Chng 05Thit b mng

MNG5MY5TNHThng 09/2013

Ni dung

!Cc thit b mng!Collision8domain8&8Broadcast8domain

Collision!Collision8(ng ):8khi c hai hay8nhiunode8cng gi DL8ln ng truyn chia scng lc

Gii thiu

!Chc nng" H tr truy cp mng

NIC" Dng phn tch mng hoc m rng mng

Router Switch,8Bridge,8hub,8repeater,8gateway

" Dng truy cp t xa Modem,8ADSL8modem

Cc thit b mng

!Tng 1:8modem,8repeater,8hub!Tng 2:8bridge,8switch!Tng 3:8router!Khc:8NIC,8access8point

Modem5E 1

!MODEM5=5MOdulate and8DEModulate!L thit b cho php cc my tnh truyn thng vinhau qua8mng in thoi

Modem5E 2

!Chc nng:" iu ch [Modulate]:8chuyn i tn hiu s (digital)8trn

my tnh thnh tn hiu tng t (analog)8trn in thoi." Gii iu ch [Demodulate]:8chuyn i tn hiu tn hiu

tng t trn in thoi thnh tn hiu s trn my tnh

Repeater5E 1

!Repeater l thit b mng ni kt 2 nhnh mng" nhn tn hiu mt nhnh mng" khuych i tn hiu (khng x l ni dung)" truyn i tip vo nhnh mng cn li

!S lng repeater trong 1 mng LAN c hn

Repeater5 minh5ha tn hiu mng

Hub

!L thit b mng cho php tp kt dy dn mng!Tn hiu vo 1 port ca Hub s c chuyn ra tt c cc

port" Mi port8l 18shared8link

Hub5 minh5ha tn hiu mng

Hub5 phn loi

!Passive hub:" Khng khuych i tn hiu

!Active Hub" Khuych i tn hiu" Nh 1 repeater nhiu cng

!Intelligent Hub" L 1 active hub" Chuyn mch (switching): chuyn tn hiu n ng port

ca my nhn

Repeater5&5hub

!Chc nng:8Ti sinh tn hiu mng v chuyn tnhiu mng n cc segment8mng cn li

!c im:" Khng th lin kt cc segment

Khc ng mng Khc phng php truy cp ng truyn dng phng tin truyn dn khc nhau

" Khng th nhn dng8packet" Khng cho php gim ti mng" Cho8php m rng mng d dng

Bridge5E 1

!L thit b mng cho php ni kt 2 nhnh mngvt l

!Chc nng:8chuyn c chn lc cc gi tin8nnhnh mng cha trm nhn gi tin." Duy tr bng a ch

MAC8 Port khi to v duy tr t ng hoc th cng

" Nu trm nhn cng segment8vi trm gi,8hy gi tin8ngc li chuyn gi tin8n segment8ch

Bridge5 minh5ha tn hiu mng

00000CAAAAAA

A B

C D

00000CBBBBBB

00000CCCCCCC 00000CDDDDDD

00000CAAAAAA 00000CDDDDD

1

2

MAC Address Port00000CAAAAAA 100000CBBBBBB 100000CCCCCCC 200000CDDDDDD 2

D

Src MAC Dst MAC

Bridge5 minh5ha tn hiu mng

00000CAAAAAA

A

C D

00000CBBBBBB

00000CCCCCCC 00000CDDDDDD

1

2

MAC Address Port00000CAAAAAA 100000CBBBBBB 100000CCCCCCC 200000CDDDDDD 2

D

B

Src MAC Dst MAC

00000CAAAAAA 00000CBBBBB

Bridge5E 3

!c im:" Cho php m rng cng mt mng logic vi nhiu kiu chy

cp khc nhau" Tch mt mng thnh nhiu phn nhm gim lu lng

mng.8" Chm hn repeater do phi x l cc gi tin" Khng c kh nng tm ng i ti u trong trng hp c

nhiu ng i." t tin hn repeater

Switch5E 1

!L 18bridge8nhiu port!H tr fullduplex!Duy tr bng CAM8(Content8Addressable8Memory)

" MAC8 Port

Switch5E 2!Chc nng:

" Hc a ch MAC8(self8learning)" Filtering/Forwarding" Trnh loop

!Cc ch chuyn mch:" Storeandforward

c ht ni dung8gi tin m bo chnh xc

" Cutthrough c 148bytes8u tin Khng pht hin c gi tin8b li

" Fragmentfree c 18phn gi tin

Switch5 hc a ch mac E 1

MAC$addr port TTL

Nhn gi tin

flood

Gin port tng ng

Dest -MAC c trongswitch table?

NN

YY

Ghi nhn link tng ng vi host gi

Switch5 hc a ch mac E 2

A

A

B

B

C

C

1 23

45

6

A22A

Source:2ADest:2A Switch2table2

(gi s ban2u rng)

A2AA2AA2AA2AA22A

A22A

MAC$addr port TTLMAC$addr port TTL

A 1 60

MAC$addr port TTL

A 1 60

A 4 60

Switch5 hc a ch mac E 3

!Hi:8Khi A8gi cho F818gi tin???

A

B

S1

C D

E

FS2

S4

S3

H

I

G

Switch5 VLAN

!VLAN8=8Virtual8LAN!Nhm mt s port8thnh 18mng LAN8o

Router

!Chc nng:" Ni kt cc mng logic khc nhau." S dng a ch logic (IP) x l gi tin

" nh tuyn (Routing) Chy cc thut ton nh tuyn (OSPF, RIP, BGP,) # to ra bngnh tuyn

" Chuyn tip (Forwarding) Chuyn gi tin t cng vo (incoming port) ra cng ra (outcoming

port)

NIC

!NIC8=8Network8Interface8Card!L thit b chuyn i tn hiu my tnh thnh tnhiu trn phng tin truyn dn v ngc li

!Cung cp kt ni vt l n phng tin truyndn

Access5Point

!L8thit8b8cho8php8thit8b8truy8cp8mng8khng8dy

!ng8vai8tr8nh818hub!Thnh8phn:" B8thu:8thu8tn8hiu8radio8v8chuyn8thnh8tn8hiu8mng" B8pht:8chuyn8tn8hiu8mng8thnh8tn8hiu8radio

!Ngy8nay,8mt8s8AP8cn8tch8hp8chc8nng8ca818Router

THIT5B5MNG

Nhu cu Thit bKt ni nhiumy tnh trong 12Net SW,2Hub,2BridgeKt ni nhiu Net RouterTruyn qua2in thoi ModemKo di dy cp RepeaterThit lp mng khng dy AP

Ni dung

!Cc thit b mng!Collision8domain8&8Broadcast8domain

Collision5domain5E Broadcast5domain5

!Collision8domain8(min ng ):8l min c kh nngxy ra ng " L min dng chung (chia s)" Hai segment8thuc cng 18collision8domain8nu chng gy racollision8khi ng thi gi d liu xung ng truyn

!Broadcast8domain8(min broadcast):8l min nhnc gi tin8broadcast" Gm nhiu collision8domain8(18 n)" Collision8domain8A88v B8thuc cng 18broadcast8domain8nucc node8mng trong collision8domain8B8nhn c gi tin8broadcast8t 18node8trong collision8domain8A

Cc thit b mng

!Thit b m rng collision8domain:" Repeater" Hub"

!Thit b phn tch collision8domain" Switch" Bridge

!Thit b phn tch broadcast8domain" Router

V d 1

Bridge Switch

Collision Domains:

Broadcast Domains:

Hub Router

1

1

4

1

4

1

4

4

V d 2

Ti liu tham kho

!Slide8ca J.F8Kurose8and8K.W.8Ross8v Computer8Networking:8A8Top8Down8Approach

!http://www.eie.polyu.edu.hk/~ensmall/eng224