AP® Cybersecurity glossary
Address resolution protocol (ARP)
Also called: ARP
The protocol that finds the media access control (MAC) address belonging to an internet protocol (IP) address on the same local area network (LAN), and stores the pair in an ARP table.
Appears in the course and exam description (CED): 3.1.A.13.5.E.3
Why it matters in Unit 3
ARP accepts replies that nobody asked for and cannot verify them, which is the weakness ARP poisoning exploits.
Example
A laptop broadcasts “Who has 192.168.1.1?” and the router replies with its MAC address. The laptop caches the pair in its ARP table.
Learn it properly, with a checkpoint Addresses: MAC, IP, ARP, DNS and ICMP