CompTIA Network+ Rapid Review: Network Concepts

Comptia Network+ Objectives n10-007

This part from CompTIA Network+ Rapid Review (Exam N10-005) covers points to assist you with getting ready for Exam N10-005, for example, the OSI reference model, fundamental systems administration capacities, for example, IP tending to, and that's only the tip of the iceberg.

The Network Concepts area represents roughly 21% of the CompTIA Network+ test, however more than that, it covers the absolute most crucial standards of PC organizing. These are ideas that you experience over and over, both as you get ready for the test and as you work in the IT field.

To exceed expectations at this target, you should have a decent handle of certain authoritative ideas, for example, the OSI reference model; a comprehension of essential systems administration capacities, for example, IP tending to; and some retained statistical data points, for example, surely understood port numbers.

This section covers the accompanying targets: 

Objective 1.1: Compare the layers of the OSI and TCP/IP models

Objective 1.2: Classify how applications, gadgets, and conventions identify with the OSI model layers

Objective 1.3: Explain the reason and properties of IP tending to

Objective 1.4: Explain the reason and properties of directing and exchanging

Objective 1.5: Identify normal TCP and UDP default ports

Objective 1.6: Explain the capacity of normal systems administration conventions

Objective 1.7: Summarize DNS ideas and parts

Objective 1.8: Given a situation, execute appropriate system investigating technique

Objective 1.9: Identify virtual system segments

Objective 1.1: Compare the layers of the OSI and TCP/IP models

For this test objective, you should know the structure of the two essential models characterizing the systems administration process: the OSI reference model and the TCP/IP model. The OSI model is intended to be autonomous of a particular systems administration usage, and subsequently, it doesn't adjust correctly to the systems administration stacks when all is said in done utilize today. On the other hand, the TCP/IP model was structured in light of explicit conventions, and is appropriate just on systems utilizing those conventions. Be that as it may, practically all systems today use TCP/IP, so the TCP/IP model is as reasonable as the OSI model for show, documentation, and talk purposes.

Test need to know

OSI model 

For instance: Do you realize that the OSI reference model comprises of seven layers: Layer 1 – Physical; Layer 2 – Data interface; Layer 3 – Network; Layer 4 – Transport; Layer 5 – Session; Layer 6 – Presentation; and Layer 7 – Application?

TCP/IP model 

For instance: Do you realize that the model of the TCP/IP convention stack comprises of four layers: the system interface layer (otherwise called the connection layer); the web layer; the vehicle layer; and the application layer?

OSI model 

The Open Systems Interconnection (OSI) reference model is a hypothetical case of a system convention stack, which organizing instructors and chairmen use to classify and characterize a PC's different systems administration capacities. The highest point of the model collaborates with the applications running on the PC, which may now and again require the administrations of the system. The base of the model associates with the system medium over which the framework transmits its signs, as appeared in Figure 1-1. There are various conventions working at the different layers of the model, every one of which gives capacities expected to finish the system correspondence process.

Genuine or bogus: The layers of the OSI reference model relate to the initials of the mental aide "All People Seem To Need Data Processing."

Answer: True. The layers of the OSI model, start to finish, are application, introduction, session, transport, organize, information connect, and physical.

Test Tip 

While the vast majority of the memory helpers that understudies use to recollect the OSI model layers show them through and through, the OSI model layers are customarily numbered from base to top, with the physical layer being Layer 1 and the application layer being Layer 7. One mental helper for this is "Kindly Do Not Tell Secret Passwords Anytime."

More Info 

The upper layers of the OSI model are only sometimes referenced by number. The most widely recognized use for the layer numbers is in exchanges of directing and exchanging innovations. Switches work essentially at Layer 2, the information interface layer, and switches at Layer 3, the system layer. In any case, these gadgets can have abilities that length to different layers, bringing about references to advances, for example, Layer 3 exchanging. For more data, see Objective 1.2 and 1.4.

TCP/IP model 

The advancement of the TCP/IP conventions started a very long time before the archives characterizing the OSI reference model were distributed, yet the conventions fit in with a layered model similarly. Rather than the seven layers utilized by the OSI model, the TCP/IP model—now and then called the Department of Defense (DoD) model—has four layers. The TCP/IP model layers, in examination with those of the OSI model, are appeared in Figure 1-2.

The TCP/IP model layers—even those with similar names—are not actually comparable to the OSI model layers, nor were the models made with a similar goal. The OSI model is planned to be a guide for the production of systems administration conventions, though the TCP/IP model is a portrayal of conventions that as of now exist.