Classless Inter-Domain Routing tau tsim nyob rau xyoo 1990 los ua tus qauv txheej txheem rau routing network tsheb thoob plaws hauv internet. Ua ntej CIDR thev naus laus zis tau tsim, cov routers hauv internet tau tswj xyuas kev sib txuas hauv network raws li chav kawm ntawm IP chaw nyob. Hauv qhov system no, tus nqi ntawm tus IP chaw nyob txiav txim siab nws cov subnetwork rau lub hom phiaj ntawm routing.
CIDR yog lwm txoj hauv kev rau IP subnetting. Nws npaj IP chaw nyob rau hauv subnetworks ywj siab ntawm tus nqi ntawm qhov chaw nyob lawv tus kheej. CIDR tseem hu ua supernetting vim nws ua tau zoo tso cai rau ntau lub subnets los ua pawg ua ke rau kev sib txuas lus.
CIDR Notation
CIDR qhia meej txog qhov chaw nyob IP uas siv kev sib txuas ntawm tus IP chaw nyob thiab nws lub npog ntsej muag sib txuas.
xxx.xxx.xxx.xxx/n
CIDR sau tseg siv hom ntawv saum toj no, qhov twg n yog tus lej ntawm (sab laug kawg) 1 khoom hauv daim npog ntsej muag.
192.168.12.0/23
Qhov piv txwv saum toj no siv lub npog ntsej muag network 255.255.254.0 rau 192.168 network, pib ntawm 192.168.12.0. Cov ntawv sau no sawv cev rau qhov chaw nyob 192.168.12.0 txog 192.168.13.255.
Piv rau kev sib tham hauv chav kawm, 192.168.12.0/23 sawv cev rau kev sib sau ntawm ob chav C subnets 192.168.12.0 thiab 192.168.13.0, txhua tus muaj lub npog ntsej muag ntawm 255.255.255..
Ntawm no yog lwm txoj hauv kev kom pom nws:
192.168.12.0/23=192.168.12.0/24 + 192.168.13.0/24
Ntxiv thiab, CIDR txhawb nqa qhov chaw nyob hauv internet faib thiab cov lus xa tawm ywj pheej ntawm cov chav kawm ib txwm muaj ntawm qhov chaw nyob IP muab.
10.4.12.0/22
Qhov piv txwv saum toj no sawv cev rau qhov chaw nyob thaj tsam 10.4.12.0 txog 10.4.15.255 (network mask 255.255.252.0). Qhov no faib qhov sib npaug ntawm plaub chav kawm C network hauv qhov chaw loj dua Class A.
Qee zaum koj yuav pom CIDR cov cim siv txawm tias tsis yog CIDR tes hauj lwm. Hauv qhov tsis yog-CIDR IP subnetting, txawm li cas los xij, tus nqi ntawm n raug txwv rau 8 (Class A), 16 (Class B), lossis 24 (Class C).
Nov yog qee qhov piv txwv:
- 10.0.0.0/8
- 172.16.0.0/16
- 192.168.3.0/24
How CIDR ua haujlwm
Thaum thawj zaug siv hauv Is Taws Nem, cov txheej txheem tseem ceeb xws li Border Gateway Protocol thiab Open Shortest Path First tau hloov kho los txhawb CIDR. Kev siv tsis siv neeg lossis tsawg dua cov txheej txheem routing tej zaum yuav tsis txhawb CIDR.
CIDR kev siv yuav tsum tau muaj qee yam kev txhawb nqa kom muab tso rau hauv lub network routing raws tu qauv.
CIDR kev sib sau ua ke yuav tsum muaj cov ntu sib txuas sib txuas ua ke (ntau tus nyob ib sab) hauv qhov chaw nyob. CIDR tsis tuaj yeem, piv txwv li, suav nrog 192.168.12.0 thiab 192.168.15.0 rau hauv ib txoj kev tshwj tsis yog qhov chaw nyob nruab nrab.13 thiab.14 suav nrog.
Txhua tus internet WAN lossis lub nraub qaum routers - cov uas tswj kev khiav tsheb ntawm cov chaw muab kev pabcuam hauv internet - feem ntau txhawb CIDR kom ua tiav lub hom phiaj ntawm kev txuag IP chaw nyob. Cov neeg siv khoom siv hluav taws xob feem ntau tsis txhawb CIDR, yog li kev sib koom tes ntiag tug suav nrog cov network hauv tsev thiab txawm tias cov koom haum me me (LANs) feem ntau tsis ua haujlwm.
CIDR thiab IPv6
IPv6 siv CIDR routing thev naus laus zis thiab CIDR cov cim ib yam li IPv4. IPv6 tau tsim los rau qhov chaw nyob tsis muaj chaw nyob.
