What device makes routing decisions based on IP addresses?

The device that makes routing decisions based on IP addresses is a router. Routers operate at the network layer of the OSI model, where they utilize logical addressing (specifically IP addresses) to determine the best path for forwarding packets between different networks.

When a packet is received, the router examines the destination IP address, consulting its routing table to decide where to send the packet next. This process involves analyzing the available paths and determining the most efficient route, which enables data to be transmitted across complex networks, including the internet.

Routers also perform additional functionalities, such as network address translation (NAT), firewall filtering, and Quality of Service (QoS) configurations, enhancing network security and performance. In contrast, other devices like hubs and switches handle traffic at different layers without the ability to route between different IP networks or make intelligent forwarding decisions based on IP addresses. Hubs operate at the physical layer, simply forwarding data based on electrical signals, while switches (operating at the data link layer) use MAC addresses for forwarding decisions within the same local network segment. ARP (Address Resolution Protocol) broadcasts are used for mapping IP addresses to MAC addresses, but do not perform any routing function themselves.

Thus, a router is the device