Which protocol is used to discover neighboring devices and exchange capabilities on a network, typically via a dedicated discovery protocol?

Which protocol is used to discover neighboring devices and exchange capabilities on a network, typically via a dedicated discovery protocol?

• A. Link Layer Discovery Protocol
• B. Neighbor Discovery Protocol
• C. Address Resolution Protocol
• D. Internet Control Message Protocol

Answer: (A)

On a local network, devices benefit from learning who sits on each end of a link and what they can do. That’s exactly what a dedicated link-layer discovery protocol provides. The Link Layer Discovery Protocol operates at the data-link layer and sends periodic advertisements that carry information like device identity, port identity, and supported capabilities. This exchange is vendor-neutral and happens independent of IP, so switches, routers, and other devices can map the immediate neighborhood and understand what each device can offer. That makes LLDP the best fit for discovering neighboring devices and exchanging capabilities through a dedicated discovery protocol. By contrast, ARP resolves IPv4 addresses to MAC addresses, ICMP handles diagnostic messages and errors, and IPv6’s Neighbor Discovery Protocol focuses on IP-layer neighbor reachability and autoconfiguration rather than broad link-layer device discovery.

On a local network, devices benefit from learning who sits on each end of a link and what they can do. That’s exactly what a dedicated link-layer discovery protocol provides. The Link Layer Discovery Protocol operates at the data-link layer and sends periodic advertisements that carry information like device identity, port identity, and supported capabilities. This exchange is vendor-neutral and happens independent of IP, so switches, routers, and other devices can map the immediate neighborhood and understand what each device can offer. That makes LLDP the best fit for discovering neighboring devices and exchanging capabilities through a dedicated discovery protocol. By contrast, ARP resolves IPv4 addresses to MAC addresses, ICMP handles diagnostic messages and errors, and IPv6’s Neighbor Discovery Protocol focuses on IP-layer neighbor reachability and autoconfiguration rather than broad link-layer device discovery.