ADC 3 Managing the Address Resolution Protocol (ARP)

ADC Telecommunications, Inc.
284 CHAPTER 14: CONFIGURING IP
Managing the Address Resolution Protocol (ARP)
On a physical network on which devices have Media Access Control (MAC)
addresses (for example, Ethernet), ARP is used to map the MAC addresses to
IP addresses. Managing ARP consists of the following tasks:
■Displaying the ARP cache
■Adding ARP entries
■Deleting ARP entries
■Configuring the ARP Timeout
■Clearing the ARP Cache
Each host on an IP network has two addresses:
■MAC address — Identifies the host at layer 2, the datalink layer, of the
OSI model.
■IP address — Identifies the host at layer 3 of the OSI model and indicates
the network to which it belongs.
To forward packets to a host on an IP network, an interface must know the
IP address of the target host. Once the interface learns IP-to-MAC address
mapping for a host, it stores this information in its ARP cache.