Yadda tsarin PIM ke aiki

Ka'idar PIM saitin ka'idoji ne don watsa multicast a cikin hanyar sadarwa tsakanin masu amfani da hanyar sadarwa. An gina alakar maƙwabta ta hanya ɗaya da na ƙayyadaddun ƙa'idodi masu ƙarfi. PIMv2 yana aika saƙonnin Sannu kowane sakan 30 zuwa adireshin multicast da aka tanada 224.0.0.13 (Duk-PIM-Routers). Saƙon yana ƙunshe da masu ƙidayar lokaci - yawanci daidai yake da 3.5*Hello Timer, wato 105 seconds ta tsohuwa.

PIM yana amfani da manyan hanyoyi guda biyu na aiki - Yanayin mai yawa da kuma Sparse. Bari mu fara da yanayin mai yawa.
Bishiyoyin Rarraba Tushen.
Yanayin yanayi mai yawa yana da kyau a yi amfani da shi a yanayin ɗimbin abokan ciniki na ƙungiyoyin multicast daban-daban. Lokacin da na'ura mai ba da hanya tsakanin hanyoyin sadarwa ya karɓi zirga-zirgar multicast, abu na farko da yake yi shine duba shi don tsarin RPF. RPF - ana amfani da wannan ƙa'idar don bincika tushen multicast tare da tebur mai tuƙi na unicast. Wajibi ne cewa zirga-zirgar zirga-zirgar ta isa wurin da ke bayanta wanda wannan rundunar ke ɓoye bisa ga sigar tebirin tuƙi na unicast. Wannan tsarin yana magance matsalar madauki da ke faruwa yayin watsa multicast.

R3 zai gane tushen multicast (Source IP) daga saƙon multicast kuma ya duba guda biyu daga R1 da R2 ta amfani da tebur unicast. Za a ƙara watsa rafi daga mahaɗin da aka nuna ta tebur (R1 zuwa R3) kuma za a watsar da rafi daga R2, tunda don isa ga tushen multicast, kuna buƙatar aika fakiti ta hanyar S0/1.
Tambayar ita ce, menene zai faru idan kuna da hanyoyi guda biyu masu daidai da ma'auni ɗaya? A wannan yanayin, na'ura mai ba da hanya tsakanin hanyoyin sadarwa zai zaɓi na gaba-hop daga waɗannan hanyoyin. Duk wanda ke da adireshin IP mafi girma ya ci nasara. Idan kana buƙatar canza wannan hali, zaka iya amfani da ECMP. Karin bayani a nan.
Bayan duba ka'idar RPF, na'ura mai ba da hanya tsakanin hanyoyin sadarwa yana aika fakitin multicast zuwa duk maƙwabtan PIM, ban da wanda aka karɓi fakitin daga gareshi. Sauran hanyoyin sadarwa na PIM suna maimaita wannan tsari. Hanyar da fakitin multicast ya ɗauka daga tushe zuwa masu karɓa na ƙarshe yana samar da bishiyar da ake kira itacen rarraba tushen tushe, itace mafi gajeriyar hanya (SPT), itacen tushe. Sunaye daban-daban guda uku, zaɓi kowane ɗaya.
Yadda za a magance matsalar da wasu na'urorin sadarwa ba su yi kasa a gwiwa ba a kan wasu rafi na multicast kuma babu wanda zai aika zuwa gare shi, amma na'ura mai ba da hanya tsakanin hanyoyin sadarwa ya aika masa. An kirkiro tsarin Prune don wannan.
Datsa Saƙo.
Misali, R2 zai ci gaba da aika da multicast zuwa R3, ko da yake R3, bisa ga tsarin RPF, ya sauke shi. Me yasa ake loda tashar? R3 yana aika saƙon PIM Prune kuma R2, lokacin karɓar wannan saƙon, zai cire masarrafar S0/1 daga jerin abubuwan dubawa mai fita don wannan kwarara, jerin musaya waɗanda yakamata a aika wannan zirga-zirga.

Mai zuwa shine ƙarin ma'anar saƙon PIM Prune:
Ana aika saƙon PIM Prune ta hanyar na'ura mai ba da hanya tsakanin hanyoyin sadarwa zuwa na'ura mai ba da hanya tsakanin hanyoyin sadarwa na biyu don sa na'ura mai ba da hanya tsakanin hanyoyin sadarwa na biyu ya cire hanyar haɗin da aka karɓi Prune daga wani takamaiman (S,G) SPT.

Bayan karɓar saƙon Prune, R2 yana saita mai ƙidayar Prune zuwa mintuna 3. Bayan minti uku, zai sake fara aika zirga-zirga har sai ya sami wani sakon Prune. Wannan yana cikin PIMv1.
Kuma a cikin PIMv2 an ƙara mai ƙidayar refresh na Jiha (daƙiƙa 60 ta tsohuwa). Da zaran an aika saƙon Prune daga R3, wannan lokacin yana farawa akan R3. Bayan ƙarewar wannan lokacin, R3 zai aika da saƙon Wartsakewa na Jiha, wanda zai sake saita Timer Prune na mintuna 3 akan R2 don wannan rukunin.
Dalilan aika saƙon Prune:

• Lokacin da fakitin multicast ya gaza duban RPF.
• Lokacin da babu abokan ciniki da ke da alaƙa a cikin gida waɗanda suka nemi ƙungiyar multicast (IGMP Join) kuma babu maƙwabtan PIM waɗanda za a iya aika zirga-zirgar zirga-zirgar multicast zuwa gare su (Interface mara amfani).

Saƙon Saƙo.
Bari mu yi tunanin cewa R3 ba ya son zirga-zirga daga R2, aika Prune kuma ya karbi multicast daga R1. Amma ba zato ba tsammani, tashar tsakanin R1-R3 ta fadi kuma an bar R3 ba tare da multicast ba. Kuna iya jira mintuna 3 har sai lokacin Prune akan R2 ya ƙare. Minti 3 yana da tsayi, don kada ku jira, kuna buƙatar aika saƙon da zai kawo wannan haɗin S0/1 zuwa R2 daga yanayin da aka yanke. Wannan sakon zai zama saƙon Graft. Bayan karɓar saƙon Graft, R2 zai amsa tare da Graft-ACK.
Gyaran Juya.

Bari mu kalli wannan zane. R1 yana watsa shirye-shiryen multicast zuwa yanki tare da hanyoyin sadarwa guda biyu. R3 yana karɓa kuma yana watsa zirga-zirga, R2 yana karɓa, amma ba shi da wanda zai watsa zirga-zirga zuwa gare shi. Yana aika saƙon Prune zuwa R1 a wannan ɓangaren. R1 yakamata ya cire Fa0/0 daga jerin kuma ya daina watsa shirye-shirye a wannan sashin, amma menene zai faru da R3? Kuma R3 yana cikin kashi ɗaya, kuma ya karɓi wannan sakon daga Prune kuma ya fahimci bala'in halin da ake ciki. Kafin R1 ya daina watsa shirye-shirye, yana saita lokaci na daƙiƙa 3 kuma zai daina watsawa bayan daƙiƙa 3. 3 seconds - wannan shine adadin lokacin R3 don kada ya rasa multicast. Saboda haka, R3 yana aika saƙon Join na Pim don wannan rukunin da wuri-wuri, kuma R1 baya tunanin daina watsa shirye-shirye. Game da Shiga saƙonnin da ke ƙasa.
Tabbatar da Saƙo.

Bari mu yi tunanin wannan yanayin: hanyoyin sadarwa guda biyu suna watsawa zuwa cibiyar sadarwa ɗaya lokaci ɗaya. Suna karɓar rafi iri ɗaya daga tushen, kuma duka biyu suna watsa shi zuwa cibiyar sadarwa iri ɗaya a bayan ƙirar e0. Don haka, suna buƙatar tantance wanda zai zama ɗaya kuma kawai mai watsa shirye-shiryen wannan hanyar sadarwa. Ana amfani da saƙon faɗakarwa don wannan. Lokacin da R2 da R3 suka gano kwafi na zirga-zirgar multicast, wato, R2 da R3 suna karɓar multicast wanda su da kansu suke watsawa, masu amfani da hanyar sadarwa sun fahimci cewa wani abu ba daidai ba ne a nan. A wannan yanayin, masu amfani da hanyoyin sadarwa suna aika saƙonnin Assert, waɗanda suka haɗa da Distance Administrative da ma'aunin hanyoyin da aka kai tushen multicast - 10.1.1.10. An tantance wanda yayi nasara kamar haka:

1. Wanda ke da ƙananan AD.
2. Idan AD daidai suke, to waye ke da ƙananan awo.
3. Idan akwai daidaito a nan, to, wanda ke da IP mafi girma a cikin hanyar sadarwar da suke watsa wannan multicast.

Wanda ya lashe wannan kuri'a ya zama Na'ura mai ba da hanya tsakanin hanyoyin sadarwa. Ana kuma amfani da Pim Hello don zaɓar DRs. A farkon labarin, an nuna sakon PIM Hello, za ku iya ganin filin DR a can. Wanda ke da mafi girman adireshin IP akan wannan hanyar haɗin yanar gizon ya ci nasara.
Alama mai amfani:

Teburin MROUTE.
Bayan kallon farko na yadda ka'idar PIM ke aiki, muna buƙatar fahimtar yadda ake aiki tare da tebur mai ɗaukar hoto da yawa. Teburin mroute yana adana bayanai game da waɗanne rafukan da aka nema daga abokan ciniki da kuma waɗanne rafukan ke gudana daga sabar multicast.
Misali, lokacin da aka karɓi Rahoton Memba na IGMP ko haɗin haɗin gwiwa na PIM akan wasu ƙa'idodi, ana ƙara rikodin nau'in (*, G) zuwa tebirin kewayawa:

Wannan shigarwa yana nufin cewa an karɓi buƙatar zirga-zirga tare da adireshin 238.38.38.38. Tutar DC tana nufin cewa multicast ɗin zai yi aiki a yanayin Dense kuma C yana nufin cewa mai karɓa yana haɗa kai tsaye zuwa na'ura mai ba da hanya tsakanin hanyoyin sadarwa, wato, na'ura mai ba da hanya tsakanin hanyoyin sadarwa ya karɓi Rahoton Memba na IGMP da Join PIM.
Idan akwai rikodin nau'in (S,G) yana nufin muna da rafi mai yawa:

A cikin filin S - 192.168.1.11, mun yi rajistar adireshin IP na tushen multicast, wannan shine tsarin RPF zai bincika. Idan akwai matsaloli, abu na farko da kuke buƙatar yi shine bincika tebur unicast don hanyar zuwa tushen. A cikin filin Interface mai shigowa, yana nuna mahaɗin da aka karɓi multicast. A cikin tebirin tuƙi na unicast, hanyar zuwa tushen dole ne ta koma wurin da aka kayyade anan. Interface mai fita yana ƙayyadaddun inda za'a juya multicast. Idan babu komai, to na'ura mai ba da hanya tsakanin hanyoyin sadarwa bai sami wani buƙatun wannan zirga-zirgar ba. Ana iya samun ƙarin bayani game da duk tutoci a nan.
PIM Sparse-yanayin.
Dabarun Sparse-mode shine kishiyar yanayin mai yawa. Lokacin da yanayin Sparse-mode ya karɓi zirga-zirgar ababen more rayuwa, zai aika da zirga-zirgar ababen hawa ne kawai ta waɗancan musaya waɗanda aka sami buƙatun wannan kwarara, misali Pim Join ko rahoton saƙon IGMP da ke buƙatar wannan zirga-zirga.
Makamantan abubuwa na SM da DM:

• An gina alaƙar maƙwabta ta hanya ɗaya da a cikin PIM DM.
• Dokar RPF tana aiki.
• Zaɓin DR yayi kama.
• Tsarin Prune Overrides da Assert saƙonni iri ɗaya ne.

Don sarrafa wanda, inda kuma wane nau'in zirga-zirgar zirga-zirgar multicast da ake buƙata akan hanyar sadarwa, ana buƙatar cibiyar bayanai gama gari. Cibiyar mu za ta kasance Rendezvous Point (RP). Duk wanda yake son wani nau'in zirga-zirgar multicast ko wani ya fara karɓar zirga-zirgar multicast daga tushen, sannan ya aika zuwa RP.
Lokacin da RP ya karɓi zirga-zirgar zirga-zirgar multicast, zai aika zuwa waɗancan masu amfani da hanyar sadarwa waɗanda a baya suka nemi wannan zirga-zirga.

Bari mu yi tunanin topology inda RP yake R3. Da zaran R1 ya karɓi zirga-zirga daga S1, yana ɗaukar wannan fakitin multicast zuwa saƙon Rijistar PIM na unicast kuma ya aika zuwa RP. Ta yaya ya san wanene RP? A wannan yanayin, an saita shi a tsaye, kuma zamuyi magana game da daidaitawar RP mai ƙarfi daga baya.

ip pim rp-adireshin 3.3.3.3

RP zai duba - shin akwai bayani daga wanda ke son karɓar wannan zirga-zirga? Bari mu ɗauka ba haka ba ne. Sa'an nan RP zai aika R1 a PIM Register-Stop saƙon, wanda ke nufin cewa babu wanda ke bukatar wannan multicast, rajista ba a hana. R1 ba zai aika multicast ba. Amma mai watsa shiri na multicast zai aika shi, ta yadda R1, bayan karɓar Rijista-Stop, zai fara lokacin Rijista-Suppression daidai da 60 seconds. Daƙiƙa 5 kafin wannan lokacin ya ƙare, R1 zai aika saƙon Rijista mara komai tare da bit-Register (wato, ba tare da fakitin multicast ɗin da aka rufe ba) zuwa RP. RP, bi da bi, zai yi aiki kamar haka:

• Idan babu masu karɓa, to za ta amsa da saƙon Tsaida Rijista.
• Idan masu karɓa sun bayyana, ba zai amsa ta kowace hanya ba. R1, bayan bai sami ƙi yin rajista a cikin daƙiƙa 5 ba, zai yi farin ciki kuma ya aika saƙon Rajista tare da ruɓaɓɓen simintin RP zuwa RP.

Muna da alama mun gano yadda multicast ya isa RP, yanzu bari muyi kokarin amsa tambayar yadda RP ke ba da zirga-zirga ga masu karɓa. Anan ya zama dole don gabatar da sabon ra'ayi - bishiyar tushen hanyar (RPT). RPT itace kafe a cikin RP, girma zuwa ga masu karɓa, reshe akan kowane na'ura mai ba da hanya tsakanin hanyoyin sadarwa PIM-SM. RP yana ƙirƙira shi ta karɓar PIM Join saƙonnin kuma yana ƙara sabon reshe zuwa bishiyar. Sabili da haka, kowane na'ura mai ba da hanya tsakanin hanyoyin sadarwa yana yi. Ka'ida ta gama gari tayi kama da haka:

• Lokacin da na'ura mai ba da hanya tsakanin hanyoyin sadarwa na PIM-SM ya karɓi saƙon haɗin gwiwa na PIM akan kowane keɓancewar hanyar sadarwa wanda RP ke ɓoye, yana ƙara sabon reshe zuwa bishiyar.
• Hakanan ana ƙara reshe lokacin da PIM-SM na'ura mai ba da hanya tsakanin hanyoyin sadarwa ke karɓar Rahoton Membobin IGMP daga mai haɗin kai kai tsaye.

Bari mu yi tunanin cewa muna da abokin ciniki multicast akan na'ura mai ba da hanya tsakanin hanyoyin sadarwa R5 don rukunin 228.8.8.8. Da zaran R5 ya karɓi Rahoton Memba na IGMP daga mai watsa shiri, R5 yana aika haɗin PIM a cikin hanyar RP, kuma ita kanta tana ƙara ma'amala ga bishiyar da ke kallon mai watsa shiri. Bayan haka, R4 yana karɓar PIM Join daga R5, yana ƙara ƙirar Gi0/1 zuwa itacen kuma aika PIM Join a cikin hanyar RP. A ƙarshe, RP (R3) yana karɓar PIM Join kuma yana ƙara Gi0/0 zuwa itacen. Don haka, ana yiwa mai karɓar multicast rajista. Muna gina bishiya tare da tushen R3-Gi0/0 → R4-Gi0/1 → R5-Gi0/0.
Bayan wannan, za a aika haɗin PIM zuwa R1 kuma R1 zai fara aika zirga-zirgar ababen more rayuwa. Yana da mahimmanci a lura cewa idan mai watsa shiri ya nemi zirga-zirga kafin fara watsa shirye-shiryen multicast, to RP ba zai aika PIM Join ba kuma ba zai aika komai zuwa R1 kwata-kwata ba.
Idan ba zato ba tsammani yayin da ake aika multicast, mai watsa shiri ya daina son karɓa, da zaran RP ya karbi PIM Prune akan Gi0/0 interface, nan da nan zai aika da PIM Register-Stop kai tsaye zuwa R1, sa'an nan kuma PIM Prune. saƙo ta hanyar Gi0/1 interface. PIM Register-Stop Ana aika ta hanyar unicast zuwa adireshin da PIM ta fito.
Kamar yadda muka fada a baya, da zarar na'ura mai ba da hanya tsakanin hanyoyin sadarwa ya aika PIM Join zuwa wani, misali R5 zuwa R4, sai a kara rikodin zuwa R4:

Kuma an fara mai ƙidayar lokaci cewa R5 dole ne koyaushe sake saita wannan mai ƙidayar lokaci PIM Haɗa saƙonni akai-akai, in ba haka ba R4 za a cire shi daga jerin masu fita. R5 zai aika kowane saƙon Haɗin PIM 60.
Canjin Bishiyar Mafi Gajerewar Hanya.
Za mu ƙara ma'amala tsakanin R1 da R5 mu ga yadda zirga-zirga ke gudana tare da wannan topology.

Bari mu ɗauka cewa an aika da karɓar zirga-zirga bisa ga tsohon makirci R1-R2-R3-R4-R5, kuma a nan mun haɗa kuma mun daidaita haɗin tsakanin R1 da R5.
Da farko dai, dole ne mu sake gina tebirin tuƙi na unicast akan R5 kuma yanzu an isa cibiyar sadarwar 192.168.1.0/24 ta hanyar R5 Gi0/2 interface. Yanzu R5, yana karɓar multicast akan dubawar Gi0/1, ya fahimci cewa tsarin RPF bai gamsu ba kuma zai zama mafi ma'ana don karɓar multicast akan Gi0/2. Ya kamata ya cire haɗin daga RPT kuma ya gina guntun itace mai suna Shortest-Path Tree (SPT). Don yin wannan, ya aika PIM Join zuwa R0 ta hanyar Gi2/1 kuma R1 ya fara aika multicast kuma ta hanyar Gi0/2. Yanzu R5 yana buƙatar cire rajista daga RPT don kar ya karɓi kwafi biyu. Don yin wannan, ya aika da saƙon Prune wanda ke nuna adireshin IP na tushen da saka bit na musamman - RPT-bit. Wannan yana nufin cewa ba kwa buƙatar aika mani zirga-zirga, Ina da itace mafi kyau a nan. RP kuma yana aika saƙonnin PIM Prune zuwa R1, amma baya aika saƙon Tsaida Rijista. Wani fasali: R5 yanzu zai ci gaba da aika PIM Prune zuwa RP, yayin da R1 ke ci gaba da aika rajistar PIM zuwa RP kowane minti daya. Har sai babu sababbin mutane da ke son wannan zirga-zirga, RP zai ƙi shi. R5 yana sanar da RP cewa yana ci gaba da karɓar multicast ta hanyar SPT.
Neman RP mai ƙarfi.
Auto-RP.
Wannan fasahar mallakar ta Cisco ce kuma ba ta shahara musamman ba, amma har yanzu tana raye. Ayyukan Auto-RP ya ƙunshi manyan matakai guda biyu:
1) RP yana aika saƙonnin RP-Sanarwa zuwa adireshin da aka tanada - 224.0.1.39, yana bayyana kansa RP ko dai ga kowa da kowa ko na takamaiman ƙungiyoyi. Ana aika wannan sakon kowane minti daya.
2) Ana buƙatar wakilin taswirar RP, wanda zai aika saƙonnin RP-Discovery da ke nuna ƙungiyoyin da ya kamata a saurari RP. Daga wannan sakon ne masu amfani da hanyar sadarwa na PIM na yau da kullum zasu ƙayyade RP don kansu. Wakilin Taswirar na iya zama ko dai na'ura mai ba da hanya tsakanin hanyoyin sadarwa na RP kanta ko kuma na'ura mai ba da hanya tsakanin hanyoyin sadarwa na PIM. Ana aika RP-Discovery zuwa adireshin 224.0.1.40 tare da mai ƙidayar lokaci na minti ɗaya.
Bari mu kalli tsarin daki-daki:
Bari mu saita R3 azaman RP:

ip pim send-rp-sanar da loopback 0 scope 10

R2 a matsayin wakilin taswira:

ip pim send-rp-discovery loopback 0 scope 10

Kuma akan duk sauran za mu sa ran RP ta hanyar Auto-RP:

ip pim autorp mai saurare

Da zarar mun saita R3, zai fara aika RP-Announce:

Kuma R2, bayan kafa wakilin taswira, zai fara jira saƙon RP-Announce. Sai kawai idan ya sami aƙalla RP guda ɗaya zai fara aika RP-Discovery:

Ta wannan hanyar, da zaran hanyoyin sadarwa na yau da kullun (PIM RP Listener) sun sami wannan sakon, za su san inda za su nemi RP.
Ɗaya daga cikin manyan matsalolin Auto-RP shine don karɓar saƙonnin RP-Announce da RP-Discovery, kuna buƙatar aika PIM Join zuwa adireshin 224.0.1.39-40, kuma don aikawa, kuna buƙatar sanin inda RP yana nan. Classic kaza da matsalar kwai. Don magance wannan matsalar, an ƙirƙira PIM Sparse-Dense-Mode. Idan mai amfani da na'ura mai ba da hanya tsakanin hanyoyin sadarwa bai san RP ba, to yana aiki a cikin Yanayin Dense; idan ya yi, to a cikin yanayin Sparse-mode. Lokacin da aka saita yanayin PIM Sparse-mode da ip pim autorp mai sauraron umarni akan musaya na masu amfani da na'urori na yau da kullun, na'ura mai ba da hanya tsakanin hanyoyin sadarwa zai yi aiki a cikin Yanayin Dense kawai don multicasting kai tsaye daga ka'idar Auto-RP (224.0.1.39-40).
BootStrap Router (BSR).
Wannan aikin yana aiki kama da Auto-RP. Kowane RP yana aika sako zuwa ga wakilin taswira, wanda ke tattara bayanan taswira sannan ya gaya wa duk sauran hanyoyin sadarwa. Bari mu kwatanta tsari kamar Auto-RP:
1) Da zarar mun saita R3 a matsayin ɗan takara don zama RP, tare da umarnin:

ip pim rp-dan takara loopback 0

Sa'an nan R3 ba zai yi wani abu ba, don fara aika saƙonni na musamman, da farko yana buƙatar nemo wakilin taswira. Don haka, za mu ci gaba zuwa mataki na biyu.
2) Sanya R2 azaman wakilin taswira:

ip pim bsr-dan takara loopback 0

R2 ta fara aika saƙonnin Bootstrap PIM, inda yake nuna kanta a matsayin wakili na taswira:

Ana aika wannan sakon zuwa adireshin 224.0.013, wanda ka'idar PIM kuma ke amfani da ita don sauran saƙonta. Yana aika su ta kowane bangare don haka babu matsalar kaza da kwai kamar yadda ake yi a Auto-RP.
3) Da zaran RP ta karɓi saƙo daga na'ura mai ba da hanya tsakanin hanyoyin sadarwa na BSR, nan take za ta aika saƙon unicast zuwa adireshin BSR na'ura mai ba da hanya tsakanin hanyoyin sadarwa:

Bayan haka, BSR, bayan samun bayanai game da RPs, za ta aika su ta multicast zuwa adireshin 224.0.0.13, wanda duk masu amfani da PIM ke saurare. Saboda haka, analog na umarnin ip pim autorp mai saurare don masu amfani da hanyar sadarwa na yau da kullun ba a cikin BSR ba.
Anycast RP tare da Multicast Source Discovery Protocol (MSDP).
Auto-RP da BSR suna ba mu damar rarraba kaya akan RP kamar haka: Kowane rukunin multicast yana da RP guda ɗaya kawai. Ba zai yiwu a rarraba kaya don rukunin multicast ɗaya akan RPs da yawa ba. MSDP yana yin haka ta hanyar ba da masu amfani da RP adireshin IP iri ɗaya tare da abin rufe fuska na 255.255.255.255. MSDP tana koyon bayanai ta amfani da ɗayan hanyoyin: a tsaye, Auto-RP ko BSR.

A cikin hoton muna da saitin Auto-RP tare da MSDP. Dukansu RPs an saita su tare da adireshin IP 172.16.1.1/32 akan Maɓallin Loopback 1 kuma ana amfani dashi ga duk ƙungiyoyi. Tare da RP-Announce, duka hanyoyin sadarwa suna sanar da kansu ta hanyar komawa zuwa wannan adireshin. Wakilin taswirar Auto-RP, bayan karɓar bayanin, ya aika RP-Discovery game da RP tare da adireshin 172.16.1.1/32. Muna gaya wa masu amfani da hanyar sadarwa game da hanyar sadarwar 172.16.1.1/32 ta amfani da IGP kuma, daidai da haka. Don haka, masu ba da hanya tsakanin hanyoyin sadarwa na PIM suna buƙatar ko rajista suna gudana daga RP wanda aka ƙayyade azaman na gaba-hop akan hanyar zuwa hanyar sadarwar 172.16.1.1/32. Ka'idar MSDP ita kanta an ƙirƙirata ne don RPs da kansu don musayar saƙonni game da bayanan multicast.
Yi la'akari da wannan topology:

Switch6 yana watsa zirga-zirga zuwa adireshin 238.38.38.38 kuma ya zuwa yanzu RP-R1 kawai ya san game da shi. Switch7 da Switch8 sun nemi wannan rukunin. Masu ba da hanya R5 da R4 za su aika PIM Join zuwa R1 da R3, bi da bi. Me yasa? Hanyar zuwa 13.13.13.13 don R5 za ta koma R1 ta amfani da ma'aunin IGP, kamar na R4.
RP-R1 ya san rafi kuma zai fara watsa shi zuwa R5, amma R4 bai san komai game da shi ba, tunda R1 ba zai aika shi kawai ba. Don haka MSDP ya zama dole. Mun saita shi akan R1 da R5:

ip msdp peer 3.3.3.3 tushen haɗin yanar gizo Loopback1 akan R1

ip msdp peer 1.1.1.1 tushen haɗin yanar gizo Loopback3 akan R3

Za su tada zama a tsakanin juna kuma lokacin karbar duk wani kwarara za su kai rahoto ga makwabcin su RP.
Da zaran RP-R1 ta karɓi rafi daga Switch6, nan take za ta aika da saƙon MSDP Source-Active na unicast, wanda zai ƙunshi bayanai kamar (S, G) - bayani game da tushen da kuma inda ake zuwa na multicast. Yanzu da RP-R3 ya san cewa tushe irin su Switch6, lokacin karɓar buƙatu daga R4 don wannan kwararar, zai aika PIM Join zuwa Switch6, ta hanyar tebur mai jagora. Saboda haka, R1 ya sami irin wannan haɗin PIM zai fara aika zirga-zirga zuwa RP-R3.
MSDP yana gudana akan TCP, RPs suna aika saƙon kiyaye juna don duba rayuwa. Mai ƙidayar lokaci shine daƙiƙa 60.
Ayyukan rarraba takwarorinsu na MSDP zuwa yankuna daban-daban ya kasance ba a sani ba, tunda saƙonnin Keepalive da SA ba sa nuna mamba a kowane yanki. Har ila yau, a cikin wannan topology, mun gwada wani tsari wanda ke nuna yankuna daban-daban - babu bambanci a cikin aiki.
Idan wani zai iya fayyace, zan yi farin cikin karanta shi a cikin sharhi.

source: www.habr.com