MÔ HÌNH OSI VÀ NGHI THỨC QUẢN TRỊ MẠNG SNMP (Autosaved)

7/30/2019 M HNH OSI V NGHI THC QUN TR MNG SNMP (Autosaved)

1/33

B GIO DC V O TOTRNG I HC GIAO THNG VN TI

KHOA: IN - IN TB MN: K THUT THNG TIN

---------o0o ---------

An Ton & Qun Tr Mng Thng Tin

Ti: Qun Tr Mng, cc giao thc qun tr mngng dng qun tr trong m hnh OSI

Gio vin hng dn: THS.Phm Hng Qun

Chuyn ngnh : K Thut Thng Tin & Truyn Thng

Kha : 50

H Ni 8/2012


2/33

M hnh OSI v nghi thc qun tr mng SNMP

B GIO DC V O TOTRNG I HC GIAO THNG VN TI

KHOA: IN - IN TB MN: K THUT THNG TIN

---------o0o ---------

An Ton & Qun Tr Mng Thng Tin

Ti: Qun Tr Mng, cc giao thc qun tr mngng dng qun tr trong m hnh OSI

Gio vin hng dn: THS. Phm Hng Qun

Chuyn ngnh : K Thut Thng Tin & Truyn Thng

Kha : 50Nhm sinh vin thc hin:

Ng Ngc Lu Ng Th Thanh Nhn

Nguyn nh Lu Nguyn Vit Nhu

Nguyn Quang Minh o Th Lan Phng

Nguyn Huy Nam Nguyn Vn Qunh

Nguyn Vn Nam Nguyn Cnh Trng SaPhm Vn Nng Nguyn Duy Tn

H Ni 8/2012

Nhm 3 - Lp k thut thng tin v truyn thng K50 Page 2


3/33


LI NI U

Ngy nay, cng ngh thng tin l mt phn quan trng v khng th thiutrong bt k lnh vc no ca i sng nht l vi vic hi nhp ton cu. Nhngnm gn y, cng ngh thng tin pht trin vi tc nhanh chng v si ngvi vic cc mng my tnh pht trin rng khp v mnh m mi ni.

Mng my tnh gp phn tch cc v thit thc vo cng vic, hc tp vgii tr ca con ngi. Nh nh, ngi ngi u s dng my tnh ni mng nhmt cng c c lc v khng thit yu.

Cng chnh tc pht trin nhanh ca h thng mng my tnh m viclp t, khai thc, bo dng v qun l mng my tnh cng c nhng yu cucao hn, nhm khai thc ti a hiu qu ca mng cng nh an ton cho mngmy tnh. Nu trc y, cc nh cung cp mng s dng nhn cng qun lh thng mng ca mnh th ngy nay, mng my tnh pht trin n mt

phng thc qun l mng mi bng cch s dng cc phn mm, cc giao thcc lp trnh sn trn my tnh. N gip x l linh hot, nhanh chng v chnhxc hn rt nhiu vic qun tr mng bng nhn cng.

Trong bi tp ln ca nhm em, chng em xin c trnh by mt cch tngquan nht v mng my tnh, cc phng thc qun tr mng hin hnh v ngdng qun tr mng trong qun tr m hnh OSI. Bi tp ln ca nhm em baogm 3 phn chnh.

- Phn I: Tng quan v mng v qun l mng.

- Phn II: Cc nghi thc qun tr mng.

- Phn III: ng dng qun tr mng trong m hnh OSI.



4/33


MC LC

PHN I: MNG V QUN TR MNG.............................................................6

2.2.1. Nghi thc SNMP .....................................................................................12

2.2.2. Nghi thc CMIS/CMIP ...........................................................................14

2.2.3. Nghi thc CMOT ....................................................................................17

PHN III: NG DNG QUN TR MNG TRONG M HNH OSI.............19

3.1.2.Chc nng ca cc tng trong m hnh OSI................................................21

3.1.3.Nguyn tc lm vic.....................................................................................23

3.2.Nghi thc qun tr mng n gin SNMP......................................................25

3.2.2.Thnh phn...................................................................................................263.2.3.Hot ng ca SNMP..................................................................................26

KT LUN..........................................................................................................32

TI LIU THAM KHO....................................................................................33



5/33


DANH SCH THUT NG VIT TT V KHIU

K hiu Thut ng y nghaDN Data Network Mng d liuNM Network Management Qun l mng

ISO International StandardsOrganization

T chc tiu chun quc t

NMS Network Management System H thng qun l mng

CMIP Common ManagementInfomation Protocol

Giao thc qun tr thng tinthng dng

SNMP Simple Network ManagementProtocol

Giao thc qun tr mngn gin

IAB Internet Activities Board Hi ng cng tc Internet

IETF Internet Engineering Task Force Nhm c nhim pht trinInternet

IRTF Internet Research Task Force Nhm c nhim nghincu Internet

HEMS High-level Entity ManagementSystem H thng cao cp qun lvt thSGMP Simple Gateway Monitoring

ProtocolGiao thc gim st cng

kt ni n gin



6/33


PHN I: MNG V QUN TR MNG1.1. nh ngha

Mt mng d liu (Data Network, vit tt l DN) l mt tp hp cc thitb v cc mch, nh c th cung cp cc phng tin chuyn giao thng tinv d liu gia cc my tnh, cho php ngi dng cc khu vc khc nhaudng chung cc ngun ti nguyn trn mt my tnh khc.

Do nhu cu trao i thng tin ca ngi dng ngy cng tng, p ngnhu cus dng ca ngi dng i hi kch c ca mng phi ln hay

phc tp ca mngcao, ng thi chi ph hot ng ca mng ngy cngln. iu ny to nn ng lc thc y s pht trin ca mng, tuy nhin mng hot ng tt i hi kh nng mng truyn dn phi tt, ng thi phi cthit b gim st tp trung trn mng. Trm trung tm cung cp cc gii

php cng nh k thut nhm thc hin vic thay i cu hnhmngcng nh to ra cc cnh bo khi pht hin li trn mng. Chnh v vy rt cn cmt phng thc qun tr mng hp l.

1.2. Qun l mngQun l mng (NM: Network Management) l qu trnh iu khin cc

DN phc tp, nhm ti u ho tnh nng sut v hiu qu ca my da trn cckh nng ca chnh h thng thc thi vic qun l mng.

Qu trnh ny bao gm:

Thu thp d kin, hoc l t ng hoc l thng qua s n lc ca cc ks. N c th bao gm c vic phn tch cc d liu v a ra cc gii php v cth cn gii quyt cc tnh hung m khng cn n ngi k s.

Thm vo n c th lm cc bn bo co c ch cho cc k s trong vic qunl mng. hon tt cc cng vic mt h qun l mng cn c 5 chc nng:

Qun l li. Qun l cu hnh. Qun l an ton. Qun l hiu qu. Qun l ti khon.

Nm chc nng trn c nh ngha bi ISO trong hi ngh v mng.



7/33


1.3. Cc chc nng ca qun l mng1.3.1. Qun l li FM

Qun l li FM l mt qu trnh nh v cc li, n bao gm cc vn :

Tm ra cc li C lp li

Sa cha nu c th

S dng k thut FM, cc k s mng c th nh v v gii quyt cc vn v s c mng mt cch nhanh chng. C th tm v sa cc sai hng trckhi ngi s dng thng bo.

1.3.2. Qun l v cu hnh CMHnh trng cc thit b trong mt mng c nh hng quan trng n hot

ng ca mng. CM l qu trnh xc nh v ci t li cu hnh ca cc thit b b c vn .

Mt b CM c th a ra cho ngi k s tt c cc version hin hnh trntng cu ni. Do , n s lm cho ngi qun tr d dng xc nh c ch nocn nng cp.

1.3.3. Qun l an ninh mng SMQun l an ninh mng l qu trnh kim tra quyn truy nhp vo cc thngtin trn mng. Mt vi thng tin c lu trong cc my ni mng c th khngcho php tt c cc nhng ngi s dng c xem. Nhng thng tin ny cgi l cc thng tin nhy cm (sensitive information).

Cc h qun l an ninh mng cung cp cch theo di cc dim truy nhpmng v ghi nhn ai s dng nhng ti nguyn no trn mng.

1.3.4. Qun l hiu qu PMPM lin quan n vic o hiu qu ca mng v phn cng, phn mm vphng tin lm vic. Cc hot ng l cc bin php kim tra nng lc, tinguyn c s dng, t l cc li xy ra hoc thi gian tr li.

Dng cc thng tin v PM, k s h thng c th m bo rng mng skim tra c mng c tha mn cc yu cu ca ngi dng hay khng v thamn mc no.

Vic c sn mt cng c qun l ch lm vic gip ta c th sm phthin ra kt ni cn c nng cp thng qua cc bo co nh k.



8/33


1.3.5. Qun l ti khon AMAM bao gm cc vic theo di s dng ca mi thnh vin trong mng

hay mt nhm thnh vin c th m bo p ng tt hn yu cu ca h. Mtkhc Am cng c quyn cp pht hay thu li vic truy nhp vo mng.

1.4. H qun l mng v cu trc ca h qun l mng NMS1.4.1. Khi nim h qun l mng

H qun l mng NMS l mt b phn mm c thit k ci thinhiu qu v nng sut qun l mng. Cho d mt k s mng c th thc hin cccng vic vi cc dch v tng t ging nh h qun l mng th vn c th lmn tt hn nu c mt phn mm thc hin cc tc v . Do vy n c th gii

phng cc k s mng ra khi cc cng vic phc tp c nh sn. Bi vmt h NMS c d kin hon tt nhiu tc v ng thi cng mt lc v n cy kh nng tnh ton.

1.4.2. Cu trc ca mt h qun l mng xy dng mt h NMS th ta phi kt hp cht ch tt c cc chc nng

cn thit cung cp mt h qun l hon ho, l nhim v phc tp, ngi

k s phn mm phi hiu mc lm vic v cc yu cu ca cc k s mng.V mt c bn h phi bt u thc hin thit k mt bn cu trc cho h thng,khi cu trc h thng c ci t, k s phn mm lc s phi xy dng mtlot cc cng c hay ng dng tr gip ngi k s mng hon tt cng vicqun l. Ta thy khng c quy lt nht nh no cho cu trc ca h NMS, tuynhin khi quan tm ti tt c cc chc nng m h thng i hi th ta c th yucu mt vi im m mt NMS phi c l:

H thng phi cung cp mt giao din ha m ti n c th a rac hnh nh ca mng theo tng cp v ni kt logic gia cc h thng,n cn phi gii thch r rng cc ni kt trong biu phn cp chc nngv quan h ca chng nh th no hiu qu ca mng. Mt giao din ha phi trng vi cu trc phn cp chc nng. Mt bn mng phicung cp hnh nh chnh xc hnh trng mng (network topology) H thng phi cung cp mt c s d liu, CSDL ny c kh nng lu

gi v cung cp bt k thng tin no lin quan n hot ng v sdng mng, c bit c th qun l cu hnh v qun l ti khonmt cch c hiu qu.



9/33


H thng phi cung cp mt phng tin thu thp thng tin t tt c ccthit b mng. Trng hp l tng cho ngi dng l thng qua mtnghi thc qun l mng n gin.

H thng phi d dng m rng v nng cp cng nh thay i theo

yu cu. H thng phi d dng khi thm vo cc ng dng v cc cim yu cu ca ngi k s mng. H thng phi c kh nng theo di cc pht sinh hoc hu qu t

bn ngoi. Khi kch c v phc tp ca mng tng ln th ng dngny tr nn v gi.

1.4.3. Mt s kiu kin trc NMSC 3 phng php c cp n vic lm th no xy dng mt kin trcqun l mng ang ph bin hin nay.

Xy dng mt h thng tp trung iu khin ton mng.

Xy dng mt h thng m c th phn chia c chc nng qun lmng.

Kt hp c hai phng php trn vo mt h thng phn cp chc nng.

Mt kin trc tp trung s s dng mt c s d liu (CSDL) chung trnmt my trung tm no , mi thng tin lin quan n hot ng ca mng docc ng dng gi v y s c s dng chung trong cc ng dng qun lmng. Mt kin trc phn tn c th s dng nhiu mng ngang hng (peernetwork) cng thc hin cc chc nng qun tr mt cch ring r. Tht kh ihi hn nu mt s thit b no ch thch hp mt s ng dng qun tr. Tuynhin rt c li nu c mt CSDL tp trung lu tr cc thng tin ny. Cu trckh dng th ba l kt hp cc phng php phn cp v tp trung vo trong mth thng phn cp chc nng. Vng h thng trung tm chnh ca cu trc s cntn ti nh l gc ca cu trc phn cp, thu thp cc thng tin t cc mng cpdi v cho php truy nhp t cc phn ca mng. Khi thit lp cc h thngng mc (peer system) t cu trc phn cp, h thng trung tm ny c th giaoquyn iu hnh mng cho chc nng ging nh l cc mc con trong h phncp. S kt hp tt c cc phng php ny l c u im rt ln: cung cp rtnhiu s la chn linh ng xy dng mt cu trc NMS. Trong trng hp ltng nht l bn kin trc c th i chiu vi cu trc t chc ang dng n,nu hu ht cc vic qun l ca t chc l tp trung ti mt khu vc th mt

NMS s c nhiu thun li.



10/33


PHN II: CC NGHI THC TRONG QUN TR MNG

2.1.S pht trin ca cc nghi thc chunCc nghi thc qun tr mng chun ha ch yu l to nhng giao tip

chun gia cc phn mm qun tr vi cc ngun tin lin quan n hot ng camng t cc nt mng chuyn ti. Thng tin t cc thit b thc ra ch cung cpc cc thng tin lin quan n qun tr cu hnh, qun tr li, qun tr hiu qu,

mt cht v qun tr an ninh v ti khon.V vy trong nm kha cnh qun tr mng nu trn, cc nghi thc qun tr

mng p ng trc tip hn cho hai kha cnh l qun tr li v qu tr cu hnh.

Nhn chung khng mt mng no c th hon ton c xy dng t ccthit b (hubs, bridges, routers, hots) c cung cp bi mt cng ty duy nht. Do khi ngi k s mng c k hoch thay i v pht trin mng th h cng

phi tnh ngay n vic qun tr mng vi mt tiu chun no .

Gn y gii quyt cc vn th cc nh ch to a ra cc nghithc qun l mng chun, cc nghi thc ny cho php thu thp v ly cc thngtin t thit b mng. Mt khc cc nghi thc ny c th cung cp mt kiu truynhp ti thit b mng. C th ta phi hi:

Tn ca thit b. Phin bn phn mm trong thit b. S ca giao din trong thit b.

S ca cc gi tin i qua mt thit b trong mt khong thi gian.Cc tham s c th thit lp c i vi thit b mng c th bao gm :



11/33


Tn ca thit b. a ch ca mt giaodin mng. Trng thi hot ng ca mt thit b giao tip mng.Cc nghi thc mng c chun ho mang thm n nhng li ch mi

ch d liu truyn n v thu nhn v t cc thit b mng l nht qun.

Trc khi i ti 2 nghi thc qun tr mng tiu chun l CMIP v SNMPta cng nn im qua mt vi s kin. Trc ht l Hi ng Cng tc Internet(Internet Activities Board vit tt l IAB). Hi ng ny xem xt chung cngngh cng nh nghi thc trong cng ng cc mng da trn TCP/IP. IAB gm 2nhm c nhim l IETF (Internet Engineering Task Force) v IRTF (InternetResearch Task Force). IETF hng vo xc nh cc vn v phi hp gii

quyt vn trong lnh vc qun tr, cng ngh v hot ng ca Internet. CnIRTF chu trch nhim nghin cu cc vn lin quan n cng ng mngTCP/IP v Internet. Vo nm 1988 c ba nghi thc qun l mng khc nhaunh sau:

H thng qun l thc th mc cao (HEMS:High-level EntityManagement System).

Nghi thc gim st cng n ( SGMP: Simple Gateway Monitoring

Protocol). Nghi thc thng tin qun l chung trn TCP (CMIP : Common

Management Information Protocol ).

Nh mt gii php tm thi, IAB khuyn co ci t ngay nghi thcqun l mng n gin (SNMP) da trn nghi thc gim st cng n (SGMP)nh mt nghi thc qun l mng chung (CNMP) vi cc mng da trn TCP/IP.

IETF chu trch nhim thit lp SNMP. IAB cng nhn mnh rngSNMP trong tng li phi tp trung vo qun l li v qun l cu hnh. Dusao th ti thi im , SNMP c nhiu t chc s dng trong tt c cc lnhvc v qun l mng.

Trong thi gian di, IAB khuyn co cng ng nghin cu Internet rsot nghi thc CMIS/CMIP nh mt nn tng cho vic qun tr mng c th png c cc nhu cu trong tng lai. CMIS/CMIP c pht trin bi chunISO vi mc ch khc vi nghi thc SNMP. SNMP ch nhm vo mc ch

qun tr cc thit b kiu IP cn CMIS / CMIP c m rng tr thnh mtc t khng th tc c th qun tr ton b cc thit b mng.



12/33


Khi IAB xem xt CMIS/CMIP, CMIS/CMIP c ci t trn nn tngca TCP. S kt hp ny a ti nghi thc c tn l CMOT. Ngy nay CMOTkhng cn c s dng rng ri na.

2.2.Mt s nghi thc qun tr mng2.2.1. Nghi thc SNMP

IETF (Internet Engineering Task Force) l t chc a ra chun SNMPthng qua cc RFC. SNMP c 3 version:

SNMP version 1: chun ca giao thc SNMP c nh ngha trongRFC 1157 v l mt chun y ca IETF. Vn bo mt caSNMP v1 da trn nguyn tc cng ng, khng c nhiu password.

C 3 tiu chun: read-only, read-write v trap. SNMP version 2: phin bn ny da trn cc chui community. Do

phin bn ny c gi l SNMPv2c, c nh ngha trong RFC1905, 1906, 1907, v y ch l bn th nghim ca IETF. Mc d chl th nghim nhng nhiu nh sn xut a n vo thc nghim.

SNMP version 3: l phin bn tip theo c IETF a ra bn y .N c khuyn ngh lm bn chun, c nh ngha trong RFC 1905,

RFC 1906, RFC 1907, RFC 2571, RFC 2572, RFC 2573, RFC 2574 vRFC 2575. N h tr cc loi truyn thng ring t v c xc nhn giacc thc th.

Hu ht nghi thc qun l mng dng cho mng l nghi thc qun tr mngn gin. Thc ra u tin RFC 1067 a ra v nh ngha cc thng tinc truyn qua gia h thng qun l mng v cc Agent i vi SNMP. Tip RFC1098 c to ra v lm cho RFC1067 b li thi. Sau vi RFC1157th IAB chp nhn ngh ca RFC 1098 v chp nhn nghi thc SNMP nh

l mt nghi thc chun.RFC1157 m t m hnh Agent/Station c dng trong SNMP. Mt

agent ca SNMP l phn mm c kh nng tr li mt s cu hi hp thc tmt trm SNMP. Mt trm SNMP c th l h thng qun l mng. Mt thit bmng c th cung cp cc thng tin v MIB ti trm l mt agent SNMP. mhnh Agent/Station lm vic c bnh thng th Agent v Station phi c cngmt ngn ng ging nhau.

Cc agent v station lin kt nhau thng qua mt thng bo chun. Mimt thng bo l s trao i mt gi thng tin.V vy nghi thc SNMP s dng



13/33


tng 4 (tng UDP (userdatagramprotocol)-chnh l tng vn chuyn (transport)trong m hnh tham chiu OSI ca mng).

Nghi thc SNMP c 5 kiu thng bo:

Get-Request. Get-Response Get-Next-Request Set-Request TrapTrm SNMP dng Get-Request ly thng tin t mt thit b mng m

nc mt Agent SNMP. Agent n lt mnh thng qua Get- Responds gi trli mt thng bo c th mang thng tin v tn ca h thng, h thng chy trong

bao lu v s hiu ca thit b giao tip mng trong h thng.

Get-Next-Request c dng hi tip cc thng tin nh Get- Request hi.

Set-Request cho php thit lp t xa cc tham s cu hnh trong mt thitb. V d thng bo Set-Request c th thit lp tn mt thit b, giao din ngthoc xa mt a ch phn gii bng.

SNMP Trap (by) l mt thng bo khng phi to ra theo yu cu m domt Agent t gi ti mt Station. Thng cc by l cc thng bo bt thng vd nh mt mch b hng, khng gian a khng cn cho hot ng ca hthng.

Hin ti c by kiu Trap SNMP c MIB-II nh ngha. l:

Coldstart of system. Warmstart of a system.

Link down. Link up. Failure of authentication. Exterior Gateway Protocol (EGP) neighbor loss. Enterprise-specific.

Trong :

Coldstart trap cho bit Agent ang do cu hnh hoc nghi thc bthay i. Mt Coldstart trap xy ra khi mt thit b bt u c cp ngun in.

Trong khi mt Warmstart trap cho bit thit b t khi ng li nhng cuhnh v nghi thc khng b thay i.



14/33


15/33


Lp Cc tin trnh qun tr mng7 CMISE ISO.......

ACSE ROSE6 Presentation

5 Session4 Transport3 Network 2 Datalink 1 Physical

Dch v CMIS cung cp vic xy dng cc m un c bn (mt ng dngthnh phn) h thng c th gii quyt cc vn rc ri trong vic qun l

mng. Mi mt ng dng nh vy ta gi l mt CMISE-service-user m ta tmdch l i tng s dng dch v CMISE (TSDDV CMISE)

CMIS nh ngha 3 lp dch v nh sau :

Phi hp qun l ( Management Association) Thng bo qun l(Management Notification) Thi hnh qun l ( Management Operation )

Dch v phi hp qun l:Lp dch v phi hp qun l kim sot s phi hp ca cc h thng m

bnh ng. Dch v ny c dng ch yu cho s thit lp hay hy b lin ktgia cc h thng. Chng iu khin cc ng dng vi cc dch v sau:

M-INITIALIZE

M-TERMINATE

M-ABORT

Dch v M-INITIALIZE thit lp mt s kt hp vi mt TSDDVCMISE cho vic qun l h thng. Dch v M-TERMINATE kt thc mt ktni gia cc TSDDV CMISE cng mc. Dch v MABORT l c s dngkhi mt kt ni gia TSDDV CMISE b kt thc khng bnh thng (trnghp c li).

Mi dch v ca Management Association ny m nhim vic s dngdch v ca ACSE cho thao tc. Mt dch v CMIS khc thao tc vi ROSE.



16/33


Dch v thng bo qun l

Kiu th hai ca dch v CMIS l thng bo qun l. Dch v ny tng tnh thng bo by m SNMP dng cung cp thng tin v cc s kin trn mt

mng. Dch v thng bo qun l cung cp cc thng tin ny thng qua dch vM-EVENT-REPORT - n bo cho mt TSDDV CMISE cng mc v mt skin no c xy ra mt TSDDV CMISE khc. Nu TSDDV CMISEtrong mt h thng cn thay i gi tr (nh l trng thi ca mt thit b giaotip mng) th n c th khai bo vi h thng nh dch v M-EVENT-REPORT.Tuy nhin, so vi dch v by ca nghi thc SNMP, cc s kin y khngc xc nh cht ch. y l mt yu t m cc nh pht trin nh ra ccthng bo ph hp vi yu cu.

Dch v thi hnh qun l

Gm cc nhm nh sau :

MGET MSET MACTION MCREATE MDELETE

Trong :

Dch v M-GET l c s dng bi TSDDV CMISE ly thngtin qun l t mt TSDDV CMISE khc cng mc. N tng t nhtrong thng bo GET-REQUEST ca nghi thc SNMP.

Dch v M-SET ca CMIS cho php mt TSDDV CMISE sa ithng tin qun l ca TSDDV CMISE cng mc. Dch v ny cngtng t nh thng bo SET-REQUEST ca nghi thc SNMP cho phpsa i thng tin trn mt thit b mng.

Dch v M-ACTION l c nu ra bi mt TSDDV CMISE yucu mt TSDDV CMISE cng mc thc hin mt hnh ng mongmun.

VD: Mt h thng c th gi ICMP Echoes (pings) ti mt a im khcv yu cu gi tr li phn hi kim tra vic kt ni ti mt thit b IPkhc c thnh cng hay khng. y l mt trong nhiu hot ng m mth thng m c th yu cu mt h thng m khc thc hin. Dch v M-CREATE c dng bi mt TSDDV CMISE cung

cp mt TSDDV CMISE cng mc cho vic to lp phin bn

qun l. Phin bn ny s i din cho TSDDV CMISE trn mt hthng qun l.



17/33


Dch v cui cng l M-DELETE cho php xo phin bn to ra biM-CREATE.

Cng ging nh chui chung trong SNMP kim sot quyn s dngthng tin qun l, CMISE s dng danh sch truy nhp.

Kt hp qun l

Mt kt hp qun l l mt lin kt gia hai h thng m cng mc ivi qun l h thng. Qu trnh kt ni da trn CMISE to ra mt giao tipvi cc nghi thc.

Vi CMIS c 4 kiu phi hp c th tn ti gia cc h thng m cngmc nh sau :

S kin (Event) S kin v gim st (Event/Monitor) Gim st v iu khin (Monitor/Control) Qun l ton din v i tc (Full Manager/Agent)Mt kt hp theo kiu s kin Event cho php hai h thng m gi thng

bo M-EVENT- REPORT.

Mt kt hp theo kiu Event/Monitor l ging nh phi hp 1 Event, ngoi

ra mi h thng cng c th thu nhn v vn hnh thng bo M-GET.Mt kt hp theo kiu Monitor/Control cho php lin kt M-GET, M-SET,

M-CREATE, M-DELETE v M-ACTION yu cu, mc du khng cho phpsinh bo co.

Mt kt hp theo kiu Full Manager/AGent h tr tt c cc dch v caCMIS.

2.2.3. Nghi thc CMOT

CMOT l ch vit tt ca Common Management information Servicesand Protocol over TCP/IP.

Nghi thc ny thc cht l dng cc dch v ca CMIS trn nghi thcTCP/IP. RFC1189 nh ngha cho nghi thc CMOT v c minh ho trn mhnh ISO nh bng di y:



18/33


Tng 7

Tng 6Tng 5

Tng 4

Tng 3

Tng 2

Tng 1

Cc nghi thc ng dng c dng bi CMIS khng thay i ch thihnh ca CMOT. Nghi thc CMOT thng da vo cc nghi thc CMISE,ACSE v ROSE nh trc khi c miu t vi CMIS. Tuy nhin trong khi chi ISO thit lp nghi thc mc 6 th s dng nghi thc khc gi lLightweight presentation protocol (LPP) Layer 6 v n c nh ngha trongRFC 1085. Nghi thc ny cung cp giao tip chung cho c hai nghi thc cdng ngy nay l UDP v TCP.


ManagementApplicationProcesses

CMISE

ISO9595/9596

ACSEISO8649/8650

ROSEISO9072-1/2

LightweightPresentationProtocol(LPP)RFC1085

ISO Session

TCP UDP

IP

ISO DATA

Physical


19/33


PHN III: NG DNG QUN TR MNG TRONGM HNH OSI

3.1.Tng quan v m hnh OSI

3.1.1. Tng quan



20/33


M hnh OSI (Open Systems Interconnection Reference Model, vit ngnl OSI Model hoc OSI Reference Model) tm dch l M hnh tham chiu ktni cc h thng m l mt thit k da vo nguyn l tng cp, l gii mtcch tru tng k thut kt ni truyn thng gia cc my vi tnh v thit k

giao thc mng gia chng. M hnh ny c pht trin thnh mt phn trongk hoch Kt ni cc h thng m (Open Systems Interconnection) do ISO vIUT-T khi xng. N cn c gi l M hnh by tng ca OSI.

By lp c th c nhm thnh ba nhm: Application , Transport vNetwork. Trong hnh di, bn c th xem hnh minh ho ca m hnh OSI.Nhng chng trnh (Program) ch ni chuyn vi lp th by, ng dng(Application), trong khi lp bn di lp u tin l phng tin vt l truyn

thng mng (v d: Dy Cable hoc khng kh, trong trng hp nhng mngkhng dy). Cable mng i khi cn c gi l lp 0.

Hnh 2.1 M hnh cc h thng m OSI

Network: Nhng lp ca nhm ny l nhng lp mc thp m cnhim v truyn v nhn d liu trn mng.

Transport: Lp ny vi nhim v ca nhn d liu n t mng vbin i chng trong nh dng gn hn ti nh dng d liu m

chng trnh c th hiu c. Khi my tnh ca bn ang truyn d



21/33


liu, lp ny s nhn d liu v chia chng thnh vi gi truynchng ln mng. Khi my tnh ca bn ang nhn d liu, lp ny snhn nhng gi n v t chng li vi nhau.

Application: Nhng lp mc cao ny t d liu vo trong nhdng d liu chng trnh s dng.

3.1.2. Chc nng ca cc tng trong m hnh OSI3.1.2.1. Tng 7: Tng ng dng (Application layer)

Tng ng dng l tng gn vi ngi s dng nht. N cung cp phngtin cho ngi dng truy nhp cc thng tin v d liu trn mng thng qua

chng trnh ng dng. Tng ny l giao din chnh ngi dng tng tc vichng trnh ng dng, v qua vi mng. Mt s v d v cc ng dng trongtng ny bao gm Telnet, Giao thc truyn tp tin FTP v Giao thc truyn thin t SMTP, HTTP, X.400 Mail remote

3.1.2.2. Tng 6: Tng trnh din (Presentation layer)

Tng trnh din bin i d liu cung cp mt giao din tiu chun chotng ng dng. N thc hin cc tc v nh m ha d liu sang dng MIME

(Multipurpose Internet Mail Extensions), nn d liu, v cc thao tc tng ti vi biu din d liu trnh din d liu theo nh cch m chuyn vin phttrin giao thc hoc dch v cho l thch hp. Chng hn nh chuyn i tp vn

bn t m EBCDIC sang m ASCII, hoc tun t ha cc i tng (objectserialization) hay cc cu trc d liu (data structure)

3.1.2.3. Tng 5: Tng phin (Session layer)

Tng phin kim sot cc hi thoi (phin) gia cc my tnh. Tng ny

thit lp, qun l v kt thc cc kt ni gia trnh ng dng a phng v trnhng dng xa. Tng ny cn h tr hot ng song cng (duplex) hoc bn songcng (half-duplex) hoc n cng (single) v thit lp cc qui trnh nh duim hon thnh (checkpointing) gip vic phc hi truyn thng nhanh hnkhi c li xy ra, v im hon thnh c nh du tr hon(adjournment), kt thc (termination) v khi ng li (restart). M hnh OSI unhim cho tng ny trch nhim ngt mch nh nhng (graceful close) cc

phin giao dch (mt tnh cht ca giao thc kim sot giao vn TCP) v trch



22/33


nhim kim tra v phc hi phin, y l phn thng khng c dng ntrong b giao thc TCP/IP.

3.1.2.4. Tng 4: Tng giao vn (Transport Layer)

Tng giao vn cung cp dch v chuyn dng chuyn d liu gia ccngi dng ti u cui, nh cc tng trn khng phi quan tm n vic cungcp dch v truyn d liu ng tin cy v hiu qu. Tng giao vn kim sot tin cy ca mt kt ni c cho trc. Mt s giao thc c nh hng trngthi v kt ni (state and connection orientated). C ngha l tng giao vn c ththeo di cc gi tin v truyn li cc gi b tht bi. Mt v d in hnh ca giaothc tng 4 l TCP. Tng ny l ni cc thng ip c chuyn sang thnh ccgi tin TCP hoc UDP. tng 4 a ch c nh l address ports, thng qua

address ports phn bit c ng dng trao i.

3.1.2.5. Tng 3: Tng mng (Network Layer)

Tng mng cung cp cc chc nng v qui trnh cho vic truyn cc chuid liu c di a dng, t mt ngun ti mt ch, thng qua mt hoc nhiumng, trong khi vn duy tr cht lng dch v (quality of service) m tng giaovn yu cu. Tng mng thc hin chc nng nh tuyn. Cc thit b nh tuyn(router) hot ng ti tng ny gi d liu ra khp mng m rng, lm cho linmng tr nn kh thi (cn c thit b chuyn mch (switch) tng 3, cn gi lchuyn mch IP). y l mt h thng nh v a ch lgic (logical addressingscheme) cc gi tr c chn bi k s mng. H thng ny c cu trc phh. V d in hnh ca giao thc tng 3 l giao thc IP.

3.1.2.6. Tng 2: Tng lin kt d liu (Data Link Layer)

Tng lin kt d liu cung cp cc phng tin c tnh chc nng v quytrnh truyn d liu gia cc thc th mng, pht hin v c th sa cha ccli trong tng vt l nu c. Cch nh a ch mang tnh vt l, ngha l a ch(a ch MAC) c m ha cng vo trong cc th mng (network card) khichng c sn xut. H thng xc nh a ch ny khng c ng cp (flatscheme). Ch : V d in hnh nht l Ethernet. Nhng v d khc v cc giaothc lin kt d liu (data link protocol) l cc giao thc HDLC; ADCCP dnhcho cc mng node-to-node hoc mng chuyn mch gi (packet-switchednetworks) v giao thc Aloha cho cc mng cc b. Trong cc mng cc b theotiu chun IEEE 802, v mt s mng theo tiu chun khc, chng hn FDDI,tng lin kt d liu c th c chia ra thnh 2 tng con: tng MAC (Media



23/33


Access Control iu khin Truy nhp ng truyn) v tng LLC (LogicalLink Control iu khin Lin kt Lgic) theo tiu chun IEEE 802.2.

Tng lin kt d liu chnh l ni cc cu ni (bridge) v cc thit b

chuyn mch (switches) hot ng. Kt ni ch c cung cp gia cc nt mngc ni vi nhau trong ni b mng. Tuy nhin, c lp lun kh hp l cho rngthc ra cc thit b ny thuc v tng 2,5 ch khng hon ton thuc v tng 2.

3.1.2.7. Tng 1: Tng vt l (Physical Layer)

Tng vt l nh ngha tt c cc c t v in v vt l cho cc thit b.Trong bao gm b tr ca cc chn cm (pin), cc hiu in th, v cc c tv cp ni (cable). Cc thit b tng vt l bao gm Hub, b lp (repeater), thit b

tip hp mng (network adapter) v thit b tip hp knh my ch (Host BusAdapter) (HBA dng trong mng lu tr (Storage Area Network)). Chc nngv dch v cn bn c thc hin bi tng vt l bao gm:

Thit lp hoc ngt mch kt ni in (electrical connection) vimt phng tin truyn thng (transmission medium).

Tham gia vo quy trnh m trong cc ti nguyn truyn thngc chia s hiu qu gia nhiu ngi dng. Chng hn gii quyt

tranh chp ti nguyn (contention) v iu khin lu lng.

iu bin (modulation), hoc bin i gia biu din d liu s(digital data) ca cc thit b ngi dng v cc tn hiu tng ngc truyn qua knh truyn thng (communication channel).

Cp (bus) SCSI song song hot ng tng cp ny. Nhiu tiuchun khc nhau ca Ethernet dnh cho tng vt l cng nm trongtng ny, Ethernet nhp tng vt l vi tng lin kt d liu vo lm

mt. iu tng t cng xy ra i vi cc mng cc b nh Tokenring, FDDI v IEEE 802.11.

3.1.3. Nguyn tc lm vicMi lp ch ni chuyn c vi lp trn v lp di k vi n. Khi my

tnh ca bn ang truyn d liu, lung thng tin l xut pht t chng trnh timng (c ngha l ng d liu i t nh ti y), do chng trnh nichuyn vi lp th by , tip theo truyn ti lp th su v c nh vy. Khi mytnh ca chng ta ang nhn d liu, th lung thng tin s t mng ti chng



24/33


trnh (c ngha l ng d liu s t y i ti nh), do mng s ni chuynvi lp th nht sau truyn ti lp th hai v c nh vy.

Khi d liu c truyn, mi lp thm mt vi thng tin iu khin ti d

liu m n c nhn t lp trn, v khi d liu c nhn th qu trnh xy rangc li, mi lp s g nhng thng tin iu khin t d liu nhn c t lp

bn di.

Do vy khi d liu c gi ti mng, lp th by nhn d liu do chngtrnh gi ti v thm nhng thng tin iu khin ca ring n v gi gi d liumi ny ti lp th su. Lp th su s thm d liu iu khin ring ca n vogi d liu nhn c lp th by v gi gi d liu sau khi thm d liuiu khin ti lp th nm. Nh vy lp th nm nhn c d liu lc ny l d

liu ban u c thm nhng thng tin iu khin d liu ca lp th by vlp th su. V c nh vy, khi nhn d liu qu trnh din ra ngc li, mi lps g d liu iu khin ca n khi d liu nhn c.

Mi lp ch hiu d liu iu khin m n nhn trch nhim. Khi lp nhnd liu t lp trn n khng hiu d liu iu khin c thm vo t lp trn,do n ch hiu d liu m n nhn c ch l mt gi d liu n l.

Trong hnh di y m t cho chng ta thy thy khi my tnh gi d liui nh th no ti mng. Mi s thm vo ti d liu ban u i din cho d liuiu khin c thm vo t lp . Mi lp x l gi m n nhn c t lptrn nh l mt gi d liu n l m n khng cn phn bit d liu trong gm nhng g.

Chng ta cng c th ni rng mi lp ca my tnh truyn s ni chuyntrc tip vi cng lp ca my tnh nhn. V d: lp th t ca my nhn d lius ni chuyn trc tip ti lp th t ca my truyn d liu. Chng c c th ni

c nh vy bi v d liu iu khin c thm vo t mi lp th ch c cnglp ca my nhn mi c th hiu c.



25/33


3.2. Nghi thc qun tr mng n gin SNMP3.2.1. Khi nim

SNMP (vit tt t ting Anh: Simple Network Management Protocol) l

mt tp hp cc giao thc khng ch cho php kim tra nhm m bo cc thit



26/33


b mng nh router, switch hay server ang vn hnh m cn vn hnh mt cchti u, ngoi ra SNMP cn cho php qun l cc thit b mng t xa.

3.2.2. Thnh phnMt h thng s dng SNMP bao gm 2 thnh phn chnh:

Manager: L mt my tnh chy chng trnh qun l mng.Manager cn c gi l mt NMS (Network Management Station).

Nhim v ca mt manager l truy vn cc agent v x l thng tinnhn c t agent.

Agent: L mt chng trnh chy trn thit b mng cn c qun

l. Agent c th l mt chng trnh ring bit (v d nh daemontrn Unix) hay c tch hp vo h iu hnh, v d nh IOS(Internetwork Operation System) ca Cisco. Nhim v ca agent lthng tin cho manager.

3.2.3. Hot ng ca SNMPSNMP s dng UDP (User Datagram Protocol) nh l giao thc truyn ti

thng tin gia cc manager v agent. Vic s dng UDP, thay v TCP, bi v

UDP l phng thc truyn m trong hai u thng tin khng cn thit lp ktni trc khi d liu c trao i (connectionless), thuc tnh ny ph hp trongiu kin mng gp trc trc, h hng v.v.

SNMP c cc phng thc qun l nht nh v cc phng thc ny cnh dng bi cc gi tin PDU (Protocol Data Unit). Cc manager v agent sdng PDU trao i vi nhau.

Hu ht nghi thc qun l mng dng cho mng l nghi thc qun tr mng

n gin. Thc ra u tin RFC 1067 a ra v nh ngha cc thng tinc truyn qua gia h thng qun l mng v cc Agent i vi SNMP. Tip RFC 1098 c to ra v lm cho RFC 1067 b li thi. Sau vi RFC 1157th IAB chp nhn ngh ca RFC 1098 v chp nhn nghi thc SNMP nhl mt nghi thc chun.

RFC 1157 m t m hnh Agent/Station c dng trong SNMP. Mtagent ca SNMP l phn mm c kh nng tr li mt s cu hi hp thc t mt

trm SNMP. Mt trm SNMP c th l h thng qun l mng . Mt thit bmng c th cung cp cc thng tin v MIB ti trm l mt agent SNMP. m



27/33


hnh Agent/Station lm vic c bnh thng th Agent v Station phi c cngmt ngn ng ging nhau.

Cc agent v station lin kt nhau thng qua mt thng bo chun.

Mi mt thng bo l s trao i mt gi thng tin. V vy nghi thc SNMPs dng tng 4 (tng UDP (user datagram protocol) - chnh l tng vnchuyn (transport) trong m hnh tham chiu OSI ca mng)

Nghi thc SNMP c 5 kiu thng bo:

Get-Request

Get-Response

Get-Next-Request

Set-Request

Trap

Hnh 3.1. Cc kiu thng bo ca SNMPTrm SNMP dng Get-Request ly thng tin t mt thit b mng m

n c mt Agent SNMP. Agent n lt mnh thng qua Get-Respond s gi trli mt thng bo c th mang thng tin v tn ca h thng, h thng chy trong

bao lu v s hiu ca thit b giao tip mng trong h thng. Get-Next-Requestc dng hi tip cc thng tin nh Get-Request hi. Set-Request cho

php thit lp t xa cc tham s cu hnh trong mt thit b. V d thng bo Set-Request c th thit lp tn mt thit b, giao din ngt hoc xa mt a ch phngii bng.



28/33


SNMP Trap (by) l mt thng bo khng phi to ra theo yu cu m domt Agent t gi ti mt Station. Thng cc by l cc thng bo bt thng vd nh mt mch b hng, khng gian a khng cn cho hot ng ca hthng.

Hin ti c by kiu Trap SNMP c MIB-II nh ngha. l:

Coldstart of system.

Warmstart of a system.

Link down.

Link up.

Failure of authentication.

Exterior Gateway Protocol (EGP) neighbor loss.

Enterprise-specific.

Trong :

Coldstart trap cho bit Agent ang do cu hnh hoc nghi thc b

thay i. Mt Coldstart trap xy ra khi mt thit b bt u c cp ngun in.Trong khi mtWarmstart trap cho bit thit b t khi ng li nhng cu hnhv nghi thc khng b thay i

Link down Trap thng bo qu trnh kt ni b tht bi cn Link up Trapthng bo vic kt ni o thc hin tr li

Thng bo Failure of authentication Trap l gi ti h thng qun l mngthng bo rng station nhn c mt thng bo khng ph hp

Exterior Gateway Protocol (EGP) neighbor loss Trap l c dng bi mtAgent SNMP bo co mt i tc EGP. Khi EGP c th c np li

Cc chui chung (Community strings) SNMP khng cung cp thng tincng nh phng tin thay i cu hnh nu khng c cc bin php an ninh cnthit. Mt SNMP agent c th yu cu mt SNMP station gi thng bo c kmmt khu sau n kim tra quyn hn s dng cc thng tin MIB. Mt khu gi l chui chung. Mt s bn SNMP c quy nh cc mc an ninh khc nhau

trong nh dng ca chui chung.



29/33


30/33


hnh mc nh b thay i, NMS phi thay i ph hp vi cu hnh trnagent.

Hnh 3.3. Mng lin kt gia NMS ti Agent

Hnh 3.3 m t m hnh TCP/IP, l m hnh c bn cho tt c cc qu trnhtruyn thng TCP/IP. Ngy nay, tt c cc thit b mun tham gia vo qu trnhtruyn thng trn Internet u phi tun theo b giao thc ny. Khi NMS hayagent mun thc hin truyn thng phi theo cc tun t sau:

Application: u tin, ng dng SNMP (NMS hay agent) quytnh phi lm g. V d, n c th gi mt yu cu SNMP n agent,gi hi p yu cu SNMP (c th c gi t agent), hay gi mt

trap n NMS. Tng ng dng cung cp dch v cho ngi dng



31/33


cui, chng hn nh ngi iu hnh yu cu thng tin trng thica mt cng trn switch.

UDP: Lp tip theo trong m hnh TCP/IP, UDP cho php 2 host

truyn thng vi nhau. Ni dng ca UDP header cha nhiu thngtin, trong c cng ca thit b m n gi yu cu hay trap. Cngch c th l 161 (truy vn) hoc 162 (trap).

IP: Lp IP c gng truyn cc gi SNMP ti a ch ch c yucu.

Medium Access Control (MAC): S kin cui cng phi xy ra chomt gi SNMP c th n c ch l tng vt l, ni gi tin

c nh tuyn truyn ti ch. Lp MAC bao gm phn cngv trnh iu khin thit b a d liu ti ch. Lp MAC cng chutrch nhim cho vic nhn gi tin t tng vt l v chuyn gi tin lntng trn tip theo trong m hnh TCP/IP.

c th d hiu ta s ly mt v d m t. Gi s ta mun gi th chomt ngi bn xa mi ngi ti nh vo ma h ny. Bng cch quytnh gi mt l th mi, ta thc hin ging nh mt chng trnh SNMP.

in vo ba th a ch ca ngi nhn ging nh chc nng ca lp UDP lxc nh cng ch trong UDP header, trong trng hp ny l a ch ca nginhn. Dn tem v b vo thng th ngi a th ly i ging nh chc nngca lp IP. Hnh ng cui cng khi ngi a th n v ly l th. T y lth c gi n ch, l hp th ca ngi bn. Lp MAC ca my tnh gingnh xe a th hay my bay mang th. Khi ngi bn nhn c th, ngi cng s thc hin mt qu trnh tng t nh vy hi p.Thng qua v dtrn s l ta hnh dung cch thc gi tin c truyn.



32/33


KT LUN

Nh vy, qun tr mng c tm quan trng ln ti vic nng cao hiu qus dng ca mng, cho php ngi k s pht hin v x l li mt cch nhanhchng, qun l tt an ninh ca mng.

ng dng qun tr mng trong OSI m c th l s dng tng 4 tngmng ca m hnh OSI mt cch c hiu qu to ra hiu qu khai thc v qun trmng.

i vi chng em, y l ti kh mi so vi kin thc c trang b

trong cc gio trnh v mng, v n va l vn k thut, va l vn chun.Hn na, do hiu bit ca chng em cn hn ch, nn bi vit khng trnh khinhng thiu st v khim khuyt. Hy vng rng chng em s c thy hngdn v ch bo ti ca chng em c hon thin v pht trin.

Li cui, chng em xin chn thnh cm n s gip v hng dn cathy Phm Hng Qun gip chng em nh hng v hon thin ti ny.



33/33


TI LIU THAM KHO[1]. Mng my tnh v cc h thng m Nguyn Thc Hi.

[2]. Lun vn tt nghip qun tr mng v nghi thc qun tr mng Nguyn

Minh Sng.

[3]. Trang mng tailieu.vn, wiki, slideshare.net, .

MÔ HÌNH OSI VÀ NGHI THỨC QUẢN TRỊ MẠNG SNMP (Autosaved)

Documents

Transcript of MÔ HÌNH OSI VÀ NGHI THỨC QUẢN TRỊ MẠNG SNMP (Autosaved)