Your company operates two separate LANs (downtown office and a suburban plant). To share data and resources between these LANs over an internetwork, which device is most appropriate?

Introduction / Context:
Interconnecting distinct LANs across sites requires a device that forwards traffic at the network layer and can select paths between different IP subnets. This is a classic use case for routing rather than simple Layer-2 extension.

Given Data / Assumptions:

• Two geographically separated LANs exist (downtown and suburban plant).
• Goal is to exchange IP traffic between different subnets.
• Connectivity likely traverses a WAN link or VPN.

Concept / Approach:

Routers operate at OSI Layer 3, maintain routes, and forward packets between networks with different subnets. They can establish site-to-site VPNs or use dedicated WAN links. Hubs and simple cables do not provide Layer-3 forwarding. Bridges connect Layer-2 segments within the same broadcast domain and are not ideal for routed, multi-site internetworking.

Step-by-Step Solution:

Verification / Alternative check:

Enterprise networks universally route between sites using routers or routing-capable security appliances. This validates the choice.

Why Other Options Are Wrong:

Modem: Provides line signaling for WAN access but not full inter-LAN routing by itself.

Cable: A medium, not a routing device.

Hub: Layer-1 repeater; no IP forwarding.

Bridge: Layer-2 only; unsuitable for scalable multi-site interconnection.

Common Pitfalls:

Assuming any interconnect device suffices. Multi-site communication requires Layer-3 routing and often security policies, which routers provide.

Final Answer:

Router