I?ioieieu iaiaia ia?o?ooiie eioi?iaoeeae noaea TCP/IP
Ana i?ioieieu iaiaia ia?o?ooiie eioi?iaoeeae noaea TCP/IP ioiinyony e
eeanno aaeaioeaiuo i?ioieieia, eioi?ua a naith i/a?aaeue aeaeyony ia
aeaa a?oiiu, eaaeaeay ec eioi?uo naycaia n iaeiei ec neaaeothueo oeiia
aeai?eoiia:
· aeenoaioeeiiii-aaeoi?iue aeai?eoi (Distance Vector Algorithms, DVA),
· aeai?eoi ninoiyiey naycae (Link State Algorithms, LSA).
A aeai?eoiao aeenoaioeeiiii-aaeoi?iiai oeia eaaeaeue ia?o?ooecaoi?
ia?eiaee/anee e oe?ieiaauaoaeueii ?annueaao ii naoe aaeoi? ?annoiyiee io
naay aei anao ecaanoiuo aio naoae. Iiae ?annoiyieai iau/ii iiieiaaony
/enei i?iiaaeooi/iuo ia?o?ooecaoi?ia /a?ac eioi?ua iaeao aeieaeai i?ieoe
i?aaeaea, /ai iiiaaeao a niioaaonoaothuoth naoue. Iiaeao
eniieueciaaoueny e ae?oaay iao?eea, o/eouaathuay ia oieueei /enei
ia?aaaei/iuo ioieoia, ii e a?aiy i?ioiaeaeaiey iaeaoia ii nayce iaaeaeo
ninaaeieie ia?o?ooecaoi?aie. Iieo/ea aaeoi? io ninaaeiaai
ia?o?ooecaoi?a, eaaeaeue ia?o?ooecaoi? aeiaaaeyao e iaio eioi?iaoeeth ia
ecaanoiuo aio ae?oaeo naoyo, i eioi?uo ii ociae iaiin?aaenoaaiii (anee
iie iiaeeeth/aiu e aai ii?oai) eee ec aiaeiae/iuo iauyaeaiee ae?oaeo
ia?o?ooecaoi?ia, a caoai niiaa ?annueaao iiaia cia/aiea aaeoi?a ii naoe.
A eiioea-eiioeia, eaaeaeue ia?o?ooecaoi? ociaao eioi?iaoeeth ia
eiathueony a eioa?naoe naoyo e i ?annoiyiee aei ieo /a?ac ninaaeiea
ia?o?ooecaoi?u.
Aeenoaioeeiiii-aaeoi?iua aeai?eoiu oi?ioi ?aaioatho oieueei a iaaieueoeo
naoyo. A aieueoeo naoyo iie cani?ytho eeiee nayce eioaineaiui
oe?ieiaauaoaeueiui o?aoeeii, e oiio aea eciaiaiey eiioeao?aoeee iiaoo
io?aaaouaaoueny ii yoiio aeai?eoio ia anaaaea ei??aeoii, oae eae
ia?o?ooecaoi?u ia eiatho oi/iiai i?aaenoaaeaiey i oiiieiaee naycae a
naoe, a ?aniieaaatho oieueei iaiauaiiie eioi?iaoeeae – aaeoi?ii
aeenoaioeee, e oiio aea iieo/aiiie /a?ac iin?aaeieeia. ?aaioa
ia?o?ooecaoi?a a niioaaonoaee n aeenoaioeeiiii-aaeoi?iui i?ioieieii
iaiiieiaao ?aaioo iinoa, oae eae oi/iie oiiieiae/aneie ea?oeiu naoe
oaeie ia?o?ooecaoi? ia eiaao.
Iaeaieaa ?ani?ino?aiaiiui i?ioieieii, iniiaaiiui ia
aeenoaioeeiiii-aaeoi?iii aeai?eoia, yaeyaony i?ioieie RIP.
Aeai?eoiu ninoiyiey naycae iaania/eaatho eaaeaeue ia?o?ooecaoi?
eioi?iaoeeae, aeinoaoi/iie aeey iino?iaiey oi/iiai a?aoa naycae naoe.
Ana ia?o?ooecaoi?u ?aaioatho ia iniiaaiee iaeeiaeiauo a?aoia, /oi
aeaeaao i?ioeann ia?o?ooecaoeee aieaa onoie/eaui e eciaiaieyi
eiioeao?aoeee. Oe?ieiaauaoaeueiay ?annueea eniieuecoaony caeanue oieueei
i?e eciaiaieyo ninoiyiey naycae, /oi i?ienoiaeeo a iaaeaaeiuo naoyo ia
oae /anoi.
Aeey oiai, /oiau iiiyoue, a eaeii ninoiyiee iaoiaeyony eeiee nayce,
iiaeeeth/aiiua e aai ii?oai, ia?o?ooecaoi? ia?eiaee/anee iaiaieaaaony
ei?ioeeie iaeaoaie ni naieie aeeaeaeoeie ninaaeyie. Yoio o?aoee oaeaea
oe?ieiaauaoaeueiue, ii ii oee?eoee?oao oieueei iaaeaeo ninaaeyie e
iiyoiio ia oae cani?yao naoue.
I?ioieieii, iniiaaiiui ia aeai?eoia ninoiyiey naycae, a noaea TCP/IP
yaeyaony i?ioieie OSPF.
Aeenoaioeeiiii-aaeoi?iue i?ioieie RIP
I?ioieie RIP (Routing Information Protocol) i?aaenoaaeyao niaie iaeei ec
noa?aeoeo i?ioieieia iaiaia ia?o?ooiie eioi?iaoeeae, iaeiaei ii aei neo
ii? /?acau/aeii ?ani?ino?aiai a au/eneeoaeueiuo naoyo. Iiieii aa?nee RIP
aeey naoae TCP/IP, nouanoaoao oaeaea aa?ney RIP aeey naoae IPX/SPX
eiiiaiee Novell.
A yoii i?ioieiea ana naoe eiatho iiia?a (niinia ia?aciaaiey iiia?a
caaeneo io eniieuecoaiiai a naoe i?ioieiea naoaaiai o?iaiy), a ana
ia?o?ooecaoi?u – eaeaioeoeeaoi?u. I?ioieie RIP oe?iei eniieuecoao
iiiyoea “aaeoi? ?annoiyiee”. Aaeoi? ?annoiyiee i?aaenoaaeyao niaie iaai?
ia? /enae, yaeythueony iiia?aie naoae e ?annoiyieyie aei ieo a oiiao.
Aaeoi?a ?annoiyiee eoa?aoeeiiii ?ani?ino?aiythony ia?o?ooecaoi?aie ii
naoe, e /a?ac ianeieueei oaaia eaaeaeue ia?o?ooecaoi? eiaao aeaiiua i
aeinoeaeeiuo aeey iaai naoyo e i ?annoiyieyo aei ieo. Anee naycue n
eaeie-eeai naoueth ia?uaaaony, oi ia?o?ooecaoi? ioia/aao yoio oaeo oai,
/oi i?enaaeaaao yeaiaioo aaeoi?a, niioaaonoaothuaio ?annoiyieth aei yoie
naoe, iaeneiaeueii aiciiaeiia cia/aiea, eioi?ia eiaao niaoeeaeueiue
niune – “nayce iao”. Oaeei cia/aieai a i?ioieiea RIP yaeyaony /enei 16.
Ia ?enoiea 8.1 i?eaaaeai i?eia? naoe, ninoiyuae ec oanoe
ia?o?ooecaoi?ia, eiathueo eaeaioeoeeaoi?u io 1 aei 6, e ec oanoe naoae
io A aei F, ia?aciaaiiuo i?yiuie naycyie oeia “oi/ea-oi/ea”.
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?en. 8.1. Iaiai ia?o?ooiie eioi?iaoeeae ii i?ioieieo RIP
Ia ?enoiea i?eaaaeaia ia/aeueiay eioi?iaoeey, niaea?aeauayny a
oiiieiae/aneie aaca ia?o?ooecaoi?a 2, a oaeaea eioi?iaoeey a yoie aea
aaca iinea aeaoo eoa?aoeee iaiaia ia?o?ooiuie iaeaoaie i?ioieiea RIP.
Iinea ii?aaeaeaiiiai /enea eoa?aoeee ia?o?ooecaoi? 2 aoaeao ciaoue i
?annoiyieyo aei anao naoae eioa?naoe, i?e/ai o iaai iiaeao auoue
ianeieueei aeueoa?iaoeaiuo aa?eaioia ioi?aaee iaeaoa e naoe iacia/aiey.
Ionoue a iaoai i?eia?a naoueth iacia/aiey yaeyaony naoue D.
I?e iaiaoiaeeiinoe ioi?aaeoue iaeao a naoue D ia?o?ooecaoi?
i?iniao?eaaao naith aaco aeaiiuo ia?o?ooia e auae?aao ii?o, eiathuee
iaeiaiueoaa ?annoiyiey aei naoe iacia/aiey (a aeaiiii neo/aa ii?o,
naycuaathuee aai n ia?o?ooecaoi?ii 3).
Aeey aaeaioaoeee e eciaiaieth ninoiyiey naycae e iai?oaeiaaiey n
eaaeaeie caienueth oaaeeoeu ia?o?ooecaoeee naycai oaeia?. Anee ca a?aiy
oaei-aooa ia i?eaeao iiaia niiauaiea, iiaeoaa?aeaeathuaa yoio ia?o?oo,
oi ii oaeaeyaony ec ia?o?ooiie oaaeeoeu.
I?e eniieueciaaiee i?ioieiea RIP ?aaioaao ya?enoe/aneee aeai?eoi
aeeiaie/aneiai i?ia?aiie?iaaiey Aaeeiaia-Oi?aea, e ?aoaiea, iaeaeaiiia n
aai iiiiuueth yaeyaony ia iioeiaeueiui, a aeeceei e iioeiaeueiiio.
I?aeiouanoaii i?ioieiea RIP yaeyaony aai au/eneeoaeueiay i?inoioa, a
iaaeinoaoeaie – oaaee/aiea o?aoeea i?e ia?eiaee/aneie ?annueea
oe?ieiaauaoaeueiuo iaeaoia e iaiioeiaeueiinoue iaeaeaiiiai ia?o?ooa.
Ia ?enoiea 8.2 iieacai neo/ae iaonoie/eaie ?aaiou naoe ii i?ioieieo RIP
i?e eciaiaiee eiioeao?aoeee – ioeaca eeiee nayce ia?o?ooecaoi?a M1 n
naoueth 1. I?e ?aaioiniiniaiii ninoiyiee yoie nayce a oaaeeoea ia?o?ooia
eaaeaeiai ia?o?ooecaoi?a anoue caienue i naoe n iiia?ii 1 e
niioaaonoaothuei ?annoiyieai aei iaa.
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?en. 8.2. I?eia? iaonoie/eaie ?aaiou naoe i?e eniieueciaaiee i?ioieiea
RIP
I?e ia?uaa nayce n naoueth 1 ia?o?ooecaoi? I1 ioia/aao, /oi ?annoiyiea
aei yoie naoe i?eiyei cia/aiea 16. Iaeiaei iieo/ea /a?ac iaeioi?ia a?aiy
io ia?o?ooecaoi?a I2 ia?o?ooiia niiauaiea i oii, /oi io iaai aei naoe 1
?annoiyiea ninoaaeyao 2 oiia, ia?o?ooecaoi? I1 ia?aueaaao yoi ?annoiyiea
ia 1 e ioia/aao, /oi naoue 1 aeinoeaeeia /a?ac ia?o?ooecaoi? 2. A
?acoeueoaoa iaeao, i?aaeiacia/aiiue aeey naoe 1, aoaeao oee?eoee?iaaoue
iaaeaeo ia?o?ooecaoi?aie I1 e I2 aei oao ii?, iiea ia enoa/ao a?aiy
o?aiaiey caiene i naoe 1 a ia?o?ooecaoi?a 2, e ii ia ia?aaeano yoo
eioi?iaoeeth ia?o?ooecaoi?o I1.
Aeey eneeth/aiey iiaeiaiuo neooaoeee ia?o?ooiay eioi?iaoeey ia ecaanoiie
ia?o?ooecaoi?o naoe ia ia?aaeaaony oiio ia?o?ooecaoi?o, io eioi?iai iia
i?eoea.
Nouanoaotho e ae?oaea, aieaa neiaeiua neo/ae ianoaaeeueiiai iiaaaeaiey
naoae, eniieuecothueo i?ioieie RIP, i?e eciaiaieyo a ninoiyiee naycae
eee ia?o?ooecaoi?ia naoe.
Eiiaeie?iaaiea ?acee/iuo i?ioieieia iaiaia. I?ioieieu EGP e BGP naoe
Internet
Aieueoeinoai i?ioieieia ia?o?ooecaoeee, i?eiaiyaiuo a nia?aiaiiuo naoyo
n eiiiooaoeeae iaeaoia, aaaeoo naia i?ienoiaeaeaiea io naoe Internet e
aa i?aaeoanoaaiieoeu – naoe ARPANET. Aeey oiai, /oiau iiiyoue eo
iacia/aiea e iniaaiiinoe, iieacii nia/aea iiciaeiieony ni no?oeoo?ie
naoe Internet, eioi?ay iaeiaeeea ioia/aoie ia oa?ieiieiaeth e oeiu
i?ioieieia.
Internet ecia/aeueii no?ieeanue eae naoue, iauaaeeiythuay aieueoia
eiee/anoai nouanoaothueo nenoai. N naiiai ia/aea a aa no?oeoo?a
auaeaeyee iaaeno?aeueioth naoue (core backbone network), a naoe,
i?eniaaeeiaiiua e iaaeno?aee, ?anniao?eaaeenue eae aaoiiiiiua nenoaiu
(autonomous systems). Iaaeno?aeueiay naoue e eaaeaeay ec aaoiiiiiuo
nenoai eiaee naia nianoaaiiia aaeieieno?aoeaiia oi?aaeaiea e nianoaaiiua
i?ioieieu ia?o?ooecaoeee. Iauay noaia a?oeoaeoo?u naoe Internet iieacaia
ia ?enoiea 8.3. Aeaeaa ia?o?ooecaoi?u aoaeoo iacuaaoueny oethcaie aeey
neaaeiaaiey o?aaeeoeeiiiie oa?ieiieiaee Internet.
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?en. 8.3. A?oeoaeoo?a naoe Internet
Oethcu, eioi?ua eniieuecothony aeey ia?aciaaiey iiaenaoae aioo?e
aaoiiiiiie nenoaiu, iacuaathony aioo?aiieie oethcaie (interior
gateways), a oethcu, n iiiiuueth eioi?uo aaoiiiiiua nenoaiu
i?eniaaeeiythony e iaaeno?aee naoe, iacuaathony aiaoieie oethcaie
(exterior gateways). Iaiin?aaenoaaiii ae?oa n ae?oaii aaoiiiiiua nenoaiu
ia niaaeeiythony. Niioaaonoaaiii, i?ioieieu ia?o?ooecaoeee,
eniieuecoaiua aioo?e aaoiiiiiuo nenoai, iacuaathony i?ioieieaie
aioo?aiieo oethcia (interior gateway protocol, IGP), a i?ioieieu,
ii?aaeaeythuea iaiai ia?o?ooiie eioi?iaoeeae iaaeaeo aiaoieie oethcaie e
oethcaie iaaeno?aeueiie naoe – i?ioieieaie aiaoieo oethcia (exterior
gateway protocol, EGP). Aioo?e iaaeno?aeueiie naoe oaeaea iiaeao
eniieueciaaoueny ethaie nianoaaiiue aioo?aiiee i?ioieie IGP.
Niune ?acaeaeaiey anae naoe Internet ia aaoiiiiiua nenoaiu a aa
iiiaio?iaiaaii i?aaenoaaeaiee, /oi iaiaoiaeeii aeey ethaie e?oiiie
nenoaiu, niiniaiie e ?anoe?aieth a aieueoeo ianooaaao. Aioo?aiiea oethcu
iiaoo eniieueciaaoue aeey aioo?aiiae ia?o?ooecaoeee aeinoaoi/ii
iiae?iaiua a?aou naycae iaaeaeo niaie, /oiau aua?aoue iaeaieaa
?aoeeiiaeueiue ia?o?oo. Iaeiaei, anee eioi?iaoeey oaeie noaiaie
aeaoaeecaoeee aoaeao o?aieoueny ai anao ia?o?ooecaoi?ao naoe, oi
oiiieiae/aneea aacu aeaiiuo oae ?ac?anooony, /oi iio?aaotho iaee/ey
iaiyoe aeaaioneeo ?acia?ia, a a?aiy i?eiyoey ?aoaiee i ia?o?ooecaoeee
iai?aiaiii aic?anoao.
Iiyoiio aeaoaeueiay oiiieiae/aneay eioi?iaoeey inoaaony aioo?e
aaoiiiiiie nenoaiu, a aaoiiiiioth nenoaio eae aaeeiia oeaeia aeey
inoaeueiie /anoe Internet i?aaenoaaeytho aiaoiea oethcu, eioi?ua
niiauatho i aioo?aiiai ninoaaa aaoiiiiiie nenoaiu ieieiaeueii
iaiaoiaeeiua naaaeaiey – eiee/anoai IP-naoae, eo aae?ana e aioo?aiiaa
?annoiyiea aei yoeo naoae io aeaiiiai aiaoiaai oethca.
I?e eieoeeaeecaoeee aiaoiee oethc ociaao oieeaeueiue eaeaioeoeeaoi?
ianeoaeeaaaiie ei aaoiiiiiie nenoaiu, a oaeaea oaaeeoeo aeinoeaeeiinoe
(reachability table), eioi?ay iicaieyao aio acaeiiaeaenoaiaaoue n
ae?oaeie aiaoieie oethcaie /a?ac iaaeno?aeueioth naoue.
Caoai aiaoiee oethc ia/eiaao acaeiiaeaenoaiaaoue ii i?ioieieo EGP n
ae?oaeie aiaoieie oethcaie e iaiaieaaoueny n ieie ia?o?ooiie
eioi?iaoeeae, ninoaa eioi?ie iienai auoa. A ?acoeueoaoa, i?e ioi?aaea
iaeaoa ec iaeiie aaoiiiiiie nenoaiu a ae?oaoth, aiaoiee oethc aeaiiie
nenoaiu ia iniiaaiee ia?o?ooiie eioi?iaoeee, iieo/aiiie io anao aiaoieo
oethcia, n eioi?uie ii iauaaony ii i?ioieieo EGP, auae?aao iaeaieaa
iiaeoiaeyuee aiaoiee oethc e ioi?aaeyao aio iaeao.
A i?ioieiea EGP ii?aaeaeaiu o?e iniiaiua ooieoeee:
· onoaiiaeaiea ninaaeneeo ioiioaiee,
· iiaeoaa?aeaeaiea aeinoeaeeiinoe ninaaea,
· iaiiaeaiea ia?o?ooiie eioi?iaoeee.
Eaaeaeay ooieoeey ?aaioaao ia iniiaa iaiaia niiauaieyie cai?in-ioaao.
Oae eae eaaeaeay aaoiiiiiay nenoaia ?aaioaao iiae eiio?ieai naiaai
aaeieieno?aoeaiiai ooaoa, oi ia?aae ia/aeii iaiaia ia?o?ooiie
eioi?iaoeeae aiaoiea oethcu aeieaeiu niaeaneoueny ia oaeie iaiai.
Nia/aea iaeei ec oethcia iinueaao cai?in ia onoaiiaeaiea ninaaeneeo
ioiioaiee (acquisition request) ae?oaiio oethco. Anee oio niaeanai ia
yoi, oi ii ioaa/aao niiauaieai iiaeoaa?aeaeaiea onoaiiaeaiey ninaaeneeo
ioiioaiee (acquisition confirm), a anee iao – oi niiauaieai ioeac io
onoaiiaeaiey ninaaeneeo ioiioaiee (acquisition refuse), eioi?ia
niaea?aeeo oaeaea i?e/eio ioeaca.
Iinea onoaiiaeaiey ninaaeneeo ioiioaiee oethcu ia/eiatho ia?eiaee/anee
i?iaa?youe ninoiyiea aeinoeaeeiinoe ae?oa ae?oaa. Yoi aeaeaaony eeai n
iiiiuueth niaoeeaeueiuo niiauaiee (i?eaao (hello) e ss-oneuoae-oaay
(I-heard-you)), eeai ano?aeaaieai iiaeoaa?aeaeathuae eioi?iaoeee
iaiin?aaenoaaiii a caaieiaie iau/iiai ia?o?ooiiai niiauaiey.
Iaiai ia?o?ooiie eioi?iaoeeae ia/eiaaony n iinueee iaeiei ec oethcia
ae?oaiio niiauaiey cai?in aeaiiuo (poll request) i iiia?ao naoae,
ianeoaeeaaaiuo ae?oaei oethcii e ?annoiyieyo aei ieo io iaai. Ioaaoii ia
yoi niiauaiea neoaeeo niiauaiea iaiiaeaiiay ia?o?ooiay eioi?iaoeey
(routing update). Anee aea cai?in ieacaeny iaei??aeoiui, oi a ioaao ia
iaai ionueaaony niiauaiea ia ioeaea.
Ana niiauaiey i?ioieiea EGP ia?aaeathony a iiea aeaiiuo IP-iaeaoia.
Niiauaiey EGP eiatho caaieiaie oeene?iaaiiiai oi?iaoa (?enoiie 8.4).
Iiey Oei e Eiae niaianoii ii?aaeaeytho oei niiauaiey, a iiea Noaoon –
eioi?iaoeeth, caaenyuoth io oeia niiauaiey. Iiea Iiia? aaoiiiiiie
nenoaiu – yoi iiia?, iacia/aiiue oie aaoiiiiiie nenoaia, e eioi?ie
i?eniaaeeiai aeaiiue aiaoiee oethc. Iiea Iiia? iineaaeiaaoaeueiinoe
neoaeeo aeey neio?iiecaoeee i?ioeanna cai?inia e ioaaoia.
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?en. 8.4. Oi?iao niiauaiey i?ioieiea EGP
Iiea IP-aae?an enoiaeiie naoe a niiauaieyo cai?ina e iaiiaeaiey
ia?o?ooiie eioi?iaoeee iaicia/aao naoue, niaaeeiythuoth aeaa aiaoieo
oethca (?enoiie 8.5).
Niiauaiea ia iaiiaeaiiie ia?o?ooiie eioi?iaoeee niaea?aeeo nienie
aae?ania naoae, eioi?ua aeinoeaeeiu a aeaiiie aaoiiiiiie nenoaia. Yoio
nienie oii?yaei/ai ii aioo?aiiei oethcai, eioi?ua iiaeeeth/aiu e
enoiaeiie naoe e /a?ac eioi?ua aeinoeaeeiu aeaiiua naoe, a aeey
eaaeaeiai oethca ii oii?yaei/ai ii ?annoiyieth aei eaaeaeie aeinoeaeeiie
naoe io enoiaeiie naoe, a ia io aeaiiiai aioo?aiiaai oethca. Aeey
i?eia?a, i?eaaaeaiiiai ia ?enoiea 8.5, aiaoiee oethc R2 a naiai
niiauaiee oeacuaaao, /oi naoue 4 aeinoeaeeia n iiiiuueth oethca R3 e
?annoiyiea aa ?aaii 2, a naoue 2 aeinoeaeeia /a?ac oethc R2 e aa
?annoiyiea ?aaii 1 (a ia 0, eae anee au oethc ecia?ye aa ?annoiyiea io
naay, eae a i?ioieiea RIP).
I?ioieie EGP eiaao aeinoaoi/ii iiiai ia?aie/aiee, naycaiiuo n oai, /oi
ii ?anniao?eaaao iaaeno?aeueioth naoue eae iaeio iaaeaeeioth
iaaeno?aeue.
?acaeoeai i?ioieiea EGP yaeyaony i?ioieie BGP (Border Gateway Protocol),
eiathuee iiiai iauaai n EGP e eniieuecoaiue ia?yaeo n iei a iaaeno?aee
naoe Internet.
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?en. 8.5. I?eia? aaoiiiiiie nenoaiu
I?ioieie ninoiyiey naycae OSPF
I?ioieie OSPF (Open Shortest Path Firs) yaeyaony aeinoaoi/ii nia?aiaiiie
?aaeecaoeeae aeai?eoia ninoiyiey naycae (ii i?eiyo a 1991 aiaeo) e
iaeaaeaao iiiaeie iniaaiiinoyie, i?eaioe?iaaiiuie ia i?eiaiaiea a
aieueoeo aaoa?iaaiiuo naoyo.
I?ioieie OSPF au/eneyao ia?o?oou a IP-naoyo, nio?aiyy i?e yoii ae?oaea
i?ioieieu iaiaia ia?o?ooiie eioi?iaoeeae.
Iaiin?aaenoaaiii naycaiiua (oi anoue aeinoeaeeiua aac eniieueciaaiey
i?iiaaeooi/iuo ia?o?ooecaoi?ia) ia?o?ooecaoi?u iacuaathony “ninaaeyie”.
Eaaeaeue ia?o?ooecaoi? o?aieo eioi?iaoeeth i oii, a eaeii ninoiyiee ii
aai iiaieth iaoiaeeony ninaae. Ia?o?ooecaoi? iieaaaaony ia ninaaeiea
ia?o?ooecaoi?u e ia?aaeaao ei iaeaou aeaiiuo oieueei a oii neo/aa, anee
ii oaa?ai, /oi iie iieiinoueth ?aaioiniiniaiu. Aeey auyniaiey ninoiyiey
naycae ia?o?ooecaoi?u-ninaaee aeinoaoi/ii /anoi iaiaieaathony ei?ioeeie
niiauaieyie HELLO.
Aeey ?ani?ino?aiaiey ii naoe aeaiiuo i ninoiyiee naycae ia?o?ooecaoi?u
iaiaieaathony niiauaieyie ae?oaiai oeia. Yoe niiauaiey iacuaathony
router links advertisement – iauyaeaiea i naycyo ia?o?ooecaoi?a (oi/iaa,
i ninoiyiee naycae). OSPF-ia?o?ooecaoi?u iaiaieaathony ia oieueei
naieie, ii e /oaeeie iauyaeaieyie i naycyo, iieo/ay a eiioea-eiioeia
eioi?iaoeeth i ninoiyiee anao naycae naoe. Yoa eioi?iaoeey e ia?acoao
a?ao naycae naoe, eioi?ue, anoanoaaiii, iaeei e oio aea aeey anao
ia?o?ooecaoi?ia naoe.
E?iia eioi?iaoeee i ninaaeyo, ia?o?ooecaoi? a naiai iauyaeaiee
ia?a/eneyao IP-iiaenaoe, n eioi?uie ii naycai iaiin?aaenoaaiii, iiyoiio
iinea iieo/aiey eioi?iaoeee i a?aoa naycae naoe, au/eneaiea ia?o?ooa aei
eaaeaeie naoe i?iecaiaeeony iaiin?aaenoaaiii ii yoiio a?aoo ii aeai?eoio
Aeyeeno?u. Aieaa oi/ii, ia?o?ooecaoi? au/eneyao iooue ia aei eiie?aoiie
naoe, a aei ia?o?ooecaoi?a, e eioi?iio yoa naoue iiaeeeth/aia. Eaaeaeue
ia?o?ooecaoi? eiaao oieeaeueiue eaeaioeoeeaoi?, eioi?ue ia?aaeaaony a
iauyaeaiee i ninoiyieyo naycae. Oaeie iiaeoiae aeaao aiciiaeiinoue ia
o?aoeoue IP-aae?ana ia nayce oeia “oi/ea-oi/ea” iaaeaeo
ia?o?ooecaoi?aie, e eioi?ui ia iiaeeeth/aiu ?aai/ea noaioeee.
Ia?o?ooecaoi? au/eneyao iioeiaeueiue ia?o?oo aei eaaeaeie aae?anoaiie
naoe, ii caiiieiaao oieueei ia?aue i?iiaaeooi/iue ia?o?ooecaoi? ec
eaaeaeiai ia?o?ooa. Oaeei ia?acii, ?acoeueoaoii au/eneaiee iioeiaeueiuo
ia?o?ooia yaeyaony nienie no?ie, a eioi?uo oeacuaaaony iiia? naoe e
eaeaioeoeeaoi? ia?o?ooecaoi?a, eioi?iio ioaeii ia?aneaoue iaeao aeey
yoie naoe. Oeacaiiue nienie ia?o?ooia e yaeyaony ia?o?ooiie oaaeeoeae,
ii au/eneai ii ia iniiaaiee iieiie eioi?iaoeee i a?aoa naycae naoe, a ia
/anoe/iie eioi?iaoeee, eae a i?ioieiea RIP.
Iienaiiue iiaeoiae i?eaiaeeo e ?acoeueoaoo, eioi?ue ia iiaeao auoue
aeinoeaioo i?e eniieueciaaiee i?ioieiea RIP eee ae?oaeo
aeenoaioeeiiii-aaeoi?iuo aeai?eoiia. RIP i?aaeiieaaaao, /oi ana iiaenaoe
ii?aaeaeaiiie IP-naoe eiatho iaeei e oio aea ?acia?, oi anoue, /oi ana
iie iiaoo iioaioeeaeueii eiaoue iaeeiaeiaia /enei IP-oceia, aae?ana
eioi?uo ia ia?ae?uaathony. Aieaa oiai, eeanne/aneay ?aaeecaoeey RIP
o?aaoao, /oiau auaeaeaiiua eeiee “oi/ea-oi/ea” eiaee IP-aae?an, /oi
i?eaiaeeo e aeiiieieoaeueiui cao?aoai IP-aae?ania.
A OSPF oaeea o?aaiaaiey ionoonoaotho: naoe iiaoo eiaoue ?acee/iia /enei
oinoia e iiaoo ia?ae?uaaoueny. Iiae ia?ae?uoeai iiieiaaony iaee/ea
ianeieueeeo ia?o?ooia e iaeiie e oie aea naoe. A yoii neo/aa aae?an naoe
a i?eoaaeoai iaeaoa iiaeao niaianoue n aae?anii naoe, i?enaiaiiui
ianeieueeei ii?oai.
Anee aae?an i?eiaaeeaaeeo ianeieueeei iiaenaoyi a aaca aeaiiuo
ia?o?ooia, oi i?iaeaeaathuee iaeao ia?o?ooecaoi? eniieuecoao iaeaieaa
niaoeeoe/aneee ia?o?oo, oi anoue aae?an iiaenaoe, eiathuae aieaa
aeeeiioth ianeo.
Iai?eia?, anee ?aai/ay a?oiia ioaaoaeyaony io aeaaiie naoe, oi iia eiaao
aae?an aeaaiie naoe ia?yaeo n aieaa niaoeeoe/aneei aae?anii,
ii?aaeaeyaiui ianeie iiaenaoe. I?e auai?a ia?o?ooa e oinoo a iiaenaoe
yoie ?aai/ae a?oiiu ia?o?ooecaoi? iaeaeao aeaa iooe, iaeei aeey aeaaiie
naoe e iaeei aeey ?aai/ae a?oiiu. Oae eae iineaaeiee aieaa niaoeeoe/ai,
oi ii e aoaeao aua?ai. Yoio iaoaieci yaeyaony iaiauaieai iiiyoey
“ia?o?oo ii oiie/aieth”, eniieuecoaiiai ai iiiaeo naoyo.
Eniieueciaaiea iiaenaoae n ?acee/iui eiee/anoaii oinoia yaeyaony aiieia
anoanoaaiiui. Iai?eia?, anee a caeaiee eee eaiiona ia eaaeaeii yoaaea
eiathony eieaeueiua naoe, e ia iaeioi?uo yoaaeao eiiiuethoa?ia aieueoa,
/ai ia ae?oaeo, oi aaeieieno?aoi? iiaeao aua?aoue ?acia?u iiaenaoae,
io?aaeathuea iaeeaeaaiua o?aaiaaiey eaaeaeiai yoaaea, a ia
niioaaonoaothuea ?acia?o iaeaieueoae iiaenaoe.
A i?ioieiea OSPF iiaenaoe aeaeyony ia o?e eaoaai?ee:
· “oino-naoue”, i?aaenoaaeythuay niaie iiaenaoue ec iaeiiai aae?ana,
· “ooieeiaay naoue”, eioi?ay i?aaenoaaeyao niaie iiaenaoue,
iiaeeeth/aiioth oieueei e iaeiiio ia?o?ooecaoi?o,
· “o?aiceoiay naoue”, eioi?ay i?aaenoaaeyao niaie iiaenaoue,
iiaeeeth/aiioth e aieaa /ai iaeiiio ia?o?ooecaoi?o.
O?aiceoiay naoue yaeyaony aeey i?ioieiea OSPF iniaui neo/aai. A
o?aiceoiie naoe ianeieueei ia?o?ooecaoi?ia yaeythony acaeiii e
iaeiia?aiaiii aeinoeaeeiuie. A oe?ieiaauaoaeueiuo eieaeueiuo naoyo,
oaeeo eae Ethernet eee Token Ring, ia?o?ooecaoi? iiaeao iineaoue iaeii
niiauaiea, eioi?ia iieo/ao ana aai ninaaee. Yoi oiaiueoaao iaa?oceo ia
ia?o?ooecaoi?, eiaaea ii iinueaao niiauaiey aeey ii?aaeaeaiey
nouanoaiaaiey nayce eee iaiiaeaiiua iauyaeaiey i ninaaeyo. Iaeiaei, anee
eaaeaeue ia?o?ooecaoi? aoaeao ia?a/eneyoue anao naieo ninaaeae a naieo
iauyaeaieyo i ninaaeyo, oi iauyaeaiey caeioo iiiai ianoa a iaiyoe
ia?o?ooecaoi?a. I?e ii?aaeaeaiee iooe ii aae?anai o?aiceoiie iiaenaoe
iiaeao iaia?oaeeoueny iiiai ecauoi/iuo ia?o?ooia e ?acee/iui
ia?o?ooecaoi?ai. Ia au/eneaiea, i?iaa?eo e ioa?aeiaeo yoeo ia?o?ooia
oeaeao iiiai a?aiaie.
Eiaaea ia?o?ooecaoi? ia/eiaao ?aaioaoue a ia?aue ?ac (oi anoue
einoaeee?oaony), ii iuoaaony neio?iiece?iaaoue naith aaco aeaiiuo ni
anaie ia?o?ooecaoi?aie o?aiceoiie eieaeueiie naoe, eioi?ua ii
ii?aaeaeaieth eiatho eaeaioe/iua aacu aeaiiuo. Aeey oi?iuaiey e
iioeiecaoeee yoiai i?ioeanna a i?ioieiea OSPF eniieuecoaony iiiyoea
“auaeaeaiiiai” ia?o?ooecaoi?a, eioi?ue auiieiyao aeaa ooieoeee.
Ai-ia?auo, auaeaeaiiue ia?o?ooecaoi? e aai ?aca?aiue “iaia?iee”
yaeythony aaeeinoaaiiuie ia?o?ooecaoi?aie, n eioi?uie iiaue
ia?o?ooecaoi? aoaeao neio?iiece?iaaoue naith aaco. Neio?iiece?iaaa aaco
n auaeaeaiiui ia?o?ooecaoi?ii, iiaue ia?o?ooecaoi? aoaeao
neio?iiece?iaai ni anaie ia?o?ooecaoi?aie aeaiiie eieaeueiie naoe.
Ai-aoi?uo, auaeaeaiiue ia?o?ooecaoi? aeaeaao iauyaeaiea i naoaauo
naycyo, ia?a/eneyy naieo ninaaeae ii iiaenaoe. Ae?oaea ia?o?ooecaoi?u
i?inoi iauyaeytho i naiae nayce n auaeaeaiiui ia?o?ooecaoi?ii. Yoi
aeaeaao iauyaeaiey i naycyo (eioi?uo iiiai) aieaa e?aoeeie, ?acia?ii n
iauyaeaiea i naycyo ioaeaeueiie naoe.
Aeey ia/aea ?aaiou ia?o?ooecaoi?a OSPF ioaeai ieieioi eioi?iaoeee –
IP-eiioeao?aoeey (IP-aae?ana e ianee iiaenaoae), iaeioi?ay eioi?iaoeey
ii oiie/aieth (default) e eiiaiaea ia aeeth/aiea. Aeey iiiaeo naoae
eioi?iaoeey ii oiie/aieth aanueia iioiaea. A oi aea a?aiy i?ioieie OSPF
i?aaeoniao?eaaao aunieoth noaiaiue i?ia?aiie?oaiinoe.
Eioa?oaen OSPF (ii?o ia?o?ooecaoi?a, iiaeaea?aeeaathuaai i?ioieie OSPF)
yaeyaony iaiauaieai iiaenaoe IP. Iiaeiaii iiaenaoe IP, eioa?oaen OSPF
eiaao IP-aae?an e ianeo iiaenaoe. Anee iaeei ii?o OSPF iiaeaea?aeeaaao
aieaa, /ai iaeio iiaenaoue, i?ioieie OSPF ?anniao?eaaao yoe iiaenaoe
oae, eae anee au iie auee ia ?aciuo oece/aneeo eioa?oaenao, e au/eneyao
ia?o?oou niioaaonoaaiii.
Eioa?oaenu, e eioi?ui iiaeeeth/aiu eieaeueiua naoe, iacuaathony
oe?ieiaauaoaeueiuie (broadcast) eioa?oaenaie, oae eae iie iiaoo
eniieueciaaoue oe?ieiaauaoaeueiua aiciiaeiinoe eieaeueiuo naoae aeey
iaiaia neaiaeueiie eioi?iaoeeae iaaeaeo ia?o?ooecaoi?aie. Eioa?oaenu, e
eioi?ui iiaeeeth/aiu aeiaaeueiua naoe, ia iiaeaea?aeeaathuea
oe?ieiaauaiea, ii iaania/eaathuea aeinooi ei iiiaei oceai /a?ac iaeio
oi/eo aoiaea, iai?eia? naoe O.25 eee frame relay, iacuaathony
iaoe?ieiaauaoaeueiuie eioa?oaenaie n iiiaeanoaaiiui aeinooiii eee NBMA
(non-broadcast multi-access). Iie ?anniao?eaathony aiaeiae/ii
oe?ieiaauaoaeueiui eioa?oaenai ca eneeth/aieai oiai, /oi
oe?ieiaauaoaeueiay ?annueea yioee?oaony iooai iinueee niiauaiey
eaaeaeiio ninaaeo. Oae eae iaia?oaeaiea ninaaeae ia yaeyaony
aaoiiaoe/aneei, eae a oe?ieiaauaoaeueiuo naoyo, NBMA-ninaaee aeieaeiu
caaeaaaoueny i?e eiioeao?e?iaaiee a?o/ioth. Eae ia oe?ieiaauaoaeueiuo,
oae e ia NBMA-eioa?oaenao iiaoo auoue caaeaiu i?ei?eoaou ia?o?ooecaoi?ia
aeey oiai, /oiau iie iiaee aua?aoue auaeaeaiiue ia?o?ooecaoi?.
Eioa?oaenu “oi/ea-oi/ea”, iiaeiaiua PPP, ianeieueei ioee/athony io
o?aaeeoeeiiiie IP-iiaeaee. Oioy iie e iiaoo eiaoue IP-aae?ana e
iiaeianee, ii iaiaoiaeeiinoe a yoii iao.
A i?inouo naoyo aeinoaoi/ii ii?aaeaeeoue, /oi ioieo iacia/aiey
aeinoeaeei e iaeoe ia?o?oo, eioi?ue aoaeao oaeiaeaoai?eoaeueiui. A
neiaeiuo naoyo iau/ii eiaaony ianeieueei aiciiaeiuo ia?o?ooia. Eiiaaea
oioaeinue au eiaoue aiciiaeiinoe ii onoaiiaeaieth aeiiieieoaeueiuo
e?eoa?eaa aeey auai?a iooe: iai?eia?, iaeiaiueoay caaea?aeea,
iaeneiaeueiay i?iioneiay niiniaiinoue eee iaeiaiueoay noieiinoue (a
naoyo n iieaoie ca iaeao). Ii yoei i?e/eiai i?ioieie OSPF iicaieyao
naoaaiio aaeieieno?aoi?o iacia/aoue eaaeaeiio eioa?oaeno ii?aaeaeaiiia
/enei, iacuaaaiia iao?eeie, /oiau ieacaoue ioaeiia aeeyiea ia auai?
ia?o?ooa.
*enei, eniieuecoaiia a ea/anoaa iao?eee iooe, iiaeao auoue iacia/aii
i?iecaieueiui ia?acii ii aeaeaieth aaeieieno?aoi?a. Ii ii oiie/aieth a
ea/anoaa iao?eee eniieuecoaony a?aiy ia?aaea/e aeoa a 10-oe
iaiinaeoiaeiuo aaeeieoeao (10 Ia/n Ethernet’o iacia/aaony cia/aiea 10, a
eeiee 56 Ea/n – /enei 1785). Au/eneyaiay i?ioieieii OSPF iao?eea iooe
i?aaenoaaeyao niaie noiio iao?ee anao i?ioiaeeiuo a iooe naycae; yoi
i/aiue a?oaay ioeaiea caaea?aeee iooe. Anee ia?o?ooecaoi? iaia?oaeeaaao
aieaa, /ai iaeei iooue e oaeaeaiiie iiaenaoe, oi ii eniieuecoao iooue n
iaeiaiueoae noieiinoueth iooe.
A i?ioieiea OSPF eniieuecoaony ianeieueei a?aiaiiuo ia?aiao?ia, e n?aaee
ieo iaeaieaa aaaeiuie yaeythony eioa?aae niiauaiey HELLO e eioa?aae
ioeaca ia?o?ooecaoi?a (router dead interval).
HELLO – yoi niiauaiea, eioi?ui iaiaieaathony ninaaeiea, oi anoue
iaiin?aaenoaaiii naycaiiua ia?o?ooecaoi?u iiaenaoe, n oeaeueth
onoaiiaeoue ninoiyiea eeiee nayce e ninoiyiea ia?o?ooecaoi?a-ninaaea. A
niiauaiee HELLO ia?o?ooecaoi? ia?aaeaao naie ?aai/ea ia?aiao?u e aiai?eo
i oii, eiai ii ?anniao?eaaao a ea/anoaa naieo aeeaeaeoeo ninaaeae.
Ia?o?ooecaoi?u n ?aciuie ?aai/eie ia?aiao?aie eaii?e?otho niiauaiey
HELLO ae?oa ae?oaa, iiyoiio iaaa?ii neiioeao?e?iaaiiua ia?o?ooecaoi?u ia
aoaeoo aeeyoue ia ?aaioo naoe. Eaaeaeue ia?o?ooecaoi? oeao niiauaiea
HELLO eaaeaeiio naiaio ninaaeo ii e?aeiae ia?a iaeei ?ac ia i?ioyaeaiee
eioa?aaea HELLO. Anee eioa?aae ioeaca ia?o?ooecaoi?a enoaeaao aac
iieo/aiey niiauaiey HELLO io ninaaea, oi n/eoaaony, /oi ninaae
ia?aaioiniiniaai, e ?ani?ino?aiyaony iiaia iauyaeaiea i naoaauo naycyo,
/oiau a naoe i?iecioae ia?an/ao ia?o?ooia.
I?eia? ia?o?ooecaoeee ii aeai?eoio OSPF
I?aaenoaaei naaa iaeei aeaiue ec aeecie o?aiceoiie eieaeueiie naoe.
Ionoue o ian eiaaony naoue Ethernet, a eioi?ie anoue o?e ia?o?ooecaoi?a
– Aeaeii, O?aae e ?ia (eiaia /eaiia ?aai/ae a?oiiu Internet,
?ac?aaioaaoae i?ioieie OSPF). Yoe ia?o?ooecaoi?u naycaiu n naoyie a
ae?oaeo ai?iaeao n iiiiuueth auaeaeaiiuo eeiee.
Ionoue i?iecioei ainnoaiiaeaiea naoaaiai ieoaiey iinea naiy.
Ia?o?ooecaoi?u e eiiiuethoa?u ia?acaa?oaeathony e ia/eiatho ?aaioaoue ii
naoe Ethernet. Iinea oiai, eae ia?o?ooecaoi?u iaia?oaeeaatho, /oi ii?ou
Ethernet ?aaioatho ii?iaeueii, iie ia/eiatho aaia?e?iaaoue niiauaiey
HELLO, eioi?ua aiai?yo i eo i?enoonoaee a naoe e eo eiioeao?aoeee.
Iaeiaei ia?o?ooecaoeey iaeaoia ia/eiaao inouanoaeyoueny ia n?aco –
nia/aea ia?o?ooecaoi?u aeieaeiu neio?iiece?iaaoue naie ia?o?ooiua aacu
(?enoiie 8.6).
picscalex11
?en. 8.6. Aeiioaoe/aneay naoue n OSPF ia?o?ooecaoi?aie
Ia i?ioyaeaiee eioa?aaea ioeaca ia?o?ooecaoi?u i?iaeieaeatho iinueaoue
niiauaiey HELLO. Eiaaea eaeie-eeai ia?o?ooecaoi? iinueaao oaeia
niiauaiea, ae?oaea aai iieo/atho e ioia/atho, /oi a eieaeueiie naoe
anoue ae?oaie ia?o?ooecaoi?. Eiaaea iie iinueatho neaaeothuaa HELLO, iie
ia?a/eneytho oai e naiaai iiaiai ninaaea.
Eiaaea ia?eiae ioeaca ia?o?ooecaoi?a enoaeaao, oi ia?o?ooecaoi? n
iaeaunoei i?ei?eoaoii e iaeaieueoei eaeaioeoeeaoi?ii iauyaeyao naay
auaeaeaiiui (a neaaeothuee ca iei ii i?ei?eoaoo ia?o?ooecaoi? iauyaeyao
naay ?aca?aiui auaeaeaiiui ia?o?ooecaoi?ii) e ia/eiaao neio?iiece?iaaoue
naith aaco aeaiiuo n ae?oaeie ia?o?ooecaoi?aie.
N yoiai iiiaioa a?aiaie aaca aeaiiuo ia?o?ooiuo iauyaeaiee eaaeaeiai
ia?o?ooecaoi?a iiaeao niaea?aeaoue eioi?iaoeeth, iieo/aiioth io
ia?o?ooecaoi?ia ae?oaeo eieaeueiuo naoae eee ec auaeaeaiiuo eeiee. ?ia,
iai?eia?, aa?iyoii iieo/ee eioi?iaoeeth io Ieei e ?iaeia ia eo naoyo, e
ii iiaeao ia?aaeaaaoue ooaea iaeaou aeaiiuo. Iie niaea?aeao eioi?iaoeeth
i nianoaaiiuo naycyo ia?o?ooecaoi?a e iauyaeaiey i naycyo naoe.
Aacu aeaiiuo oaia?ue neio?iiece?iaaiu n auaeaeaiiui ia?o?ooecaoi?ii,
eioi?ui yaeyaony Aeaeii. Aeaeii noiie?oao naith aaco aeaiiuo n eaaeaeie
aacie aeaiiuo naieo ninaaeae – aacaie O?aaea, ?iaa e Aeaeaooa –
eiaeeaeaeoaeueii. A eaaeaeie neio?iiece?othuaeny ia?a iauyaeaiey,
iaeaeaiiua oieueei a eaeie-eeai iaeiie aaca, eiie?othony a ae?oaoth.
Auaeaeaiiue ia?o?ooecaoi?, Aeaeii, ?ani?ino?aiyao iiaua iauyaeaiey
n?aaee ae?oaeo ia?o?ooecaoi?ia naiae eieaeueiie naoe. Iai?eia?,
iauyaeaiey Ieei e ?iaeia ia?aaeathony Aeaeiio ?iaii, a Aeaeii a naith
i/a?aaeue ia?aaeaao eo O?aaeo e Aeaeaoo?e. Iaiai eioi?iaoeeae iaaeaeo
aacaie i?iaeieaeaaony iaeioi?ia a?aiy, e iiea ii ia caaa?oeony,
ia?o?ooecaoi?u ia aoaeoo n/eoaoue naay ?aaioiniiniaiuie. Iinea yoiai iie
naay oaeiauie n/eoatho, iioiio /oi eiatho anth aeinooiioth eioi?iaoeeth
i naoe.
Iiniio?ei oaia?ue, eae ?iaei au/eneyao ia?o?oo /a?ac naoue. Aeaa ec
naycae, i?eniaaeeiaiiuo e aai ii?oai, i?aaenoaaeytho eeiee T-1, a iaeia
– eeieth 56 Ea/c. ?iaei nia/aea iaia?oaeeaaao aeaoo ninaaeae – ?iaa n
iao?eeie 65 e Ieei n iao?eeie 1785. Ec iauyaeaiey i naycyo ?iaa ?iaei
iaia?oaeee iaeeo/oee iooue e Ieei ni noieiinoueth 130, iiyoiio ii ioaa?a
iaiin?aaenoaaiiue iooue e Ieei, iineieueeo ii naycai n aieueoae
caaea?aeeie, oae eae i?ioiaeeo /a?ac eeiee n iaiueoae i?iioneiie
niiniaiinoueth. ?iaei oaeaea iaia?oaeeaaao o?aiceoioth eieaeueioth naoue
n auaeaeaiiui ia?o?ooecaoi?ii Aeaeiiii. Ec iauyaeaiee i naycyo Aeaeiia
?iaei ociaao i iooe e O?aaeo e, iaeiiaoe, ociaao i iooe e
ia?o?ooecaoi?ai Eaeee e Aeaeaooo e e eo ooieeiaui naoyi.
Iinea oiai, eae ia?o?ooecaoi?u iieiinoueth aoiaeyo a ?aai/ee ?aaeei,
eioaineaiinoue iaiaia niiauaieyie ?acei iaaeaao. Iau/ii iie iinueatho
niiauaiea HELLO ii naiei iiaenaoyi eaaeaeua 10 naeoiae e aeaeatho
iauyaeaiey i ninoiyiee naycae eaaeaeua 30 ieioo (anee iaia?oaeeaathony
eciaiaiey a ninoiyiee naycae, oi iauyaeaiea ia?aaeaaony, anoanoaaiii,
iaiaaeeaiii). Iaiiaeaiiua iauyaeaiey i naycyo neoaeao aa?aioeae oiai,
/oi ia?o?ooecaoi? ?aaioaao a naoe. Noa?ua iauyaeaiey oaeaeythony ec aacu
/a?ac ii?aaeaeaiiia a?aiy.
I?aaenoaaei, iaeiaei, /oi eaeay-eeai auaeaeaiiay eeiey naoe ioeacaea.
I?eniaaeeiaiiua e iae ia?o?ooecaoi?u ?ani?ino?aiytho naie iauyaeaiey, a
eioi?uo iie oaea ia oiiieiatho ae?oa ae?oaa. Yoa eioi?iaoeey
?ani?ino?aiyaony ii naoe, aeeth/ay ia?o?ooecaoi?u o?aiceoiie eieaeueiie
naoe. Eaaeaeue ia?o?ooecaoi? a naoe ia?an/eouaaao naie ia?o?oou,
iaoiaey, iiaeao auoue, iiaua iooe aeey ainnoaiiaeaiey oo?a/aiiiai
acaeiiaeaenoaey.
N?aaiaiea i?ioieieia RIP e OSPF ii cao?aoai ia oe?ieiaauaoaeueiue o?aoee
A naoyo, aaea eniieuecoaony i?ioieie RIP, iaeeaaeiua ?anoiaeu ia iaiai
ia?o?ooiie eioi?iaoeeae no?iai oeene?iaaiu. Anee a naoe eiaaony
ii?aaeaeaiiia /enei ia?o?ooecaoi?ia, oi o?aoee, nicaeaaaaiue
ia?aaeaaaaiie ia?o?ooiie eioi?iaoeeae, iienuaathony oi?ioeie (1):
(1) F = (/enei iauyaeyaiuo ia?o?ooia/25) x 528 (aaeoia a niiauaiee) x
(/enei eiiee a aaeeieoeo a?aiaie) x 8 (aeoia a aaeoa)
A naoe n i?ioieieii OSPF caa?ocea i?e iaeciaiiii ninoiyiee eeiee nayce
nicaeaaony niiauaieyie HELLO e iaiiaeaiiuie iauyaeaieyie i ninoiyiee
naycae, /oi iienuaaaony oi?ioeie (2):
(2) F = [ 20 + 24 + 20 + (4 x /enei ninaaeae)] x (/enei eiiee HELLO a
aaeeieoeo a?aiaie) x 8 + [(/enei iauyaeaiee x n?aaeiee ?acia?
iauyaeaiey) x (/enei eiiee iauyaeaiee a aaeeieoeo a?aiaie)] x 8,
aaea 20 – ?acia? caaieiaea IP-iaeaoa,
24 – caaieiaie iaeaoa OSPF,
20 – ?acia? caaieiaea niiauaiey HELLO,
4 – aeaiiua ia eaaeaeiai ninaaea.
Eioaineaiinoue iinueee niiauaiee HELLO – eaaeaeua 10 naeoiae, iauyaeaiee
i ninoiyiee naycae – eaaeaeua iie/ana. Ii naycyi “oi/ea-oi/ea” eee ii
oe?ieiaauaoaeueiui eieaeueiui naoyi a aaeeieoeo a?aiaie iinueaaony
oieueei iaeia eiiey niiauaiey, ii NBMA naoyi oeia frame relay eaaeaeiio
ninaaeo iinueaaony naiy eiiey niiauaiey. A naoe frame relay n 10
ninaaeieie ia?o?ooecaoi?aie e 100 ia?o?ooaie a naoe (iiae?acoiaaaaony,
/oi eaaeaeue ia?o?oo i?aaenoaaeyao niaie ioaeaeueiia OSPF-iaiauaiea i
naoaauo naycyo e /oi RIP ?ani?ino?aiyao eioi?iaoeeth i anao yoeo
ia?o?ooao) o?aoee ia?o?ooiie eioi?iaoeee ii?aaeaeyaony niioiioaieyie (3)
e (4):
(3) RIP: (100 ia?o?ooia / 25 ia?o?ooia a iauyaeaiee) x 528 x (10 eiiee /
30 nae) = 5 632 a/n
(4) OSPF: [20 + 24 + 20 + (4 x 10) x (10 eiiee / 10 nae)] + [100
ia?o?ooia x (32 + 24 + 20) + (10 eiiee / 30 x 60 nae] x 8 = 1 170 a/n
Eae aeaeii ec iieo/aiiuo ?acoeueoaoia, aeey iaoaai aeiioaoe/aneiai
i?eia?a o?aoee, nicaeaaaaiue i?ioieieii RIP, ii/oe a iyoue ?ac
eioaineaiae o?aoeea, nicaeaaaaiiai i?ioieieii OSPF.
Eniieueciaaiea ae?oaeo i?ioieieia ia?o?ooecaoeee
Neo/ae eniieueciaaiey a naoe oieueei i?ioieiea ia?o?ooecaoeee OSPF
i?aaenoaaeyaony iaeiaa?iyoiui. Anee naoue i?eniaaeeiaia e Internet’o, oi
iiaoo eniieueciaaoueny oaeea i?ioieieu, eae EGP (Exterior Gateway
protocol), BGP (Border Gateway Protocol, i?ioieie iia?aie/iiai
ia?o?ooecaoi?a), noa?ue i?ioieie ia?o?ooecaoeee RIP eee nianoaaiiua
i?ioieieu i?iecaiaeeoaeae.
Eiaaea a naoe ia/eiaao i?eiaiyoueny i?ioieie OSPF, oi nouanoaothuea
i?ioieieu ia?o?ooecaoeee iiaoo i?iaeieaeaoue eniieueciaaoueny aei oao
ii?, iiea ia aoaeoo iieiinoueth caiaiaiu. A iaeioi?uo neo/ayo
iaiaoiaeeii aoaeao iauyaeyoue i noaoe/aneeo ia?o?ooao,
neiioeao?e?iaaiiuo a?o/ioth.
A OSPF nouanoaoao iiiyoea aaoiiiiiuo nenoai ia?o?ooecaoi?ia (autonomous
systems), eioi?ua i?aaenoaaeytho niaie aeiiaiu ia?o?ooecaoeee,
iaoiaeyueany iiae iauei aaeieieno?aoeaiui oi?aaeaieai e eniieuecothuea
aaeeiue i?ioieie ia?o?ooecaoeee. OSPF iacuaaao ia?o?ooecaoi?, eioi?ue
niaaeeiyao aaoiiiiioth nenoaio n ae?oaie aaoiiiiiie nenoaiie,
eniieuecothuae ae?oaie i?ioieie ia?o?ooecaoeee, iia?aie/iui
ia?o?ooecaoi?ii aaoiiiiiie nenoaiu (autonomous system boundary router,
ASBR).
A OSPF ia?o?oou (eiaiii ia?o?oou, oi anoue iiia?a naoae e ?annoiyiey aei
ieo ai aiaoiae iao?eea, a ia oiiieiae/aneay eioi?iaoeey) ec iaeiie
aaoiiiiiie nenoaiu eiii?oe?othony a ae?oaoth aaoiiiiioth nenoaio e
?ani?ino?aiythony n eniieueciaaieai niaoeeaeueiuo aiaoieo iauyaeaiee i
naycyo.
Aiaoiea ia?o?oou ia?aaaouaathony ca aeaa yoaia. Ia?o?ooecaoi? auae?aao
n?aaee aiaoieo ia?o?ooia ia?o?oo n iaeiaiueoae aiaoiae iao?eeie. Anee
oaeiauo ieacuaaaony aieueoa, /ai 2, oi auae?aaony iooue n iaiueoae
noieiinoueth aioo?aiiaai iooe aei ASBR.
Iaeanoue OSPF – yoi iaai? niaaeiuo eioa?oaenia (oa??eoi?eaeueiuo eeiee
eee eaiaeia eieaeueiuo naoae). Aaaaeaiea iiiyoey “iaeanoue” neoaeeo
aeaoi oeaeyi – oi?aaeaieth eioi?iaoeeae e ii?aaeaeaieth aeiiaiia
ia?o?ooecaoeee.
Aeey iiieiaiey i?eioeeia oi?aaeaiey eioi?iaoeeae ?anniio?ei naoue,
eiathuoth neaaeothuoth no?oeoo?o: oeaio?aeueiay eieaeueiay naoue naycaia
n iiiiuueth 50 ia?o?ooecaoi?ia n aieueoei eiee/anoaii ninaaeae /a?ac
naoe X.25 eee frame relay (?enoiie 8.7). Yoe ninaaee i?aaenoaaeytho
niaie aieueoia eiee/anoai iaaieueoeo oaeaeaiiuo iiae?acaeaeaiee,
iai?eia?, ioaeaeia i?iaeaae eee oeeeaeia aaiea. Ec-ca aieueoiai ?acia?a
naoe eaaeaeue ia?o?ooecaoi? aeieaeai o?aieoue ia?iiiia eiee/anoai
ia?o?ooiie eioi?iaoeee, eioi?ay aeieaeia ia?aaeaaaoueny ii eaaeaeie ec
eeiee, e eaaeaeia ec yoeo ianoiyoaeuenoa oaei?iaeaao naoue. Oae eae
oiiieiaey naoe i?inoa, oi aieueoay /anoue yoie eioi?iaoeee e
nicaeaaaaiiai ath o?aoeea ia eiatho niunea.
Aeey eaaeaeiai ec oaeaeaiiuo oeeeaeia iao iaiaoiaeeiinoe eiaoue
aeaoaeueioth ia?o?ooioth eioi?iaoeeth i anao ae?oaeo oaeaeaiiuo ioenao,
a iniaaiiinoe, anee iie acaeiiaeaenoaotho a iniiaiii n oeaio?aeueiuie
eiiiuethoa?aie, naycaiiuie n oeaio?aeueiuie ia?o?ooecaoi?aie.
Aiaeiae/ii, oeaio?aeueiui ia?o?ooecaoi?ai iao iaiaoiaeeiinoe eiaoue
aeaoaeueioth eioi?iaoeeth i oiiieiaee naycae n oaeaeaiiuie ioenaie,
niaaeeiaiiuie n ae?oaeie oeaio?aeueiuie ia?o?ooecaoi?aie. A oi aea a?aiy
oeaio?aeueiua ia?o?ooecaoi?u ioaeaeathony a eioi?iaoeee, iaiaoiaeeiie
aeey ia?aaea/e iaeaoia neaaeothuaio oeaio?aeueiiio ia?o?ooecaoi?o.
Aaeieieno?aoi? iia au aac o?oaea ?acaeaeeoue yoo naoue ia aieaa iaeeea
aeiiaiu ia?o?ooecaoeee aeey oiai, /oiau ia?aie/eoue iauaiu o?aiaiey e
ia?aaea/e ii eeieyi nayce ia yaeythuaeny iaiaoiaeeiie eioi?iaoeee.
Iaiauaiea ia?o?ooiie eioi?iaoeee yaeyaony aeaaiie oeaeueth aaaaeaiey
iaeanoae a OSPF.
picscalex11
?en. 8.7. Aieueoay naoue n oiiieiaeae caacaea
A i?ioieiea OSPF ii?aaeaeyaony oaeaea iia?aie/iue ia?o?ooecaoi? iaeanoe
(ABR, area border router). ABR – yoi ia?o?ooecaoi? n eioa?oaenaie a
aeaoo eee aieaa iaeanoyo, iaeia ec eioi?uo yaeyaony niaoeeaeueiie
iaeanoueth, iacuaaaiie iaaeno?aeueiie (backbone area). Eaaeaeay iaeanoue
?aaioaao n ioaeaeueiie aacie ia?o?ooiie eioi?iaoeee e iacaaeneii
au/eneyao ia?o?oou ii aeai?eoio OSPF. Iia?aie/iua ia?o?ooecaoi?u
ia?aaeatho aeaiiua i oiiieiaee iaeanoe a ninaaeiea iaeanoe a iaiauaiiie
oi?ia – a aeaea au/eneaiiuo ia?o?ooia n eo aanaie. Iiyoiio a naoe,
?acaeoie ia iaeanoe, oaea ia aeaenoaoao ooaa?aeaeaiea i oii, /oi ana
ia?o?ooecaoi?u iia?e?otho n eaeaioe/iuie oiiieiae/aneeie aacaie aeaiiuo.
Ia?o?ooecaoi? ABR aa?ao eioi?iaoeeth i ia?o?ooao OSPF, au/eneaiioth a
iaeiie iaeanoe, e o?ainee?oao aa a ae?oaoth iaeanoue iooai aeeth/aiey
yoie eioi?iaoeee a iaiauaiiia noiia?iia iauyaeaiea (summary) aeey aacu
aeaiiuo ae?oaie iaeanoe. Noiia?iay eioi?iaoeey iienuaaao eaaeaeoth
iiaenaoue iaeanoe e aeaao aeey iaa iao?eeo. Noiia?iay eioi?iaoeey iiaeao
auoue eniieueciaaia o?aiy niiniaaie: aeey iauyaeaiey ia ioaeaeueiii
ia?o?ooa, aeey iaiauaiey ianeieueeeo ia?o?ooia eee aea neoaeeoue
ia?o?ooii ii oiie/aieth.
Aeaeueiaeoaa oiaiueoaiea o?aaiaaiee e ?ano?nai ia?o?ooecaoi?ia
i?ienoiaeeo a oii neo/aa, eiaaea iaeanoue i?aaenoaaeyao niaie ooieeiaoth
iaeanoue (stub area). Yoio ao?eaoo aaeieieno?aoi? naoe iiaeao i?eiaieoue
e ethaie iaeanoe, ca eneeth/aieai iaaeno?aeueiie. ABR a ooieeiaie
iaeanoe ia ?ani?ino?aiyao aiaoiea iauyaeaiey eee noiia?iua iauyaeaiey ec
ae?oaeo iaeanoae. Aianoi yoiai ii aeaeaao iaeii noiia?iia iauyaeaiea,
eioi?ia aoaeao oaeiaeaoai?youe ethaie IP-aae?an, eiathuee iiia? naoe,
ioee/iue io iiia?ia naoae ooieeiaie iaeanoe. Yoi iauyaeaiea iacuaaaony
ia?o?ooii ii oiie/aieth. Ia?o?ooecaoi?u ooieeiaie iaeanoe eiatho
eioi?iaoeeth, iaiaoiaeeioth oieueei aeey au/eneaiey ia?o?ooia iaaeaeo
niaie iethn oeacaiey i oii, /oi ana inoaeueiua ia?o?oou aeieaeiu
i?ioiaeeoue /a?ac ABR. Oaeie iiaeoiae iicaieyao oiaiueoeoue a iaoae
aeiioaoe/aneie naoe eiee/anoai ia?o?ooiie eioi?iaoeee a oaeaeaiiuo
ioenao aac oiaiueoaiey niiniaiinoe ia?o?ooecaoi?ia ei??aeoii
ia?aaeaaaoue iaeaou.
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