ARP ARP ARP

What this ARP networking fundamentals question tests

This is a foundational networking question that appears in technical interviews for infrastructure and systems roles. It probes whether you understand the core purpose and operation of the Address Resolution Protocol—one of the essential mechanisms that enables communication on local networks.

The question rewards clarity on the relationship between network-layer and link-layer addressing, and on how hosts discover the physical (MAC) addresses they need to send frames to their neighbours. A strong answer articulates the problem ARP solves and explains when and why it is invoked in a real communication scenario.

• Network-layer vs. link-layer addressing
• The broadcast domain and local-network scope
• ARP request and reply mechanics
• ARP caching and timeout behaviour