Which device is commonly used to connect multiple networks and can perform NAT to share a single public IP?

• A. Switch
• B. Bridge
• C. Hub
• D. Router

Answer: (D)

Connecting multiple networks and sharing a single public IP relies on routing and network address translation. A router acts as the gateway between networks, directing IP packets from one network to another. It can also perform NAT, translating many private addresses to a single public address (or a small set of them) so devices inside a private network can access external networks like the Internet using one public IP. This combination—inter-network connectivity plus NAT—is what allows multiple devices to share one public IP.

Switches operate at the data link layer, forwarding frames using MAC addresses within a single network. They don’t route between networks or perform NAT. Bridges do similar Layer 2 work to segment a network but still don’t handle inter-network routing or NAT. Hubs simply repeat signals to all ports and provide no segmentation or NAT.