ccna2 (v.5.0) - chapter 1 instructor ppt

8/9/2019 CCNA2 (v.5.0) - Chapter 1 Instructor PPT

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2008 Cisco Systems, Inc. Al l r ights reserved. Cisco ConfidentialPresentation_ID

Cha!ter " Introd#ction

to S$itched %et$or&s

Routing and Switching


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Presentation_ID 2 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Chapter 1

.0 Introd#ction

. 'A% Design

.2 S$itched (nvironment

.) S#mmary


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Presentation_ID ) 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Chapter 1: Objectives

*!on com!letion of this cha!ter, yo# $ill +e a+le to"

Descri+e convergence of data, voice, and video in the contet ofs$itched net$or&s.

Descri+e a s$itched net$or& in a small-to-medi#m-sied +#siness.

(!lain the !rocess of frame for$arding in a s$itched net$or&.

Com!are a collision domain to a +roadcast domain.


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Presentation_ID / 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Converged Networks

Growing Complexit o! Networks

#r digital $orld ischanging.

Information m#st

+e accessed fromany$here in the$orld.

%et$or&s m#st +esec#re, relia+le,

and highlyavaila+le.


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Converged Networks

"lements o! a Converged Network

Colla+oration is are#irement.

3o s#!!ort colla+oration,net$or&s em!loy

converged sol#tions.

Data services incl#devoice systems, IP !hones,voice gate$ays, videos#!!ort, and video

conferencing. Call control, voice

messaging, mo+ility, anda#tomated attendant arealso common feat#res.


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Converged Networks

#ene!its o! a Converged Network

5#lti!le ty!es of traffic6

only one net$or& to

manage.

S#+stantial savings over

installation and

management of

se!arate voice, video,

and data net$or&s.

Integrates I3management.


7/26Presentation_ID 7 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Converged Networks

#orderless Switched Networks

3he Cisco orderless %et$or& is a net$or& architect#re thatallo$s organiations to connect anyone, any$here, anytime,and on any device sec#rely, relia+ly, and seamlessly.

Cisco orderless %et$or& is designed to address I3 and+#siness challenges, s#ch as s#!!orting the convergednet$or& and changing $or& !atterns.



Converged Networks

$ierarch in the #orderless Switched

Network

orderless

s$itched net$or&

design g#idelines

are +#ilt #!on the

follo$ing !rinci!les"

9ierarchical

5od#larity

:esiliency

;lei+ility


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Switched Networks

Role o! Switched Networks

S$itching technologies are cr#cial to net$or& design.

S$itching allo$ traffic to +e sent only $here it is needed in mostcases, #sing fast methods.

A s$itched 'A%" Allo$s more flei+ility

Allo$s more traffic management

S#!!orts #ality of service, additional sec#rity, $ireless, IP

tele!hony, and mo+ility services


11/26Presentation_ID 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Switched Networks

(orm (actor

(ixed)lat!orm



Switched Networks

(orm (actor *cont+,

-odular

)lat!orm


13/26Presentation_ID ) 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Switched Networks

(orm (actor *cont+,

Stackable

)lat!orm


14/26Presentation_ID / 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

(rame (orwarding

Switching as a General Concept

A s$itch ma&es a decision +ased on ingress and a destination

!ort.

A 'A% s$itch &ee!s a ta+le that it #ses to determine ho$ to

for$ard traffic thro#gh the s$itch.

Cisco 'A% s$itches for$ard (thernet frames +ased on thedestination 5AC address of the frames.



(rame (orwarding

&namicall )opulating a Switch -'C

'ddress .able A s$itch m#st first learn $hich devices eist on each !ort +efore it

can transmit a frame.

It +#ilds a ta+le called a 5AC address or content addressa+le

memory =CA5> ta+le.

3he ma!!ing device ?-@ !ort is stored in the CA5 ta+le. CA5 is a s!ecial ty!e of memory #sed in high-s!eed searching

a!!lications.

3he information in the 5AC address ta+le #sed to send frames.

hen a s$itch receives an incoming frame $ith a 5AC address thatis not fo#nd in the CA5 ta+le, it floods it to all !orts, +#t the one that

received the frame.



(rame (orwarding

Switch (orwarding -ethods

'dd a header



(rame (orwarding

Store/and/(orward Switching

Allo$s the s$itch to" Chec& for errors =via ;CS

chec&>

Perform a#tomatic

+#ffering

Slo$er for$arding !rocess



(rame (orwarding

Store/and/(orward Switching *cont+,


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(rame (orwarding

Cut/.hrough Switching *cont+,



Switching &omains

Collision &omains

A collision domain is the segment $here devices m#st com!ete tocomm#nicate.

All !orts of a h#+ +elong to the same collision domain.

(very !ort of a s$itch is a collision domain on its o$n.

A s$itch +rea& the segment into smaller collision domains, easingdevice com!etition.



Switching &omains

#roadcast &omains

A +roadcast domain is the etend of the net$or& $here a +roadcastframe can +e heard.

S$itches for$ard +roadcast frames to all !orts6 therefore, s$itches

do not +rea& +roadcast domains.

All !orts of a s$itch, $ith its defa#lt config#ration, +elong to thesame +roadcast domain.

If t$o or more s$itches are connected, +roadcasts are for$arded to

all !orts of all s$itches, ece!t for the !ort that originally received

the +roadcast.


23/26Presentation_ID 2) 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Switching &omains

'lleviating Network Congestion

S$itches hel! alleviating net$or& congestion +y"

;acilitating the segmentation of a 'A% into se!arate collision

domains

Providing f#ll-d#!le comm#nication +et$een devices

3a&ing advantage of their high-!ort density

#ffering large frames

(m!loying high-s!eed !orts

3a&ing advantage of their fast internal s$itching !rocess

9aving a lo$, !er-!ort cost


24/26Presentation_ID 2/ 2008 Cisco Systems, Inc. Al l r ights reserved. Cisco Confidential

Chapter 1: Summar

In this cha!ter, yo# learned"

3he trend in net$or&s is to$ards convergence #sing a single set of$ires and devices to handle voice, video, and data transmission.

3here has +een a dramatic shift in the $ay +#sinesses o!erate.

3here are no !hysical offices or geogra!hic +o#ndaries constraints.:eso#rces m#st no$ +e seamlessly availa+le anytime andany$here.

3he Cisco orderless %et$or& architect#re ena+les differentelements, from access s$itches to $ireless access !oints, to $or&

together and allo$ #sers to access reso#rces from any !lace at anytime.


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Chapter 1: Summar *cont+,

3he traditional, three-layer hierarchical design model divides thenet$or& into core, distri+#tion, and access layers, and allo$s each!ortion of the net$or& to +e o!timied for s!ecific f#nctionality.

It !rovides mod#larity, resiliency, and flei+ility, $hich !rovides afo#ndation that allo$s net$or& designers to overlay sec#rity,

mo+ility, and #nified comm#nication feat#res. S$itches #se either store-and-for$ard or c#t-thro#gh s$itching.

(very !ort on a s$itch forms a se!arate collision domain allo$ing foretremely high-s!eed, f#ll-d#!le comm#nication.

S$itch !orts do not +loc& +roadcasts and connecting s$itches canetend the sie of the +roadcast domain, often res#lting in degradednet$or& !erformance.


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ccna2 (v.5.0) - chapter 1 instructor ppt

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