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The TCP/IP Guide

TCP/IP Protocols 1 TCP/IP Network Interface Layer (OSI Data Link Layer) Protocols

The TCP/IP protocol suite is largely defined in terms of the protocols that constitute it; several dozen are covered in this Guide. Most of the critical protocols of the suite function at the lower layers of the OSI Reference Model: layers 2, 3 and 4, which correspond to the network interface, internet and transport layers in the TCP/IP model architecture. Included here are the all-important Internet Protocol (IP) at layer 3 and Transmission Control Protocol (TCP) at layer 4, which combine to give TCP/IP its name.

Due to the importance of these and other TCP/IP protocols at the lower layers, this is the largest chapter of The TCP/IP Guide. It contains four subsections. The first describes the two TCP/IP protocols that reside at the network interface layer, layer 2 of the OSI model: PPP and SLIP. The second describes a couple of “special” protocols that reside architecturally between layers 2 and 3: ARP and RARP. The third covers the TCP/IP internet layer (OSI network layer, layer 3), including IP and several other related and support protocol. The fourth describes the TCP/IP transport layer protocols TCP and UDP.

TCP/IP Protocols 1 TCP/IP Network Interface Layer (OSI Data Link Layer) Protocols