2.0—Protocols and Standards

A MAC address is a 6-byte address that allows a NIC to be uniquely identified on the network. The first three bytes (00:D0:59) identify the manufacturer of the card; The last three bytes (09:07:51) are the Universal LAN MAC address, which makes the interface unique.

OSI Model

As data is passed up or down through the OSI model structure, headers are added (going down) or removed (going up) at each layer—a process called encapsulation (added) or decapsulation (removed).

Table 12 provides a summary of the OSI model layers, and Table 13 shows how each device maps to the OSI model.

Table 12. Summary of the OSI Model
OSI Layer Major Functions
Application Provides access to the network for applications and certain end-user ...

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