Kajeno re tla qala ho ithuta li-routers. Haeba u qetile thupelo ea ka ea video ho tloha thutong ea pele ho ea ho ea 17, joale u se u ithutile lintho tsa motheo tsa li-switches. Hona joale re fetela ho sesebelisoa se latelang - router. Joalokaha u tseba thutong e fetileng ea video, e 'ngoe ea lihlooho tsa thupelo ea CCNA e bitsoa Cisco Switching & Routing.
Letotong lena, re ke ke ra ithuta li-routers tsa Cisco, empa re tla sheba mohopolo oa ho tsamaisa ka kakaretso. Re tla ba le lihlooho tse tharo. Ea pele ke kakaretso ea seo u seng u ntse u se tseba ka li-routers le puisano ea hore na e ka sebelisoa joang hammoho le tsebo eo u e fumaneng ha u ntse u ithuta li-switches. Re hloka ho utloisisa hore na li-switches le li-routers li sebetsa hammoho joang.
Ka mor'a moo, re tla sheba hore na routing ke eng, e bolelang, le hore na e sebetsa joang, ebe re fetela mefuteng ea mekhoa ea ho tsamaisa. Kajeno ke sebelisa topology eo u seng u e bone lithutong tse fetileng.
Re ile ra sheba hore na data e tsamaea joang marang-rang le hore na ho ts'oarana ka matsoho ka litsela tse tharo tsa TCP ho etsoa joang. Molaetsa oa pele o rometsoeng holim'a marang-rang ke pakete ea SYN. A re shebeng hore na ho ts'oarana ka letsoho ka litsela tse tharo ho etsahala joang ha k'homphieutha e nang le IP address 10.1.1.10 e batla ho ikopanya le seva 30.1.1.10, ke hore, e leka ho theha khokahanyo ea FTP.
Ho qala khokahanyo, k'homphieutha e etsa mohloli oa mohloli o nang le nomoro e sa tloaelehang ea 25113. Haeba u lebetse hore na sena se etsahala joang, ke u eletsa hore u hlahlobe lithuto tsa video tse fetileng tse ileng tsa tšohla taba ena.
Ka mor'a moo, e beha nomoro ea boema-kepe ka foreiming hobane e tseba hore e lokela ho hokela port 21, ebe e eketsa tlhahisoleseling ea OSI Layer 3, e leng aterese ea eona ea IP le aterese ea IP eo e eang ho eona. Lintlha tse nang le matheba ha li fetohe ho fihlela li fihla pheletsong. Ha li se li fihlile ho seva, le tsona ha li fetohe, empa seva se eketsa lintlha tsa boemo ba bobeli ho foreimi, ke hore, aterese ea MAC. Sena se bakoa ke taba ea hore li-switches li bona feela lintlha tsa OSI level 2. Boemong bona, router ke eona feela sesebelisoa sa marang-rang se nahanang ka tlhahisoleseling ea Layer 3; ka tlhaho, komporo e sebetsa le tlhahisoleseling ena. Kahoo, phetoho e sebetsa feela ka boitsebiso ba boemo ba XNUMX, 'me router e sebetsa feela ka boitsebiso ba boemo ba XNUMX.
Phetoho e tseba mohloli oa aterese ea MAC XXXX:XXXX:1111 mme e batla ho tseba aterese ea MAC ea seva eo komporo e kenang ho eona. E bapisa aterese ea IP ea mohloli le aterese ea moo e eang teng, e hlokomela hore lisebelisoa tsena li fumaneha ho li-subnet tse fapaneng, 'me e etsa qeto ea ho sebelisa heke ho fihlella subnet e fapaneng.
Hangata ke botsoa potso ea hore na ke mang ea etsang qeto ea hore na aterese ea IP ea heke e lokela ho ba efe. Ntlha ea pele, e khethoa ke mookameli oa marang-rang, ea etsang marang-rang mme a fana ka aterese ea IP ho sesebelisoa ka seng. Joaloka molaoli, u ka abela router ea hau aterese leha e le efe ka har'a mefuta e mengata ea liaterese tse lumelletsoeng ho subnet ea hau, hangata ena ke aterese ea pele kapa ea ho qetela e nepahetseng, empa ha ho na melao e thata ea ho e abela. Tabeng ea rona, mookameli o ile a fana ka aterese ea heke, kapa router, 10.1.1.1 'me a e fa port F0/0.
Ha u theha marang-rang k'homphieutheng e nang le aterese ea IP e tsitsitseng ea 10.1.1.10, u fana ka mask a subnet ea 255.255.255.0 le heke ea kamehla ea 10.1.1.1. Haeba u sa sebelise aterese e tsitsitseng, joale komporo ea hau e sebelisa DHCP, e fanang ka aterese e matla. Ho sa tsotellehe hore na k'homphieutha e sebelisa aterese efe ea IP, e tsitsitseng kapa e matla, e tlameha ho ba le aterese ea heke ho fihlella marang-rang a mang.
Kahoo, komporo ea 10.1.1.10 e tseba hore e tlameha ho romela foreimi ho router 10.1.1.1. Phetiso ena e etsahala ka har'a marang-rang a lehae, moo aterese ea IP e sa tsotelleng, ke aterese ea MAC feela e bohlokoa mona. A re nke hore k'homphieutha ha e e-s'o buisane le router pele 'me ha e tsebe aterese ea eona ea MAC, kahoo e tlameha ho qala ho romela kopo ea ARP e botsang lisebelisoa tsohle ho subnet: "hey, ke mang ho lōna ea nang le aterese ea 10.1.1.1? Ke kopa o mpolelle aterese ea hau ea MAC! Kaha ARP ke molaetsa oa phatlalatso, o romelloa likoung tsohle tsa lisebelisoa tsohle, ho kenyelletsa le router.
Khomphuta 10.1.1.12, ha e se e fumane ARP, e nahana: "Che, aterese ea ka ha se 10.1.1.1," 'me e lahla kopo; komporo ea 10.1.1.13 e etsa se tšoanang. Router, ha e se e fumane kopo, e utloisisa hore ke eena ea botsoang, mme e romela aterese ea MAC ea port F0 / 0 - 'me likou tsohle li na le aterese e fapaneng ea MAC - ho k'homphieutha 10.1.1.10. Hona joale, ka ho tseba aterese ea heke XXXX:AAAA, eo tabeng ena e leng aterese ea moo u eang teng, k'homphieutha e e eketsa qetellong ea foreimi e lebisitsoeng ho seva. Ka nako e ts'oanang, e beha hlooho ea foreimi ea FCS/CRC, e leng mokhoa oa ho hlahloba phoso ea phetisetso.
Ka mor'a sena, foreimi ea k'homphieutha 10.1.1.10 e romelloa holim'a lithapo ho router 10.1.1.1. Ka mor'a ho fumana foreimi, router e tlosa FCS / CRC e sebelisa algorithm e tšoanang le k'homphieutha bakeng sa ho netefatsa. Lintlha ha se letho haese pokello ea tsona le li-zero. Haeba data e senyehile, ke hore, 1 e fetoha 0 kapa 0 e fetoha e le 'ngoe, kapa ho na le leak ea data, e atisang ho etsahala ha u sebelisa hub, joale sesebelisoa se tlameha ho khutlisetsa foreimi hape.
Haeba cheke ea FCS / CRC e atlehile, router e sheba mohloli le liaterese tsa MAC tsa moo e eang teng ebe oa li tlosa, kaha sena ke tlhahisoleseding ea Layer 2, 'me e fetela pele ho' mele oa foreimi, o nang le boitsebiso ba Layer 3. Ho eona o ithuta hore tlhahisoleseding e teng ka foreime e reretsoe sesebelisoa se nang le aterese ea IP 30.1.1.10.
Router ka tsela e itseng e tseba moo sesebelisoa sena se leng teng. Taba ena ha re ea bua ka eona ha re sheba hore na li- switch li sebetsa joang, joale re tla e sheba hona joale. Router e na le likou tse 4, kahoo ke kentse likhokahano tse 'maloa ho eona. Kahoo, router e tseba joang hore data ea sesebelisoa se nang le aterese ea IP 30.1.1.10 e lokela ho romelloa ka port F0/1? Ke hobane'ng ha e sa li romele ka port F0/3 kapa F0/2?
'Nete ke hore router e sebetsa le tafole ea ho tsamaisa. Router e 'ngoe le e' ngoe e na le tafole e joalo e u lumellang hore u etse qeto ea hore na u tla fetisetsa foreimi e itseng ka koung efe.
Tabeng ena, port F0/0 e lokiselitsoe ho aterese ea IP ea 10.1.1.1 'me sena se bolela hore e hokahane le marang-rang 10.1.1.10/24. Ka mokhoa o ts'oanang, koung ea F0 / 1 e lokiselitsoe ho aterese ea 20.1.1.1, ke hore, e hokahane le marang-rang 20.1.1.0/24. Router e tseba marang-rang ana ka bobeli hobane a hokahane ka kotloloho le likoung tsa eona. Ka hona, tlhahisoleseding ea hore sephethephethe bakeng sa marang-rang 10.1.10 / 24 se lokela ho feta koung ea F0 / 0, le bakeng sa marang-rang 20.1.1.0 / 24 ka port F0 / 1, e tsejoa ka ho feletseng. Router e tseba joang hore na ke likou life tse lokelang ho sebetsa le marang-rang a mang?
Rea bona hore marang-rang a 40.1.1.0/24 a hokahane le koung ea F0/2, marang-rang 50.1.1.0/24 a hokahane le port F0 / 3, mme marang-rang 30.1.1.0/24 a kopanya router ea bobeli ho seva. Router ea bobeli e boetse e na le tafole ea ho tsamaisa, e bolelang hore marang-rang 30. e amana le koung ea eona, a re e bolele 0/1, 'me e hokahane le router ea pele ka port 0/0. Router ena e tseba hore boema-kepe ba eona 0/0 bo hokahane le marang-rang a 20., 'me koung ea 0/1 e hokahane le marang-rang 30.,' me ha e tsebe letho le leng.
Ka mokhoa o ts'oanang, router ea pele e tseba ka marang-rang a 40. le 50. a kopantsoeng le likoung tsa 0/2 le 0/3, empa ha a tsebe letho ka marang-rang a 30. Protocol ea routing e fana ka li-routers boitsebiso boo ba se nang bona ka ho feletseng. Mokhoa oo li-routers tsena li buisanang ka oona ke motheo oa ho tsamaisa, 'me ho na le mokhoa o tsitsitseng le o tsitsitseng.
Tsela e tsitsitseng ke hore router ea pele e fuoa tlhahisoleseding: haeba u hloka ho ikopanya le marang-rang 30.1.1.0/24, joale u lokela ho sebelisa port F0/1. Leha ho le joalo, ha router ea bobeli e fumana sephethephethe ho tswa ho seva se reretsoeng k'homphieutha 10.1.1.10, ha e tsebe seo e lokelang ho se etsa ka eona, hobane tafole ea eona ea ho tsamaisa e na le boitsebiso bo mabapi le marang-rang a 30 le 20. Ka hona, router ena e boetse e hloka ho ngolisa static routing : Haeba e amohela sephethephethe bakeng sa marang-rang a 10., e lokela ho e romella ka port 0/0.
Bothata ba ho tsamaisa static ke hore ke tlameha ho lokisa router ea pele ka letsoho ho sebetsa le marang-rang 30. le router ea bobeli ho sebetsa le marang-rang 10. Sena se bonolo haeba ke na le li-routers tse 2 feela, empa ha ke e-na le li-router tse 10, ho theha. static routing e nka nako e ngata. Tabeng ena, hoa utloahala ho sebelisa routing e matla.
Kahoo, ha u se u fumane foreimi e tsoang khomphuteng, router ea pele e sheba tafole ea eona ea ho tsamaisa 'me e etsa qeto ea ho e romella ka port F0/1. Ka nako e ts'oanang, e eketsa aterese ea MAC ea mohloli XXXX.BBBB le aterese ea MAC ea XXXX.CCSS ho foreimi.
Ha e se e fumane foreimi ena, router ea bobeli e "khaola" liaterese tsa MAC tse amanang le lera la bobeli la OSI ebe e fetela tlhahisoleseling ea lera la boraro. O bona hore aterese ea IP ea sebaka 3 ke ea marang-rang a tšoanang le koung ea 30.1.1.10/0 ea router, e eketsa mohloli oa aterese ea MAC le aterese ea MAC ea sebaka ho foreimi ebe e romela foreimi ho seva.
Joalokaha ke se ke boletse, joale ts'ebetso e ts'oanang e phetoa ka lehlakoreng le leng, ke hore, mohato oa bobeli oa ho ts'oarana ka letsoho o etsoa, moo seva se romellang molaetsa oa SYN ACK. Pele e etsa sena, e lahla tlhahisoleseling eohle e sa hlokahaleng mme e siea feela pakete ea SYN.
Ha u se u fumane pakete ena, router ea bobeli e hlahloba tlhahisoleseding e fumanoeng, e e tlatse le ho e romella.
Kahoo, lithutong tse fetileng re ithutile hore na switch e sebetsa joang, 'me joale re ithutile hore na li-routers li sebetsa joang. Ha re arabeng potso ea hore na ho tsamaisa litsela ke eng lefatšeng ka bophara. A re re u kopana le letšoao le joalo la tsela le kentsoeng mateanong a litsela. U ka bona hore lekala la pele le lebisa ho RAF Fairfax, la bobeli ho ea boema-fofane, la boraro ho ea ka boroa. Haeba u nka tsela ea bone ea ho tsoa u tla be u shoele, empa ka la bohlano u ka khanna bohareng ba toropo ho ea Braxby Castle.
Ka kakaretso, ho tsamaisa ke hona ho qobellang router ho etsa liqeto mabapi le hore na o tla romela sephethephethe hokae. Tabeng ena, uena, joaloka mokhanni, u tlameha ho etsa qeto ea hore na u tla nka tsela efe ea ho tsoa mateanong a litsela. Marang-rang, li-routers li tlameha ho etsa liqeto mabapi le hore na li tla romela lipakete kapa liforeimi hokae. U tlameha ho utloisisa hore routing e u lumella ho etsa litafole ho latela hore na li-routers li etsa liqeto life.
Joalokaha ke boletse, ho na le routing e tsitsitseng le e matla. Ha re shebeng static routing, eo ke tla hula lisebelisoa tse 3 tse hokahaneng, ka sesebelisoa sa pele le sa boraro se hokahaneng le marang-rang. A re nke hore marang-rang a le mong 10.1.1.0 a batla ho buisana le marang-rang a 40.1.1.0, 'me pakeng tsa li-routers ho na le marang-rang 20.1.1.0 le 30.1.1.0.
Tabeng ena, likou tsa router li tlameha ho ba tsa li-subnet tse fapaneng. Router 1 ka ho feletseng e tseba feela ka marang-rang a 10. le 20. 'me ha a tsebe letho ka marang-rang a mang. Router 2 e tseba feela ka marang-rang a 20. le 30. hobane a hokahane le eona, 'me router 3 e tseba feela ka marang-rang a 30. le 40. Haeba marang-rang 10. a batla ho ikopanya le marang-rang a 40., ke tlameha ho bolella router 1 ka marang-rang a 30. .
Ke tlameha ho fana ka litsela tse 2 ho router ea bobeli: haeba e batla ho fetisetsa pakete ho tloha marang-rang a 40 ho ea ho marang-rang a 10., joale e tlameha ho sebelisa marang-rang 20., le ho fetisetsa pakete ho tloha marang-rang 10 ho ea marang-rang 40. - marang-rang. port 30. Ka ho tšoanang, ke tlameha ho fana ka boitsebiso ba router 3 mabapi le marang-rang a 10. le 20.
Haeba u na le marang-rang a manyane, joale ho theha static routing ho bonolo haholo. Leha ho le joalo, ha marang-rang a ntse a hōla, ho na le mathata a mangata a hlahang ka static routing. Ha re nahane hore u thehile khokahano e ncha e hokahanyang li-routers tsa pele le tsa boraro ka kotloloho. Tabeng ena, protocol e matla ea ho tsamaisa e tla ntlafatsa tafole ea routing ea Router 1 ka se latelang: "haeba u hloka ho ikopanya le Router 3, sebelisa tsela e tobileng"!
Ho na le mefuta e 'meli ea mekhoa ea ho tsamaisa: Internal Gateway Protocol IGP le External Gateway Protocol EGP. Protocol ea pele e sebetsa tsamaisong e ikemetseng, e ikemetseng e tsejoang e le sebaka sa marang-rang. Ak'u nahane hore u na le mokhatlo o monyenyane o nang le li-routers tse 5 feela. Haeba re bua feela ka kamano pakeng tsa li-routers tsena, joale re bolela IGP, empa haeba u sebelisa marang-rang a hau ho buisana le Inthanete, joalo ka bafani ba ISP, joale u sebelisa EGP.
IGP e sebelisa li-protocol tse 3 tse tsebahalang: RIP, OSPF le EIGRP. Kharikhulamo ea CCNA e bua feela ka liprothokholo tse peli tsa ho qetela hobane RIP e siiloe ke nako. Ena ke eona e bonolo ka ho fetisisa ea mekhoa ea ho tsamaisa 'me e ntse e sebelisoa maemong a mang, empa ha e fane ka tšireletso e hlokahalang ea marang-rang. Lena ke le leng la mabaka a entseng hore Cisco e qhelele RIP thupelong ea koetliso. Leha ho le joalo, ke tla u bolella ka eona leha ho le joalo hobane ho ithuta eona ho u thusa ho utloisisa lintlha tsa motheo tsa ho tsamaisa.
Phapang ea protocol ea EGP e sebelisa liprothokholo tse peli: BGP le EGP protocol ka boeona. Thutong ea CCNA, re tla koahela BGP, OSPF, le EIGRP feela. Pale e mabapi le RIP e ka nkoa e le tlhahisoleseding ea bonase, e tla bontšoa ho e 'ngoe ea lithuto tsa video.
Ho na le mefuta e meng e 2 ea liprothokholo tsa ho tsamaisa: Liprothokholo tsa Vector tsa Distance Vector le li-protocol tsa Link State routing.
Phase ea pele e sheba sebaka le li-vector tsa tataiso. Ka mohlala, nka theha kgokelo ka ho toba pakeng tsa router R1 le R4, kapa nka etsa kgokelo tseleng R1-R2-R3-R4. Haeba re bua ka li-protocol tsa routing tse sebelisang mokhoa oa vector hole, joale ntlheng ena khokahano e tla lula e etsoa ka tsela e khuts'oane. Ha ho na taba hore khokahano ena e tla ba le lebelo le tlase. Tabeng ea rona, sena ke 128 kbps, e leng butle haholo ho feta khokahanyo haufi le tsela ea R1-R2-R3-R4, moo lebelo le leng 100 Mbps.
Ha re nahaneng ka RIP ea protocol ea vector. Ke tla hula marang-rang a 1 ka pel'a router R10, le marang-rang a 4 ka mor'a router R40. A re nke hore ho na le lik'homphieutha tse ngata marang-rang ana. Haeba ke batla ho buisana pakeng tsa marang-rang a 10. R1 le marang-rang a 40. R4, joale ke tla abela static routing ho R1 joaloka: "haeba u hloka ho hokela marang-rang a 40., sebelisa khokahanyo e tobileng ho router R4." Ka nako e ts'oanang, ke tlameha ho hlophisa RIP ho li-routers tsohle tse 4. Joale tafole ea ho tsamaisa R1 e tla bolela hore haeba marang-rang 10 a batla ho buisana le marang-rang 40., e tlameha ho sebelisa khokahanyo e tobileng R1-R4. Leha tsela e ka thoko e bonahala e potlakile, protocol ea Distance Vector e ntse e tla khetha tsela e khuts'oane e nang le sebaka se khuts'oane sa phetisetso.
OSPF ke sehokelo-mmuso routing protocol hore kamehla sheba boemo ba likarolo tsa marangrang. Tabeng ena, e lekola lebelo la likanale, 'me haeba e bona hore lebelo la phetisetso ea sephethephethe mocheng oa R1-R4 le tlase haholo, e khetha tsela ka lebelo le phahameng la R1-R2-R3-R4, leha e le ea eona. bolelele bo feta tsela e kgutshoane haholo. Ka hona, haeba ke lokisa protocol ea OSPF ho li-routers tsohle, ha ke leka ho hokahanya marang-rang 40. ho marang-rang a 10., sephethephethe se tla romelloa tseleng ea R1-R2-R3-R4. Kahoo, RIP ke protocol ea vector ea hole, 'me OSPF ke sehokelo sa litsamaiso tsa naha.
Ho na le protocol e 'ngoe - EIGRP, e leng "Cisco routing protocol". Haeba re bua ka lisebelisoa tsa marang-rang tse tsoang ho baetsi ba bang, mohlala, Juniper, ha ba tšehetse EIGRP. Ena ke protocol e ntle ea ho tsamaisa e sebetsang hantle haholo ho feta RIP le OSPF, empa e ka sebelisoa feela marang-rang a thehiloeng ho lisebelisoa tsa Cisco. Hamorao ke tla u bolella ka ho qaqileng hore na ke hobane'ng ha protocol ena e le ntle hakana. Hajoale, ke tla hlokomela hore EIGRP e kopanya likarolo tsa liprothokholo tsa vector tsa hole le li-protocol tsa li-link-state routing, tse emelang protocol e nyalisitsoeng.
Thutong e latelang ea video re tla atamela haufi le maikutlo a li-routers tsa Cisco; Ke tla u joetsa hanyane ka sistimi ea ts'ebetso ea Cisco IOS, e etselitsoeng li-switches le li-routers. Ka ts'epo, ka Letsatsi la 19 kapa Letsatsi la 20, re tla kena ka botlalo mabapi le li-protocol tsa litsela, 'me ke tla bontša mokhoa oa ho lokisa li-routers tsa Cisco ho sebelisa marang-rang a manyane e le mehlala.
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Source: www.habr.com