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Chuyên đề Nghiên cứu một số vấn đề tấn công lớp mạng của mạng tùy biến không dây giới thiệu tổng quan mạng MANET, các kỹ thuật tấn công và các biện pháp ngăn ngừa trong mạng MANET. Để biết rõ hơn về nội dung chi tiết, mời các bạn cùng tham khảo.
r BO MAO DVC VA DAO T40 TRUtING Dig HQC MANG LONG —o0o CHUYEN DE TOT NGHIEP De thi: Nghien Cot MOt SO Vin De Tin Cong Lop Mpg Cim Mang Tay Bien Khong Day Ciao viers hirerng dan Sinh vien Ma sinh vien Chuyen nginh : Th.S Holing Trung Minh : Phan Trung Nghia : A08348 : TC - Mang vien thong DINO - 2013 • Phan Trung Nghia A08348 MU C L U C MUC LUC THUAT NG° VIET TAT DANH MIX HINH ANH LOI MO DAU LOI CAM ON CHUONG I TONG QUAN VE MANG MANET 1.1 Gild thieu 1.2 Lich sir 1.3 tog dung 1.4 Cic dAc diim cha luting MANET 1.5 Kieu kit nai vi chi di kW ding 1.5.1 Clic Idiu kit [Jai topo mpg 1.5.2 Chi di) hogt ding 1.6 Phfin lohi MANET 1.6.1 Theo giao thin 1.6.2 Theo chirc nAng 1.7 Kit Ian CHUONG II DINH TUYEN VA CAC DE DQA BAO MAT TRONG MANET 2.1 Vain di djnh tuyin myng MANET 2.1.1 Clic that Win djnh tuyin truyin thing 2.1.2 Cu yeti au chinh Ai vii viec dish tuyin ingng MANET 2.1.3 Phan loqi cic k9 that djnh tuyin 2.2 Cie giao they djnh tuyin chlnh ming MANET 2.2.1 Giao thirc djnh tuyin DSDV 2.2.2 Giao thic djnh tuyin OLSR 2.2.3 Giao thirc djnh tuyEn AODV 2.2.4 Giao thirc djnh tuyin DSR 2.2.5 Giao they djnh tuyin TORA 2.3 Cie mai de don Igo mfit mpg MANET 23.1 Ting ctuan 23.2 Clic diem yin cis mimg MANET 2.3.3 Clic cuQc tan ding vio MANET 2.3.4 CAc bin phi!) dii phi 2.4 Hiring nghien cfru twang lai 2.5 KM lufin CHIJONG III TAN CONG LOP MANG VA LOP TRUYEN TAI TRONG MANG MANET 3.1 Gild thieu 3.2 Cu colic tin ding lop infog ching Ihi MANET 3.2.1 Tin cong Wormhole 3.2.2 Tin cfing hi den (Blackhole) I 8 9 10 11 11 12 13 13 15 17 17 17 17 18 19 22 22 24 25 28 29 31 31 32 34 41 48 49 50 50 51 54 56 Phan Trung Nghia A08348 3.2.3 Tan cling pink typ (Byzantine) 3.2.4 Tan cong clan dap (Rushing) 3.2.5 Tan cong tieu hao di nguyen 3.2.6 Cie tan thong chitin gilt lien kit vi Wm gii lien kit 3.2.7 Tan cong phAn hid 3.3 Cie cuac tan cong 616.p giao van chang lyi MANET 3.3.1 Tan cong trin ng$p gni SYN 3.3.2 Tan cong chitin dot phien 3.4 Throng nghien niu tuong lai 3.4.1 Nein ngfra vi phlt hifn :em nhap 3.4.2 CIc ky that ma h6a 3.43 Khi Ming phyc 116i 3.5 Kit lu$n TAI LIEU THAM KHAO 59 59 60 61 62 63 63 64 65 66 66 67 67 68 Phan Trung Nghla A08348 THU T NGU VIET TAT Tir viet tit ACK AODV AP CA CREP CREQ DARPA DEMEM DoS DSDV DSR EKE FSM GPS IDS IEEE IGRP IS-IS KS LMR MAC MANET MPR OLSR Nghla fling &nil Nghla hang vie ViC nhon Acknowledgement Adhoc On-demand Distance Giao thirc djnh tuyen vecto khofing each theo yeu cau Vector Diem truy nhp Access Point Ca quan chirng nh$n Certification Authority Phim hei xic talon tuyen Route confirmation response Route confirmation request Yeu au xac nh?n tuyen Cuc nghien mitt cfic dv an Defense Advanced phi:mg thit cai tien Research Projects Agency Trao deli tin th6c dly bed Distributed Evidence chimg cu phan tan Driven Message Exchange Tir chi Bich vy Denial of Service Giao thfrc djnh tuyen vecto Destination-Sequenced Ichoing each tan ty dich Distance-Vector Giao thfrc djnh tuyen nguem Dynamic Source Routing deng Trao del kh6a ma hem Encrypted Key Exchange May tinh tong hp the Finite State Machine He thOng dinh vi tom cau Global Positioning System Intrusion Detection System He thong phat hie'n xam nh3p VIP Id nghe dien vi dien tir Institue of Electrical and Electronics Engineers Giao thfrc djnh tuyen thing Interior Gateway Routing vio nei Protocol Giao thirc djnh tuyen he Intermediate system-tothong trtmg gian Intermediate system May chithquan Mpg Key Server Dinh tuyen di Ong trvng so Light-Weight Mobile thep Routing Ma )(tic thvc tin Message Authentication Code Mang tigh biett di dOng Mobile Adhoc Network Kip chuyen tiep da diem Multi-Point Relays Giao thirc djnh tuyen Van Optimized link state thai lien ket tth uu Routing Phan Trung Nghia A08348 OSPF Open Shortest Path First RDP CEP RIP Route Discovery Protocol Route Reply Routing Information Protocol Route Request Route Error Robust Source Routing RREQ RRER RSR SAODV SPF Sercure Adhoc On-demand Distance Vector Shortest path first SYN TC Statistically Unique and Cryptographically Verifiable Synchronize Topology Control TCP Transport Control Protocol UDP User Datagram Protocol VANET WSN Vehicular Adhoc Network Wireless Sensor Network SUCV Giao thIrc djnh tuyen duo ng ngin nhat dim tien ma , Giao they kham phi tuyen Tin phin he'i tuyen Giao thin thong tin djnh tuyen Tin yeu cau tuyen Tin for tuyen Giao thirc djnh tuyen nguon math me Giao thirc vector khoing cash theo yeu cau bio not Thuat than tim diking ngan nhat Kiem tra ma hes vi thOng ke nhat Deng be h6a Dieu khien de hinh Giao dare dieu khien giao van Giao thirc geli du lieu ngueri dung Mang xe ce tily bien Mang cam bien khong day Phan Trung Nghia A08348 DANH MVC H1NH ANH Trang Hinh 1.1: MS hinh met mpg MANET Hinh 1.2: Mang may chi' di dOng 11 Hinh 1.3: Mang cac thiet bi di ding khemg d6ng nhat 12 Hinh 1.4: Che dO IEEE-Adhoc 12 Hinh 1.5: Che dO tang 13 Hinh 1.6: Giao thirc don buoy 14 Hinh 1.7: Giao thirc da bare 14 Hinh 1.8: Mang MANET phan cap 16 Hinh 1.9: Mang MANET kit hcfp 16 Hinh 2.1: Cac giao thirc dinh tuyen MANET 22 Hinh 2.2: Dinh tuyen DSDV 23 With 2.3: Quy trinh chuyen tiep gen tin sir dung MPR 25 Hinh 2.4: OLSR ngtin chin vong litp bing each sir dung MPR 25 Hinh 2.5: Qua trinh kham pha tuyen AODV 26 Hinh 2.6: Giao thirc DSR 28 Hinh 2.7: Lien kit gifra cac node mpg MANET 32 Hinh 2.8: Met cu0c tan tong lam gia RREP 39 Hinh 2.9: Tin cong Wormhole 41 Hinh 3.1: Co the dm melt ctujc tan cling dinh tuyen don gifin 52 Hinh 3.2: Kich ban met cuoc tan cling Wormhole 54 Hinh 3.3: Kich ban met cuec ten ding 1-16 den 57 Hinh 3.4: Topo mang MANET "M" thwc hien tin ding dOn dip 60 Hinh 3.5: Co the bit tay ba Were TCP 63 Hinh 3.6: Clic btrecc gay m bAo TCP-ACK 64 Phan Trung Nghia A08348 Loi MO D AU Cimg yeti stir phat triers mph me cita khoa hac tong nghe, d#c biet la tong nghe thong tin IA dien tir vien thong, nhu au trao dei thong tin va der lieu cita ngtreri ngly clang cao Mang may tinh dang dang vai tro quan tang mai Milt vgc cua doi sing Ben earth nen tang mang may tinh hint tuyen oft day, mang khong day tir den da the hien dugc nhcmg tru diem vugt trOi ve str lien dung, firth host Cie thiet bj di dOng new ding nho gun hat, kha nang xir Ii va Itru trey ding tang len dim den sg bimg nfi cita cac mang thy hien khong day not chung cling nhu mpg thy bien khong day di dOng (MANET) not rieng Chang cang dugc sir dung rang di va di vao cac ling dung thgc to cuOc sting Cling giOng nhu a the mpg tiger' thong bao mit la yin de nit quan tang mong MANET, han nfra cac doe diem cita minh cling yen mai trutmg lien ket khong day ma chimg cang de bj tin cong Chuyen de em xin giesi thieu tong quan ye mang MANET, the ky thuilt tin ding va cac bien phap ngAn ngira mong MANET NOi dung chuyen de dugc Chia ba chuang Chuang I: glen thieu ye mang no, bien not chung va mpg MANET not rieng bao gam ljch sir phat triers, img dung, cac dOc diem, the hoot dOng va ket tut Tir cho to mat cai thin tong quit ve mang MANET Chuang II: tim hieu ve cite giao thirc dinh tuyen mong thy bien kh8ng day, cac diem yeu cita mong MANET, cac de daa bao mat va mat set bien phap ngitn ngira chung (bao mat dinh tuyen vi cac he thong phat hien xam nhop) Chuang III: t#p trung phial tich cac cuOc tin conga tang mpg va giao von nhim vao MANET cling nhu nu nhtrqc diem cita cac phuang phap phong chting M#c di da co ging nghien ciru de holm chuyen de cita minh, nhtmg kin thirc va thtti gian httn the nen chuyen de kh8ng birth khoi nhemg thieu sot Em rat mong nhOn dirge cac dong gap, nhOn xet tir phia thity c6 va cac ban! Em xin chin cam an! Hi NOi, 08 thing 07 nim 2013 Sinh vien thgc hien Phan Tnmg Nghia Phan Trung Ngtifit A08348 Lta CAM ON Em xin chin thimh cam on dilly giao, Th.S Hoang Trong Minh, ngu&i da ten tinh huong den va &up der em sad qua trinh thtrc hien chuyen de Em xin girl loi cam on sau sic den clic they, co trtrOng dai hoc Thing Long di ten tinh truyen dot kien thee than gian em hoc tap tai inning NM -mg kien thirc me em nhan dirge tren giartg dui:mg dai hoc se la hanh trang &up em vUng buoy Prong lai Em xin gfri Ibi cam on den gia dinh va ban be, nhettg ngtreri luon b ben em, giim da ye to dieu kien cho em holm chuyen de Ha Nei, ngly 08 thing 07 nim 2013 Sinh vien thtrc hien Phan Trung NghTa 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 da phucmg tier' va man hinh man da tr6 nen phO bien dbi song hang va 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 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 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 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 Phan Trung Nghia A08348 1.2 Ljch sir Nguyen 1Y lam viec caa mang Adhoc bit nguOn tir nrun 1968 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 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 van chin bao gia tai thy ngtrai dung cho den chuan 802.11 IEEE di dOi ten mang vo tuyen gin tin mang Adhoc 1.3 irng dyng Quilt; Hogt dOng phi tap trung ciut mpg Adhoc va khong phi thuOc vio co so tang mang la mOt yeu to thiet yeu doi yeti vvc quern sv, nhat la the tithing hqp chien kh6c lief citc co se tang mang bj phi hity Lk mang , Adhoc la Iva chqn s6 mOt de cac thiet bj truyen thong lien lac yen *it each nhanh chimg Truying hpc: Chung ta cling co the thiet lap cic mang Adhoc 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 ma van dam him kat not truyen taidfr Kit net ccic thiit bj din ni vbi nhau: Trong nhltng nam ten ma cic thiet bj din tir deu duqc gin clic giao tiep khong day, glop chting c6 the trao d6i giao tiap Phan Trung Nghia A08348 sai cac tin lei tuyen va ngiin chen node nguem (node nan nhan twang hgp nay) tir lien ket vei dich Tan cong o giai dogn chuyin tiep citi lieu: rid nhieu cac cuec ten cong cheng lai giao thee djnh tuyen MANET lqi dung chirc nang chuyen trap thong tin cim cac node MANET or lap mang NhOng ke ten cong trtrimg hgp IchOng lam gian doan qua trinh khiun pha tuyen vaiho(tc tri Thay vio d6 chfing san sang phi v0 the gOl dit lieu chuyen tiep theo thong tin bang djnh tuyen beri mot s6 phtrcmg tien Vi du: met ngtreci dung dOc hai co the am them drop hoac phat lai hoec them chi chinh sira not dung gel di ye Ngoiti ra, cac lien kat nhay cam than gian c6 the bj gian doan ben each lam tre viec chuyen tiep cac gei du lieu den cac dich tiep theo ttrcmg img hoec don giim lit dua vito ve chuyen tiep cac gel gia 3.2.1 Tin cong Wormhole Ten cong wormhole la met nhang de dqa phirc tap va nghiem &let dei vei djnh tuyen MANET, bao gem mot 4p nhung ke ten cong Hai ke tat' cong thong deng de ghi lai cac g6i o met vi tri rieng topo mang va xem lai b melt node Ichic bang each sir dung met mang rieng ofic cao RREQ4— IREP4— lien kgt wormhole t6c cao Hinh 3.2: Kjch ban mot cuoc tan cong wormhole Hinh tren cho they met kjch ban vi du ve cuec ten cong nay, de "Ml" va "M2" le nhi-mg ke ten cling thong deng va "V" la node nan nhan Kb "V" quang ba mot tin RREQ de tim molt tuyen den node "D" (vi MA: "V" va "D" la cac node nguan ve dich), lap tirc the node ling gieng cite "V", ci s' the la "A" va "F" 54 Phan Trung Nghia A08348 chuy'an tiep tin RREQ den Wing gieng Wong **mg ciut chting la "B" vi "Ml" Tuy nhien, "Ml" nh#n duqc tin RREQ tir "F", no chuyin tin RREQ qua met dtrOng hiun den ceng tac dm no "M2" Sau quang ba tin RREQ den ling gieng Goa no la node "G", thong qua tin RREQ duqc giri den node dich "D" Do cac lien kat Mc de cao duqc chon beri throng ham giva "Ml" vi "M2", can thin gian ngin han cho tuyen d4c biet de giri tin RREQ den "D" tucmg phan yen thin gian thtrc hien or throng dan {V-A-B-C-D-E} Kat qua lit tuyen {D-G-F-V} trec bra chcon it ring cho "D" de phat met tin RREP nhu mot phan hai den "V" Vi 4y, "D" b6 qua tin RREQ tuang to den sau do tuyen hqp phap {V-A-B-C-E-D} mat hien lye Dieu buec "V" lua chqn tuyen {V-F-G-D} ma tren thuc to la di qua "Ml" va "M2" la nhang ngu&i dung dec hai co the gia mgo cac gal dit lieu a) Ccic bien phcip chang lgi tan cling Wormhole De phat hien va chOng lgi tan ding wormhole, co hai kieu kiem soat chat the goi tin duce gich thieu nhu met kg, thujt hieu qua, cu the la thin gian va dja ly CS kiem soat thin gian, tit ca cac node MANET tinh toan thai gian hat han goi Te va bao gom Te cac goi tin ca.% no de cac gal khong the di xa met khofing each a; the L Khi met goi china thong tin den met node, node !thin so shah theri gian hien tai voi gia tri cita Te goi Voi thong tin d6, node dich sau da th the quyet djnh, cho de met tin RREQ duqc gin qua duimg ham qua met lien ket Mc de cao de phuc vu mqc dich xau Ngoii ra, Te duqc xitc thuc bin cite dau cuOi tham gia vi the no co the Ichong bi lim gia Uri cac node dec hai nhu MI va M2 Tuy nhien, kiem soat thiri gian can tat ca cac node MANET de dOng be thin gian met cach chit che khac, truimg hqp kiem soat dja ly tit ca cac node phai hitt hai logi thong tin lit vi tri ttrung img cua no MANET vi thin gian truyen Dieu cho phop node nh#n danh gilt the lien ket van hang x6m bang cach tinh toan khoang each gifra no va ngulm cua goi tin duqc phat Wien de chaong lgi Dora vim thong tin vi tri, cac giai phitp tiep cac cuec tin cling wormhole Vi du: nghien ciru cfia minh Dhillon vi vac dOng nghiep cung cap str bao ve chOng Igi tin citing wormhole, die biet la mpg MANET bang each sir dung giao thirc OLSR djnh tuyen Tuy !Alien dieu you au mot su tich hqp dui ding kh6a cling khai veri theri gian deng be gift tit ca cac node lit ca cac node phat met tin HELLO, chen vi tri hien tai cua no va cung in diu thin gian hien tgi a g6i HELLO Met node tilfitn g6i HELLO tir node ling gieng cua no co the sau d6 sir dung thOng tin gin vito goi de tinh than khoing each gifts no va hang x6m Trong throng 55 Phan Trung Nghia A08348 hqp khoing each firth toan virqt qua pham vi truyen din tai da, tin HELLO bi coi la Tact kha nghi (co the dtrqc chuyen qua dtrerng him thong qua tin ding wormhole) Phan tich thong ke cling duce sir dung de phat hien cac cups tit' t ding wormhole Vi du: Qian va ding nghiep di gieri thieu met phan tich thing ke tren dinh tuyen da dutmg Cach tinh tat ca tan so tuang del dm tat ca cac lien ket o tat ca cac tuyen duce hinh thimh met kham pha tuytn don Tin s6 cao nhit duce ?CAC (filth la lien ket wormhole M#c du each di tang phi thip ap dung cho dinh tuyen da diremg, no lam viec khong tat vii cac giao thee dinh tuyen khring phai la da &tong nhu AODV Met giai phap kha thi ngin ch#n cac cuec tin cong wormhole la tich hop he thing phat hien veilhotic cac hg thing ngAn ch#n MANET Cite hien phap khac cling duqc xem xet, ngoli cac he thong phat hien xam nhop dies tren phin mem, thiet ke phan ding doe biet va cac ky thuftt xir 15, tin hieu Nhfmg gia thiet ding sau cac giai phap de nghi la neu cac bit de lieu &roc giri qua mot so module doe filet chi duqc biet den beri cac node king gieng, chimg co the khong bi anh huemg ben die tan cong wormhole gan 3.2.2 Tin cong his den (Blackhole) Trong truing hqp tan cong h6 den, node dee hui "M" tuyen b6 co met tuyen tei Int tir node nguOn, "V", den dich "D" va truyen th8ng tin dinh tuyen gia an cac node khac MANET Ket qua la nheng ngueri dung khac bi lira chuyen tiep cac g6i de lieu ctia hQ qua node dee NIL Vi du: neu mang muc tieu MANET sir dung AODV la giao thirc dinh tuyen, "M" c6 the tuo met tin RREP sai china met so the to dich Bong ton tui, no bang ho#c cao hunt so yeti tin RREQ tir node nun nhan (node nguOn "V") Dieu co nglea la node dee hai "M" tuyen be no set him met tuyen men dAy de den dich Dieu thee day "V" lira chop tuyen d#c the (V-A-B-M) de girl cac goi de lieu qua ke tin cong 56 Phan Trung Nghia A08348 Hinh 3.3: Kjch ban met cuec ten cong he den Do de "M" ce the ttr lam tre/drop cac g6i de lieu hoc thay 461 not dung cita cac g6i Tuy nhien, "M" c6 the g#p nil ro tir cac node ling gieng coa no, vi dv: "B" va/ho#c "F" c6 the giam sat va tim cac cuec tan cong De trtinh bi phat hien, "M" co the ties Minh cac phien ben phirc top has cea tan cling he den d6 cac &Si tin bi chk va drop tat ca gel di! lieu, cac g6i bi ch(in duqc chuyen tiep met each chon loc That v#y, "M" chi sirs dei cac g6i den tir "V" ma khong tae deng den cac g6i tir "B" hoc "F", no gitim nguy co bi phat hien bed cac node ling giong a) Cow bien phdp ch eng 10 ten cong he den De cluing lai cac cuec tan cong hO den co the xay ra, giao thirc (Firth tuyen adhoc bao m(it nhiin thirc (aware) hay SAR de duce thiet ke, no dtra tree cac giao thirc dinh tuyen MANET theo you au thong thuang nhtr AODV va DSR SAR sir dung hai ky thuit nhu sau Dau Wen mot gia tri (metric) bao mot duqc then vao gei RREQ De dot duce met mire tin coy tot (vi dv: de birth ditnh cap nhk dung hoc nh#n dong gia moo), SAR sir dung chia se bi m#t don gian de too met ma h6a dei xirng tren moi mire de tin c3y sir dung ne duqc cac gel me hea Nei each khitc, met node ce mire de tin coy khac khong the Ate duqc cac gei RREQ hoc RREP me h6a Thir hai la co the kham pha mot tuyen thay the duce sir dung Khi cac node khac fret' cimg met tuyen nhan cac gei RREQ tir mot nguan cu the, chung the mink mire bio met lien quan den thong tin so (metric) bao m#t duqc nhimg cac gel tin Neu mac de tin coy dot duqc thee men, met node trung gian se bat dau xir li gai tin (vi dv: chuyen tiep ne den node tiep theo) Neu mitt de tin coy Meng th6a men, node 57 Phan Trung NghTa A08348 trung gian se drop gel tin KW node dich theta man cac thuec tinh bao mat ho#c cac mac tin coy ket hop yeti toast be dtremg din du cuei (end-to-end) tir nguan den cac node dich, no tao met goi RREP vei se bao mat cu the Neu khong, no th8ng bio cho node nguin lien ket kh8ng the tiep tnc qua tuyen (vi no c6 the da bj xam nh3p) va do cho phop node girl dieu chinh mac bio mat cis no de tim kiem met tuyen thay the Thtrc te, c6 the la ca hei node dee hai thay dei so bao m#t cao han hoc thip han va lam gifin (loan luting gei tin Day la met nhugc diem cua phuang phap SAR Trong so the phuang phap khac cheng Iii tin cong he den, Lee va cac doing nghiep gi6i thieu cac giao thirc djnh tuyen se ding yeu au va phan hoii xac nhon tuyen, dugc bieu dien tuang ang la CREQ va CREP C3 phuang phap mei node trung gian ngoai viec girt tin RREP, no gai met tin CREQ den node ling gieng cia no theo huOng cia node dich Sau nhOn dugc tin CREQ, node ling gieng tim kiem be dem elm no met tuyen den dich Neu tuyen den dich co the sir dung, node ling gieng truyen tin CREP den node nguin Node nguen sau nhon tin CREP nay, kiem tra xem dueng Mn tin RREP c6 gieng CREP kh6ng Neu dung thi thong tin djnh tuyen la chinh xac Tuy nhien, phuung phap la chua di de" del ph6 yeti met c#p node cau ket yeti ce ging thvc hien the cuec tin ding he den Bei vi met node ling gieng la node ciu ket, no cc!) the two va gai cac tin CREP gia chtia cac tuyen sai De khic phvc yin de nay, Al-Shurman va cac ding nghiep da phat minh met ca the lam cho node ripen phai dqi cac tin RREP den tir it nhat hai node Tir cac gel RREP, node nguin co the danh gia chinh xac thong tin cac (Meng din Phuang phap co mot diem yeu chinh la de tre tang node nguin phiti dqi cac tin RREP den Met each tiep khac kh8ng the cheng Igi the cuec tan cong he den nhung co the phat hie'n chang Cich tiep clin dva hen cac phan tich efts Kurosawa vi ding nghiep Ho phat hien ring met node dee hai phii tang se the to dich de thuyet phyc node nguen tuyen dugc cung cap IA di tog tm Theo cac phan tich nay, met m8 hinh phat hien thong ke co the dirge xay dung de phit hien cac bit thubng, sir Mac biet tang Lang gift so tit* to dich cua the tin RREP nhjn, dieu de im chi met cac cuec ten cong he den c6 the thy Trong cac phuang phap phat hien xam nhOp dtra tren scr bat thubng kh8ng them vito luu luting djnh tuyen hoc yeu ciu bat kt str thay doi nao giao chting c6 the bj Mn thuang do lam gian (loan cac thee djnh tuyen ten lien ket 58 Phan Tnmg Nghia A08348 3.2.3 Tin cong phirc top (Byzantine) Met cute tan cong pink typ co the lit met node thea hiep hose met 'them the node thea hiep/au ket ten tuyen tit ngtain den dich Cac node thea hiep Vitt cong mpg MANET biing each thoe hie'n the cute Yin ding nhu to the Wing Isp djnh tuyen va hueng the gei der lieu qua cac tuyen khong tOi uu dieu din den so giam sot hok glen don elm cac dich vu djnh tuyen a) Bien phap phong chdng Crepeau va ding nghiep dim phuang phip djnh tuyen nguan mgnh me (RSR), met giao thee djnh tuyen theo you au bito mot MANET c6 kha Ming cung cap cac g6i den dich twang img cue chimg ca tan cong phtic top nhu cac dieu kien dOi lip RSR sir Mpg the g6i FR (Fore-Runner), thong bao cho cac node trung gian trerTh tuyen chimg dang cher the dung dr lieu cy the cac khung thin gian (firth Neu met node trung gian khong !Mon dirge bit Icy lutmg dfr lieu nio thiyi gian kien, no se" thong bao cho node nguen Bing each nay, cac lien ket yeti the node ce 14 (selfish) va/hotic cac node dee hai co the IA phat hi'e'n vi co lip 3.2.4 Tin cong don d3p (Rushing) Wit hinh thirc mei cue tan cong djnh tuyen duce goi la Mn cong din dip, no hoot dOng nhu met foal Mn cong DoS hieu qua chting lai tit a cac giao thee djnh tuyen theo yen au MANET Tren thoc te, ke the the giao thee djnh tuyen bito mot (nhu SAODV vi AODV dugc bao mot vbi SUCV(Statistically Unique and Cryptographically Verifiable)) deu duce chi 11 de bi ton thuang lxzri cac cuec tan cling den dip Trong met giao thirc djnh tuyen adhoc theo yeu au dien hinh, met node co djnh kham phi met tuyen den dich de lam ngep lyt mpg moc tieu vii cac gei RREQ De gift cho tae deng cue ng#p lut nhe 'that c6 the, cac node the giao thac djnh tuyen thong thuang chuyen tiep nit& met yeu au den node dAu tier moi giai clop kham phi tuyen Dk diem dm qua trinh kham phit tuyen dirge Mn cong din dip Igi dung Vi do: tririmg hop Ulm phi tuyen cita DSR, node "S" va "D" thorn khao cac node nguin vi dich twang img, "M" la node tan cong din clop, "G" va "H" lit et 59 Phan Trung Nghia A08348 RREQ tit M RREQ tit S 4— 4— G logibecicyeu au agn muOn tit S Oat Wit 1441 be ac yeu clu muon ;Si Hinh 3.4: Topo mgng MANET "M" thirc hien tan cong clan deg, node ling gieng caa "D" Neu cac tin RREQ a qui trinh kham phi duqc chuyen tiep bed "M" la cac tin dau tien den "G" va "H" (dieu la holm man co the), sau bat ky tuyen nao duqc kham phi bed qui trinh kham phi tuyen se bao g6m mot bulk (hop) qua "M" MOt each don gian mot ling gi6ng caa node "D" la "G" hoOc "H" nhOn tin RREQ d6n dap tir Ice tan ding, no sb chuyen tiep yeu citu d6 mot mirth va kh8ng chuyen tiep bat ky tin RREQ nao khac tir qui trinh kham phi tuyen Ngay ca the tin RREQ khong tan cong tir "S" den "G" va "H" a thbi diem sau, cac yeu cau hop le se bj loai bd Ket qua la "S" kh8ng kham phi duqc bat ky tuyen nao co the sir dong hoc tuyen an toin ma khong co so tham gia caa ke tan cong a) Gicii phcip MOt giao thIrc dinh tuyen duqc de xuat la RDP co the thay the co the tieu chuan cua cac giao thirc dinh tuyen adhoc thong thuemg vim da de bi Mn thirong bed cac cueic tan cling d6n tap Tren thoc te, RDP ket hop ba ky thuot de ngan nera tan cong dim dap la: co the khim pha ling gieng bao mot, giao thirc chap talon ay thic tuyen an toan, va loa chqn ngau nhien tin RREQ de chuy& tiep 3.2.5 Tin cong tieu hao Wi nguyen Tan clang tieu hao tai nguyen hay tan ding mat nga (Sleep Deprivation) china mot ke tan cong ho$c node them hip de tieu tho tai nguyen dia node nan nhan Vi do: moc tieu caa tan cong ngop lot la tieu hao tai nguyen nhu bang thong mpg so Phan Trung Nghia A08348 bang each chuyen tiep qua nhieu cac gal den cac node nan nhan, hoc cong suit tinh toan va niing Wang elm node nan nhan bing each yeu eau qua mire the tuyen king can thiet Mat vi du don gifin mat node the dich nhan den giao Wire dinh tuyen AODV bang each truyen mat Wang fern cac g6i RREQ mat khoing tiled gian ngin den node dich king ton tai Vi king co node phan hAi the tin RREQ nay, the g6i tin se lam nap lot MANET, tieu hao bang thong mang vi lam can kiet cong suet nguen cum cac node Han nova, met se nghien cuu chimg minh rang tan cong ngap lvt co the lam suy giam thong Wang MANET den 84% a) Ghiaphew Yi va cac ang nghiep dtra mat ca the don gian nhung hieu qua de ngan ngira tAn cong tieu hao tai nguyen, dac biet IA MANET sir dung AODV lam giao thus dinh tuyen Trong ca the nay, mei node giim sat va tinh toan tjr Ig RREQ Wang img veri cac ling gieng cita no Neu tj , lei RREQ elm mot node ling gieng dirge tim they vugt qua mat nguOrng dirge xac dinh sin, node ling • Deng se duqc dua vao (lath sach den vi drop the tin RREQ tir node ling gieng VAn de chinh cua ca the la no xi)/ loi, c6 the dua nhAm cac node hqp phip vim danh sach den mg khic, sir dung mat ca the phat hien dip tren sv bit thuang tucmg t4 thay vi sfr dtmg mat ngtremg c6 dinh, hqc duqc tir the phan tich thong ke tst l khic elm the gai RREQ vi tinh toan nguang a 3.2.6 Cie tin ding chiem gift lien ket va him gii lien ket Trong throng hqp tan cong tir chOi lien ket, mat node doe hai ty y gift lai hoac bo qua the you cAu de quang cito tuyen den mat node cu the hoc tip hqp the node Ket qua la cac node khac king co kha nang tim kiem cac lien lc& de lien lac vii cac node khac Trong mat tan cong chiem gift lien ket thvc hien de ch&tg lai cac tin TC (Topology Control) OLSR, Kannhavong va ding nghiep chi ring mat node doe hai co the co lop mat node cu the va ngan no lien ket veri the node khac mang MANET Ho de xult mat ky thujt phat hien lam viec dva ten gia thuyet ring neu met node chi Wien mat tin HELLO tir MPR elm no, nhung kitting nhon bit kt tin TC nio tir MPR, node &nit gia MPR de xem xet Sau node chuyen sang MPR khic Tuy nhien, each tiep viec phat hien the cuac tAn cong &nye thus hien beri hai node cong tic dale hai nim a node ke tiep den node khac, node doe hai dAu tien gia WY de quit% ctio mat tin TC node dew hai thir hai loaf be gai TC 61 Phan Thing Nghia A08348 Met khae, tan ding lam gia lien ket, mOt node dOc hal quing tho the tuyen gia Vi du: mot ke tin &Ong c6 the cluing ba mOt lien ket gia yeti cac tang khoimg hai buoc (hop) dm node non nhan mong MANET dimg gieng giao thtle OLSR KM qua la, node non nhan chip node dOc hoi la MPR cue no Nhu mot MPR, node doe hoi c6 the loci be the tin TC vi tun luting djnh thy& ichfic tir node non nhan, ho#c chinh sire the g6i dir WO den tir node non !than den mot node dich khic De phat hiOn tin cong gia moo lien ket, Ratio va deng nghrep dua mOt phucmg phip phat hiOn dip tren thong tin thu duce tir GPS vi &au thin gian duqc mi h6a Mei node phucmg phap nay, quimg tho den the node khric toa dO GPS vit dau thei gian ctia no Do de, no co the phit hiOn cac tan cong gia moo lien ket bAng each tinh town cac khoang each lien node tha hai node dua vi cling de kiem tra xem Chung c6 nem phom vi truyen tei da hay thong Van chinh cue giai phap la mei node phii &gm lap dM GPS dieu kitting phai hic nio Ming kha thi 3.2.7 TAn cling phAn hoi Topo ctia mpg MANET thud:mg xuyen thay del tinh di ding cue cac node Dieu co nghTa la topo mong co the thubng xuyen thay doi them tri sau vai giay Trong tan cong phim hoi, cac node dOc hoi ghi loi cac tin dieu khien hop phap (vd: cac tin TC giao thfrc OLSR) cue the node khic vi phat loi chimg sau mot than gian KM qua la bang djnh tuyen cac node MANET cep nh#t cac tuyen da cu Bing each nay, tan ding phin hoi c6 the lqi dung de moo danh mot node a; the hoic den gian la phi vb the hoot dung dinh tuyen elm mong MANET De bao vg MANET khei cac cuOc tan cong phan hoi, mot giai phip duqc dua dua tren cac dau thfri gian vi mi hort bit del ximg Giii phip don gian la so skill Uteri gian hiOn toi yeti &Au thei gian dtrot nhimg the tin dieu lchien dA nh(in tir the node khic Neu dau than gian co sal loch Ion so yeti than gian hiOn toi, node nhtin c6 the xem xet no la mot cutjc tin cong phin hoi vi tool be gel de Minh cep nh#t thong tin eQ vito bang djnh tuyen Tuy nhien, giiti phip de bj Mn thuong Uri cac etajc tan cling wormhole bao gem mot cop node tar cong eau ket sir dung mot mong toe cao Cho cac tin phat loft tai mot dja diem a xa vol dO tre kha Map 62 Phan Trung Nghia A08348 3.3 Cac cuQc tan conga Ifrp giao vin chting lei MANET Cac giao thirc 16p giao van nhu giao thirc dieu khien giao van (TCP) dirge sir dung mung MANET de thiet I p ket not dau can gioa cac node va citing dim bao cac g6i clang tin c$y duqc girl qua lien ket dau cu6i Ngoai ra, ttrcmg to nhu cac lien ket co day, dieu khien luOng vi tic cling co the mung MANET bing each sir dung TCP nhu cac giao thirc truyen tai Tuy nhien, cac nhuqc diem cua giao thirc TCP, ngop hit goi SYN hoic tan Gong chiem doat phien co kha nang xay mung MANET Han an, mung MANET thutong c6 ty 14 181 k'enh truyen cao han so veri mung c6 day Yeu to lien quan den mOt so vin de vi TCP kh8ng co kha ning phan biet dtrqc bin chat cita str mat mat (vi du: str thiet hai dit la tic nghen, Ioi ngau nhien, loi kenh truyen, hay tan Gong dOe hai) va ket qua la no lam giam &lieu Ian elm the cua no Dieu anh huong ding k'e den hieu suit elm MANET Phan tiep theo se dua cal !Min tong quit han ye tan cong ngap lot tin SYN va tan cong chiem clout phien MANET 3.3.1 Tin ding trio ngtip gai SYN Hai node MANET thiet lap mot ket n6i TCP, chimg can thuc hien met ca the bit tay ba buOc bu6c dau tien, node ngubn "S" bit diu ket n6i yeti Hinh 3.5: Ca chi bat tay ba binftc TCP node dich D bang each giri mOt gal SYN veri mot s6 thin to "P" "D" phan hoi bing each girl den "S" mOt tin SYN/ACK gom chinh s6 thin to ctia no "Q" va mot s6 63 Phan Trong Nghia A08348 xac nhon "P+1" CS bark cu6i cong , "S" phat melt tin ACK (veri se ACK "Q+I") den "D" Nhu voy " S" va "D" thiet 1(ip meat lien ket TCP Trong truimg hqp ten cong ng6p lot gel SYN, "S" kheti tao meat s6 luqng ton cac lien ket TCP veri node nan nhan "D" Tuy nhien, "S" lam gia dja chi trer lai cua cac g6i SYN va do khring hoth btrec cac ket not TCP (vi do: chring be der gicra chang) "D" sau nhan duqc gel SYN tir ke tan cong "S", 13p tire phat cac gei SYNACK den dja chi gia moo, no thu&ng khong ton tot Ket qui la, "D" char nhen cac gen ACK (6 buck ba cfra cu the bit tay TCP) Meat s6 hrcmg Ion cac ket not ma co the bi tran be dtrqc tri beri "D" Tran bei dem "D" dan taxi no khong the chap nh3n bet ky yeu cau hqp Ig nit° de thiet lop ket mit TCP veti cac node khic mang MANET Mee dir melt ket not ma birth thuerng se het han mOt khoing than gian time-out, ke tan cong co the lqi dung dieu bang each truyen cac goi SYN vei dia chi gia mao yeti Mc dO nhanh hem gia ft.' time-out 3.3.2 Win chiem dogt phien Ke ten cong mOt kjch ban chiem doat phien lqi dung cac phien khong duce boo ve thiet 16p ban dAu Ke lAn citing lam gia dia chi IP circa node nan tinh town so the to kien, sau de thoc hien met cueic fin cong DoS cheng lai node nan nhan Bing each lam nhu v6y, ke tan cong mao danh node nan than va tri lien ket yeti moc tieu qua phien TCP dA duqc thiet lip Melt vi ve tan ding chiem doot phien la van de bAo TCP-ACK nhu mo to hinh Node "Ni" va "N2" dA thiet It" melt lien ket TCP Hinh 3.6: Ccic Mt& gay &To TCP-ACK 64 Phan Trung Nghia A08348 Ka tan ding "M" lam gia dia chi IP cim "N2" va dua du lieu vao cac phien cim node "Ni" Sau "NI" xic titian da nh#n th6ng tin bang each girl met gel ACK den node "N2" "N2" thong bao met se thin tkr khic goi ACK tilt nIgin ti' "Ni", no phat lai gai ACK cuti cimg cua no den "NI" de (king be lai phien TCP Qua trinh lap di lap lai dan den met can bao ACK Tren thvc te, tan ding chiem doktt phien de thvc hien han tree cac giao thee truyen tai it ket not nhu UDP (User Datagram Protocol) 3.4 iltramg nghien cow Wong lai Bao mat thvc sv lit van de quan tong quyet djnh sv thiuth ding va sir (king rang rai dva tren MANET Cac nghien cau tuang lai nen top trung vao viec giam chi phi thief ke va trien khai cho viec cung cep bao mat de thing phi hop han cho mang MANET va the m8i tnrbng adhoc khong day khitc nhtr VANET va WSN Han ncra, phin Ion cac ca the bito mot th8ng throng co ging tim hieu the de dos va dei ph6 voi thing met each rieng re N6i each khic, cac bin phip dei ph6 v6i mot mot de dqa cv the (vd: ten ding he den) co the khong that thief da hieu qua dei yeti cac kieu tan cong khitc Do d6, dieu quan tang cho cac nghien dru twang lai la phiti chit y han ten viec cheng lai cac cuOc tan ding meti/chua biet den Han nua, cac cuijc tan ding 16p, cac ca the bao mat can phai ducfc thvc thi tree tirng lap dan den tong kenh Dieu can duqc khai thitc nhieu han twang lai de lam cho mang MANET bio mat va ding tin coy han Theo djnh nghia, MANET la met mpg tv to chic va thing khong bj rang buOc heti bat kY ca se tang nio (infrastructure) Dieu dan den mot boat the thach thee nghien cfru me, bao gam khaa quart ly tv to chirc, khuyen khich hop tac, dieu khien va xic thvc truy nhalp, va chit luong bao mot djch Ngoai co met pham vi nghien elm khitc de tich hop cac bao met gec vao cite hg thOng dva tren MANET Vi dy: cac giao thec kh6a wan 1Y co the fling cao mac de btu) mot king the caa MANET That vay, cac nghien dm co the top trung vao vies thiet ke cac he thong khoa quan ly initial me, the giao this djnh tuyen dva tren sv tin coy, tich hop xic thvc va ma hem b cac lop khic Cac nghien dm co the Chia thinh hat huong 65 Phan Trung Nghia A08348 3.4.1 Ngin ngira vi phit hiSn aim nhop vi Wong day khae, MANET co cac die firth rieng Dial lap yen the mpg e6 'thy ban chat met, kha !tang di dOng cao ctia the node, vi topo thay doi dOng Ket qua la the phuang phip ngin ngira vi phat hien xam nhop thong ththang thong ap dung duqc cho mpg MANET Cie van ve phat hien xam nhip c6 tam quan tong ding ke vier phat hien molt ethic tan Gong tiem tang truck no the dOng nghiem tong den mpg muc tieu va cac node nttn than Tom 1$, the ky thuot phat hien xam nh#p ductc ap dung molt than gian dai a cac mpg kh8ng day cii kh8ng phu hqp trip tiep yeti m8i throng MANET Cac hg dying phat hien xam nh#p twang lai cho MANET vi the mpg adhoc khic can phai duqc ca hai phan phei vi hqp tae theo mit node nen tham gia vio qua trinh phat hien xam nifty Phat hien xam nhtip duqc thue hien cue b0 a tat ca the node vi ten quy mo rOng han ncti cac node ling gieng Chia se th8ng tin phat hien xam nhitp vi cong tic voi cac node kit de theo doi the lien ket ding net Han nits, phat hien mot cuoc tan cong hose xam nhop, mot phin ling day cling duce you au Clic hg thOng nem ngira xam nhap va/hok dip ling duqc phitt trien de halo ming MANET tuang lai vi the mot ph3m vi tong Ian cac dip ling co the duqc th8ng qua Dip ling co the lien quan den cai dat l3i kenh hen ket gifra cac node, truy tim ter lni cac node thaa hiep, loci b6 thong klaii MANET Tren dive te, hiu het the bien phip phang nem Vim nhtip va dip ling hien tai duqc coi Ii tuyen phong tint thir hai Xay dung molt khung dun tree str tin coy cho mpg MANET vi tich hqp no vio cac phuang phip ngin ngira hien Gni co the kha thi cac nghien elm thong lai 3.4.2 Cic ky thu#t mi hoa Cfic hoot dOng mat ma nhu ma h6a vi giai ma the gal di: li'eu, thong tin dieu Ithien can phai dupe sir dung et bait ca nai nio co the ap dung de tang cueing bao mat dm mpg MANET Dieu doi heti the phuang phip khoa quitn 1S , day du Cie phuang phip ma has kh6a tong khai thwang phi; thuOc vao care thyme the CA tam vi vim de tap trung la trai yeti ban chat de thiet ke vi the chirc fang dot duqc MANET Thue te, molt se nghien eau da dieu tra xem the node MANET co the phan tan de hoot dong nhu the CA dua tree ca the Chia se bio mot Tuy nhien, su di chuyen cua cac node lam no kh6 khan de cau hinh lag molt each thing dOng nhu CA vit vain de vim chua duqc giii quyet Cac nha nghien eau ding nen quyet djnh c6 nen ap dung han nfta the m6 hinh phan phiti tin coy hieu qua nhu PGP hose sir dung cac tinh tomtit dun gian nIumg hieu qua ma haa dOi 66 Phan Trung NgIda A08348 thug de tiet kiem fling lugng han cht cita cac node khong day adhoc Van de ditnh did lien quan den mire dg bao mot vi tinh hieu qua tr6 third) mOt van de dkr phi:mg him mot MANET 3.4.3 Khit fling phyc hoi Do thnc to mOt s6 cuOc tan cong chring 13i MANET la khong the hitt truerc, nen mOt giai phip bao mot huerng phnc hid can phai dirge phat tri'en twang lai Dieu gifip cac node hqp phip co the phnc hOi tir sir c6 mpg nhanh nhat co the Trong cac giai phip ma hem dirge cung cap troll t chi cung cap mOt tjp rho cac giai phap, cac gild phip town dien hiremg tai mOt kien true MANET din htd se doge phat trien twang lai 3.5 Ket lutin Trong theri gian gin day, the mpg di dOng adhoc da not len nhu mOt cling nghe day him hen va danh duqc su quan tam lem tir cac nhi nghien ciru Ke tir cac mang c6 the nhanh chi:mg trier khai ma khong can bat ky ea se tang xfic djnh truerc, chimg co the de clang ap clung cho che truimg hqp khic tir cac hoot dung ciru nan den the dish vu qufin su, mang lueri xe cO, va cac filth vuc nhay cam Ichac Tuy nhien, viec thieu ca sb tang va/ho#c ca quan chirng nhon (CA) tao nhieu ca hOi de the node dOc hai tier hanh mOt loot cac cuOc tan cong.Vi v#y, de bao vg cac th8ng tin rthay cam dirge trao dad MANET, viec cung cap bao mOt la rat quan MOt nhfrng thfich thine nghien cim chinh cua bao mot MANET IA cac mang bi hart che tai nguyen Vi du: MANET en ning Itrqng pin han che, han che kha Wing tinh toltn/xit l5r vi bang thong gieri han Ket qua la the bien phip &to m#t thong thitimg cho mang co day vi the mpg khong day khic the kitting ap dung true tiep cho mpg MANET Van de lam cho MANET de bi ton throng han bed cac cuijc tin cong Chuang xem xdt hien trang cua the CI* tan cong dish tuyen Dad biet lit cac bien phap cheng lyi cac cuOc tan cong (Anil tuyen ding v6i namg uu va nhugc diem cita chimg cling dune mieu tit Phan lem cac bien phip a Chuang chi tjp trung vio mOt kieu tan cong ghat djnh Vi vey, vim xa meri dat dirge mOt giai phip hoan hao c6 the tich hgp tat ea cac giii phap bao mot mOt each hien qua 67 Phan Trung Nghia A08348 TAI LIEU THAM KHAO Al-Sakib Khan Pathan — Security of Self-Organizing Networks Bulent Tavli, Wendi Heinzelman - Mobile Ad hoc Networks MCA so trang web tham khao http://en.wikipedia.org/wiki/Ad hoc http://en.wikipedia.org/wiki/Mobile ad hoc network http://megavnn.com.vn/chi-tietkac-giao-thuc-dinh-tuven-trong-mangmanet/526.html http://tinsp211.forums-free.cotn/manet-t473.html 68