Which command dumps the system's ARP cache showing hosts on the same subnet that have sent packets to or from the target machine?

• A. arp -a
• B. Netstat -na
• C. ifconfig -a
• D. route -n

Answer: (A)

ARP mappings on the local network are kept in the ARP cache, a small table the host uses to quickly translate IP addresses to MAC addresses for devices on the same subnet. To see who the host has recently communicated with, you inspect this cache. The arp -a command prints the entire ARP table, showing IP addresses and their associated MAC addresses for devices on the local subnet that have sent or received packets with the target machine. This directly reveals which hosts on the same subnet have interacted with the system.

Other commands pull up different networks details. Netstat -na focuses on active connections and listening ports, not ARP mappings. Ifconfig -a shows interface configuration like IP and MAC addresses but not the ARP table. Route -n displays the routing table, which guides where to send packets, but it doesn’t reveal local ARP entries.