Which command-line tool displays and manages the ARP cache, mapping IP addresses to MAC addresses?

Which command-line tool displays and manages the ARP cache, mapping IP addresses to MAC addresses?

• A. Wireshark
• B. arp
• C. nmap
• D. tcpdump

Answer: (B)

ARP maps IP addresses to MAC addresses on a local network, and the ARP cache stores these mappings to speed up communication. The command-line tool arp is designed to display and manage that table, letting you view current entries and add or delete mappings as needed. You can typically display the cache with a simple show command (often labeled something like -a or -n) and modify it by adding static entries or removing stale ones. This makes it the natural choice for viewing and controlling the ARP mappings directly. Other tools mentioned serve different purposes. Wireshark (and tcpdump) are packet analyzers that can capture and inspect ARP traffic, but they don’t manage the ARP cache themselves. Nmap is a network scanner used for discovering hosts and services, not for maintaining ARP mappings.

ARP maps IP addresses to MAC addresses on a local network, and the ARP cache stores these mappings to speed up communication. The command-line tool arp is designed to display and manage that table, letting you view current entries and add or delete mappings as needed. You can typically display the cache with a simple show command (often labeled something like -a or -n) and modify it by adding static entries or removing stale ones. This makes it the natural choice for viewing and controlling the ARP mappings directly.

Other tools mentioned serve different purposes. Wireshark (and tcpdump) are packet analyzers that can capture and inspect ARP traffic, but they don’t manage the ARP cache themselves. Nmap is a network scanner used for discovering hosts and services, not for maintaining ARP mappings.