Address resolution protocol cache definition
In computer networks, the address resolution protocol cache or ARP works like a temporary table operating system that maps IP addresses to MAC addresses in the local network frame. When computers communicate with other external devices in the local network, they check the ARP cache to resolve the device’s IP address into the MAC address. If the mapping is not in the cache, the ARP requests to discover it. Afterward, the response is stored in the ARP cache for future interactions. Regarding cybersecurity, an ARP cache would be critical for understanding specific network attacks and vulnerabilities. Since this mechanism is used in regular network communications, it is a favorable medium for cyber attackers who use ARP spoofing or ARP poisoning attacks. In these attacks, fraudsters send fake ARP messages into the network, which causes devices to update their ARP caches with counterfeit or incorrect MAC addresses, redirect network traffic, cause network disruptions, or enable man-in-the-middle attacks.
See also: netwalker ransomware
Common ARP cache applications in cybersecurity:
- Network Segmentation: Organizations and businesses segment their networks to control and minimize the impact of ARP spoofing attacks. That way, the broadcast domain is reduced. It becomes more difficult for attackers to enable and launch ARP spoofing attacks.
- ARP cache poisoning detection: Today, the majority of network security tools have the ability to monitor ARP traffic for various anomalies. Finding and identifying an unexpected ARP response or unverified ARP update can help to detect ARP poisoning attacks.