Undersanding LAN Prt1

8/15/2019 Undersanding LAN Prt1

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1.2 Understand local area networks (LANs)1.5 Understand network topologies and access

methods

Module 1:Understanding LocalArea Networks



Agenda

1 Local Area Networks

2 ata !rans"er on a LAN

# !$pes o" Local Area Network



Local AreaNetworks



%hat is a network&• A network is two de'ices connected to each other w

ph$sical medium such as wires or radio signals• !he connection allows those two de'ices to echang



%hat is the purpose o" networks

Networks enhance man$ aspects o" li"e and *usiness "

indi'iduals and organi+ations including:• communication and colla*oration

• sharing in"ormation and resources

• organi+ing data

• sa'ing costs



,ow are networks organi+ed&• Networks are organi+ed

*ased on their geographiclocation

• A Local Area Network orLAN is a group o" computersor de'ices that:

•

are con-ned to a small geographic areasuch as a single *uilding

• share a common communicationmedium such as ca*led or wirelessconnections

• are connected to a central connectingde'ice like a hu* switch or router



Network ocumentation• escri*es de-nes and

eplains the ph$sical andlogical method "orconnecting de'ices

• !he documentation phaseoccurs *e"ore a network is

*uilt or when changes aremade to the network

• Microso"t isio is a tool thatcan *e used to documentnetworks



%hat de'ices make up LANs&

,u* /

0outer

Laptops honesesktops

/er'ers !a*lets

,3/!/ 4N!0A3NN4!44



%hat are hosts&• esktop s laptops cell phones ser'ers routers a

• A host can *e an$ de'ice that has an IP address 7 used to send and recei'e data in a network

• IP addresses help identi"$ de'ices and the networks where the$ are l



%hat are central connecting de'• ,u*s switches and routers act as central connectin

• entral connecting de'ices are responsi*le "or:• connecting hosts

• transmitting data

• i8erent central connecting de'ices per"orm these "di8erent wa$s



,ow do hu*s "unction&• ,osts send data to a hu*

• !he hu* then *roadcasts thatdata to all other connectedhosts on the network



,ow do switches "unction&• ,osts send data to a switch

• /witches direct data to itsintended destination

• Unlike hu*s switches cansend and recei'e datasimultaneousl$

• /witches are the mostcommon de'ice used toconnect hosts to a network



,ow do routers "unction&• 0outers are at the edge o"

LANs• !he$ act as a gatewa$ to other

networks

• 0outers allow communication*etween hosts on di8erentnetworks

nternet

192.1;.1.1

2<.1#.=2.11>



%hat are central connecting de'• omputers ha'e network adapters also

known as Network nter"ace ards (Ns)that allow them to connect to networks

• Ns 'ia wires or wireless signals• %ired adapters "eature an RJ45 port

• %ireless adapters "eature an antenna and connect tonetworks using Wireless Access Points (WAPs)



4thernet a*les• 4thernet ca*les are made o"

copper wires• !ransmit data in the "orm o"

electrical pulses• %ireless connections rel$ on di8erent

technologies

RJ45PLUG



4thernet a*les• %As pro'ide a central point o"

access "or de'ices that want toconnect to a Local Area Network(LAN)

• %ireless networks can consist o"man$ t$pes o" de'ices other than

traditional s:• /mart phones

• As

• !a*let computers

• Micro computers

• s and laptops e?uipped with wireless network

adapters can connect to these networks as well



ata !rans"eron a LAN



/erial ata !rans"er• !rans"er o" one *it at a time

•

ata can tra'el in a single *itstream in *oth directions

• epends on t$pe o" connection

10

011010

111



,ow "ast does data tra'el&• A data transfer rate is the maimum bits per se

(bps) that can *e transmitted o'er a network• /igni-ed with a lowercase *

• !he lowercase * di8erentiates *its "rom *$tes

10M bps

BIRA!



ata trans"er in LANs @ /ending

e"ore data is trans"erred it has

to go through the "ollowingprocess:1. Large chunks o" data are *roken into

se"#ents

2. Addressing in"ormation is added toeach segment making it a packet

#. ackets then tra'el to the networkadapter where a little morein"ormation is added and the$ *ecome4thernet fra#es.

<. 4ach "rame is then *roken into a datastrea# o" *its 7 >s and 1s 7 thattra'el o'er ph$sical media

Brame

acket

Address

MAAddress



ata trans"er in LANs @ 0ecei'in

%hen data is recei'ed it goes

through the process in re'erse:1. !he recei'ing computer reassem*les

the bits into an 4thernet fra#e

2. t remo'es the "rame in"ormation andchecks the packet in"ormation tomake sure it was the intendedrecipient

#. !he packet in"ormation is thenstripped and the data se"#ent isreassem*led into the -le that we clickon in %indows 4plorer

Brame

acket



,ow does data know where to g

Most e'er$ computer and man$ other de'ices ha'e an

Protocol (IP) address• Uni?uel$ identi-es a de'ice and its associated network

A t$pical eample o" an IP$4 address would *e 192.1

4'er$ address is *roken down into two parts *$ a s%#ask •

Network 192.1;.1• ,ost 1



/u*net Mask• A group o" "our num*ers that de-ne a computerCs n

•

&'! All o" the 255s in a su*net mask collecti'el$the network portion whereas the >s re"er to the hos

!$pe o"Address

Birst 3ctet /econd3ctet

!hird 3ctet Bourth3ctet

Address 192 1; 1 1/u*net Mask 255 255 255 >



!$pes o" LocalArea Networks



%ired LANs (%LANs)

,osts such as s or laptops

are connected to centralconnecting de'ices *$ copper@*ased twisted pair ca*ling



%ired LANs (%LANs)• ,osts connect to networks

through %As• !o connect to a %A a

de'ice must ha'e a wirelessnetwork adapter

• n larger %LANs the %A has

to connect to a wired switch



irtual LANs (LANs)

%ith LANs de'ices in a LAN

are grouped *ased on their"unction

mplemented to:• organi+e networks

• enhance per"ormance

• increase securit$

h$sical location o" de'icesdoes not matter

LAN2>

LAN2>

LAN#>

!4A,40/

/!U4N!/

/!U4N!/



erimeter Networks• erimeter networks or

de#ilitaried ones(*+,s) are small LANs thatare set up outside o" anorgani+ationCs LAN

• MDs t$picall$ consist o"

ser'ers that pro'ide ser'iceslike we* hosting or email

• !his setup allows usersoutside o" an organi+ationCsLAN to access the ser'ers

*ut not the organi+ationCs

nternet

perimeter

LAN



/ummar$

1 Local Area Networks

2 ata !rans"er on a LAN

# !$pes o" Local Area Network



E 2>15 Microso"t orporation. All rights reser'ed.

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Undersanding LAN Prt1