Amakilasi we-IP-amakheli. I-Class A, B, C ikheli le-IP

I-IP yindlela yokuxhumana esetshenziselwa inethiwekhi encane kunazo zonke amadivaysi enethiwekhi yomniningwane womhlaba jikelele. Ikheli le-IP iyisihlonzi esiyingqayizivele se-node ethile (idivaysi) eyabelwe kwinethiwekhi ethize.

Ukurekhoda kwekheli le-IP

Ikheli libukeka njengenombolo engu-32-bit ebangeni kusukela ku-0 kuya ku-4294967295. Lokhu kubonisa ukuthi yonke i-Inthanethi ingaqukatha amakheli angaphezu kwezigidi ezingu-4 eziyingqayizivele yezinto. Uma ubhala amakheli kwifomu kanambambili noma yedesimali, lokhu kubangela ukuphazamiseka kwakho ekugcineni noma ekucubunguleni. Ngakho-ke, ukuze kube lula ukuloba kwamakheli anjalo, kunqunywe ukuhlukanisa ikheli lonke kuma-byte amane (izinombolo ezingu-8-bit) ezahlukaniswa isikhathi. Isibonelo: ikheli elisistimu ye-hexadecimal libukeka njenge-C0290612, irekhodi lekheli le-IP lizobukeka njengo-192.41.6.18. Kule nkinga, ikheli elincinyane kunazo zonke ama-zeros amane, kanti iningi liyiqembu lama-255. Isifunda esiphezulu (esisodwa ngakwesobunxele samaqembu amadijithi kusuka kunoma yimaphi amaphuzu ahlukanisayo) sithathwe indawo yekheli, isifunda esingaphansi (ngakwesokudla kwesigaba sokuhlukanisa esifanayo ) Ibonisa inombolo ye-interface kule nethiwekhi. Isikhundla somngcele phakathi kwe-host and izingxenye zenethiwekhi sincike kwinani lezinkinobho ezibekwe kwinombolo yenethiwekhi, ingahluka, ukuhlukaniswa kuhamba kuphela emngceleni we-octet (amaphuzu phakathi kwabo) futhi ikuvumela ukuba uchaze amakilasi ekheli le-IP.

Imodeli yekheli lesiklasi

Emashumini ambalwa eminyaka, amakheli ahlukaniswe ngezigaba ezingu-5. Lesi sigaba esiphelelwe yisikhathi sabizwa ngokukhuluma ngokugcwele. Amakilasi amakheli e-IP abizwa ngokuthi izinhlamvu zezinhlamvu zesiLatini ezivela ku-A kuya ku-E. Izigaba A kuya ku-E zinikeza ikhono lokucacisa izihlonzi zamanethiwekhi angu-128 anezixhumanisi zenethiwekhi eziyizigidi ezingu-16 kumanethiwekhi ngamunye, angu-16384 namadivayisi angu-64 000 nama-2 million amanethiwekhi anama-256 interfaces. Amakilasi we-IP-amanethiwekhi D anikezwa ukuhlukanisa okuningi, lapho amaphakethe emilayezo athunyelwa kubamakhethi abaningana ngesikhathi esisodwa. Amakheli anezinhlamvu zokuqala ezingu-1111 azigcinelwe ukusetshenziswa esikhathini esizayo.

Ngezansi itafula lamakheli e-IP. Amakilasi anqunywa amabhuzu aphezulu kakhulu amakheli.

I-Class A

Amakilasi A A amakheli e-IP abonakala nge-bit ephakeme kakhulu yekheli kanye nesayizi yenethiwekhi yesishiyagalombili. Irekhodiwe ifomu:

Ngokusekelwe kulokhu, inani elikhulu kunawo wonke lamanethiwekhi ase-Class A angaba ngu-2 ⁷ , kodwa ngamunye wabo uyoba isikhala sekheli lamadivayisi ^angu-24 . Njengoba ibanga lokuqala lekheli li-0, wonke amakheli we-IP we-class A azoba ebangeni le-octet eliphakeme kakhulu ukusuka ku-0 kuya ku-127, okungeze kwalokho, kuyoba inombolo yenethiwekhi. Kulesi simo, ikheli le-zero kanye ne-127 ligcinwe ngamakheli enkonzo, ngakho ngeke isetshenziswe. Ngenxa yalesi sizathu, inani eliqondile lama-Class A amanethiwekhi angu-126.

Ikheli lama-nodes enethiwekhi ye-Class A yi-3 bytes (noma ama-24 bits). Ukubalwa okulula kubonisa ukuthi ungafaka inhlanganisela yebhanana engu-16 777 216 (amakheli e-interface). Njengoba amakheli ahlanganisa ama-zero amaningi futhi ahlukile, inani lamanethiwekhi ase-Class A ancipha kuya kumakheli angu-16 777.214.

Amakilasi B noC

Isici esiyinhloko esihlukanisayo sekheli le-IP leklasi b liyi-bits ezimbili eziphakeme, ezilingana no-10. Kulesi simo, ubukhulu benxenye yenethiwekhi buzolingana nama-16 bits. Ifomethi yekheli yale nethiwekhi ibonakala kanje:

Ngenxa yalesi sizathu, inamba enkulu kakhulu yamanethiwekhi wekilasi B ingaba ngu-2 ¹⁴ (16384) ngekhala lekheli 2 ¹⁶ ngayinye. I-Class B Amakheli e-IP aqala ebangeni kusukela ku-128 kuya ku-191. Lesi sici esihlukile lapho ungakwazi khona ukuthi inethiwekhi ingokwalabo ekilasini. Ama-bytes amabili anikezwe amakheli ala manethiwekhi, ahlukumezeka futhi ahlanganisa amakheli amakheli, angakha inani lezinombolo ezilingana no-65,534.

Noma yiliphi ikheli le-C C IP liqala ngo-192 kuya ku-223, nenombolo yenethiwekhi ephethe ama-octet aphezulu amathathu. NgokweSikimu, ikheli linesakhiwo esilandelayo:

Lezi zinhlamvu ezintathu eziphawulekayo ziyi-110, ingxenye yenethiwekhi ingama-24 bits. Inombolo enkulu kunazo zonke amanethiwekhi kulolu klasi yi-2 ²¹ (lokhu kunamanethiwekhi angu-2,097,152). Ikheli lama-nodes ekhelini le-IP lamanethiwekhi wesigaba se-C ngu-1 byte, okungama-hosts angu-254 kuphela.

Amakilasi weNethiwekhi engeziwe

Amakilasi D no-E afaka amanethiwekhi nge-octet ephakeme ngaphezulu kwezingu-224. Lawa amakheli agcinwe ngezinhloso ezikhethekile, njengokuthi, ama-datagrams okuthumela ama-multi-distributing kumaqembu athile wezinethiwekhi.

Ububanzi besigaba D sisetshenziselwa ukuthumela amaphakethe namanga ebangeni kusukela ku-224.0.0.0 kuya ku-239.255.255.255. Iklasi lokugcina, E, ligcinelwe ukusetshenziswa esikhathini esizayo. Ihlanganisa amakheli kusuka ku-240.0.0.0 kuya ku-255.255.255.255. Ngakho-ke, uma ungafuni izinkinga ngokubhekana nazo, kunconywa ukuthi ungathathi amakheli e-IP kusuka kulezi zigaba.

Amakheli e-IP agcinwe

Kukhona amakheli angeke anikezwe kunoma yimaphi amadivaysi, kungakhathaliseki ukuthi ikheli le-IP liphi. Amakheli e-IP eSevisi anenhloso ethize. Isibonelo, uma ikheli lenethiwekhi linama-zero, khona-ke lokhu kusho ukuthi le node ingokwenethiwekhi yamanje noma ingxenye ethile. Uma zonke izingxenye zikhona, khona-ke leli yikheli lamaphakethe okusakaza.

Esiklasini A kunamanethiwekhi amabili akhethekile azinikezele ngezinombolo 0 no 127. Ikheli elilingana no-zero lisetshenziswe njengomzila ozenzakalelayo, futhi 127 ikhombisa ukukhuluma ngokwayo (isikhombimsebenzisi se-feedback). Isibonelo, ukungena ku-IP 127.0.0.1 kusho ukuthi i-node ixhumana kuphela ngokwayo ngaphandle kokukhipha kwamadokhumenti ezingeni le-medium transfer data. Ukuze ungqimba lokuthutha, uxhumano olunjalo alufani nokuxhumana ne-node eyihlane, ngakho-ke leli kheli lempendulo livame ukusetshenziswa ukuhlola isofthiwe yenethiwekhi.

Thola ukuthi izixhumanisi zenethiwekhi nezingadi

Ukwazi ikheli le-IP lwedivayisi uma kunombuzo mayelana nendlela yokunquma iklasi lamakheli e-IP, kwanele nje ukubheka i-octet yokuqala yekheli. Uma ivela ku-1 kuya ku-126, ke inethiwekhi yeklasi A, kusukela ngo-128 kuya ku-191 inethiwekhi yeklasi B, kusukela ngo-192 ukuya ku-223-inethiwekhi yeklasi C.

Ukubona inethiwekhi, khumbula ukuthi eklasini lena inombolo yokuqala ekheli le-IP, ku-B - izinombolo ezimbili zokuqala, ku-C - izinombolo ezintathu zokuqala. Okunye okuyizihlonzi ze-interfaces yenethiwekhi (ama-node). Isibonelo, ikheli le-IP 139.17.54.23 likheli leklasi B, kusukela inombolo yokuqala engu-139 - engaphezulu kuka-128 nangaphansi kuka-191. Ngakho-ke, i-ID yenethiwekhi izoba ngu-139.17.0.0, i-ID ye-node ngu-54.23.

Izansi

Ngesiza sama-routers namabhuloho, ungandisa inethiwekhi ngokwengeza izingxenye kuwo, noma ukuhlukanisa zibe ngaphansi kwamanothi ngokushintsha i-ID yenethiwekhi. Kulokhu, i-mask isethayi ithathwa, ekhombisa ukuthi iyiphi ingxenye yekheli le-IP izosetshenziswa njenge-ID entsha ye-subnet. Uma lezi zihlonzi zifanelana, ungaphetha ngokuthi lezi zinombolo ziyi-subnet efanayo, kungenjalo zizobe zingaphansi kwamanothi angaphansi futhi zizodinga i-router ukuze zixhumane nazo.

Amakilasi ekheli le-IP aklanyelwe ukuze inani lamanethiwekhi namakhadi enhlangano ethile inqunywe kusengaphambili. Ngokuzenzakalelayo, enhlanganweni, ungahambisa inethiwekhi eyodwa kuphela ngezinombolo zamadivayisi axhunyiwe kwinethiwekhi. Kukhona isihlonzi senethiwekhi ethile kanye nenamba yamanothi anomkhawulo ngokuhambisana nesigaba senethiwekhi. Ngenani elikhulu lama-node, inethiwekhi izoba nomkhawulokudonsa ophansi, ngoba ngisho nanoma yikuphi ukusabalalisa okusakaza, ukusebenza kuyokwehla.

Ama-Masks ase-Subnet

Ukuze uhlukanise isihlonzi, kuyadingeka ukuthi usebenzise i-mask mask - ithempulethi esiza ukuhlukanisa izihlonzi zenethiwekhi ezivela kumakheli we-node kwamakheli e-IP. Amakilasi ekheli le-IP awafaki imikhawulo kumaski e-subnet. I-mask ibonakala njengekheli ngokwayo - amaqembu amane amadijithi kusuka ku-0 kuya ku-255. Ngesikhathi esifanayo, izinombolo ezinkulu zilandela kuqala, zilandelwa izincane. Isibonelo, i-255.255.248.0 yi-mask, i-255.248.255.0 engalungile. I-mask 255.255.255.0 icacisa ama-atit okuqala amathathu ekheli le-IP njenge-ID ye-subnet.

Uma uklama ukuhlukaniswa kwenethiwekhi yebhizinisi, kubalulekile ukuthi ukulungisa i-IP kuhlelwe kahle. Amakilasi amakheli e-IP, ahlukaniswe abe izingxenye usebenzisa ama-masks, avumele hhayi kuphela ukwandisa inani lamakhompyutha enethiwekhi, kodwa futhi ahlele ukusebenza kwawo okuphezulu. Iklasi ngalinye lekheli linomaski wenethiwekhi okuzenzakalelayo.

Ukuze uthole ama-subnets angeziwe, ama-masks ajwayelekile ukusetshenziswa, kodwa ngabanye. Isibonelo, ikheli le-IP 170.15.1.120 lingasebenzisa i-subnet mask ye-255.255.255.0 nge-ID yenethiwekhi ye-170.15.1.0, futhi akudingekile ukuthi isebenzise i-subnet mask ye-255.255.0.0 nge-identifier 170.15.0.0, esetshenziswe ngokuzenzakalelayo. Lokhu kukuvumela ukuba uhlukanise inethiwekhi yenhlangano ye-Class B ekhona ne-170.15.0.0 kwi-subnet esebenzisa ama-masks ahlukahlukene.

Ukubalwa kwemingcele ye-subnetwork

Emva kokulungisa i-subnet ku-interface ngayinye, isofthiwe ye-protocol yenethiwekhi izohlola ikheli le-IP isebenzisa i-subnet mask ukuze ihlonze ikheli le-subnet. Kukhona amafomula amabili alula wokubala inani eliphakeme lama-subnets nama-Hosts kunethiwekhi:

• 2 ^{(inani lezinkinobho elilingana nelinye emasikini)} - 2 = inani elikhulu lezintambo;
• 2 ^{(inani lama-zero ku-mask mask)} - 2 = inani elikhulu lamadivayisi ku-subnet.

Isibonelo, thatha ikheli elilingana no-182.16.52.10 ngesisindo 255.255.224.0. I-mask kwifom yebhanana ibonakala kanje: 11111111.11111111.11100000.00000000. Uma sibheka i-octet yokuqala, le nethiwekhi iyingxenye yeklasi B, ngakho-ke siyacubungula ama-bytes okwesithathu nowesine. Amayunithi amathathu kanye nama-zero ayishumi nesishiyagalolunye afakwe esikhundleni samafomula futhi sithola ama-23-2 = ama-subnets angu-21 no-213- 2 = ama-hostel angu-8190.

Uma usebenzisa i-Mask yenethiwekhi ye-Standard B B kwifomu 255.255.255.0, inethiwekhi ingaba namadivayisi axhunyiwe angu-65534. Uma ikheli le-subnet lisebenza ngokugcwele kwe-node, khona-ke inani lamadivaysi axhunyiwe kwi-subnet ngayinye liyancipha libe yi-254. Uma udinga ukudlula le nombolo yamadivaysi, kungase kube nezinkinga zokuxazulula ngokunciphisa i-subnet ikheli le-mask field noma ukwengeza ikheli elilodwa le-second in the interface of the router. Kodwa kulokhu, kuzoba nokuncipha kwenani lamanethiwekhi angenzeka.

Uma udala amanothi ngaphansi kwenethiwekhi C, khumbula ukuthi ukukhetha kuzoba mncane kakhulu nge-octet eyodwa kuphela. Lapho uhlola amakheli we-zero nokusakaza, kungenzeka ukudala ama-subnet amashadi angu-4: i-subnet eyodwa yama-hosts angu-253, ama-subnets amabili ama-host hosts angu-125, ama-subnets amane ama-Host hosts angu-61, ama-subnet ayisishiyagalombili angu-29. Izinketho ezisele zokuhlukanisa zizobangela izinkinga ekusetshenzisweni nasekuhanjisweni, noma nje kubangele ukuphazamiseka ekubhekaneni nezibalo phakathi kwamabandla.

Ukwenza ama-subnets kumanethiwekhi e-class B kakade kulula, ngoba kunenkululeko enkulu yokuzikhethela. Ngokuzenzakalelayo, i-mask subnet ngu-255.255.0.0, uma isisebenzisa, sithola ama-hostel angu-65534. Lapho udala amaskethi we-subnet, izingcezu ezingabonakaliswa ezingakwesokunxele ze-octrothi 3 no-4 zabiwe amakheli abo. Ngokubala kungenzeka ukuthola amanethiwekhi angcono ngezinombolo 32, 64, 96, 128, 160 no-192.

Amanethiwekhi we-Class A anamakheli amakhulu kakhulu, okusemandleni okudala ama-subnet. Ukusebenzisa imaski ye-subnet, ungasebenzisa kuze kufike ku-32 bits. Ukusebenzisa ifomula engenhla, singanquma ukuthi inani eliphezulu lezintambo zingaphezu kuka-254. Ngesikhathi esifanayo, amasbitshi angu-16 asele kumakheli ehostela, okungukuthi, ama-nodes angu-65534 angaxhunyaniswa.

Yiqiniso, lezi zibalwa kuphela zokubala. Uma udala imikhakha futhi usebenza nama-subnets, kubalulekile ukucabangela izinto eziningi ezixhomeke kumhlinzeki nakwezinga lebhizinisi.