ARP

ARP maps IPv4 addresses to MAC addresses on a local network.

Updated: 2026-03-05

Definition

Address Resolution Protocol (ARP) finds the MAC address associated with an IPv4 address in the local subnet.

Hosts use ARP before sending frames to the correct destination MAC.

Key points

Local subnet resolution
ARP cache improves performance
ARP spoofing can enable MITM

Common mistakes

Confusing ARP (L2/L3 mapping) with DNS (name to IP).
Ignoring ARP poisoning risk in flat networks.

Related exams

CompTIA Network+ (N10-009)

Free Network+ N10-009 mini test. Continue in the app for offline packs and detailed explanations.

Cisco CCNA (200-301)

Free CCNA 200-301 mini test. Continue in the app for offline packs and detailed explanations.

CompTIA Security+ (SY0-701)

Free Security+ SY0-701 mini test. Continue in the app for offline packs and detailed explanations.

Related terms

Want to practice this in exam-style questions?

Use the mini tests on each exam page, then continue in the app for offline packs and detailed explanations.