An ARP cache is a collection of

Address Resolution Protocol The Address Resolution Protocol (ARP) is a communication protocol for discovering the link layer address, such as a MAC address, associated with a internet layer address, typically an IPv4 address. The protocol, part of the Internet protocol s ...

entries (mostly dynamic), that are created when an

IP address An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...

is resolved to a

MAC address A MAC address (short for medium access control address or media access control address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This use i ...

(so the computer can effectively communicate with the IP address). The term can be used interchangeably with ARP table, although the latter is sometimes a distinct statically configured table. An ARP cache has the disadvantage of potentially being used by

hackers A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bugs or exploits to break ...

and cyberattackers (an

ARP cache poisoning In computer networking, ARP spoofing (also ARP cache poisoning or ARP poison routing) is a technique by which an attacker sends ( spoofed) Address Resolution Protocol (ARP) messages onto a local area network. Generally, the aim is to associate t ...

attack). An ARP cache helps the attackers hide behind a fake IP address. Beyond the fact that ARP caches may help attackers, it may also prevent the attacks by "distinguish ngbetween low level IP and IP based vulnerabilities".

References

Address Resolution Protocol Computer network technology {{compu-network-stub