Nghiên cứu một số vấn đề tấn công lớp mạng của mạng tùy biến không dây.PDF

Phan Trung Nghia A08348 CHU'ONG I. TONG QUAN YE MANG MANET 1.1. Gifri thieu Cac thiet bi di dOng nhu cac may tinh xach tay, vbi dac tnmg la cong suit CPU, b0 nh6 km, dung lin;mg dia hang tram gigabyte, !chi nang am thanh da phucmg tier' va man hinh man da tr6 nen phO bien trong dbi song hang ngay va trong cong viec. Ding thin, cac yeu cau ket nOi mang de sir dung cac thiet hi di dOng gia tang din ke, bao gOm viec hi trq cac sari phim mong v8 tuyen dtra tat v8 tuyen hoac hOng ngoai ngay can nhieu. Vei kieu thiet bi dien toan di dOng nay, thi gift nhang ngubi sir dung di dung luon mong muOn c6 su chia se thong tin. Met mang thy bien la met tOp hqp cac thiet hi di dOng hinh thanh nen met mang tom thin ma {thong can str trq &Op cua bit kj , sr quart 15 , top trung hoac cac dich vu ho trq chuan nao dun:mg co ten mpg dien rOng ma a d6 cac thiet bi di dOng co the ket not duqc. Cac node duqc to do di chuyen va thiet 10p no thy Sr. Do do, topo mang khong day co the thay dOi met each nhanh chong va !thong the du bao. Hinh 1.1: M6 hinh mot mgng MANET 8 Phan Trung Nghia A08348 1.2. Ljch sir Nguyen 1Y lam viec caa mang Adhoc bit nguOn tir nrun 1968 khi ck mang ALOHA ductc thvc hien. Tuy the tram lam viec la c6 djnh nhtmg giao thirc ALOHA da thvc hien viec quern ly truy cap kenh truyen dm% dang phan tan, day la co sir ly thuyet de phit trien ky thuot truy cop kenh phan tan vao mang Adhoc. Nam 1973 to chirc DARPA di bit du lam viec tren mang vo tuyen g6i tin PRnet. Day la mang vo tuyen g6i tin da chang dAu tien. Trong d6 cic node kip tic veri nhau de girl dU lieu ten mOt node nim a xa khu vvc ket not th6ng qua mOt node khic. N6 cung cap co the cho viec quern ly hoat Ong tren co sir tap trung va phan tan. MOt lqi diem dm lam viec da chang so yeti don ching la triAn Thai da chang tho thuon lqi cho viec dung lai tai nguyen kenh truyen ve ca khong gian, thin gian va giam ning Itging phit can thiet. Sau d6 co nhieu mang v6 tuyen ea tin phat trim nhtmg cic hg thOng khong day nay van chin bao gia tai thy ngtrai dung cho den khi chuan 802.11 ra IEEE di dOi ten mang vo tuyen gin tin thanh mang Adhoc. 1.3. irng dyng Quilt; Hogt dOng phi tap trung ciut mpg Adhoc va khong phi thuOc vio co so ha tang mang la mOt yeu to thiet yeu doi yeti  vvc quern sv, nhat la trong the tithing hqp chien  kh6c lief , citc co se ha tang mang bj phi hity. Lk nay mang Adhoc la Iva chqn s6 mOt de cac thiet bj truyen thong lien lac yen nhau *it each nhanh chimg. Truying hpc: Chung ta cling co the thiet lap cic mang Adhoc trong true:mg hoc, lop hoc, thu vien, san truing, de ket not the thiet bj di dOng (laptop, smartphone) lai yeti nhau, giup sinh vien, they co giio c6 the trao dal bai mOt each nhanh cheong thong qua mang adhoc vira tho. Gia clink: Tai nha ban co the tao nhanh mang Adhoc de ket nil the thiet bj di dOng dm ban yeti nhau, nher d6 ta co the di chuyen ttr do ma van dam him kat not truyen taidfr Kit net ccic thiit bj din ni vbi nhau: Trong nhltng nam ten khi ma cic thiet bj din tir deu duqc gin clic giao tiep khong day, glop chting c6 the trao d6i giao tiap 9 Phan Trung Nghia A08348 voi nhau thi mpg Adhoc se rat phu hqp de tp nen mOt he th6ng thong mirth co kha flan lien ket yeti nhau. 1.4. Clic d$c dam ctia mang MANET Thiet bj t r tri dau cu . & (Autonomous terminal): trong MANET, mOi thiet bj di dOng diu cuOi la mOt node tv tri. NO c6 the mang chirc niing cita host va router. Ben canh kha rang xir 15 , cc ban ctia mOt host, et node di Ong nay c6 the chuyen d6i chfre nang nhu met router. Vi vOy thiet bj du emit va chuyen mach la khong the phan biet ductc trong mpg MANET. Hoot &Ong phan tan (Distributed operation): vi khong c6 he then mpg ha tang cho ten tam kiem soat hot dung dui mpg nen vied kiem soat va quan ly ho#t dOng ciut mang duqc chia cho cac thiet bi dau cuOi. Cac node trong MANET doi h6i phai c6 sv cong tic yeti nhau. Khi can thiet cac node hog Ong nhu mtjt relay de thvc hien chat 'tang cita minh. Vi dv nhu djnh tuyen va bio mitt. Dinh tuyen da chtemg (Muftihop):thusia town di/1h tuyen kh6ng day co ban co the (filth tuyen mOt chong va nhieu ch(ing dva vio the thuOc firth lien ket khac nhau va giao thlic djnh tuyen. Singlehop MANET den gian hen multihop a van de cAu true VI thvc hien vei chi phi thip hen, it ling dung. Khi truyen cac gei dfr lieu tir nguOn den dich trong phiun vi truyen tai true tiep kh8ng day, cac goi du lieu se ductc chuyen tiep qua mOt hok nhieu nut trung gian. Topo wing dOng (Dynamic network topology): vi cac node la di dOng nen au true mpg eel the thay &it nhanh va kh8ng biet twee, cac ket not giara cac thiet bi c6 the thay del theo th&i gian. MANET se thich img tuyen va dieu kien Ian truyen giOng nhu nniu di dOng va the node mpg di dOng. Cie node trong mang thiet lop djnh tuyen dung v6i nhau khi chimg di chuyen, hinh thanh mang rieng dui cheng. Han nita mOt nguari dfing trong MANET co the khong chi hog gong trong mang ken di dOng d#c biet, ma con c6 the yeu au truy cep vio mpg cong cong nhu Internet. Giao dOng ve dung lutmg lien kit (Fluctuating link capacity): ban chat ti le Mt bit cao dui ket not khong day an quan tarn trong mpg MANET. Ket not tir dau emit nay den du cuOi kia co the duqc this se qua mot vai ch#ng. Keith giao tit? a 10 Phan Trung Nghia A08348 dau cuOi chju inh hoeing dm nhieu, hieu img da dubng, sg giao thoa, va bang th8ng clut no it hon so vol mpg co day. Trong mot vai tinh hueing, truy cep cua hai nguai dung co the qua nhieu lien ket khong day vi the lien ket nay co the khong dOng nhAt. rdi uu hoa cho thiet bf dint mai (light-weight terminals):trong hAu het cac twang hgp cac node mpg MANET la thiet bi dau cu6i vat toe de xir 15 , curt CPU thip, b0 nhe it va ltru ter dien nang it. Vi v3y an phai tOi tru hem cac thuet man va car che. 1.5. Kieu kit ntii va chi (10 host dOng 1.5.1. Cic kieu ket not topo mpog a) Along may cha di Ong CS topo nay cac thiet bi chi lien ket voi met may chit duy that, cac thiet bi lien kat yen may chit W tan mit% aware au Maps Hinh 1.2: Mang may chn di tong 11 Phan Trung Nghia A08348 b) Mgng c6 cac thiit tn di Jong khong clang nhiit topo nay cac may co the lien ket trip tiep yeti nhau trong pham vi phi song cua minh. S Hinh 1.3: Mgng cac that obi di Ong khong dung nhiit 1.5.2. Che dq hoat Ong a) Chi dO IEEE-Adhoc the do nay the node di Ong truyen thong true tiep yea nhau ma kh8ng an co so tang, cac lien ket !thong thuc hien qua nhieu cheng. Hinh 1.4: Chi dO IEEE-Adhoc 12 Phan Trung Nghia A08348 b) Chi do co so. ha king Che do nay mpg bao gom the diem truy cep AP c6 djnh va cac node di dOng tham gia vao mang, dive hien truyen thong qua the diem truy cep. Cac lien kit có the thwc hien qua nhieu chAng v the dO My. Binh 1.5: Chi do hg tang 1.6. Phan loni MANET 1.6.1. Theo giao thin a) Single-hop Mpg MANET djnh tuyen Singel-hop 11 logi mpg adhoc don gifin nhAt. Trong do, tat ca cac node deu nim trong tang met yang pith song, nghin la the node co the ket not nye tiep yeti nhau ma kung can node Ming gian.Ctic node có the di chuyen ty do nhtmg chi trong phqm vi nhAt djnh du de the node lien ket trkrc tiep yeti cac node khic trong mang. 13 Phan Trung Nghia A08348 Hinh 1.6: Giao thee don bribe b) Multi-hop Day la me hit ph6 Bien nhat trong mpg MANET, no khic vai mo hinh trate la cac node co the ket not vm cac node Mt trong mang ma co the 'thong can ket not tnrc tiep sten nhau. Cie node c6 the djnh tuyen yen cac node khfic thong qua cac node trung gian trong mang. De mo hinh nay host dOng mot each hoin him thi can phai c6 giao thfrc djnh tuyen phu hop vei mo hinh mpg MANET. Hinh 1.7: Giao thee da bribe 14 Phan Tnmg Nghia A08348 c) Mobile Multihop Me hinh nay cling tuang nr vei mo hinh multi-hop nhung sv khfic biet a day la mo hinh nay tap trung vao the ling ding co tinh chat thin gian thvc: audio, video. 1.6.2. Theo chile ning a) Mgng MANET cldng cap (Flat) Trong kien true nay tit ca the node co vai fro ngang hang yen nhau (peer to peer) va cac node d6ng vai tr6 nhu cac router dinh tuyen de lieu g6i tren mpg. Trong nhOmg mpg Ion thi eau true Flat Wang to:Si uu hea viec se ding tai nguyen bring thong dm mpg vi rilang tin dieu khien phai truyen tren toitn be mpg. N6 thich hqp yen nhemg topo co the node di chuyen nhieu. b) Mgng MANET pluin cap (Hierarchical) Day la mo hinh sir dgng phi) bien 'that. Trong mo hinh nay thi mang chia thimh cac domain, trong mei domain bao gem met ho4c nhieu cluster mei cluster Chia thanh nhieu node. CO hai logi node lit master node va normal node. Master node 11 node quitn trj co nhiem vu truyen du lieu dm the node trong ding cluster den cac node trong cluster khic va ngugc Igi, not each khic no nhu met gateway. Normal node la cac node nam trong cling met cluster. NO co the kat nOi yeti cac node trong cluster hoac ket Wri cluster lchfic thong qua Master node. Vei cac co the tren, mpg sir dung tai nguyen bang thong hieu qui bon vi cac tin Stan chi phai truyen trong met cluster. Tuy nhien vier quan 15 , firth chuyen deng cua cac node tre n'en phirc tap hon. Kien true m(mg phan cap thich hqp cho cac mang co firth chuyen deng thip. 15 Phan Trung Nghia A08348 Hinh 1.8: Mang MANET phan cap c) Mang MANET kit hqp (Aggregate) m6 hinh nay met mang gem nhieu Wing (zone), met Wing g6m nhieu node. M8i node bao gOm hai mix topo: topo mac thitp (node level), va topo mat cao (zone level).MOi node dic trung bin: node ID va zone ID. Trong met zone c6 the tip dung kien true ding cap hoc phan cep. Hinh 1.9: Mang MANET kit hqp 16 Phan Trung Nghia A08348 1.7. Wet lu#n Chuang nay cung cap nhOng kien thic tong quan ye ming thy bien adhoc not chung vi ming MANET not rieng, tir cac doe diem, cite kieu ket not Ara the dO hog clOng, phan !oil dira UM ' mOt set giao thfrc vi chire nitng lam ca so cho cac nOi dung trong chuang sau. CHIJONG II. DJNHTUYEN VA CAC DE DQA BAO MAT TRONG MANET 2.1. Viin de djnh tuyen trong mting MANET 2.1.1. Cac think toin djnh tuyen truyen thOng Cie giao thus djnh tuyen truyen thing sir ding hai giiti thuot: • Distance Vector: RIP, IGRP, Nguyen tic hog dOng: mr3i router se giri bang djnh tuyen cis minh cho tat ca cac router dirge not trite tiep veri no. Cie router de so sanh yeti bang djnh tuyen ma minh hien co va Iciem tra Iai cac tuyen duemg dm mirth veti cac tuyen duang meri diem dirge, tuyen duong nao tei tm han se dirge dim vao bang djnh tuyen. Cie goi tin cap nhit se dirge giri theo djnh IcS , (30 gitly yeti RIP ,90 giay cleti yeti IGRP) UV diem: a ciu hinh, router khong phiti xir 15 , nhieu nen khong Mn nhieu dung lircmg130 nher WI CPU co hie do xit ly nhanh han. Nhugc diem: he thong metric qua don glen (nhu Rip chi la hop-count ) din den vier cac tuyen dtrimg dirge chgn vao bang dinh tuyen chtra phai tuyen duang tot nhit.Vi cac gig tin cep nhit dirge girl theo dinh 16 , nen met lugng Wing th8ng ding ke se IA chiem. Do router hOi tit chum, din den vise sai lech trong bang din!' tuyen gay nen hien tugng yang lOp (loop). • Link State: OSPF, IS-IS Nguyen tic hoot dOng: cac router khong gin bang djnh tuyen ciut minh, ma chi giri tinh trong ctia cac dyeing lien ket trong ca sir dir lieu trong thii lien ket (linkstate-database) dm minh di cho eke router khac, cac router se ap dung giiti 17