Daim npog ntsej muag subnet yog qhov yooj yim txheej txheem rau kev sib cais lub network chaw nyob ntawm tus tswv tsev chaw nyob. Xws li lub tshuab tau tsim tsa hauv thawj tus IP tus qauv hauv lub Cuaj Hli 1981. Txhawm rau ua kom yooj yim txoj kev ncig thiab nce kev ua kom tau zoo, koj yuav tsum muaj peev xwm xam lub ntsej muag cuav.
Cov Lus Qhia
Kauj ruam 1
Lub ntsej muag subnet, zoo li lub chaw nyob hauv network, yog sawv cev los ntawm plaub tus ib-byte tus naj npawb (rau IPv4 raws tu qauv, nyob rau hauv IPv6 raws tu qauv, lawv yog 8 pawg ntawm kaum-lub lej-tsawg). Piv txwv li: IP chaw nyob 192.168.1.3, subnet daim npog 255.255.255.0. Hauv TCP / IP networks, daim npog ntsej muag yog me ntsis uas qhia tias qhov twg ntawm qhov chaw nyob hauv lub xaib yog qhov chaw nyob hauv lub network thiab qhov twg yog qhov chaw nyob tus tswv. Txhawm rau ua qhov no, lub ntsej muag subnet yuav tsum sawv cev hauv binary. Cov npib teeb tsa rau ib qho qhia qhov chaw nyob hauv network, thiab cov khoom me me teev rau xoom qhia tus tswv tsev chaw nyob. Piv txwv li, sub daim npog qhov ncauj yog 255.255.255.0. Koj tuaj yeem sawv cev nws hauv binary: 11111111.11111111.11111111.00000000. Tom qab ntawd rau qhov chaw nyob 192.168.1.1 qhov 192.168.142 yuav chaw nyob hauv lub network, thiab.142 yuav yog chaw nyob chaw nyob.
Kauj ruam 2
Raws li koj tuaj yeem pom los ntawm cov kauj ruam dhau los, muaj kev txwv rau tus naj npawb ntawm cov tswv thiab tes hauj lwm. Nws tau txais los ntawm qhov kev txwv ntawm tus xov tooj ntawm cov hloov pauv tau sawv cev los ntawm tus lej ntawm cov khoom. Ib me ntsis tuaj yeem sau tau tsuas yog 2 lub xeev: 0 thiab 1. 2 lub hauv paus - plaub lub xeev: 00, 01, 10, 11. Feem ntau, n cov lej encode 2 ^ n xeev. Txawm li cas los xij, nco ntsoov tias txhua tus thiab txhua tus lej hauv tus tswv tsev thiab chaw nyob hauv lub network tau tshwj tseg los ntawm tus qauv txhais tau tias "tus tswv tsev tam sim no" thiab "txhua tus tswv." Yog li, nws hloov tawm tias tag nrho cov nodes hauv lub network tau txiav txim los ntawm tus qauv N = (2 ^ z) -2, qhov twg N yog tag nrho cov nodes, z yog tus lej ntawm tus lej hauv tus sawv cev binary. subnet daim npog qhov ncauj.
Kauj ruam 3
Nco ntsoov tias daim npog yuav tsis yog qhov tsim los ntawm cov lej xaj. Thawj cov kab ntawm daim npog yog ib txwm, qhov kawg ntawm xoom. Yog li no, qee zaum koj tuaj yeem nrhiav cov chaw nyob hauv daim ntawv 192.168.1.25/11. Nws txhais tau tias thawj 11 kab ntawm qhov chaw nyob yog chaw nyob hauv lub network, 21 kawg yog qhov chaw nyob ntawm nev nev. Cov ntawv sau sib raug rau qhov chaw nyob 192.168.1.25 thiab subnet daim npog 255.224.0.0. Thaum suav lub ntsej muag subnet, xav txog pes tsawg lub khoos phis tawj nyob hauv lub network. Xav txog nws txoj kev nthuav dav ntxiv: yog tias cov lej ntawm cov khoos phis tawm ntau dua qhov ua kom tau rau lub network, nws yuav tsim nyog hloov tag nrho cov chaw nyob thiab cov qhov ncauj qhov ntswg ntawm txhua lub computer.
Kauj ruam 4
Chaw nyob yog qhov tsis muaj chaw thiab tsis muaj hom. Kev sib cais hauv chav kawm tau siv thaum ntxov ua raws li kev cai, thiab tom qab ntawd, nrog txoj kev loj hlob ntawm Is Taws Nem, nws tau ntxiv los ntawm qhov tsis muaj chaw nyob. Chav nyob ntawm qhov sib txawv muaj 5 chav kawm: A, B, C, D, E. Chav kawm txiav txim siab tias yuav muaj pes tsawg qhov chaw nyob rau hauv chaw nyob hauv lub network, thiab muaj pes tsawg - rau lub chaw nyob. Hauv qhov no, koj yuav tsis tas suav txhua yam. Hauv chav kawm A, 7 tshooj yog faib rau qhov chaw nyob ntawm lub network, hauv chav B - 14 khoom, hauv chav kawm C - 21 khoom. Chav D yog siv rau multicasting thiab chav E yog tseg rau kev siv. Hauv qhov no, thawj ob peb ntu ntawm qhov chaw nyob raug siv los txiav txim nws chav kawm. Hauv chav kawm A nws yog 0 hauv thawj ntsis, hauv chav kawm B - 10, hauv chav kawm C - 110, hauv chav kawm D - 1110, hauv chav kawm E - 11110.
Kauj ruam 5
Cov chaw nyob ntawm chav kawm ua rau muaj qhov tsis yooj yim ntawm IP hais txog kev faib chaw nyob, thiab txo tus lej ntawm cov chaw nyob tau. Yog li ntawd, cov chaw nyob tsis muaj chav nyob tau saws. Txhawm rau nrhiav lub npog ntsej muag, ua ntej txiav txim siab ntau npaum li cas cov nodes koj yuav muaj nyob hauv koj lub network, suav nrog cov rooj vag thiab lwm cov khoom siv network. Ntxiv ob qho rau tus lej ntawd thiab puag ncig mus rau lub zog ze rau ob. Piv txwv li, koj muaj 31 lub koos pij tawj npaj. Ntxiv ob qho rau qhov no, koj tau txais 33. Lub zog ze tshaj plaws ntawm ob yog 64, uas yog, 100 0000. Tom qab ntawd, ua tiav txhua qhov tseem ceeb tshaj plaws nrog ib. Tau txais daim npog 1111 1111. 1111 1111. 1111 1111. 1100 0000, uas yog 255.255.255.192 hauv tsawg. Hauv kev sib koom tes nrog lub ntsej muag zoo li no, koj tuaj yeem tau 62 qhov chaw nyob IP sib txawv uas tsis tau tshwj tseg hauv tus qauv.
