Address resolution protocol

OBJECTIVES
To make a difference between logical address (IP address), which is used at the network layer, and physical address (MAC address),which is used at the data link layer.
To describe how the mapping of a logical address to a physical address can be static or dynamic.
To show how the address resolution protocol (ARP) is used to dynamically map a logical address to a physical address

ADDRESS MAPPING:
Mapping of a logical address to a physical address can be static or dynamic.
Static mapping contains a list of logical and physical addresses; maintenance of the list requires high overhead.

Static mapping:
creating a table that associates a logical address with a physical address. This table is stored in each machine on the network. Each machine that knows, for example, the IP address of another machine but not its physical address can look it up in the table. This has some limitations because physical addresses may change in the following ways:
A machine could change its NIC, resulting in a new physical address.
A mobile computer can move from one physical network to another, resulting in a change in its physical address.
To implement these changes, a static mapping table must be updated periodically. This overhead could affect network performance.