VLAN vs Subnet
VLAN yog dab tsi?
VLAN yog ib pab pawg neeg tsim kev sib txuas tsim txawm tias lawv qhov chaw nyob ntawm lub cev uas pab tsim cov xov xwm me me hauv qhov hloov pauv. Rau cov VLANs no, cov chaw nres nkoj sib txawv tuaj yeem raug muab. Yog tsis muaj VLANs, qhov hloov pauv xav txog txhua qhov cuam tshuam rau qhov hloov pauv hauv ib qho kev tshaj tawm. VLANs muab kev tshaj tawm kev lim dej, chaw nyob ruaj ntseg, kev sib sau ua ke, kev tswj hwm kev khiav tsheb thiab txo cov haujlwm ua haujlwm rau Spanning Tree Protocol los ntawm kev txwv VLAN mus rau ib qho kev nkag mus. Qhov no yuav pab tau thaum txheej 3 tes hauj lwm yuav tsum tau tsim nyob rau hauv ib tug txheej 2 hloov. VLANs yog ib hom kev sib txuas ntawm cov keyboards; lawv tuaj yeem txuas ua ke, lossis txheej 3 hloov lossis lub router tuaj yeem cuam tshuam lawv. VLANs muaj cov yam ntxwv zoo ib yam li LAN tab sis lawv muab cov khoom siv tsis hais lawv qhov chaw nyob. Txhua qhov hloov pauv muaj lub neej ntawd VLAN ntawm VLAN 1 tau qhib rau ntawm qhov hloov. Txawm hais tias lub npe rau VLAN raug muab, tsuas yog VLAN tus lej tseem ceeb thaum xa cov tsheb khiav. VLAN ID, uas yog tib yam li tus lej VLAN, tau ntxiv thaum lub pob ntawv tawm ntawm qhov chaw nres nkoj. Cov khoom siv hauv ib pab pawg VLAN siv tib VLAN ID. Feem ntau VLAN raws tu qauv yog dot1q thiab isl, thiab lawv yog siv rau inter VLAN kev sib txuas lus. Muaj ob txoj hauv kev los muab VLAN; lawv hu ua static VLAN thiab dynamic VLAN. Static VLANs yog qhov chaw nres nkoj raws thiab dynamic VLANs yog tsim siv softwares. VLAN tus qauv yog IEEE 802.1 Q.
Subnet yog dab tsi?
Subnet lossis subnetwork yog ib qho kev faib tawm ntawm IP network. Kev tawg lub network loj hauv ntau lub network me yog hu ua subnetting. Peb pab pawg network nrog lub npog ntsej muag kom tsim tau lub ntsej muag subnet. Subnetting txo cov tsheb khiav hauv network, txhim kho kev ua haujlwm hauv network thiab ua kom yooj yim rau kev tswj hwm. Subnetwork nce routing complexity, vim hais tias, nyob rau hauv ib lub rooj, txhua subnet yog sawv cev los ntawm ib tug cais nkag. Yuav tsum muaj lub router los txuas cov network no. Hauv IPv4, qhov laj thawj tseem ceeb rau subnetting yog txhawm rau txhim kho kev ua tau zoo thiab siv qhov chaw nyob hauv network tsawg. IPv4 network muaj 256 tus IP chaw nyob. Yog tias tsuas yog 14 tus IP chaw nyob ntawm 256 no raug xa mus rau VLAN, qhov seem 240 yuav tsis muaj txiaj ntsig, txhawm rau kov yeej qhov pov tseg ntawm IP chaw nyob peb tuaj yeem faib cov network ntawd rau hauv subnets, uas muaj 16 IP chaw nyob. Tom qab ntawd muab cov chaw nyob no rau cov pab pawg cuam tshuam thiab muab lwm qhov chaw nyob rau lwm pab pawg lossis khaws cia rau kev siv yav tom ntej. Ib lub network hauv zos, uas yog ib tus tswv cuab ntawm lub ntiaj teb internet ua haujlwm, feem ntau hu ua subnet routers. Daim npog qhov chaw nyob yog siv los txheeb xyuas thaj tsam chaw nyob, uas yog hu ua subnet mask rau lub network tshwj xeeb no.
Qhov txawv ntawm VLAN thiab Subnet yog dab tsi?
• VLANs tso cai rau cais me me subnet ntawm ib lub cuab yeej. Nrog rau lub subnet me me, koj muaj cov khoom siv tsawg dua, thiab nws ua rau kev tshaj tawm tsawg dua. Tab sis qhov no nce unicast tsheb ntim ntawm tes hauj lwm, uas ua rau siab CPU siv.
• Nruab nrab ntawm VLANs thiab subnets ib qho rau ib qho kev sib raug zoo, uas txhais tau hais tias ib lub subnet tuaj yeem raug xa mus rau ib VLAN. Txawm hais tias nws tuaj yeem ua tau, sim muab ntau tshaj ib lub subnet rau VLAN tsis yog kev npaj tsim network zoo.
• VLAN ciam teb cim qhov kawg ntawm lub logical subnet.
• Rau MPLS, tsim cov subnets ntau dua yog qhov zoo dua li tsim VLANs ntau dua, vim MPLS tsim shortcuts ntawm IP subnets kom ua tau zoo.
• VLANs muaj txiaj ntsig thaum peb xav tau los tsim IPsubnets uas nthuav dav hauv thaj chaw dav xws li tsev kawm ntawv thaum txuas cov tsev kawm lossis cov tsev.
• Yooj yim, VLAN=tus tshaj tawm xov xwm=IP subnet.
