gen-briefly-explain-arp-and-one-common-misconception-about-it-faa6

Briefly explain ARP and one common misconception about it.

# ARP (Address Resolution Protocol) **What it is:** ARP is a network protocol used to map IP addresses to MAC (physical hardware) addresses on a local network. When a device knows the IP address of another device on the same network but needs to send data at the link layer, it broadcasts an ARP request asking "Who has IP address X.X.X.X?" The device with that IP responds with its MAC address, allowing communication to proceed. ## Common Misconception **"ARP works across the internet/between different networks"** ARP only operates within a single local network (broadcast domain). It cannot and does not resolve MAC addresses for devices on remote networks. When communicating with a device on another network, your computer uses ARP to find the MAC address of your **default gateway (router)**, not the destination device. The router then handles forwarding the packet toward the actual destination. This is why you'll never see your distant web server's MAC address in your local ARP cache—only your router's.