To reduce the number of address resolution requests, a client normally caches the resolved addresses for a short period of time. The ARP cache is a finite size. When any device wants to send data to another target device in a subnet, it must first determine the MAC address of that target even though the sender knows the receiver's IP address. These IP to MAC address mappings are derived from an ARP cache maintained on each device. An unused entry is deleted, which frees some space in the cache. Use the arp –a command to see the ARP cache, as shown in the following screenshot:
The ARP cache
ARP spoofing, also known as ARP cache ...
