Nghien Cuu IPv4 & IPv6

7/31/2019 Nghien Cuu IPv4 & IPv6

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Trung tm pht trin CNTT-HQG TP. H ch minhTrung tm o to cng ngh cao Bch Khoa

Gio vin hng dn : Th.S H Mnh o

1

Li cm nChng em xin chn th nh cm n thy gio thc

s H Mnh o trc tip hng dn chng em xydng v ho n th nh n.

Chng em xin chn th nh cm n cc thy ctrong trung tm cng ngh cao Bch Khoa HTC to

mi iu kin gip chng em ho n th nh n n y.

H Ni, thng 06 nm 2005

Hc vinNguyn Quc Tun

T Ho ng AnhNguyn Th Thu


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Chng 1 Nhng hn ch ca IPv4 v c im ca IPv6

1.1 Nhng hn ch ca IPv4:- Giao thc tng mng trong b giao thc TCP/IP hin ti ang l

IPv4 (Internet- working protocol verision 4). IPv4 cung cp truyn thnhost-to-host gia nhng h thng trn Internet. Mc d IPv4 c thit kkh tt, s thng i thng tin tin trin t lc khi u IPv4 v o nhnm 1970, nhng IPv4 c nhng s thiu ht khin cho n khng ng bcho s pht trin nhanh ca Internet, gm nhng th sau:

+ IPv4 c 2 level cu trc a ch (netid v hostid) phn nhm v olp (A, B, C, D v E). S s dng nhng a ch l khng hiu qu. Vnh khi cos mt t chc c cp cho 1 a ch lp A, 16 triu a cha ch c phn phi duy nht cho t chc s dng. Nu 1 t chc cp cho 1 a ch lp C, mt khc ch c 256 a ch c phn phchc, y khng phi l mt s . Cng vy, nhiu triu a ch b ltrong nhm D v E. Phng thc phn a ch n y dng ht nhng ch ca IPv4, v mau chng s khng cn a ch n o cn cp cho bmt h thng mi n o mun kt ni v o Internet. Mc d sch lc subnetv supernet gim bt nhng vn v a ch, nhng subnet v sup l m cho ng truyn tr ln kh khn hn.

+ Internet phi thch nghi c vi s chuyn giao audio v videothi gian thc. Loi chuyn giao n y yu cu nhng sch lc tr ho n tnht v s t trc ca t i nguyn khng c cung cp trong thit k.

+ Internet phi thch nghi c vi s m ho v s chng nhn cad liu cho mt s ng dng. Khng mt s m ho v s chng nhn n oc cung cp trong IPv4.- khc phc thiu st trn IPv6 c bit n nh l IPng (Interworking Protocol, next generation), c xng v nay l mt chun.

1.2 c im ca IPv6:- Trong IPv6 giao thc Internet c ci tin mt cch rng ln thnghi c s pht trin khng bit trc c ca Internet. nh dng v d i ca nhng a ch IP cng c thay i vi nhng gi nh dNhng giao thc lin quan, nh ICMP cng c ci tin. Nhng giao thkhc trong tng mng nh ARP, RARP, IGMP hoc b xo hoc trong giao thc ICMPv6. Nhng giao thc tm ng nh RIP, OSPF cnc ci tin kh nng thch nghi vi nhng thay i n y. Nhng chuygia truyn thng d on l IPv6 v nhng giao thc lin quan vi n snhanh chng thay th phin bn IP hin thi.Th h mi ca IP hay IPv6 c nhng u im nh sau:


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1.2.1 Khng gian a ch ln IPv6 c a ch ngun v ch d i 128 bt. Mc d 128 bt c th

hn 3,4*1038 t hp, khng gian a ch ca IPv6 c thit k d phngln cho php phn b a ch v mng con t trc xng sng internet tng mng con trong mt t chc. Cc a ch hin ang phn b

dng ch chim mt lng nh v vn cn tha rt nhiu a ch sncho s dng trong tng lai. Vi khng gian a ch ln n y, cc k thubo tn a ch nh NAT s khng cn cn thit na.

1.2.2 a ch phn cp, h tng nh tuyn hiu qu Cc a ch to n cc ca Ipv6 c thit k to ra mt h t

nh tuyn hiu qa, phn cp v c th tng qut ho da trn s phnthng thy ca cc nh cung cp dch v Internet (ISP) trn thc t. Trmng Internet da trn IPv6, cc router mng xng sng (backbone) c s mc trong bng nh tuyn nh hn rt nhiu.

1.2.3 Khun dng header n gin ho - Header ca IPv6 c thit k gim chi ph n mc ti thiun y t c bng cch chuyn cc trng khng quan trng v cc trngla chn sang cc header m rng c t pha sau ca IPv6 headKhun dng header mi ca IPv6 to ra s x l hiu qu hn ti ccrouter.

1.2.4 T cu hnh a ch n gin cho vic cu hnh cc trm, IPv6 h tr c vic t c

hnh a ch stateful nh kh nng cu hnh server DHCP v t cu hn

ch stateless (khng c server DHCP). Vi t cu hnh a ch dstateless, cc trm trong lin kt t ng cu hnh chng vi a ch IPca lin kt (a ch cc b lin kt) v vi a ch rt ra t tin t qung b bi router cc b. Thm tr nu khng c router, cc trm trncng mt lin kt c th t cu hnh chng vi cc a ch cc b lin kgiao tip vi nhau m khng phi thit lp cu hnh th cng.

1.2.5 Kh nng xc thc v bo mt an ninh Tch hp sn trong thit k IPv6 gip trin khai d d ng m b

tng tc ln nhau gia cc nt mng.

1.2.6 H tr tt hn v cht lng dch v QoS Lu thng trn mng c phn th nh cc lung cho php s l mc

u tin khc nhau ti cc router.

1.2.7 H tr tt hn tnh nng di ng


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Kh nng di ng MobileIP tn dng c cc u im ca IPv6 svi IPv4.

1.2.8 Kh nng m rng Thit k ca IPv6 c d phng cho s pht trin trong tng lai

thi d d ng m rng khi c nhu cu.1.3 Cu trc a ch IPv61.3.1 a ch IPv6

Mt a ch gm c 16 byte, l 128 bt d i. Kiu k hiu dchm trong h m 16 ( Hexadecimal Colon Notation):

l m cho nhng a ch tr nn c th c c nhiu hn, IPtrnh by r trong kiu k hiu du 2 chm trong h m 16. Trong kihiu n y, 128 bt c chia th ng 8 phn, mi phn rng 2 byte. 2 byttrong kiu k hi h m 16 yu cu 4 ch s trong h m 16 n y. Vcho nn a ch gm c 32ch s trong h m 16 vi mi 4 ch s mtc mt du : chm(Hnh1)

128 bt= 16 bytes= 32ch s trong h m 16

FDEC : : 7654 3210 ADBF 2922 FFFF

111111101111101100..111111111111

Hnh 1: a ch IP phin bn 6 ( IPv6 Address)

*Su rt gn:+ Mc d l a ch IP ngay c khi trong nh dnh h s m 16, vd i, nhiu ch s 0 trong mt a ch.

Th d: 1080:0000:0000:0000:0008:0800:200C:417A

Do c ch nn a ch c dng biu din d d ng hn cc lch dng n y. Ta khng cn vit cc s 0 u cc nhm, nhng nhng s0 bn trong th khng th xo.


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Cha rt gn

1080:0000:0000:0000:0008:0800:200C:417A rt gn

1080: 0: 0: 0: 8: 800:200C:417A

Hnh 2 : S rt gn a ch (Abbreviated Address)

Hn na ta c th s dng k hiu :: ch mt chui cc s 0. Tnhin k hiu trn ch c s dng mt ln trong mt a ch. a chc d i c nh, ta c th tnh c s cc bit 0 m k hiu biu d

Ta c th p dng u hay cui a ch. Cch vit n y c bit c lbiu din cc a ch multicast, loopback hay cc i ch cha ch

Cha rt gn

1080: 0: 0: 0: 8: 800:200C:417A rt gn

1080::8:800:200C:417A

Hnh 3: S rt gn a ch c s 0 lin tip(Abbreviated Address with consecutive zeros)

Vic khi phc li s rt gn a ch l rt n gin: thm s 0 vcho n khi nhn c a ch nguyn bn (4 ch s trong 1 phn , 32s trong mt a ch)

IPv6 cho php gim ln a ch v c biu din theo k phCIDR.V d: Biu din mng con c d i tin t 80 bt:


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1080:0:0:0:8::/80

Hnh 4 : a ch CIDR ( CIDR Address)

1.3.2 Khng gian a chKhng gian a ch c d i ln hn IPv4( 128 bt so vi 32 bt)

cung cp khng gian a ch ln hn rt nhiu. Trong khi khng gianch 32 bt ca IPv4 cho php khong 4 t a ch, khng gian a chth c khong 6.5*10

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a ch trn mi mt vung b mt tri t. a IPv6 128 bt c chia th nh cc min phn cp theo trt t trn InternN to ra nhiu mc phn cp v linh hot trong a ch ho v nh tuhin khng c trong IPv4.

Khng gian a ch c nhiu mc ch khc nhau. Ngi ta thia ch IP chia khng gian a ch th nh 2 phn, vi phn u ckiu tin t. Phn gi tr tin t n y cho bt mc ch ca a ch. m s c thit k sao cho khng c m s n o ging phn u ca bt km s n o khc. Do khng c s nhp nhng khi mt a ch c trkiu tin t c th d d ng xc nh c. Hnh 5 cho chng ta thy dca a ch IPv6:

128 bt

Bin Bin

Kiu tin t Phn cn li ca a ch

Hnh 5 : Cu trc a ch ( Address Structure)

Khng gian IPv6 c chia trn c s cc bt u trong a chTrng c d i thay i bao gm cc bt u tin trong a ch gi l t nh dng ( Format Prefix) FP. C ch phn b a ch nh sau:

Phn b Tin t nh dng T l trong khng gian


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a chD phng 0000 0000 1/256D phng 0000 0001 1/256D phng cho a ch NSAP 0000 001 1/128D phng cho a ch IPX 0000 010 1/128

Cha cp pht 0000 011 1/128Cha cp pht 0000 1 1/32Cha cp pht 0001 1/16a ch da trn v tr a l (Hin loi b)

001 1/8

Cha cp pht 101 1/8Cha cp pht 110 1/8Cha cp pht 1110 1/16Cha cp pht 1111 0 1/32Cha cp pht 1111 10 1/64

Cha cp pht 1111 110 1/128Cha cp pht 1111 1110 0 1/512a ch lin kt cc b 1111 1110 10 1/1024a ch site cc b 1111 1110 11 1/1024a ch multicast 1111 1111 1/256

Hnh 6 : C ch phn b a ch

1.3.3 Cp pht a ch IPv61.3.3.1 a ch unicast trn c s ngi cung cp

a ch trn c s ngi cung cp c s dng chung bi 1 hosbnh thng nh 1 a ch unicast. nh dng a ch c din t nh

128 bits

8 bits

3 bits 5 bits

ProviderIndentifler

SubscriberIndentifler

SubnetIndentifler

NodeIndentifler

010 Registry


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Hnh 7: a ch trn c s ngi cung cp (Provider-based Address)

Nhng trng cho a ch ngi dng trn c s cung cp nh sau :+ Chng thc kiu (Type indentifier): Trng 3 bt n y nh ngha

nhng a ch nh l 1 a ch trn c s ngi cung cp.+ Chng thc ng k (Registry indentifier) : Trng 5 bt n y

trnh b y chi nhnh ng k a ch. Hin thi th c 3 trung tm c nh ngha:

RIPE- NCC (m 01000): Ti Chu u.INTERNIC (m 11000): Ti Bc M.APNIC (m 10100): Ti Chu - Thi Bnh Dng+ Chng thc h cung cp (Provider indentifier): Trng d i

tu bin n y xc nhn nh cung cp (provider) cho truy cp Internet 16 bi

d i l khuyn co i vi trng n y.+ Chng thc thu bao (Subscriber indentifier): Khi mt t chct mua Internet d i hn thng qua 1 nh cung cp, n c cp pht 1 thnhn dng ngi t mua (Subscriber indentification). 24 bt d ikhuyn co i vi trng n y.

+ Chng thc Subnet (Subnet indentifier): Mi subscriber c thc nhiu subnetwork khc nhau, v mi network c th c nhiu chngthc. Chng thc. Chng thc subnet nh ngha mt network c th dkhu vc ca subscriber. 32 bt d i l khuyn co i vi trng n y.

+ Chng thc None (None indentifier): trng cui cng nhngha nhn dng giao im kt ni ti subnet. d i 8 bt l khuyn cvi trng n y l m n thch hp vi a ch link 48 bt (Vt l) dng bi Ethernet. Trong tng lai a ch link n y c l s ging a cvt l node.

Chng ta c th ngh v mt i ch cung cp trung tm nh 1 cp chng th c mt s tin t. Nh nhng g thy hnh 8, mi tinnh ngha mt cp bc ca h thng. Kiu tin t nh ngha kiu


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nh nghi 1 cch duy nht v nh cung cp bc ng k, tin t nh cucp nh ngha 1 cch duy nht v nh cung cp, tin t subnet nh ncch duy nht v subscriber, v tin t subnet nh ngha 1 cch duy nv subnet.

Subnet

Subscriber

Provider

ProviderIndentifier

Subscriberindentifier

SubnetIndentifier

Nodeindentifier

Hnh 8 : H thng a ch (Address Hierarchy)

1.3.3.2 a ch d tr (Reserved Address):Nhng a ch m s dng tin t d tr (0000 0000) s c th

lun mt cch ngn gn ti y.+ a ch khng xc nh (Unspecified Address):y l mt a

ch m phn khng phi tin t ch cha ch s 0. Ni mt cch khc phcn li ca a ch gm to n zero. a ch n y c s dng khi host khhiu c a ch ca chnh n v gi 1 cu hi thm tm a chTuy nhin trong cu hi thm phi nh ngha 1 a ch ngun. akhng xc nh c th c s dng cho mc ch n y. Ch l a khng th c s dng l m a ch ch. a ch n y c trnh b yhnh sau :

8 bt 120 bit

00000000 Tt c to n bt 0

Hnh 9 : a ch khng r (Unspecified Address)


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+ a ch vng ngc (Loopback Address):y l mt a chc s dng bi 1 host kim tr n m khng cn v o mng. Trongtrng hp n y 1 thng ip c to ra tng ng dng n gi ti tngchuyn ti v i qua tng mng. Tuy nhin thay v i n mng vt l nli tng chuyn ti v i qua tng ng dng. a ch n y rt hu dng c

vic kim tra nhng gi phn mm chc nng trong tng n y trc khi thch c vic kt ni my tnh v o mng. a ch c m t trong hnh y gm c tin t 0000 0000 v theo sau l 119 bit 0 v 1 bit 1.

8 bt 120 bit

00000000 000000000000.00000000000001

Hnh 10 : a ch vng ngc ( Loopback Address)

+ a ch IPv4:Nhng g chng ta thy c trong sut qu trnhchuyn i t a ch IPv4 v IPv6, host c th s dng a ch IPv4 c nhng v o a ch IPv6. C 2 nh dng a ch c thit mc ch n y: thch ng ( compatible) v ho (mapped)

+ a ch thc ng ( Compatile Address):L mt a ch ca 96bit 0 theo sau 32 bit ca a ch IPv4. a ch n y c s dng khi 1 mtnh s dng IPv6 mun gi mt thng ip sang 1 my tnh s dng IPTuy nhin gi tin phi i qua mt min m mng vn s dng IPv4

Ngi gi s dng a ch thch ng IPv4 l m cho thun tin vic cgi tin qua min s dng IPv4.Th d: a ch IPv4 l 2.13.17.14 (nh dng du chm trong

m 10) c chuyn th nh 0::020D:110E (nh dng du 2 chm trongm 16). a ch IPv4 c thm 96 bt 0 to ra a ch IPv6 128


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hoc a ch nhng hoc a ch y v nhng bt 0 hoc bl bi ca 16, khng c bt k mt tc ng n o ln vic tnh tonchecksum. a ch n y quan trng v nu a ch ca gi tin c chuyIPv6 sang IPv4 bi router, vic tnh ton checksum s khng c tton.

1.3.3.3 a ch cc b ( Local Address)Nhng a ch m s dng tin t d tr (1111 1110) s c th

kun mt cch ngn gn ti y.+ a ch link cc b ( Link local Address):Nhng a ch n y

c s dng khi 1 mng LAN mun s dng giao thc Internet nhngkhng kt ni Internet v l do an ninh. Kiu a ch n y s dng ti1111 1110 10. i ch link cc b c s dng trong mng c lp vkhng c nh hng chung n o. Khng ai ngo i mng c lp n y c thgi thng ip n nhng my tnh gia nhp 1 mng s dng nhng n y.

10 bt 70 bt 48 bt

11111111010 Tt c bt 0 a ch Node

Hnh 13 : a ch link cc b ( Link local Address)

+ a ch site cc b (Site Local Address):Nhng a ch n y cs dng nu nh 1 site c mt s mng s dng giao thc Internet nhngkhng kt ni Internet v nhng l do an ninh. Kiu a ch n y s dngt 1111 1110 11. a ch site cc b c s dng trong mng c lp vkhng c nh hng chung n o. Khng ai ngo i mng c lp n y c thgi thng ip n my tnh gia nhp mng s dng nhng a ch n y

10 bt 38 bt 32 bt 48 bt

11111111010 Tt c bt 0 a ch Subnet a ch Node

Hnh 14 : a ch site cc b ( Site Local Address)

1.3.3.4 a ch Multicast


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- a ch multicast c s dng nh ngha cho mt nhm cc hostv ch 1. Tt c u s dng tin t 1111 1111 trong trng u Trng th hai l c (flag) nh ngha 1 nhm a ch hoc c nhtm thi. Mt nhm a ch c nh c nh ngha bi nh cm qInternet v c th truy cp bt c lc n o. Mt nhm a ch tm thi, n

mt cch khc c s dng mt cch tm thi. H thng tham d v o mthi ngh t xa c th s dng mt nhm tm thi. Trng th 3 nh nghphm vi hot ng ca nhm a ch. Nhiu phm vi c nh ngh

Hnh 15 : a ch Multicast (multicast address)

1.3.4 nh dng gi tin trong IPv6Gi tin trong IPv6 c thy nh trong hnh di y. Mi gi ti

bao gm mt vng header nn tng bt buc theo sau bi payload. Payloadgm c 2 phn: nhng vng Header m rng tu chn v d liu t tngcao hn. Vng Header nn tng chim gi 40 byte, trong khi nhnvng Header m rng v d liu t tng cao hn cha n 65535 byte thntin.

11111111 C Phm vi ID nhm

8 bt 4 bt 4 bt 112 bt

0000 D nh trc0001 Node cc b0010 Link cc b0101 Site cc b1000 t chc cc b1110 Chung1111 D nh ting


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40 byte C th ln n 65535 byte

u mc nn tng Payload

u mc m rng(tu la chn)

Gi d liu t tng caohn

Hnh 16 : nh dng gi tin IPv6 (IPv6 Data Packet Format)

1.3.4.1 Vng nn tng ( Base Header)Vng header nn tng trong hnh 17 cho ta thy n c 8 trng,nhng trng n y m t nh sau:

VER PRI Flow lable

d i PayloadVng Headerk tip

Gii hnnhy

Nhng a ch ngunNhng a ch chNhng u mc m rng Payload+Gi d liu t tng cao hn

Hnh 17 : nh dng ca 1 n v d liu IPv6( Format of an IPv6 datagram)

+ Phin bn (VER- version): Trng 4 bt n y nh ngha s phinbn ca IP. Vi IPv6 gi tr l 6.

+ Quyn u tin (PRI- prority): Trng 4 bt n y nh ngha s utin ca nhng gi tin i vi s tc nghn giao thng.


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+ Nhn lu lng (Flow lable): Nh n lu lng l mt trng 3byte 24 bit c thit k cung cp s iu khin c bit i vlu lng c bit ca d liu.

+ d i Payload (Payload Length): Trng d i Payload 2 byten y c nh ngha d i tng cng ca n v d liu IP tr vng He

nn tng.+ Vng Header k tip (Next Header): Vng Header k tip l 1trng 8 bt nh ngha 1 u mc m theo sau vng Header nn tng tn v d liu. Vng header k tip l 1 trong nhng vng m rng tula chn c s dng bi IP hoc vng Header cho 1 giao thc tng cahn nh UDP hay TCP. Mi vng Header m rng li c cha trng n y.Bng sau cho chng ta thy nhng gi tr ca vng Header k tip.

M s Vng Header k tip02617434450515960

Tu chn nhy tng bc mtICMP TCP UDP Routing ngunS phn mingPayload bo mt m hoS chng thcTrng ( Khng vng Header k tip)Tu chn ch

Gii hn nhy ( Hot Limit): Trng gii hn nhy 8 bt n y

phc v cho mc ch tng t trng TTL trong IPv4. a ch ngun ( Source Address):Trng a ch ngun l 1i ch Internet 16 byte (128 bit) m xc minh ngun bn gc ca n v dliu

a ch ch ( Destination Address):Trng a ch ch l 1a ch Internet 16 byte ( 128 bit) m thng xc minh ch cui cng cn v d liu. Tuy nhin nu router ngun c s dng th trng n ycha a ch ca router k tip.

+ Quyn u tin (Priority): Trng quyn u tin ca gi tin IPv6nh ngha quyn u tin ca tng gi tin c quan h vi nhng gi tin khtrong cng 1 ngun. V d khi 1 trong 2 n v d liu lin tip phi b b i v cht chi, n v d liu c quyn u tin nh hn s b loiIPv6 chia giao thng (traffic) l m 2 loi: iu khin tc nghn (congestiocontrolled) v iu khin khng tc nghn (nocongestion- controlled).

Giao thng iu khin tc nghn ( congestion- controlledtraffic): Nu 1 ngun t iu chnh giao thng chm li khi c tc nghgiao thng s gn cho giao thng iu khin tc nghn. V d nh giao t


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TCP s dng giao thc ca s trt (Sliding window protocol), c th dd ng p ng giao thng. Trong giao thng iu khin tc nghn n hiu l nhng gi tin c th n chm hoc thm ch mt hoc ngo i yu cu. D liu iu khin tc nghn c cp pht quyn u ti0 n 7 c th hin bng sau:

Quyn u tin M t01234567

Khng c giao thng c thD liu nnGiao thng d liu khng c quan tmD tr Giao thng d liu tham d khi liD tr Giao thng tng giaoGiao thng iu khin

C th m t quyn u tin nh sau:Khng c giao thng c th ( No specific traffic): quyn u tin 0

c cp pht cho gi tin khi tin trnh khng nh ngha 1 u tin n o.D liu nn (Background data): nhm n y (quyn u tin 1) n

ngha dl iu thng xuyn c nhn nn. S nhn tin tc l 1 v d.Giao thng d liu khng c quan tm (unattended data tranffic)

Nu ngi s dng ang khng i d liu s c nhn, gi tin s quyn u tin 2. Email thuc nhm n y. Mt ngi s dng gi email chongi s dng khc, nhng ngi nhn khng bit email s n smThm v o email thng c lu tr trc khi c gi i.

Giao thng d liu tham d khi ln ( Attended bulk data tranffi):Giao thc m chuyn phn ln d liu khi ngi s dng ang i nhn liu (c th tr ho n) c quyn u tin 4. FTP v HTTP thuc nhm n y

Giao thng tng dao (Interactive tranffic): Giao thc dng nh TELNET cn s tng giao vi ngi s dng cp s tng giao vi ngs dng c cp u tin cao th 2 (6) trong nhm.

Giao thng iu khin (Control traffic): Giao thng diu khin quyn u tin cao nht (7) trong loi n y. Giao thc routing nh OSPF vRIP v giao thc qun tr SNMP s dng quyn u tin n y.

Giao thng iu khin khng tc nghn ( Noncongestion-controlled tranffic): Kiu n y gn cho kiu giao thng m ch i mt s h on li nh nht. Loi b gi tin khng phi l tt. S chuyn giao litrong hu ht tnh hung l c th hti h nh c. Ni 1 cch khc ngunkhng sa li n thch nghi vi s tc nghn. Audio v video thi gian thcl nhng v d in hnh cho dng giao thng n y.

Quyn u tin t 8 n 15 c cp pht cho giao thng iu khin khtc nghn. Mc d y khng c bt k mt s cp pht chun c


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n o cho loi d liu n y, quyn u tin thng c cp pht d v o s lng cu d liu nhn c th b tc ng bi vic loi b gi tin. D licha t s rm r (nh audio v video cht lng thp) c th c aquyn u tin cao hn (15). D liu cha nhiu s rm r (nh video vaudio cht lng cao) c th b a 1 quyn u tin thp hn (8).

Quyn u tin M t8...15

D liu vi nhiu s rm r nht

D liu vi t s rm r nht

+ Nhn lu lng ( Flow Lable):Mt d y cc gi tin c gi t 1 ngun ring n ch ring, cn s

iu khin c bit t router gi l lu lng ca nhng gi tin. S ktca a ch ngun v gi tr ca nh n lu lng nh ngha 1 cch duy n1 lu lng ca nhng gi tin.

i v router 1 lu lng l 1 d y cc gi tin chia s cng c tnhnh l vic di chuyn cng 1 ng, s dng cng mt ngun, c cng kiuan to n vv Mt router m h tr s iu khin ca nh n lu lng c 1bng nh n lu lng. Bng n y c 1 mc v o cho mi nh n lu lng hotng, mi mc nh ngha 1 dch v c yu cu bi nh n lu lng tng. Khi router nhn c 1 gi tin n tra cu bng nh n lu lng ca n tm mc v o tng ng cho gi tr nh n lu lng c nh ngha tgi tin. Sau n cung cp cho gi tin nhng dch v cp trong m

v o. Tuy nhin ch l nh n lu lng t n khng cung cp thng tin chonhng mc v o ca bng nh n lu lng, thng tin c cung cp binhng th khc nh l tu chn nhy tng bc mt hay nhng giao thckhc.

Trong hnh thc n gin nht ca n, 1 nh n lu lng c th s dng tng tc 1 tin trnh ca 1 gi tin bi 1 router. Khi router nhc gi tin thay v xem bng tm ng v i n thut ton tm nh ngha a ch cu bc nhy k tip, n c th d d ng c nhtrong 1 bng nh n lu lng cho bc nhy k tip.

Trong hnh thc rc ri hn ca n 1 nh n lu lng c th c sdng h tr qu trnh chuyn giao audio v video thi gian thc. Audiv video thi gian thc mt cch c bit trong hnh thc k thut s nhng ngun nh bng thng rng, buffer ln, thi gian tin trnh d i vvMt tin trnh c th t trc ch cho nhng ngun n y trc ml d liu thi gian thc s khng b tm ho n do thiu ngun. S s dngd liu thi gian thc v ch t trc ca nhng ngun i hi nhng githc khc nh l giao thc thi gian thc ( Real- Time Protocol- RTP) hay


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giao thc t trc ngun (Resource Reservation Protocol- RRP) trong bsung ca IPv6.

cho php nhng hiu qu s dng ca nh n lu lng 3 ilut c a ra :

Nh n lu lng c cp pht cho 1 gi tin bi 1 host gc. Nh n

l mt s bt k t 1 n 224

-1. N s khng s dng li mt nh n lu lngcho 1 lu lng mi khi lng dang tn ti vn hot ng.Nu nh 1 host khng h tr nh n lu lng, n s t trng n y

l 0. Nu nh 1 router khng h tr nh n lu lng, n n gin s pht l i .

Tt c nhng gi tin thuc cng 1 lu lng c th c cng ngun,cng ch, cng s u tin v cng nhng tu chn.1.3.4.2 So snh gia vng header ca IPv4 v IPv6

Trng d i vng header b loi i trong IPv6 v d i vngheader c x l trong phin bn n y.

Trng kiu dch v b loi i trong IPv6. Trng quyn u tiv nh n lu lng cng kim sot chc nng ca trng kiu dch v.

Trng d i tng cng b loi i trong IPv6 v c thay thbng trng d i payload.

Nhng Trng chng thc ( identification ), Trng c ( flag ), vnhng Trng offset b loi b t vng header nn tng trong IPv6Chng c i km trong vnh header m rng tng ming.

Trng TTL c gi l Gii hn nh y trong IPv6.Trng giao thc dc thay th bi Trng vng header k tip.Vng header checksum b loi i v checksum c cung cp b

giao thc ca tng cao hn n v th khng cn thit y.

Nhng Trng tu chn trong IPv4 c trang b nh nhng vngheader m rng trong IPv6.

1.3.5 Vng header m rng d i ca vng header c b tr 40 byte. Tuy nhin, em

nhiu chc nng hn cho n v d liu IP vng header nn tng c th theo sau n 6 vng header m rng. Nhiu vng header n y l nhng tuchn trong IPv4.


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VER PRI Flow label d i Payload Vng Header k tip Gii hn nhy

a ch nguna ch ch

Vng Header k tip d i vng Header



Hnh 18 : nh dng vng header m rng( Extenion header format )

Su loi vng header c nh ngha. Chng l tu chn nhytng bc, l trnh ngun, s phn mnh, s chng thc, Payload bo mm ho v tu chn ch (Xem hinh 19).


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Hnh 19 : Nhng loi vng header m rng (Extension header types)

1.3.5.1 Tu chn nhy tng bc (Hopbyhop option)Tu chn nhy tng bc c s dng khi ngun cn chuyn thng

tin qua tt c cc router c thm bi n v d liu. V d, khng chnhng router s phi b gy ra bi s qun tr, s g ri hay nhng chnng iu khin n o .Hay,nu nh d i ca n v d liu rngthng thng l 65,535 byte, nhng router phi c thng tin n y. Hnh 20cho thy nh dng ca vng header k tip trong mt chui vng heade d i vng header nh ngha s byte trong vng headerbao gm ctrng vng header k tip). Phn cn li ca vng header cha nhng tuchn khc nhau.

Vng header nn tng

Nhng tu chn

Vng header k tip d i vng header

Phn cn li ca Payload

Hnh 20 : nh dng vng header tu chnj nhy tng bc(Hop by hop option header format )

Nhng vngHeader m rng

Tu chn nhy tng bc

Ngun tm ng

S phn ming

S chng thc

Bo mt Payload m ho

Tu chn ch


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Xa hn, ch c 3 tu chn c nh ngha: Pad1, PadN v jumpayload (Xem hnh 21).

Hnh 21 : nh dng ca nhng tu chn ca vngheader tu chn nhy tng bc

(Format of options in a hopbyhop option header)

Pad1: Tu chn n y d i 1 byte v n c thit k cho nhng mc chsp nhm. Mt s tu chn cn phi bt u 1 bit ring bit trong 32 b(xem m t jumbo payload). Nu mt tu chn ca s yu cu n y rtchnh xc l 1 byte, Pad1 s c thm v o l m nn s khc bit. Pad1khng cha trng d i tu chn m cn khng c cha trng d liutu chn. N gm c duy nht trng m tu chn vi tt c cc bt ct l 0 ( h nh ng l 00, C l kiu 00000). Pad1 c th c chn v o bk ch n o trong vng header tu chn nhy tng bc.

M s (8 bt) d i (8 bt) D liu ( d i c ththay i)

H nh C Kiu

2 bt 1 bt 5 btH nh ng : s thc hin nu tu chn khng c xc nhn00 B qua tu chn Kiu01 Loi b n v d liu khng c h nh ng n o na 00000 Pal110 Loi b n v d liu v gi 1 thng ip li 00001 PadN11 Nh m 10, nhng nu ch khng phi a ch munlticastC: (change) gi tr thay i tu chn 00010 jumbo payload0 : khng b thay i trong vn chuyn1 : C th b thay i trong vn chuyn


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Hnh 22 : Pad1

PadN: PadN ging Pad1 v tng. S khc nhau l PadN c s dng khi 2 hay nhiu bt c cn cho vic sp nhm. Tu chn n y gc 1 byte m tu chn, 1 byte d i tu chn, v mt bin s nhng s 0l m byte m. Gi tr ca m tu chn l 1 (h nh ng l 00, C l 0 v kiul 00001). d i tu chn cha s byte m.

M d i D liu00000001 Tt c bt 0

1 byte 1 byte s byte c th thay i Hnh 24: Jumbo Payload

1.3.5.2 L trnh ngun (Source Routing)Vng header m rng l trnh ngun kt hp vi tng ca nhng tu

chn l trnh ngun chnh xc v l trnh ngun khng chnh xc ca IPvVng header l trnh ngun cha mt s nh nht ca 7 trng. Hai trngu tin, vng header k tip v d i vng header, l ng vi vngheader m rng nhy tng bc.

Trng kiu nh ngha l trnh l chnh xc hoc khng chnhTrng nhng a ch cn li ch ra s bc nhy cn ti ch. Tmt n tuyt i/ tng i xc nh s chc chn ca l trnh. Nu l tuyt i, l trnh phi theo chnh xc nhng g c ch ra bi ngNu thay v o mt n tng i nhng router khc c th thm v o tronvng header.

M00000000

Nhng tu chnPad1

~ D liu ~a. Pad1

b. S dng l m m


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Hnh 25 : L trnh ngun (Source Routing)

a ch ch trong l trnh ngun khng tun theo s nh ngha ca chng ta (a ch cui cng trong n v d liu). Thay v o thay i t router sang router.Th d : Host mun gi ti 1 n v d liu sang host B s dng 1 l trring: A n R1 n R2 n R3 n B. Ch l a ch ch nnhng vng header nn tng. N khng lin tip nh bn mong i. Thayv o n thay i theo tng router. Nhng a ch trong vng header rng cng thay i theo tng router.

Hnh 26: V d l trnh ngun (Source Routing Example)

Vng header nn tngVng header k d i vng Kiu Nhng a chD tr Mt n tuyt i/ tng ia ch th nht

a ch th hai

a ch cui cngPhn cn li ca Payload

Ngun: Ach: R1

Cn li: 3R2R3B

Ngun: Ach: R1

Cn li: 3R2R3B

Ngun: Ach: R1

Cn li: 3R2R3B

Ngun: Ach: R1

Cn li: 3R2R3B

A B

R1 R3

R3


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1.3.5.3 S phn ming ( Fragmentation) tng v s phn ming nh trong IPv4. Tuy nhin ni m s ph

ming chim gi khng ging nhau. IPv4 ngun hoc router cn phnming nu c ca n v d liu ln hn MTU ca mng vi nhm nd liu s c a i. IPv6 ch nhng ngun nguyn thu mi cphn ming. Mt ngun phi s dng 1 k thut khm ph qu o MTU(Path MTU Discovery) tm MTU nh nht c h tr bi bt k mmng n o trong qu o. Ngun sau phn ming s khm pht n y.

Nu ngun khng se dng k thut khm ph qu o MTU n c thphn minh n v d liu th nh nhng ming c 576 byte hoc nh y l c nh nht MTU yu cu cho mi mng kt ni v o Internet. Hnhdi y cho ta thy nh dng ca vng header m rng s phn ming

Vng Header nn tng

Vng header k tip

d i vngheader

S phn ming bp

0 M

a ch th nht


Hnh 27 : S phn ming (Fragmentation)

1.3.5.4 S chng thc (Authentication)Vng header m rng s chng thc c mt mc ch kp: n l m cho

thng ip gi c gi tr v m bo s nguyn vn ca d liu. u tcn ngi nhn c th chc chn l t ngi gi tht v khng phi 1 k mo danh. iu cui cng cn kim tra l d liu khng b thay trong vn chuyn bi hacker.

nh dng ca vng Header m rng s chng thc c trnh b y hnh 28 . Trng ch mc tham gia s bo mt nh ngha thun ton

s dng cho s chng thc. Trng chng thc cha d liu cha nhng dliu tht c sinh ra bi thut ton.


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Vng Header nn tng

Ch mc tham s bo mt

S chng thc d liu


Hnh 28 : S chng thc (Authentication)

Nhiu thut ton khc nhau c th c s dng cho s chng thc

Hnh 29 phc ho nhng phng thc tnh ton trng chng thc d liu

Kho bo mt 128 bt

n v d liu IPvi nhng trngs thay i v s chng thc ct l 0

Kho bo mt 128 bt

Thut ton s chng thc

S chngthc d liu128 bt

Hnh 29 : S tnh ton ca s chng thc d liu(Calculation Of Authentication Data)


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Ngi gi i qua kho bo mt 128 bt, to n b n v d liu IPkho bo mt 128 bt ln na n thut ton. Nhng trng n y trn v d liu vi nhng gi tr c thay i trong qu trnh vn chuynd nh bc nhy) s c t l 0. n v d liu qua c thut ton cha vng header s chng thc, vi trng s chng thc d liu c

l 0. Thut ton to ra s chng thc d liu vi nhng th c a v otrong vng header m rng trc khi ti qu trnh vn chuyn n v dliu.

Nhng chc nng ngi nhn trong 1 phng php tng t. N nhnmang i kho bo mt v nhn ly n v d liu ( ln na vi nhng trthay i c t l 0) v i qua chng n thut ton s chng Nu kt qu ging s chng thc d liu, n v d liu c chng nu khng chng s b loi.

1.3.5.5 Payload bo mt m ho (Encrypted Secutity Payload - ESP) Payload b mt m ho l phn m rng m cung cp mt cch tn

nhim v bo v chng li s nghe ln. Hnh 30 trnh b y s nh dnTrng ch mc tham s bo mt 32 bt nh ngha kiu m ho / khnho c s dng.

Vng Header nn tng

Ch mc tham s bo mt

D liu m ho

Hnh 30 : Payload bo mt m ho

Trng khc cha nhng d liu ang m ho vi bt k nhng tham sthm n o c cn bi thut ton. S m ho c th c trang b trong 2cch :

Mode vn chuyn (Transport Mode): Trong mode vn chuyn mt TC

hay n v d liu ngi s dng UDP l ci u tin c m ho v gi v o trong 1 gi IPv6. S m ho trong mode vn chuyn c s dnga s m ho d liu t host sang host.


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S m ho

Vng header nntng v nhng vng

header khc

Ch mc

D kiu m hoD liu th

Hnh 31 : S m ho mode vn chuyn (Transport Mode Encryption)

Mode tunnel (Tunnel Mode): Trong mode tunnel to n b d liu IP vi nhng vng Header nn tng ca n v nhng vng Header m rng c m ho v gi v o trong 1 gi IP mi s dng vng Headerm rng Paylaod bo mt m ho. Ni cch khc chng ta c 2 vngHeader nn tng: 1 m ho, 1 cha m ho.

1.3.5.6 Tu chn ch (Destination Option):Tu chn ch c s dng khi ngun ch cn chuyn thng tin

ch. Nhng router khng ngay lp tc trao quyn truy cp cho nhthng tin n y. nh dng ca tu chn ch tng t nh tu chn nhytng bc. Xa hn ch c Pad1 v PadN c nh ngha.So snh gia IPv4 v IPv6: Chng ta h y thc hin mt s s sosnh gia nhng vng Header m rng ca IPv4 v IPv6:

Tu chn khng hot ng (no-operetion) v kt thc tu chn (end- of - option) trong IPv4 c thay bng Pad1 v PadN trong IPv6.

Tu chn bn ghi tm ng khng c trang b trong IPv6 v khng c s dng.

Tu chn ten thi gian (timestamp) khng c trang b v nkhng c s dng.

Tu chn ngun tm ng (source route) c gi l vng Headerm rng tu chn ngun tm ng trong IPv6.

Nhng trng s phn ming (fragmentation) trong khu vc vngHeader nn tng ca IPv4 c chuyn n vng Header m rng tu chs phn ming ca IPv6.

Vng Header s chng thc l mi trong IPv6.Vng Header m rng Payload bo mt m ho l mi trong IPv6.


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Chng 2

Giao thuc ICMPv6(Internet Control Message Protocol Version 6)

Mt giao thc khc c chnh sa trong phin bn 6 ca nhm giaothc TCP/IP cho ph hp l ICMP (ICMPv6). Phin bn mi n y mang theochin lc v mc ch c phin bn 4. ICMPv4 c chnh sa cho php vi IPv6. Thm na mt v i giao thc c lp trong phin bn 4 bygi l mt phn ca ICMPv6.

Giao thc ARP v IGMP phin bn 4 c kt hp trong phin bn 6.Giao thc RARP b loi khi nhm v khng thng xuyn c s dngTheo BCOTP thay th RARP.

IGM ICP

IPv4 ARP RAR

ICPMv6

IPv6

Lp mng trong phin bn 4 Lp mng trong phin bn 6

Hnh 32 : So snh gia mng li phin bn 4 v 6

Trong ICMPv4 ta chia thng ip ICMP th nh 2 loi. Nhng d sao na mi loi cng c nhiu kiu thng ip hn trc.


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Error Reporting

DestinationUnrechable

Packet tooBig

TimeExceeded

ParameterProblems

Redirection

Hnh 35: Bo co li thng ipBng 1 so snh gia tin bo li ca ICMPv4 v ICMPv6. Thng ip

ngun dp tt b loi tr phin bn 6 bi v quyn u tin v trng nh

lung cho php tuyn kim sot s tc nghn v loi b nhng thng ikhng quan trng. Trong phin bn n y khng cn thit phi nhn dngngi gi. Thng ip packet too big c thm v o bi v vic ri tmnh l trch nhim ca ngi gi trong IPv6. Nu ngi gi khng l mng quyt nh c ca gi, tuyn ng s khng c s la chn n o ngovic loi b gi v gi mt bo li cho ngi gi.

Type fo Message Version 4 Version 6Destination unreachable Yes YesSource Quench Yes NoPacket too big No YesTime Exceeded Yes YesParamenter Problem Yes YesRedirection Yes Yes

Bng 1 . So snh gia tin bo li ca ICMPv4 v ICMPv6

2.1.1 Destination unreachable ( Khng th vi ti c ni n)Khi nim v thng ip khng th vi ti c ni n ho n to

ging vi nhng g chng ta m t ICMPv4. Hnh 36 ch ra kh thip khng th vi ti ni n. N gn ging vi ci c xc nh phin bn 4, vi kiu nh gi bng 1.


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Kiu 1 M : 0 to 4 Tng kim tra

Khng s dng (All 0s)

Gi d liu b phn ca IP nhn c bao gm u mc IP cng vi 8 byte ca d liu gi d liu

Hnh 36 : nh dng thng ip khng th vi ti c ni n

M trng kiu n y ch ra nguyn nhn cho vic loi b gi d liv gii thch chnh xc ci g b li.

Code 0 : khng c ng d n n ch.Code 1 : Giao tip b cn.Code 2 : R nh ngun chnh xc khng th l m cCode 3 : a ch n khng ti.Code 4 : Cng khng sn s ng.

2.1.2 Packet too Big ( Gi qu ln )y l mt kiu thng ip mi c thm v o phin bn 6. Nu mt

ng r nh nhn c gi d liu m rng hn kh MTU (MaximumTransmission Unit) ca mng, ci gi m gi d liu cn qua th hai iu xy ra. u tin ng r nh loi b gi d liu v sau mt gi bo li,ICMP c gi cho ngun. Hng 37 ch ra kh ca gi. Cn phi ch rch c duy nht mt m (code 0) v trng MTU nh dng ngi gi cgi c ln nht c nhn bi mng.

Kiu: 2 M : 0 to 4 Tng kim tra

MTU



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Hnh 37 : Packet too big message format

2.1.3 Time Exceeded ( Vt qu thi gian)Thng ip n y gn ging vi 1 kiu thng ip tng phin bn 4

im khc bit duy nht l kiu gi tr c thay i ti 3. Hnh 38ra kh ca thng ip vt qu thi gian.

Kiu :3 M : 0 to 4 Tng kim tra

Khng s dng (All 0s)


Hnh 38 : nh dng thng ip vt qu thi gianNh trong phin bn 4, m 0 c s dng khi gi d liu b loi

khi ng r nh ph thuc v o trng bc nhy ngn- gii hn khng gitr. M 1 c s dng khi nhng on ca gi d liu b loi bi cc mnkhc khng ti c trong thi gian quy nh.

2.1.4 Parameter Problem (Vn tham s)Thng ip n y ging vi loi thng ip k tha trong phin bn 4

Nhng d sao gi tr ca kiu n y cng c thay i ti 4 v c catrng b li c tng ln th nh 4 byte. N cng c 3 m khc nhau thayv 2 m . M trng ch ra nguyn nhn loi b d liu v nguyn nhn cli :

+ Code 0: Mt trong nhng trngch c li hoc s nhp nhngTrong trng hp n y gi tr ca trng im ch ra byte c vn . Vnu gi tr bng 0, byte u tin s khng phi trng hiu qu.

+ Code 1: M n y nhn dng phn m rng ch khng th nhn ra+ Code 2: M n y nhn dng la chn khng th xy ra.


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Kiu : 4 M : 0 to 4 Tng kim tra

Offset Pointer

Gi d liu b phn ca IP nhn c bao gm u mc IP cngvi 8 byte ca d liu gi d liu

Hnh 39: Parameter- problem message format

2.1.5 Redirection (S gi li ln na):Mc ch ca thng ip n y ging vi nhng g chng ta m

trong phin bn 4. Nhng kh ca gi tin c thay i cho ph hp vic ca IP trong phin bn 6. Do o, mt la chn c thm v o host(ch) bit c a ch vt l ca ng r nh ch.


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Kiu : 137 M : 0 Tng kim tra

D tr

ch (chng trnh vn chuyn) m IP hng v o

Ni n ca a ch IP

ch (chng trnh vn chuyn) vt l hng v o

M .OPT d i .OPT

Gi d liu b phn ca IP nhn c bao gm u mc IP cngvi 8 byte ca d liu gi d liu

Hnh 40: khun dng thng bo s gi li ln na

2.2 Query (Truy vn) thm v o bo co li ICMP cng c th chun on mt v i vn

v mng. Ci n y ho n th nh to n b thng ip Query. Bn nhmthng ip khc nhau c nhn dng : hi p lp li, ng koqung co, s n i xin v qung co v nhm th nh vin.

Query

Echorequest and

Router solicitationand advertisement

Neighborsolicitation andadvertisement

Groupmembership

Hnh 41 : Query messageBng 2 cho ta thy s so snh gia thng ip Query ca phin bn 4

v phin bn 6. Hai b thng ip ca Query loi khi ICMPv6: thi gianyu cu p ng, a ch yu cu p ng, thng ip du thi gian yu


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36

v p ng b loi bi v chng l dng c ca giao thc khc nh TCP vbi v chng khng c s dng trc . Thng ip che du a chcu v p ng b loi khi IPv6 bi v phn subnet ca mt a ch php ngi t mua c s dng ti subnet th 232 -1. Trc subnet bdu i nh a ch nh dng IPv4 khng cn thit y.

Type of message ICMPv4 ICMPv6Echo Request And Reply Yes YesTimestamp Request And Reply Yes NoAddress mask Request And Reply Yes NoRouter solicitation and addvertisement Yes YesNeighbor Solicitation and advertisement ARP YesGroup Menmbership IGMP Yes

Bng 2: Comparsion of query message in ICMPv4 and ICMPv6

2.2.1 Yu cu v p ng lp li(Echo request and reply) tng v kh thng ip yu cu v p ng ging vi nhng g

trong phin bn 4. im khac duy nht l gi tr ca kiu nh c chra hnh di y:

Kiu: 128 hoc 129 M : 0 ti 4 Tng kim tra

Identifier S ni tip

D liu chnNhn bi thng bo yu cu : Lp li bi thng bo tr li

Hnh 42: Thng bo yu cu tr li thng ip

2.2.2 Router solicitation and addvertisement (Yu cu v qung cochng trnh vn chuyn) tng bn di thng ip Router solicitation and addvertisement

cng ging nh trong phin bn 4. Kh Router solicitation andaddvertisement ging nh ICMPv4. Nhng d sao mt la chn cthm v o cho php my ch thng bo a ch vt l ca n,


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r nh p li d d ng hn. Kh ca Router solicitation and addvertisementkhac vi ICMPv4: y mt ng r nh ch thng bo v n khng mathng tin a ch vt l ca ng r nh cho s tin li ca my ch. Lchn khc cho php ng r nh thng bo v c ca MTU. La chn th 3cho php ng r nh nh dng thi gian c hiu lc v c a thch.

Type 113 Code : 0 ChecksumUnused (All 0s)

Host Physical Address

Option Code:1 Option length

a. Router solicitation format

Type 134 Code : 0 Checksum

Max hop M 0Unused (All0s) Router lifetime

Reaxhability Lifetime

Reachabili Transmission Interval

Router physical Address

Option Code: Option Length

Option Code: Option length

MTU size

b. Router Advertisement Format

Hnh 43 : Khun dng thng bo yu cu v qung co chng trnhchuyn vn2.2.3 Neighbor Solicitation and advertisement ( S yu cu v qungco ln cn):- Nh c cp n mng li trong phin bn 4 cha ng 1 gthc c lp gi l ARP. Trong phin bn 6 giao thc n y b loi v nhim


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v ca n cng bao gm trong ICMPv6. tng cng trng khp nhngkh ca thng ip thay i. Hnh di y s ch ra kh ca NeiSolicitation and advertisement. Mt la chn duy nht mang thng tin caa ch vt l ngi gi chjo s thun tin ca ngi nhn.

Type: 135 Code: 0 Checksum

Unused (All 0s)

Terget IP Address

Solicitor Physical Address


a. Neighbor Solicitation

Type: 136 Code: 0 Checksum

Unused (All 0s)

Terget IP Address

Target Physical Address


b. Neighbor Advertisement

Hnh 44: Neighbor Solicitation And Advertisement Message Format

2.2.4 Group Membership ( S tham gia nhm ): Trong phin bn 6 giaothc n y b loi v nhim v ca n cng c bao gm trong ICMPv6Mc ch th ho n to n ging. C 3 loi thng ip Group Membershibo co, bng cu hi v gii hn. Thng ip bo co v gii hn c gi


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t vt ch cho ng r nh. Thng ip truy vn c gi t ng r nh cvt ch.

Host Report Router

Report

Termination

Hnh 45 : Group Membership Message

Type: 130 Code: 0 ChecksumMaximum response delay Reserved

IP multicast Addressa. Query

Type: 131 Code: 0 ChecksumReserved

IP multicast Addressb. Report

b. Report

Type: 132 Code: 0 ChecksumReserved

IP multicast Address

Hnh 46: Group Membership Message Format - Nh chng ta ch trong cuc tho lun v phin bn 4, 4 tnh hunkhc nhau ko theo thng ip Group Membhip c ch ra hnh


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Host Report Router131Group Address

a. Joining The GroupHost Query Router

131

b. Monitoring The Group

Host Report Router131

c. Membership Continuation

Host Termination Router131

d. Leaving The Group

Hnh 47: For Situation Of Group Membership Operation


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41

Chng 3 :

S chuyn tip t IPv4 ti IPv6

3.1.t vn :- Giao thc IPv6 c nhiu u im vt tri so vi IPv4, p ng c ncu pht trin ca mng Internet hin ti v trong tng lai. Do , giathc IPv6 s thay th IPv4.Tuy nhin, khng th chuyn i to n b cc nt mng IPv4 hin nay sanIPv6 trong mt thi gian ngn. Hn na, nhiu ng dng mng hin tichh tr IPv6.Theo d bo ca t chc ISOC, IPv6 s thay th IPv4 v o khong 20202030. V vy, cn c mt qu trnh chuyn i gia hai giao thc hin tng tng t nh s c Y2K.Cc c ch chuyn i (Transition mechanism) phi m bo kh ntng tc gia cc trm, cc ng dng IPv4 hin c vi cc trm v ngdng IPv6. Ngo i ra, cc c ch cng cho php chuyn tip cc lung thtin IPv6 trn h tng nh tuyn hin c.Trong giai on chuyn i, iu quan trng l phi m bo s hot bnh thng ca mng IPv4 hin ti.Yu cu i vi cc c ch chuyn i:

+ Vic th nhim IPv6 khng nh hng n cc mng IPv4 hin ahot ng.

+ Kt ni v cc dch v IPv4 tip tc hoat ng bnh thng.+ Hiu nng hot ng ca mng IPv4 khng b nh hng. Giao thc

IPv6 ch tc ng n cc mng th nghim.+ Qu trnh chuyn i din ra tng bc. Khng nht thit phi chui to n b cc nt mng sang giao thc mi.- Cc c ch chuyn i c phn th nh 2 nhm vi hai chc nng khnhau:

+ Kt ni cc mng v cc nt mng IPv6 qua h tng nh tuyn IPv4hin c. Cc c ch n y bao gm: ng hm (tunnel), 6to4, 6over4.

+ Kt ni cc nt mng IPv4 vi cc nt mng IPv6. Cc c ch n y baogm: SIIT, NAT- PT, ALG, DSTM, BIS, BIA, SOCK64.- Mi c ch u c u, nhc im v phm vi p dng khc nhau. Ttng thi im trong giai on chuyn i, mc s dng ca cc c chuyn i s khc nhau.

+ Giai on u:Giao thc IPv4 chim u th. Cc mng IPv6 kt nivi nhau trn nn h tng IPv4 hin c thng qua cc ng hm IPvqua IPv4.+ Giai on gia: Giao thc IPv4 v IPv6 c trin khai v phm vingang nhau trn mng. Cc mng IPv6 kt ni vi nhau qua h tng


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nh tuyn IPv6. Cc mng IPv4 kt ni vi cc mng IPv6 s dng cphng php chuyn i a ch giao thc nh NAT- PT, ALG

+Giai on cui: Giao thc IPv6 chim u th. Cc mng IPv4 cnli kt ni vi nhau trn h tng nh tuyn IPv6 thng qua cc nhm IPv4 qua IPv6 khi chuyn ho n to n sang IPv6.

3.2. Cc phng thc chuyn i:3.2.1. Chng hai giao thc (Dual Stack)- y l c ch n gin nht cho php nt mng ng thi h tr c hgiao thc IPv6 v IPv4. C c kh nng trn do mt trm Dual Stackc I t c hai giao thc, IPv4 v IPv6. Trm Dual Stack s giao tip bngiao thc IPv4 vi cc trm IPv4 v bng giao thc IPv6 vi cc trmIPv6.

Application

Data link (Ethernet)

Hnh 48. Chng hai giao thc

- Do hot ng vi c hai giao thc, nt mng kiu n y cn t nht mt ch IPv4 v mt a ch IPv6. a ch IPv4 c th c cu hnh trhoc thng qua c ch DHCP. a ch IPv6 c cu hnh trc tipthng qua kh nng t cu hnh a ch.- Nt mng h tr cc ng dng vi c hai giao thc. Chng trnh tra cutn min c th tra cu ng thi c cc truy vn kiu A ln kiAAAA(A6). Nu kt qu tr v l bn ghi kiu A, ng dng s s dnggiao thc IPv4. Nu kt qu tr v l bn ghi AAAA(A6), ng dng s sdng giao thc IPv6. Nu c hai kt qu tr v, chng trnh s la chnv cho ng dng mt trong hai kiu a ch hoc c hai.- u im:

TCP UDP

Ipv6Ipv4


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+ y la c ch c bn nht nt mng c th hot ng ng thic hai giao th do , n c h tr trn nhiu nn tng khc nhau nhFreeBSD, Linux, Windows v Solaris.+ Cho php duy tr cc kt ni bng c hai giao thc IPv4 v IPv6.

Nhc im:

+ Kh nng m rng km v phI s dng a ch IPv4.3.2.2. ng hm IPv6 qua IPv4 (Tunnel)- ng hm cho php kt ni cc nt mng IPv6 qua h tng nh tuyIPv4 hin c. Cc trm v cc router IPv6 thc hin bng cch ng cc gitin IPv6 bn rong gi tin IPv4.C 4 cch thc hin ng hm:

+ ng hm t router dn router.+ ng hm t trm n router.+ ng hm t trm n trm+ ng hm t router n trm.

Hnh 49. ng hm Ipv6 qua Ipv4

- Cc cch thc hin ng hm khc nhau v tr ca ng hm trtuyn ng gia hai nt mng. Trong hai cch u, gi tin c ng hm ti mt router trung gian sau , router n y s chuyn tip gtin n ch. Vi hai cch sau, gi tin c nh ng hm thng tch ch.- thc hin ng hm, hai im u ng hm phi l cc nt mh tr c hai giao thc. Khi cn chuyn tip mt gi tin IPv6, im ng hm s ng gi gi tin trong mt gi tin IPv4 bng cc thm phm u header IPv4 ph hp.- Khi gi tin IPv4 n im cui ng hm, gi tin IPv6 s c tch rax l ty theo kiu ng hm.

Ipv4host host


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IPv6 header Data

IPv4 header IPv6 header Data

IPv6 header Data

Gi tin ban u:

Gi tin ng hm:

Gi tin ra klhi ng hm

- C hai loi ng hm chnh l ng hm c cu hnh v ng hng.3.2.2.1. ng hm c cu hnh (Configured tunnel)- c im ca ng hm c cu hnh l a ch im cui nkhng c xc nh t ng m da trn nhng thng tin cu hnh trtai im u ng hm.

Hnh 50: ng hm c cu hnh.

3ff:b00:a:1::1

Src=3ffe:b00:a:1::1

192.168.1.1 192.168.2.1

IPv4IPv6

IPv4

IPv6 IPv6Header Data

IPv6 IPv6Header data

IPv4 IPv6 IPv6Header header data

3ffe:b00:a::3

Dst=3ffe:b00:a:3::2 Dst=192.168.2.1

Src=192.168.1.1


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3.2.2.2 ng hm t ng (Automatic tunnel)- c im ca ng hm t ng l a ch im cui ng hxc nh mt cch t ng. ng hm c to ra mt cch t ng vcng t ng mt i. M hnh u tin l dng a ch IPv6 c khun d

c bit: a ch IPv6 tng thch IPv4 m ha thng tin v atrong a ch IPv6.

Hnh 51: a ch IPv6 tng thch a ch IPv4

- Ti im u ng hm, nt mng ng gi s tch phn a chl m a ch im cui ng hm ng gi gi tin.u im:

+ ng hm t ng n gin, cho php hai nt mng IPv6 d d ng kni vi nhau qua kt ni IPv4 hin c m khng cn cc cu hnh bit.

Nhc im:+ Hn ch v khng gian a ch do ph thuc v o khng gian aIPv4.+ Nguy c b tn cng ph hoi bi cc tin tc.

- Do a ch cui ng hm c xc nh ho n to n t ng v ging hm s c gi n a ch IPv4 . Nu khng c c ch kc bit, gi s c mt gi tin c gii dn router ca mng (203.162.7vi a ch IPv6 ch ::203.162.7.255. a ch IPv4: 203.162.7.255 lch broadcast ca mng do , cc gi tin ng hm s c gi ti mtrm trong mng.- Do , cc ng hm t ng thng c han ch s dng. Sau nngi ta xut mt s phng php ci tin nh 6over, 6to4 3.2.3 6over4C ch cho php cc trm IPv6 c lp trn cc lin kt vt l khng c c

router IPv6 hot ng da trn cc gi tin multicast IPv4 nh mt lin ktcc b o. C ch n y cn gi l mng Ethernet o. h tr cc c ch Pht hin lng ging v t cu hnh a ch statemt s cc a ch c phm vi qun tr c s dng. Cc nhm multicas gi lp mt tng lin kt Ethernet. Do , c ch phat hin lng ging (Ngia cc trm IPv6 vi cc trm 6over4 ging nh trong tng Ethernetthng thng. Cch tip cn n y to ra lin kt IPv6 tht trn mt mng

96 bit 32 bit

0:0:0:0:0:0: IPv4 ADDR


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LAN o. im khc bit l cc trm 6over4 v o cng mt min IPv4multicast thay v mt mng chia s ng truyn.

IPv6

IPv6 over IPv4

IPv4

Hnh 52. 6over4

- Vic nh x a ch IPv6 sang a ch tng lin kt c thc hin

giao thc ND. Trong trng hp n y, ty chn a ch tng lin ktngun/ch s dng IPv4 l m tng lin kt. Do , to n b mng IPv4 coi nh mt tng lin kt chia s ng truyn thng qua vic s dng ca ch multicast sau y:

+a ch multicast tt c cc nt mng (239.X.0.1): a ch qun tr nc dng n mi nt mng trong min IPv4 h tr c ch n y.

+ a ch multicast tt c cc rouuter (239.X.0.2): a ch qun tr nc dng n mi router trong min IPv4 h tr c ch n y.

+ a ch multicast solicited-node (239.X.C.D): a ch qun tr nc dng xc nh a ch nt lng ging (C v D l hai byte thp ta ch IPv4).- Trong t c cc a ch n y, X ch nh danh cc b lin kt (thng b192).- S dng tng IPv4 l m tng lin kt loi b c hn ch ca tng vt l vi k hoch chuyn i. Cc trm c th tri trn nhiu min v thm ccch nhiu bc so vi router IPv6.- Cc trm 6over4 nhn cu hnh (a ch lin kt cc b v tin t,


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IPv4 ca router h tr IPv6) s dng giao thc ND trn cc a chmulticast IPv4.- Sau cc gi d liu IPv6 c gi trong cc gi d liu IPv4 vi kigiao thc 41. Chnh cc trm s thc hin ng hm.- u im:

+ Cc trm IPv6 khng i hi c a ch tng thch hay ng hcu hnh. Chnh cc trm s thc hin ng hm. Kin trc c s bgm mt router vi kt ni IPv6 v h tr 6over4, mt mng c khnng multicast kt ni cc trm v router. Trong mi trng , cctrm 6over4 c th kt ni vi cc trm IPv6 khc.+ C tnh m rng nh IPv6 trn hu ht cc phng tin truyn.

- Nhc im:+ Suy gim MTU ca gi tin dn n gim thng lng.+ Trong qu trnh chuyn i, cc router phi qung b t nht hai tit IPv6, mt cho lin kt LAN thc s v mt cho min 6over4. Ngo ira, d i tin t phi l 128 phn bit hai loi tn t cng c kiuFE80::/64.

3.2.4 6to4- 6to4 v bn cht l mt c ch ng hm t ng cho php kt ni mng IPv6 vi nhau thng qua h tng IPv4 ngn cch. C ch n y cc i t ti cc router bin ca mng. Cc router n y phi c a ch IPvto n cc c th nh tuyn c trn mng Internet.a ch IPv6 s dng trong cc mng 6to4 c cu trc c bit v c cpht ring mt lp a ch c tin t FP=001 v gi tr trng TLA=0x000to th nh tin t a ch 2002::/16. Mi mng s c tin t a ch mhnh th nh bng cc kt hp 16 bit tin t chung vi 3 bit a ch IPv4 c

router tng ng. Tin t n y c ln 48 bit v c th biu din didng 2002:V4ADDR::/48.


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Ipv4 Ipv6network

Ipv6network

Ipv6 IPv6Ipv4 IPv6

IPv6network

Ipv4

IPv6network

Hnh 53 : 6 to 4Khun dng ca mt a ch 6to4 nh sau:

FP TLA IPv4ADDR SLAID Interface ID

Hnh 54.. Khun dng a ch 6to4C ch hot ng:

Hnh 55 : C ch hot ng 6 to 4

6 to 4 router 6 to 4 router

192.168.99.1 192.168.30.1

Network Preix: Network Preix:2002: c0a8:6301::/48 2002: c0a8:6301::/48

Type: native IPv6 Type: IPv6 in IPv4 2002:c0a8:1e01::1Dst:2002:c0a8:1e01::1 Dst:192.168.30.1

192.168.30.1


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- Khi c mt gi tin IPv6 vi a ch ch c dng 2002::/16 c gi mt router 6to4, router 6to4 tch a ch IPv4 (a ch Ipv4 va tch chnh l a ch IPv4 ca 6to4 router ch), bc gi tin IPv6 trong gIPv4 vi a ch ch l a ch IPv4 va tch c. Sau , cc gic chuyn tip trn h tng IPv4. Khi router 6to4 ch nhn c gi

gi tin IPv6 s c tch ra v chuyn n nt mng IPv6 ch.- u im:+ Cc nt mng khng bt buc phi dng a ch IPv6 kiu tng thIPv4 nh ng hm t ng.+ Khng cn nhiu cu hnh c bit nh ng hm c cu hnh+ Khng b nh hng bi cc h thng tng la ca mng, ch crouterca mng c a ch IPv4 to n cc c th nh tuyn.

- Nhc im:+ Ch thc hin vi mt lp a ch mng c bit.+ C nguy c b tn cng theo kiu ca ng hm t ng nu phch IPv4ADDR trong a ch ch ca gi tin 6to4 l a ch brohay multicast.- Trin khai:+ 6to4 c h tr trn nhiu h iu h nh nh Linux, Windows 2000.+ Linux: radvd c th cu hnh qung b tin t a ch 6to4.+ Windows 2000: chng trnh 6to4cfg dng cu hnh mng 6to4.

3.2.5. Mi gii ng hm (Tunnel Broker)- Hin nay, mng IPv6 s dng rt nhiu ng hm trn h tng IPvTunnel Broker c a ra gim nh chi ph cu hnh v duy trng hm n y.- C ch n y s dng mt tp cc server chuyn dng gi l Tunnel Broker

cu hinh v duy tr cc ng hm. Chng c th xem nh cc ISP Io cho cc ngi dng kt ni v o Internet IPv4. C ch n y ph hpcho cc trm (hoc site) IPv6 nh c lp mun kt ni d d ng v o mngIPv6.- Cu trc ca TUnnel broker bao gm:

+ Mt server tunnel broker.+ Mt DNS server.+ Mt s cc server ng hm.


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IPv6 IPv4host

IPv4 network

IPv4 network IPv6 network

Hnh 56: Mi trng ng hm- Cch thc thc hin:

+ Cc khch h ng ca dch v Tunnel broker l cc nt mng IPv6 stackkp (host hoc router) kt ni v o Internet IPv4. Trc khi thit lng hm, cn c s trao i thng tin gia Tunnel broker vi khch h nnh xc thc, qun l v thng tin t i khon.

+ Khch h ng kt ni ti tunnel broker ng k v kch hot cc hm. Tunnel broker c th chia s ti cc im cui ng hm trn cserver ng hm. N cng c th ng k tn v a ch IPv4 cang hm pha h, tn ng k trong DNS v l mt trm hay mrouter.

+ Tunnel broker chn mt server ng hm l m im cui ng hthc s. N chn tin t cp pht cho khch h ng (t 0 n 128) v c nthi gian tn ti ca ng hm.

+ Tunnel broker ng k a ch IPv6 cp cho cc im cui ngtrong DNS.

+ Tunnel broker cu hnh ng hm pha server v thng bo cc th

tin lin quan cho khch h ng.- Sau , khch h ng c th kt ni v o mng IPv6 thng qua c ch nhm nh bnh thng.- u im:

+ Qun l tp trung cc ng hm pha server, gim bt chi ph.+ C th s dng cc ISP o trn IPv6.

- Cc Tunnel Broker trn mng Internet:


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IPv4

Internet

+ Freenet6www.freenet6.net + Hurriane Electricwww.ipv6tb.he.net

3.2.6 Dch a ch- Dch giao thc (SIIT v NAT- PT)- Dch a ch v dch giao thc c pht trin trn c s c ch Ntrong IPv4 nhm cho php cc nt mng IPv4 v IPv6 kt ni vi nhau. C

ch n y hot ng trn c s chuyn i cc khc bit gia cc gi tin IPvv IPv6.- Khc bit v a ch: Dch a ch IPv4- IPv6.- Khc bit v phn m u header: Dch giao thc thay i header gi Thit b NAT- PT c c i t ti bin gii gia mng IPv4 vi Ipv6. Cch n y khng i hi cc cu hnh dc bit tai cc my trm v cc schuyn i gi tin ti thit b NAT- PT ho n to n trong sut vi ngidng.- Mi thit b NAT- PT duy tr mt tp cc a ch IPv4 dng nh x yu cu vi a ch IPv6.- NAT- PT c th m rng th nh NAPT- PT cho php s dng mt a ch- IPv4 cho nhiu phin l m vic khc nhau.NAT- PT cng nh NAT cng nh IPv4 khng c kh nng hot ng vicc gi tin c cha a ch trong phn ti tin. Do , NAT- PT thngkm vi c ch Ca khu tng ng dng ALG. C ch n y cho php x cc gi tin ng vi tng dch v nht nh nh DNS hay FTP, ...- u im:

+ Qun tr tp trung ti thit b NAT- PT.+ C th trin khai nhiu thi b NAT- PT tng hiu nng hot

- Nhc im:+ To ln mt im gy li lon single poin of failure ti thit b NAT

PT.- Cc trin khai ca NAT- PT: NAT- PT c th nghim trn cc hiu h nh mng nh:

+ Linux, Free BSD, Microsoft Windows 2000.+ Ngo i ra, n cng l mt phn ca h iu h nh Cisco IOS IPv6 bnbeta vi hai phin bn da trn IOS v11.3 v IOS v12.0. Cc trin khain y c cho nhiu loi router khc nhau.

Hnh 57: NAI- PT

IPv4


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- SIIT (Stateless IP/ICMP Translation Algorithm) l mt chun ca IETF(RFC2765) m t b dch IPv6/IPv4 khng lu trng thi (Stateless).- Tng t c ch NAT- PT ngoi tr n khng cp pht ng a ch Icho cc trm IPv6. Chc nng chuyn i thc hin gia header IPv6 vIPv4. SIIT khng bao gm cc ty chn IPv4 v header m rng trong IPv6.

SIIT cng thc hin chuyn i cc thng ip iu khin ICMP gigiao thc.- i vi qu trnh chuyn i IPv4 sang IPv6, mt a ch IPv4 tm tc gn cho nt mng IPv6.- Cc gi tin n thit bi SIIT s c chuyn i header v a ch tsang cc a ch IPv4-dch (IPv4- translated) v IPv4- nh x (IPvmapped). Mt ac h IPv4-dch tng ng vi mt nuts mng IPv6 cn ch IPv4- nh x tng ng mt nt mng IPv4. i vi chiu ngc li,cc a ch n y s c chuyn i ngc li th nh a ch IPv4.- Do qu trnh chuyn i khng lu trng thi, c th tn ti nhiu bchuyn i gia hai mng IPv4 v IPv6. Khng c s r ng buc mi phintruyn phi i qua mt thit b duy nht nh trong NAT- PT.3.2.7. Mt s c ch khc3.2.7.1 BIS (Bump Into the Stack )- BIS l s kt hp ca hai c ch NAT- PT v DNS- ALG nhng c ct ngay ti cc nt mng IPv6. Qua , cc ng dng trn cc trm IPv4c th kt ni vi cc trm IPv6.- u im:

+ H tr nhanh chng v n gin cc ng dng IPv4 c th kt ni vicc nt mng IPv6 khc.+ C i t ngay trn tng trm nn khng ph thuc v o mt thit b

trung gian nh NAT- PT.- Nhc im:+ Khng h tr kh nng t cu hnh.+ Cn c i t v cu hnh ring r trn tng nt mng: card mng, cuhnh IP, NAT. Cc thng s cu hnh n y cn c thc hin li mi khc s thay i v topo v a ch mng.+ V lu d i v vi cc mng c kch thc ln, hot ng khng hiuqu v chi ph qun tr cao.

- Trin khai:+Phn mm Tlnet6 h tr BIS hn ch vi mt s card mang h 3Com

NE2000 di dng driver cho card mng do cng ty Hitachi cung cp.Chng trnh hot ng vi Win9x v NT cho php kt ni vi cc trmIPv6.

+Sau7 khi c i t phn driver ca card mng, cn cu hnh cc nh a ch IPv6- IPv4 trc khi c th thc hin kt ni thng qua chng NAT MAnager.3.2.7.2 BIA (Bump Into the API)


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+ Khi mt ng dng IPv4 giao tip vi mt host IPv6 khc, b dch APIpht hin cc h m APG socket m ng dng s dng v gi tng ng cch m API socket IPv6 giao tip vi host IPv6 v ngc li.

+ Qu trnh chuyn i IPv6 sang mt tp cc a ch IPv4 c thctrong module nh x tn (name resolver).

- Kin trc ca dual-stack host s dng BIA.- Module BIA gm 3 phn:+ Module tra cu tn (Name resolver): p ng cc yu c u tra cu tn

min ca cc ng dng IPv4. Khi mt ng dng gii mt truy vn cc bnghi kiu A ti name server, module n y s nhn truy vn n y, phn tch vto ra truy vn tng ng vi tn my cho c cc bn ghi kiu A vAAAA ri gii cho name server.

IPv4 Applications

Socket API (IPv4 , IPv6)

API Translator

TCP(UDP)/IPv4 TCP(UDP)/IPv6

Hnh 3- 13. Kin trc ca dual- stack host s dng BIA

Nu tr li t name server ch c bn ghi kiu AAAA, module n y s ycu module nh x a ch gn mt a ch IPv4 tng ng vi a ch

n y ri to ra mt tr li kiu A cha a ch IPv4 tr v cho ng dng+ Module nh x a ch (Address mapper).Duy tr mt bng cc cp a ch IPv4 v IPv6. Cc a ch IPv4 cmt tp cc a ch n y v cp nht thm mt mc trong bng. Qu trcp nht xy ra trong hai trng hp:

NameResolver

AddressMapper

FunctionMapper


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AF_ INET AF- INET6

sockaddr_in sockaddr_in6

gethostbyname() getaddrinfo()

gethosbyaddr() getnameinfo()inet_ntoa()/inet_addr() inet_pton()/inet_ntop()

INADDR_ANY in6addr_any

Bng 3- 2. Cc cu trc v h m API c bn

- Cc thng ip ICMPv4 c chuyn th nh ICMPv6 v ngc li gingtrong phong php SIIT.

+ Tp cc a ch IPv4 v bng nh x a ch. trnh hin tng dng ht tp a ch IPv4 dn n khng th tip ng cc yu cu trao i vi bn ngo i, BIA a ra cc c ch lb cc mc tn ti lu nht trong bng s dng trong cc yu c u mi.

+ Cc a ch IPv4 ni b. trnh ng v a ch, BIA s dng cc a ch khng c c(0.0.0.0 n 0.0.0.255).

+ Vn khng ph hp gia kt qu DNS (AAAA) vi phin bn ngdng (v4).- Nu server ng dng cha h tr IPv6 nhng chy trn mt my c h tr IPv6 v c tn di kiu bn ghi AAAA trong DNS, ng dng client c thkhng kt ni c vi server do c s khng ph hp gia bn ghi kt quDNS (AAAA) vi phin bn ng dng server (IPv4).- Mt trong cc gii php l th tt c cc a ch trong DNS v khng kthc ngay sau ln th u tin. iu n y c th ng dng bi s m rnmodule tra cu tn v b dich API trong BIA. BIA thc hin lp cng vitm kim cc a ch hot ng s dng bi cc ng dng khc bn ngocc a ch tr v t name server.3.2.7.3. C ch chuyn i hai giao thc (DSTM)- C ch n y cho php kt ni cc nt mng stack kp (IPv6/IPv4) trn mmng IPv6 vi cc nt mng IPv4 xa. DSTM khng p dng c cho cc

nt mng ch h tr IPv6.- DSTM cp mt a ch IPv4 to n cc tm thi cho nt mng IPv6 v sdng ng hm IPv4-in-IPv6 truyn gi tin IPv4 trn mng IPv6.- y l c ch hai chiu, qu trnh truyn thng c th bt u t nt mIPv6 hoc nt mng IPv4.- Cch thc hot ng:


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+ DSTM c c i t trn tt c cc nt mng trong mng IPv6 v routebin gii gia hai min IPv6 v IPv4. N cng s dng DHCPv6. Do vyDSTM cn mt server DHCPv6 v cc client ti mi nt mng.

DHCP

Border router(Y) IPv4IPv6

IPv4 only node (Z)

Dual stack node (X)

DNS

Bng 3- 3. C ch chuyn i hai giao thc (DSTM)

- Chc nng cc b phn nh sau:+ DHCPv6 Server: Cp a ch IPv4 tm thi cho cc nt mng mugiao tip vi nt mng IPv4 xa. N cng duy tr s nh x gia a chIPv4 v IPv6. h tr DSTM, DHCPv6 phi h tr mt ty chn micho php nt mng IPv6 nhn a ch IPv4 tm thi v thng bo chpha client bit a ch IPv6 ca cui ng hm.+ DSTM daemon: S dng DHCPv6 client trn nt mng yu cu ch IPv4 to n cc mi khi khi to truyn thng.

+ Giao din ng hm ng (DTI): y l mt giao din IPv4 trongnut stack kp cho php truyn cc gi tin IPv4 mt cch trosut trn mng IPv6. Cc gi tin chuyn n giao din n y c bctrong gi tin IPv6 v c gii thng qua giao din IPv6 n router bimng.


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Chng 4:Th nghim v c i t IPv6 trn windows 98 v windows 2000

4.1 C i t trn windows 98:- Bn thn windows 98 khng h tr IPv6. kt ni c vi nt mngIPv6, mt trong cc c ch chuyn i cn c c i t, th d Trumpe winsock.+ Trumpe winsock :

Chng trnh thay th th vin Winsock trong windows cho phwindows 98 kt ni IPv6.

Phin bn t 4.1 h tr IPv6 cho cc h iu h nh win9x vWin NT4.1. y l mt phn mm shareware do h nh Trumper sn xutC ch hot ng ca phn mm da trn vic thay i th vin wintrong windows h tr IPv6. Cc h m tng thch winsock 1.1 khntng thch winsock 2. Chng trnh c sn cc tin ch nh p

traceroute kim tra kt ni, dig tra cu tn min DNS.Cu hnh a ch IPv6 c th c thit lp trong chng trnh hcu hnh .4.2 C i t trn windows 2000:- Windows 2000 Service Pack 1 tr ln h tr IPv6 di dng phin bn th nghim c c i t ring.- B chng trnh bn th nghim cho IPv6 trn windows c cung ctrn mng vi tn file: tpipv6- 001205.exe.- Yu cu mc nh h thng: Windows 2000 SP1.- C i t:+ Chy file setup.exe+ C i t thm giao thc mng IPv6 : Microsoft IPv6 Protocol-Ngo i ra b c i t cng cha cc cng c khc nh:+ ipv6.exe: Hin th thng tin v giao thc IPv6. Ta c th xem trng thcc giao din, cc cache lng ging, cache kt gn, cache ch v bng tuyn.+ Trancert6.exe: Tng t trancert.exe trong IPv4 .+ Ping6.exe: Tng t ping.exe trong IPv4.+ ttcp.exe: Dng gi cc gi tin TCP/UDP gia hai nt mng. H tr chai giao thc.+ 6to4cfg.exe: S dng cu hnh kt ni kiu 6to4.

+ ipsec6.exe: Cu hnh cc chnh sch an ninh IPsec.- Cc ng dng:+ HTTP client: Th vin lin kt ng mi wininet.dll cho php webrowser IE c th kt ni n c cc web server IPv4 ln IPv6.+FTP client:Ftp.exekt ni n cc FTP server ca c hai giao thc.+ Telnet client: H tr c IPv4 ln IPv6.


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+ Telnet server: H tr c IPv4 ln IPv6.- i vi cc h thng win 2000 SP2 c th c i t theo cc bc sau:+ Sau khi gii nn chng trnh tpip6-001205.exe v p mt th mc, ta chchng trnh setup.exe vi tham s setup-x gii nn cc file v o mt thmc.

+ Sa file Hotfix.inf.+ NTServicePackVersion=256+ NTServicePackVersion=512+ Chy chng trnh Hotfix.exe+ Sau thc hin cc bc cn li nh bnh thng.


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Chng 5Kt lun v hng pht trin tip theo

Kt lun

- y l mt vn nng bng ca to n th gii ni chung v ca ViNam ni ring. Khi chuyn sang s dng IPv6, ta c th d d ng trong vitruy cp v o cc a ch trong mng Internet rng ln. Hn na cc thit kt ni trong mng c th kt ni vi nhau v thay i thng tin vi nhauTuy nhin kiu mng li n y hot ng, mi thit b trong mng cphi c mt a ch IP (l thng s ch v tr ca cc thit b trn mng)5.2 hng pht trin tip theo:- Hin nay tai Chu mt phn k hoch E Japan initiative c mc chchnh l a ng nh cng ngh thng tin Nht Bn vn ln h ng u. Chph Nht Bn t i tr cho Hi ng xc tin IPv6 (IPv6 PromotionCouncil) thit lp th nghim giao thc mi trong mng ca mn s nhcung cp. Information Service International Dentsu (ISID)- cng ty tch hh thng ti Tokyo- xy dng mng IPv6 trong cng ty n y, kt ni vihn 5.000 h thng. i din nhm nghin cu ISID cho bit : d trikhai IPv6 nhng qu trnh chuyn i trong cng ty din ra cn chm.thng mng c hai ngn phn mm d nh cho IPv4 v IPv6 tin h nh honhp tng bc. IPv6 vn cn cn pht trin tip vn bo mt kchy ho n to n trn IPv6 s mt i mt s tnh nng bo mt ca IPv4. Htr IPv6 tng la (firewall ) chng hn s l mt i hi tin quyt khccng ngh mi n y c chp nhn rng r i hn trong tng lai.

- Tuy nhin Cico nh sn xut b nh tuyn chnh thng tr th gii mch cung cp kh nng IPv6 cho cc b nh tuyn qua cc phn mmd nh ch s gii thiu phn cng h tr IPv6 trong nm nay. Ring hiu h nh Windows XP hin c sn c tnh nng IPv4 v IPv6 , ch ydng xy dng sn s ng IPv6. H iu h nh my ch hin ti ca Window2000 Server cng c sn mt b cng c pht trin phn mm d nh cho cng dng v thit b IPv6.- V o cui nm 2002 Microsoft cng gii thiu tnh nng IPv6 tng bnng cp d nh cho Windows XP v th h h iu h nh my ch k windows. Net Server. H ng Sun Microsytems h tr IPv6 trong phinbn Solari 8 pht h nh trn th trng ngay t nm 2000. Nu mt my chSolaris 8 c cm v o mng IPv6, n c th t ng trao i ccs gi IPv6.- Ring trong h iu h nh Linux, giao thc IPv6 cha c tch hp snhng n c cung cp km theo trong phin bn Red Hat khng chnthc cung cp h tr cho th nh phn IPv6. Mt s ng dng c bn, nhtruyn tp tin, email, DNS, ang c iu chnh c th l m vi


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giao thc mi, tip sau d s l nhng ng dng phc tp nh c s d liuv chng trnh CAD.- gia dng chc chn sl mt trong nhng thit b u tin c lchn kt ni v o mngIP v6, khi m vic cung cp a ch IPv6 tr ln d ng v n l v hn m li rt an to n bi tnh bo mt cao m IPv4 khng

c. Thm ch ngay by gi, cc nh sn xut gia dng ang trin khathut kt ni cc sn phm ca mnh vi mng to n cu.- Rt c th n mt ng y n o tt c cc thit b s dng dch v khdy (LAN), cc server gia nh, automobile telematics v cc vt dng khu s c kt ni vi nhau.

IPv6 bao gi c s dng ti Vit Nam?

- Trn thc t ti Vit Nam, cc doanh nghip cung cp dch v Interncha nhn thy s c n thit phi s dng n IPv6 v khng bc xc tr

nguy c cn kit tn min. Cho n thi im n y, Vit Na cha c hng thc y ng dng IP6 v cha c phn b vng a ch IPvQuc t. Hin ti ch c VNPT v NetNam tham gia t itrin khaith nghim mng IPv6 Vit Nam v kt ni mng IPv6 Quc t . VNPTcng l n v u tin yu cu a ch IPv6 v cng l doang nghipnht tiu chun cp pht a ch IPv6. Theo cc chuyn gia th vn ra i vi Vit Nam hin nay l phi xc nh b i ton liu c sc pht trin cc loi dch v v ng dng mi i theo nn tng ng dng IPvhay khng?- Hin trung tm Internet Vit Nam (VNNIC) cng thc hin mt hot ng nghin cu v cng ngh v chnh sch IPv6 ca khu vc vQuc t.- VNNIC ang xem xt phng n trin khai thit lp mng th nghiIPv6 cng cng c th da trn c s h tng c sn. theo ngh cVNNIC, cn phi c chnh sch khuyn khch pht trin cng ngh pcng, phn mm v ng dng IPv6. Ngo i ra, VNNIC cn ngh cn t cho nghin cu pht trin cc ng dng IPv6. Bn cnh , Chnh phcn phi c chin lc lu d i pht trin IPv6 bt kp s pht trincng ngh. Theo mt quan chc ca B bu chnh Vin thng trong chilc BCVT n nm 2010 cng cp n vic pht trin a min IPv6. V vy ngay t by gi B cng s phi xem xt c

chng, chnh sch i vi vn d pht trin IPv6 Vit Nam.

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