ARP (Address Resolution Protocol) operates as a fundamental protocol in computer networking to resolve IP addresses to MAC addresses for communication within a local network. There are no different types of ARP protocols; instead, ARP itself encompasses various operations and techniques used in network communication.
The four main types of ARP are ARP request, ARP reply, Reverse ARP (RARP), and Inverse ARP (InARP). ARP request is used by a host to obtain the MAC address of another host on the same network. ARP reply is the response from the host that has the requested IP address, providing its MAC address. RARP is an older protocol used to discover the IP address of a host when only the MAC address is known. InARP is used in ATM networks to map between ATM addresses and IP addresses.
ARP protocols refer to the set of rules and procedures defined by the ARP standard to resolve IP addresses to MAC addresses within a network. These protocols ensure that devices can communicate efficiently by dynamically mapping IP addresses to corresponding MAC addresses, facilitating data transmission at the data link layer of the OSI model.
The ARP cache, maintained by devices such as computers and routers, stores recently resolved ARP entries. There are two primary types of ARP cache entries: static and dynamic. Static ARP entries are manually configured and persist indefinitely, mapping specific IP addresses to MAC addresses. Dynamic ARP entries are automatically populated and maintained based on ARP requests and responses exchanged between devices on the network. These entries have a timeout period after which they are removed if not refreshed by further communication.