets in the same way. Load balancers distribute incoming network traffic across multiple servers to optimize resource use, ensure reliability, and maximize throughput, but they do not perform routing functions. NAT gateways are utilized for translating private IP addresses to public IP addresses and vice versa, primarily for enabling devices on a local network to communicate with external networks, but they themselves do not route traffic between subnets. Therefore, the router is the correct answer, as it aligns perfectly with