IP hosts thiab routers siv IGMP tswj raws tu qauv rau pab pawg network. Internet Group Management Protocol tswj hwm multicast (pab pawg) cov ntaub ntawv xa mus rau hauv tes hauj lwm. Nws nyob ntawm theem network thiab txuas tus neeg siv lub computer mus rau lub router hauv zos txhawm rau hloov cov ntaub ntawv ntawm lawv. Cov tsheb thauj mus los multicast raug xa mus rau lwm tus neeg siv khoom ntawm PIM raws tu qauv. Nws txuas lub router hauv zos mus rau tej thaj chaw deb. Ua tsaug rau kev siv IGMP, kev siv network ntawm ntau daim ntawv thov (kev ua si hauv online, streaming video) tuaj yeem siv tau zoo dua.
Koj tuaj yeem siv IGMP snooping muaj nuj nqi los txiav txim siab txog kev tshaj tawm cov tsheb mus rau qee qhov cuam tshuam. Nws yog dab tsi? Nov yog cov txheej txheem ntawm kev taug qab IGMP thov los ntawm cov neeg siv khoom (tus tswv) rau cov chaw muab kev pabcuam (multicast routers).
Lub tswv yim thiab lub hom phiaj ntawm IGMP snooping
Snooping txhais tias "eavesdropping" hauv lus Askiv. Thaum nws qhib, ib qho khoom siv nruab nrab ntawm lub network (router lossis kev sib txuas lus) pib txheeb xyuas kev hloov pauv ntawm tag nrho cov ntaub ntawv pob ntawm cov neeg siv computer,txuas mus rau nws, thiab routers uas muab kev khiav tsheb multicast. Thaum kuaj pom qhov kev thov kev sib txuas, qhov chaw nres nkoj uas tus neeg siv khoom (tus neeg siv khoom) txuas nrog yog hloov mus rau, nyob rau hauv qhov xwm txheej (Tawm thov), qhov chaw nres nkoj sib raug raug tshem tawm ntawm pawg npe.
Nyob rau hauv feem ntau cov neeg sib txuas lus, IGMP snooping muaj nuj nqi yog muaj, tab sis yuav tsum tau ua ua ntej.
Vim li cas saib xyuas kev sib txuas hauv network?
Multicast tsheb kuj tuaj yeem xa mus rau cov khoos phis tawj uas tsis nyiam nws. Qhov no hu ua broadcast relay. Txhawm rau tiv thaiv nws, txhawm rau txo cov load ntawm lub network, IGMP snooping yog siv. Nyob rau tib lub sijhawm, qhov kev lim dej zoo li no yuav tsum tau them tus nqi nco ntxiv thiab ua kom cov khoom thauj ntawm tus neeg sib txuas lus. Txawm li cas los xij, nws ua ncaj ncees.
Yog tias tus neeg sib txuas lus pib tshaj tawm ntau qhov kev sib tw ntawm txhua qhov chaw nres nkoj, ces:
- txheej txheem no tsis muaj txiaj ntsig;
- teeb meem tuaj yeem tshwm sim hauv kev ua haujlwm ntawm tus neeg txais zaum kawg (lub network ntaus ntawv), yuam kom ua cov kwj loj ntawm cov ntaub ntawv tsis tsim nyog.
Txhawm rau zam cov xwm txheej zoo li no, muaj IGMP snooping muaj nuj nqi uas ua kom muaj txiaj ntsig zoo ntawm tag nrho lub network. Nws yuav siv sij hawm mus rau hauv tus account qhov xav tau ntawm lub network (thib peb) theem thiab yog li optimizes channel (thib ob) theem ntawm cov ntaub ntawv kis tau tus mob.
Enabling the wiretapping function
txhawm rau saib xyuas cov tsheb sib tw ntau, koj yuav tsum xub ua kom IGMP snooping thiab teeb tsa koj tus kheej. Cia peb saib yuav ua li cas rau cov neeg sib txuas lusD-Txuas thaum siv cov txheej txheem hloov cov ntaub ntawv multicast. Cov lus txib kom qhib lub network mloog:
Txhawm rau tshem tawm qhov chaw nres nkoj los ntawm pab pawg network thaum tus neeg sib txuas lus tau txais daim ntawv thov tawm ntawm tus neeg siv khoom, siv IGMP Snooping Fast Leave feature. Nws tso cai rau koj kom tsis txhob kis cov ntaub ntawv tsis tsim nyog hla lub network txhawm rau ua kom nws ua haujlwm tau zoo. Txhawm rau qhib txoj haujlwm no siv cov lus txib hauv qab no:
Siv thaum nws tsim nyog los ua kom muaj ntau qhov kev lim dej ntawm qhov hloov pauv nrog cov kev sib txuas nrog koom nrog cov ntaub ntawv xa mus.
Types of IGMP sniffing
IGMP snooping tuaj yeem ua haujlwm dhau los lossis ua haujlwm. Qhov no tshwm sim li cas?
- Passive tsis lim tsheb, nws tsuas yog saib xyuas nws.
- Active - mloog thiab lim cov ntaub ntawv pob kom txo cov load ntawm pawg router.
Hom thib ob ntawm kev siv cov haujlwm no yog qhov nyiam tshaj plaws, vim nws tso cai kom txo qis cov ntaub ntawv xa mus los ntawm kev lim cov lus thov kom txuas mus rau thiab txiav tawm ntawm lub router.
Qhov kev ua haujlwm ntawm IGMP snooping kev sib txuas lus pab txo qis network thauj khoom los ntawm kev saib xyuas kev sib pauv ntawm cov ntaub ntawv ntawm cov chaw muab kev pabcuam (cov routers hauv zos) thiab cov neeg siv khoom (cov neeg siv khoos phis tawj) ntawm kev tsheb ntau ntau.
