An ARP cache is a table maintained by a device (such as a computer or router) that stores mappings of IP addresses to MAC addresses. This cache is used to speed up the process of resolving IP addresses to their corresponding MAC addresses on a local network.
When a device wants to communicate with another device on the same local network, it checks its ARP cache to see if it already has the MAC address associated with the target IP address. If the mapping is found, the device can send data directly to the MAC address without needing to send an ARP request. If the mapping is not found, the device will send an ARP request to the network to obtain the MAC address, and once received, it will store this mapping in the ARP cache for future use.
The ARP cache helps reduce network traffic and improves communication efficiency by minimizing the need for repeated ARP requests.
