1.7 High-Level Protocols and Ethernet Addresses

Computers attached to an Ethernet can send application data to one another using high-level protocol software, such as the TCP/IP protocol suite used on the worldwide Internet. The high-level protocol packets are carried between computers in the data field of Ethernet frames. The system of high-level protocols carrying application data and the Ethernet system are independent entities that cooperate to deliver data between computers.

High-level protocols have their own system of addresses, such as the 32-bit address used in the current version of IP. The high-level IP-based networking software in a given station is aware of its own 32-bit IP address and can read the 48-bit Ethernet address of its network interface, but it doesn't know what the Ethernet addresses of other stations on the network may be.

To make things work, there needs to be some way to discover the Ethernet addresses of other IP-based stations on the network. For several high-level protocols, including TCP/IP, this is done using yet another high-level protocol called the Address Resolution Protocol (ARP). As an example of how Ethernet and one family of high-level protocols interact, let's take a quick look at how the ARP protocol functions.

- Operation of the ARP Protocol

Quick Reference Guide to the Ethernet System - 04 SEP 95

[Next] [Previous] [Top] [Copyright] [Books About Ethernet]

Generated with CERN WebMaker