Network Protocols

Routed protocols are transported by routing protocols across an internetwork. These routed, or network, protocols perform functions required for communication between user applications in source and destination hosts, and these functions can differ among protocol suites. Network protocols occur at the upper five layers of the OSI reference model: the network layer (3), the transport layer (4), the session layer (5), the presentation layer (6), and the application layer (7).

Routed protocols and routing protocols are two different types of protocols, as detailed in the following list:

• Routed protocols are protocols that are routed over an internetwork. Examples of such protocols are as follows:

  - Internet Protocol (IP)

  - DECnet

  - AppleTalk

  - Novell NetWare

  - OSI (Open Systems Interconnection), not to be confused with the OSI Reference Model

  - Banyan VINES

  - Xerox Network System (XNS)

• Routing protocols are protocols implementing routing algorithms. They are used by intermediate systems to build routing tables used in path selection of routed protocols. Here are some examples of these protocols:

  - IGRP, Cisco Proprietary

  - EIGRP, Cisco Proprietary

  - OSPF

  - EGP

  - BGP

  - Intermediate System-to-Intermediate System (IS-IS)

  - Routing Information Protocol (RIP)