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Welcome to

Network+ Course

و شبکه تخصصی های دوره کننده برگزار نت نایبلینوکس

Why Certification?

IT Development Universities abilityEmployers and employees needs Cisco CCIE Certificate


Certification Companies• Cisco ( CCNA, CCNP, CCIE, … )

• Comptia (Network+, I-Net+, Server+, Linux+, Security+, e-Biz+, A+ )

• Microsoft (MCP, MCSE, MCSD, ….)

• Redhat Red Hat Certified Technician (RHCT).

• SUN Solaris


Network+

CompTIA Network+ Certification The CompTIA Network+ certification is the worldwide

standard for professionals with at least nine months of experience in network support or administration.

A Network+ certification demonstrates your technical abilities in networking administration and support, and validates your knowledge of media and topologies, protocols and standards, network implementation, and network support. If you have nine months of network administration and support experience, Network+ is ideal for you.

Network+ and Your CareerMany corporations recommend or require the Network+

certification for their IT employees.


Main Goals for this course

• A requisite for CCNA Course• Passing the Network+ Exam and get the

certification• Representing a solid background of

networking knowledge regarding Network+ standard course


Domain % of Examination

• 1.0 Network Technologies 20%• 2.0 Network Media and Topologies 20%• 3.0 Network Devices 17%• 4.0 Network Management 20%• 5.0 Network Tools 12%• 6.0 Network Security 11%• Total 100%


Basic Networking Fundamentals


What is a Computer Network?

• Two or more computers connected together, having the ability to use shared resources on each other.

• Two computers that are connected with a Network Cable through their network cards are an example of a simple network.


Networking Concepts and Components

• Something to share ( Data ) • Physical Pathway

( Transmission medium ) • Interfaces for communication

( Network Interface ) • Rules of Communication

( Protocols )


What are some of the different types of the network?

• In a clinent/server network each host will act Specifically as a Server (the provider of resources) or a Client (the receiver of resources)

What are some of the different types of the network?

• Peer to peer• In a peer to peer network every host will

act as a client AND a server

What are some of the different types of the network?• LAN –Local Area Network• Typically refers to a network contained whitin a building


• MAN – Metropolitan Area Network A network spread between non-contiguous Buildings within a single metropolitan area.


• WAN –Wide Area Network• A network spread over a wide

area ,typically covering multiple cities and countries.


Network Types ( 2 )

• Network Topologies :

1 – Bus

2 – Star

3 – Ring

4 – Mesh (Full mesh Vs. Partial mesh)

5 -Tree

6 - Hybrid


Bus Topology


Star Topology


http://i32.tinypic.com/98g6bt.jpg

Ring Topology


Mesh Topology


Tree Topology


Hybrid Topologyو شبکه تخصصی های دوره کننده برگزار نت نایب

لینوکس

Network Types ( 3 )

• Models of Network Computing :

1 – Centralized Computing

2 – Distributed Computing

3 – Collaborative Computing


Centralized Computing

• All processing takes place in the central mainframe computer

• Terminals are connected to the central computer and function only as input/output devices

• Terminals connect only to the mainframe, never to each other.


Distributed Computing

• Multiple computers are capable of operating independently.

• Tasks are completed locally on various computers

• Networks enable the computers to exchange data and services but do not provide processing assistance


Collaborative Computing

• Multiple computers cooperating to perform a task

• A network that enables the computers to exchange data and services

• Software designed to take advantage of the collaborative environment


Network Types ( 5 )

Transmission Methods :

• Circuit switching Dedicated path is created between two nodes

• Packet switching

Message is broken into small packets


Circuit Switching

1. A circuit is established, an end-to-end connection must exist to transfer data

2. The actual data transfer

3. After data transmitted, connection is terminated


Packet Switching

• Message is broken into small packets.

• Allows interactive exchanges because of small packets.

• Uses messages that are all the same length (called packets)

• Packets may be 128, 256, 512, or 1024 bits long


Network Terminology (1)

• Client• Server• Host• Workstation• Peer• PC



• Backbone A part of a network that all

segments and servers connect. (Gigabit Ethernet, FDDI, Thicknet)

• Segment

Any short section of the network that is connected to the backbone



• Half-duplex A bi-directional communication but

only one direction at a time, such as walkie-talkie

• Full-duplex

Allows communications in both directions simultaneously.



• Broadband Vs. Baseband

With baseband the whole bandwidth of the cable is used for each signal (channel), but in broadband the bandwidth is divided into descrete bands



• Broadband

-Allow Multiple communication methods to share a common media.

• Baseband -Use single communication

method.



• Bit

-bps (bits per second)

-Kbps (Kilo bits per second)

-Mbps (Mega bits per second)

-Gbps (Giga bits per second)

• Byte• Octet



• Speed • Bandwidth• Through put


Physical Media

PHYSICAL MEDIA


Physical Media

Physical Mediaو شبکه تخصصی های دوره کننده برگزار نت نایب

لینوکس

Physical MediaCopper

Coaxial Cable - Thick or ThinUnshielded Twisted Pair - CAT 3,4,5,5e&6

Optical FiberMultimodeSinglemode

WirelessShort RangeMedium Range (Line of Sight)Satellite


لینوکس

Copper Media: Coaxial CableCoaxial cable is a copper-cored cable surrounded by a heavy shielding and is used to connect computers in a network.

Outer conductor shields the inner conductor from picking up stray signal from the air.

Repeater is used to regenerate the weakened signals.

Physical Media

Category Impedance Use

RG-59 75 W Cable TV

RG-58 50 W Thin Ethernet

RG-11 50 W Thick Ethernet


7.44

BNC connectorsو شبکه تخصصی های دوره کننده برگزار نت نایب

لینوکس

Copper Media: Twisted PairTwisted-pair is a type of cabling that is used for telephone communications and most modern Ethernet networks.

A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs.

There are two basic types, shielded twisted-pair (STP) and unshielded twisted-pair (UTP).


لینوکس

Shielded Twisted Pair (STP)


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Unshielded Twisted Pair (UTP)


لینوکس

Unshielded Twisted Pair (UTP)Consists of 4 pairs (8 wires) of insulated copper wires typically about 1 mm thick.

The wires are twisted together in a helical form.

Twisting reduces the interference between pairs of wires.

High bandwidth and High attenuation channel.

Flexible and cheap cable.

Category rating based on number of twists per inch and the material used

CAT 3, CAT 4, CAT 5, Enhanced CAT 5 and now CAT 6,CAT 7


لینوکس

• EIA/TIA 568A vs 568 B


Fiber Media

Optical fibers use light to send information through the optical medium.

It uses the principal of total internal reflection.

Modulated light transmissions are used to transmit the signal.


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Total Internal Reflection


لینوکس

Fiber MediaLight travels through the optical media by the way of total internal reflection.

Two types of Fiber media :MultimodeSinglemode

Multimode Fiber can support less bandwidth than Singlemode Fiber.

Singlemode Fiber has a very small core and carry only one beam of light. It can support Gbps data rates.


لینوکس

Single and Multimode FiberSingle-mode fiber

Carries light pulses along single pathUses Laser Light Source

Multimode fiberMany pulses of light generated by LED travel at different angles


لینوکس

7.56

Modes و شبکه تخصصی های دوره کننده برگزار نت نایبلینوکس

Fiber-Optic CableContains one or several glass fibers at its core

Surrounding the fibers is a layer called cladding


لینوکس

7.58


Wireless MediaVery useful in difficult terrain where cable laying is not possible.

Provides mobility to communication nodes.

Right of way and cable laying costs can be reduced.

Susceptible to rain, atmospheric variations and Objects in transmission path.


لینوکس

Installation type

•Infrastructor


Installation type

• Ad-hoc

.


http://www.rococosoft.com/products/images/image_1.gif

7.62

Omnidirectional antenna


7.63

Unidirectional antennas


•Network Devices


Functions of network devices

• Separating (connecting) networks or expanding network• repeaters, hubs, bridges, routers,

switches, gateways

• Remote access• 56K Modems and ADSL modems


Expanding Network• Networks cannot be made larger by simply

adding new computers and more cables• Less efficient !!

• Can install components to• segment (divide) large LAN to form smaller

LANs• connect LANs

• Required components• Repeaters, bridges, routers, brouters,

switches or gateways


Repeaters and Hubs

• Repeaters or hubs work at the OSI physical layer to regenerate the network’s signal and resend them to other segments

• Primitive hub can be viewed as a multiport repeater• It regenerates data and broadcasts them to

all ports


68

Limitations and Features• Cannot link unlike segments• Cannot join segments with different access

methods (e.g. CSMA/CD and token passing)• Do not isolate and filter packets• The most

economic way of expanding networks


Bridges• Has one input and one output• Used to isolate network traffic and

computers• Has the intelligent to examine incoming

packet source and destination addresses• But cannot interpret higher-level information


How Bridges Work • Bridges work at the Media Access Control

Sub-layer of the OSI model• Routing table is built

to record the segment no. of address

• If destination address is in the same segment as the source address, stop transmit

• Otherwise, forward to the other segment


71

Differences Between Bridges and Repeaters

Repeaters Bridges

OSI layer Physical layer Data link layer

Dataregeneration

Regenerate data atthe signal level

Regenerate dataat the packetlevel

Reduce networktraffic

No Yes


72

Switches

Cisco Catalyst 2900 switch

• Switches operate at the Data Link layer (layer 2) of the OSI model

• Can interpret address information• Switches resemble bridges and can be

considered as multiport bridges

• By having multiports, can better use limited bandwidth and prove more cost-effective than bridge


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• Switches divide a network into several isolated channels

• Packets sending from 1 channel will not go to another if not specify

• Each channel has its own capacity and need not be shared with other channels

10Mbps

10Mbps

10Mbps10Mbps

Switch

Hub 3.3Mbps

3.3Mbps

3.3Mbps


74

Advantages of Switches

• Switches divide a network into several isolated channels (or collision domains)• Reduce the possibility of collision

• Collision only occurs when two devices try to get access to one channel

• Can be solved by buffering one of them for later access

• Each channel has its own network capacity• Suitable for real-time applications, e.g. video conferencing

• Since isolated, hence secure• Data will only go to the destination, but not others


75

Limitations of Switches• Although contains buffers to accommodate

bursts of traffic, can become overwhelmed by heavy traffic• Device cannot detect collision when buffer

full


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Method of Switching - Cut Through Mode

Preamble Des. Add Sour. Add Length Data FCS

Bytes

46 - 1500 Bytes 4 Bytes

• Much faster• Cannot detect corrupt packets• Can propagate the corrupt packets to the

network• Best suited to small workgroups


77

Method of Switching - Store and Forward Mode

• Read the whole packet before transmit• Slower than the cut-through mode• More accurate since corrupt packets can be

detected using the FCS• More suit to large LAN since they will not

propagate error packets

10Mbps

DB100Mbps

• Facilitate data transfer between segments of different speed


78

Using Switches to Create VLANs

• Switches can logically group together some ports to form a virtual local area network (VLAN)

Switches can be configured to communicate only within the devices in the group

HubHub

Hub

SW1

SW2

SW3

VLAN1 VLAN2


79

Routers• Layer 2 Switches cannot take advantage of

multiple paths • Routers work at the OSI layer 3 (network layer)

• They use the “logical address” of packets and routing tables to determine the best path for data delivery


80

How Routers Work

• As packets are passed from routers to routers, Data Link layer source and destination addresses are stripped off and then recreated

• Enables a router to route a packet from a TCP/IP Ethernet network to a TCP/IP token ring network

• Only packets with known network addresses will be passed - hence reduce traffic

• Routers can listen to a network and identify its busiest part

• Will select the most cost effective path for transmitting packets


81

Static and Dynamic Routers

Static Routers Dynamic Routers

Manual configurationof routes

Manual configuration of the firstroute. Automatic discovery of newroutes

Always use the sameroute

Can select the best route

More secure Need manual configuration toimprove security


Distinguishing Between Bridges and Routers

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• Routers are layer 3 devices which recognize network address

• Bridges are layer 2 devices which look at the MAC sublayer node address

• Bridges forward everything they don’t recognize

• Routers select the best path

83

Layer-3 Switches

• Layer-3 switches operate in both layer 2 (data link layer) and 3 (network layer)

• Can perform both MAC switching and IP routing• A combination of switch and router but much faster and easier to

configure than router

Why Layer-3 switches?• Traffic of LAN is no longer local• Speed of LAN is much faster• Need a much faster router,

however, very expensive


84

Summary

• Repeaters are the least expensive way to expand a network, but they are limited to connecting two segments

• Bridges function similar to repeaters, but can understand the node addresses

• Switches can be considered as multiport bridges, can divide a network into some logical channels

• Routers interconnect networks and provide filtering functions. They can determine the best route


85

• Allow computers to communicate over a telephone line

• Enable communication between networks or connecting to the world beyond the LAN

Remote Access Devices

1. Modems


86

• Cannot send digital signal directly to telephone line

• Sending end: MODulate the computer’s digital signal into analog signal and transmits

• Receiving end: DEModulate the analog signal back into digital form


87

ADSL

• ADSL stands for Asymmetric Digital Subscriber Line

• Particularly suitable for high speed multimedia communications, general Internet applications

• Asymmetric - downstream 1.5 to 6.1Mbps upstream 16 to 640kbps

• Digital - mainly for transmitting digital data still require modulation and demodulation

• Subscriber line - make use of the analog connection between household and CO


welcome to network+ course نایب نت برگزار کننده دوره های تخصصی شبکه...

Documents

network course slide

network types

network support

peer network

network topologies

computer network

network security

network media