Momwe PIM protocol imagwirira ntchito

Protocol ya PIM ndi seti ya ma protocol otumizira ma multicast mu netiweki pakati pa ma routers. Maubwenzi oyandikana nawo amamangidwa mofanana ndi momwe zimakhalira ndi ndondomeko zoyendera. PIMv2 imatumiza mauthenga a Moni masekondi 30 aliwonse ku adilesi yosungidwa ya multicast 224.0.0.13 (All-PIM-Routers). Uthengawu uli ndi Hold Timers - nthawi zambiri zofanana ndi 3.5*Moni Timer, ndiye kuti, masekondi 105 mwachisawawa.

PIM imagwiritsa ntchito njira ziwiri zazikulu - Dense ndi Sparse mode. Tiyeni tiyambe ndi Dense mode.
Mitengo Yogawira Magwero.
Dense-mode mode ndiyofunikira kuti mugwiritse ntchito makasitomala ambiri amagulu osiyanasiyana. Rauta ikalandira magalimoto ambiri, chinthu choyamba chomwe imachita ndikuwunika malamulo a RPF. RPF - lamuloli limagwiritsidwa ntchito kuyang'ana gwero la ma multicast ndi tebulo la unicast routing. Ndikofunikira kuti magalimoto afike pamawonekedwe kumbuyo komwe wolandirayo amabisika malinga ndi mtundu wa tebulo la unicast routing. Makinawa amathetsa vuto la loop yomwe imachitika panthawi yotumizira ma multicast.

R3 idzazindikira gwero la multicast (Source IP) kuchokera ku mauthenga ambiri ndikuyang'ana maulendo awiri kuchokera ku R1 ndi R2 pogwiritsa ntchito tebulo lake la unicast. Mtsinje wochokera pamawonekedwe omwe adawonetsedwa patebulo (R1 mpaka R3) upititsidwa patsogolo, ndipo mtsinje wochokera ku R2 udzagwetsedwa, chifukwa kuti mufike ku gwero la multicast, muyenera kutumiza mapaketi kudzera pa S0/1.
Funso ndilakuti, chimachitika ndi chiyani ngati muli ndi njira ziwiri zofanana zokhala ndi metric yofanana? Pankhaniyi, rauta adzasankha lotsatira-hop kuchokera njira izi. Yemwe ali ndi ma adilesi apamwamba a IP amapambana. Ngati mukufuna kusintha izi, mutha kugwiritsa ntchito ECMP. Zambiri apa.
Pambuyo poyang'ana lamulo la RPF, rauta imatumiza paketi ya multicast kwa oyandikana nawo onse a PIM, kupatulapo yemwe paketiyo idalandiridwa. Ma router ena a PIM abwereza izi. Njira yomwe paketi ya multicast yatenga kuchokera ku gwero kupita kwa olandira omaliza imapanga mtengo wotchedwa source-based distribution tree, shortest-path tree (SPT), mtengo wagwero. Mayina atatu osiyana, sankhani aliwonse.
Momwe mungathetsere vuto lomwe ma routers ena sanataye mtima pamtsinje wina wa multicast ndipo palibe amene angawatumizire, koma router yakumtunda imatumiza kwa iye. Makina a Prune adapangidwira izi.
Dulani Uthenga.
Mwachitsanzo, R2 idzapitiriza kutumiza ma multicast ku R3, ngakhale kuti R3, malinga ndi lamulo la RPF, imagwetsa. Chifukwa chiyani mumatsegula tchanelo? R3 imatumiza PIM Prune Message ndi R2, atalandira uthengawu, adzachotsa mawonekedwe a S0/1 kuchokera pamndandanda wotuluka wa mawonekedwe awa, mndandanda wamalo omwe magalimotowa ayenera kutumizidwa.

Zotsatirazi ndikutanthauzira kokhazikika kwa uthenga wa PIM Prune:
Mauthenga a PIM Prune amatumizidwa ndi rauta imodzi kupita ku rauta yachiwiri kuti apangitse rauta yachiwiri kuchotsa ulalo womwe Prune amalandila kuchokera ku (S,G) SPT.

Mukalandira uthenga wa Prune, R2 imayika chowerengera cha Prune kukhala mphindi zitatu. Pambuyo pa mphindi zitatu, iyambanso kutumiza magalimoto mpaka italandira uthenga wina wa Prune. Izi zili mu PIMv3.
Ndipo mu PIMv2 chowerengera cha State Refresh chawonjezedwa (masekondi 60 mwachisawawa). Uthenga wa Prune ukangotumizidwa kuchokera ku R3, nthawi iyi imayambika pa R3. Pakutha kwa nthawi iyi, R3 idzatumiza uthenga wa State Refresh, womwe udzakhazikitsenso Prune Timer ya mphindi 3 pa R2 ya gulu ili.
Zifukwa zotumizira uthenga wa Prune:

• Paketi ya multicast ikalephera kuyang'ana RPF.
• Ngati palibe makasitomala olumikizidwa kwanuko omwe apempha gulu la multicast (IGMP Join) ndipo palibe oyandikana nawo a PIM omwe magalimoto ambiri amatha kutumizidwa (Non-prune Interface).

Uthenga wa Graft.
Tiyerekeze kuti R3 sinafune traffic kuchokera ku R2, idatumiza Prune ndikulandila ma multicast kuchokera ku R1. Koma mwadzidzidzi, njira yapakati pa R1-R3 idagwa ndipo R3 idasiyidwa yopanda ma multicast. Mutha kudikirira mphindi zitatu mpaka Prune Timer pa R3 itatha. Mphindi 2 ndikudikirira kwanthawi yayitali, kuti musadikire, muyenera kutumiza uthenga womwe udzabweretse mawonekedwe a S3/0 nthawi yomweyo ku R1 kuchoka pamalo odulidwa. Uthenga uwu ukhala uthenga wa Graft. Pambuyo polandira uthenga wa Graft, R2 idzayankha ndi Graft-ACK.
Prune Override.

Tiyeni tiwone chithunzichi. R1 imawulutsa ma multicast kugawo lomwe lili ndi ma router awiri. R3 imalandira ndikuwulutsa magalimoto, R2 imalandira, koma alibe wina woti awulutse magalimoto. Imatumiza uthenga wa Prune ku R1 mu gawo ili. R1 iyenera kuchotsa Fa0/0 pamndandanda ndikusiya kuwulutsa mu gawoli, koma kodi R3 idzatani? Ndipo R3 ili mu gawo lomwelo, adalandiranso uthengawu kuchokera kwa Prune ndikumvetsetsa zovuta zomwe zidachitika. R1 isanayime kuwulutsa, imayika chowerengera cha masekondi atatu ndipo imasiya kuwulutsa pakadutsa masekondi atatu. Masekondi atatu - izi ndi nthawi yochuluka yomwe R3 ali nayo kuti asataye ma multicast. Chifukwa chake, R3 imatumiza uthenga wa Pim Join kwa gululi posachedwa, ndipo R3 sakuganizanso zoyimitsa kuwulutsa. Za Lowani mauthenga pansipa.
Uthenga Wabwino.

Tiyeni tiyerekeze izi: ma routers awiri amawulutsidwa ku netiweki imodzi nthawi imodzi. Amalandira mtsinje womwewo kuchokera ku gwero, ndipo onse amawuulutsa ku netiweki yomweyo kumbuyo kwa mawonekedwe e0. Chifukwa chake, akuyenera kudziwa yemwe akhale yekha komanso wowulutsa pa intanetiyi. Mauthenga otsimikiza amagwiritsidwa ntchito pa izi. R2 ndi R3 akazindikira kubwereza kwa magalimoto ambiri, ndiye kuti, R2 ndi R3 alandila ma multicast omwe amawulutsa okha, ma routers amamvetsetsa kuti pali cholakwika apa. Pankhaniyi, ma routers amatumiza mauthenga a Assert, omwe akuphatikizapo Administrative Distance ndi njira ya metric yomwe magwero a multicast amafikira - 10.1.1.10. Wopambana amatsimikiziridwa motere:

1. Omwe ali ndi AD yotsika.
2. Ngati AD ali ofanana, ndiye ndani ali ndi metric yotsika.
3. Ngati pali kufanana pano, ndiye yemwe ali ndi IP yapamwamba pamaneti omwe amawulutsirako ma multicast awa.

Wopambana pa votiyi amakhala Njira Yosankhidwa. Pim Hello imagwiritsidwanso ntchito posankha ma DR. Kumayambiriro kwa nkhaniyi, uthenga wa PIM Hello udawonetsedwa, mutha kuwona gawo la DR pamenepo. Yemwe ali ndi ma adilesi apamwamba kwambiri a IP pa ulalowu ndiye amapambana.
Chizindikiro chothandiza:

Chithunzi cha MROUTE.
Pambuyo poyang'ana koyambirira momwe protocol ya PIM imagwirira ntchito, tiyenera kumvetsetsa momwe tingagwiritsire ntchito ndi tebulo la multicast. Gome la mroute limasunga zambiri za mitsinje yomwe idafunsidwa kuchokera kwa makasitomala ndi mitsinje iti yomwe ikuyenda kuchokera ku maseva ambiri.
Mwachitsanzo, Lipoti la Umembala wa IGMP kapena PIM Join likalandiridwa pamawonekedwe ena, mbiri yamtundu ( *, G ) imawonjezedwa patebulo lolowera:

Kulowa uku kumatanthauza kuti pempho la magalimoto linalandiridwa ndi adilesi 238.38.38.38. Mbendera ya DC imatanthawuza kuti ma multicast azigwira ntchito mu Dense mode ndipo C amatanthauza kuti wolandirayo alumikizidwa mwachindunji ndi rauta, ndiye kuti, rauta idalandira Lipoti la Umembala wa IGMP ndi PIM Join.
Ngati pali mbiri ya mtundu (S,G) zikutanthauza kuti tili ndi ma stream ambiri:

M'munda wa S - 192.168.1.11, talembetsa adilesi ya IP ya gwero la multicast, ndi izi zomwe zidzayang'aniridwa ndi lamulo la RPF. Ngati pali zovuta, chinthu choyamba muyenera kuchita ndikuyang'ana tebulo la unicast panjira yopita kugwero. Mu Incoming Interface field, imasonyeza mawonekedwe omwe ma multicast amalandiridwa. Patebulo la unicast routing, njira yopita ku gwero iyenera kutanthauza mawonekedwe omwe afotokozedwa apa. Outgoing Interface imatanthawuza komwe ma multicast adzalumikizidwe. Ngati ilibe kanthu, ndiye kuti rauta sanalandire zopempha zamtunduwu. Zambiri za mbendera zonse zitha kupezeka apa.
PIM Sparse-mode.
Njira ya Sparse-mode ndiyosiyana ndi Dense-mode. Sparse-mode ikalandira kuchuluka kwa magalimoto, imangotumiza magalimoto kudzera m'malo olumikizirana omwe panali zopempha zakuyenda uku, mwachitsanzo Pim Join kapena IGMP Report mauthenga opempha magalimotowa.
Zofananira za SM ndi DM:

• Maubwenzi oyandikana nawo amamangidwa mofanana ndi PIM DM.
• Lamulo la RPF limagwira ntchito.
• Kusankhidwa kwa DR ndikofanana.
• Kachitidwe ka Prune Overrides ndi Assert mauthenga ndi ofanana.

Kuti muwongolere kuti ndani, kuti ndi mtundu wanji wamtundu wamtundu wamtundu wamtundu wamtundu wamtundu womwe ukufunika pa netiweki, malo odziwa zambiri amafunikira. Malo athu adzakhala Rendezvous Point (RP). Aliyense amene akufuna mtundu wina wa magalimoto ambiri kapena wina adayamba kulandira magalimoto ambiri kuchokera kugwero, ndiye amatumiza ku RP.
RP ikalandira kuchuluka kwa magalimoto, imatumiza kwa ma routers omwe adapempha kale magalimotowa.

Tiyeni tiyerekeze topology pomwe RP ndi R3. R1 ikangolandira kuchuluka kwa magalimoto kuchokera ku S1, imayika paketi iyi ya multicast kukhala meseji ya PIM ya Unicast ndikutumiza ku RP. Kodi akudziwa bwanji kuti RP ndi ndani? Pankhaniyi, imakonzedwa mokhazikika, ndipo tidzakambirana za kasinthidwe ka RP pambuyo pake.

IP pim rp-adilesi 3.3.3.3

RP ikuwoneka - kodi panali zambiri kuchokera kwa wina yemwe angafune kulandira izi? Tiyerekeze kuti sizinali choncho. Kenako RP idzatumiza R1 uthenga wa PIM Register-Stop, zomwe zikutanthauza kuti palibe amene amafunikira ma multicast awa, kulembetsa kumakanidwa. R1 situmiza ma multicast. Koma wolandila magwero ambiri adzatumiza, kotero kuti R1, atalandira Register-Stop, ayambitse Register-Suppression timer yofanana ndi masekondi 60. Masekondi a 5 nthawi iyi isanathe, R1 itumiza uthenga wopanda kanthu wa Register ndi Null-Register bit (ndiko kuti, wopanda paketi ya multicast) kupita ku RP. RP, nayenso, idzachita motere:

• Ngati panalibe olandira, ndiye kuti idzayankha ndi Register-Stop message.
• Ngati olandira apezeka, sangayankhe mwanjira iliyonse. R1, popeza sanalandire kukana kulembetsa mkati mwa masekondi a 5, adzakhala okondwa ndikutumiza uthenga wa Register ndi ma multicast ophatikizidwa ku RP.

Tikuwoneka kuti tazindikira momwe ma multicast amafikira ku RP, tsopano tiyeni tiyese kuyankha funso la momwe RP imaperekera magalimoto kwa olandila. Apa m'pofunika kuyambitsa lingaliro latsopano - root-path tree (RPT). RPT ndi mtengo wozikika mu RP, ukukulira kwa omwe akulandira, kukhazikika pa rauta iliyonse ya PIM-SM. RP imapanga polandira PIM Lowani mauthenga ndikuwonjezera nthambi yatsopano pamtengo. Chifukwa chake, rauta iliyonse yotsika imatero. Lamulo lalikulu likuwoneka motere:

• Pamene PIM-SM router imalandira uthenga wa PIM Join pa mawonekedwe aliwonse kupatulapo mawonekedwe omwe RP imabisika, imawonjezera nthambi yatsopano pamtengo.
• Nthambi imawonjezeredwanso pomwe rauta ya PIM-SM ilandila Lipoti la Umembala wa IGMP kuchokera kwa wolandila wolumikizidwa mwachindunji.

Tiyeni tiyerekeze kuti tili ndi makasitomala ambiri pa R5 rauta ya gulu 228.8.8.8. R5 ikangolandira Lipoti la Umembala wa IGMP kuchokera kwa wolandirayo, R5 imatumiza PIM Join motsogozedwa ndi RP, ndipo palokha imawonjezera mawonekedwe pamtengo womwe umayang'ana wolandila. Kenako, R4 ilandila PIM Join kuchokera ku R5, imawonjezera mawonekedwe a Gi0/1 pamtengo ndikutumiza PIM Join molunjika ku RP. Pomaliza, RP ( R3 ) ilandila PIM Join ndikuwonjezera Gi0/0 pamtengo. Chifukwa chake, wolandila ma multicast amalembetsa. Tikumanga mtengo ndi muzu R3-Gi0/0 → R4-Gi0/1 → R5-Gi0/0.
Pambuyo pake, PIM Join idzatumizidwa ku R1 ndipo R1 idzayamba kutumiza magalimoto ambiri. Ndikofunika kuzindikira kuti ngati wolandirayo apempha magalimoto asanayambe kuwulutsa ma multicast, ndiye kuti RP sidzatumiza PIM Join ndipo sichitumiza chilichonse ku R1.
Ngati mwadzidzidzi pamene ma multicast akutumizidwa, wolandirayo amasiya kufuna kulandira, mwamsanga RP ikalandira Prune Prune pa mawonekedwe a Gi0/0, nthawi yomweyo imatumiza PIM Register-Stop mwachindunji ku R1, ndiyeno PIM Prune. uthenga kudzera pa mawonekedwe a Gi0/1. PIM Register-stop imatumizidwa kudzera ku unicast ku adilesi yomwe PIM Register idachokera.
Monga tanena kale, rauta ikangotumiza PIM Join kwa ina, mwachitsanzo R5 mpaka R4, ndiye mbiri imawonjezedwa ku R4:

Ndipo chowerengera chimayambika kuti R5 iyenera kukonzanso nthawi yonseyi PIM Lowani mauthenga pafupipafupi, apo ayi R4 idzachotsedwa pamndandanda womwe ukutuluka. R5 idzatumiza mauthenga 60 aliwonse a PIM Join.
Njira Yaifupi Yosinthira Mtengo.
Tiwonjezera mawonekedwe pakati pa R1 ndi R5 ndikuwona momwe magalimoto amayendera ndi topology iyi.

Tiyerekeze kuti magalimoto adatumizidwa ndikulandiridwa molingana ndi dongosolo lakale R1-R2-R3-R4-R5, ndipo apa tidalumikiza ndikukonza mawonekedwe pakati pa R1 ndi R5.
Choyamba, tiyenera kumanganso tebulo la unicast routing pa R5 ndipo tsopano maukonde 192.168.1.0/24 amafikira kudzera pa R5 Gi0/2 mawonekedwe. Tsopano R5, kulandira ma multicast pa mawonekedwe a Gi0/1, akumvetsetsa kuti lamulo la RPF silikukhutitsidwa ndipo zingakhale zomveka kulandira ma multicast pa Gi0/2. Iyenera kuchoka ku RPT ndikumanga mtengo wamfupi wotchedwa Shortest-Path Tree (SPT). Kuti achite izi, amatumiza PIM Join mpaka R0 kudzera pa Gi2/1 ndipo R1 akuyamba kutumizanso ma multicast kudzera pa Gi0/2. Tsopano R5 ikufunika kusiya kulembetsa ku RPT kuti musalandire makope awiri. Kuti achite izi, amatumiza Prune uthenga wosonyeza komwe adilesi ya IP imachokera ndikuyikapo pang'ono - RPT-bit. Izi zikutanthauza kuti simuyenera kunditumizira magalimoto, ndili ndi mtengo wabwinoko pano. RP imatumizanso mauthenga a PIM Prune ku R1, koma samatumiza uthenga wa Register-Stop. Chinthu china: R5 tsopano idzatumiza Prune Prune mosalekeza ku RP, pamene R1 ikupitiriza kutumiza PIM Register ku RP mphindi iliyonse. Mpaka palibe anthu atsopano omwe akufuna magalimotowa, RP adzakana. R5 imadziwitsa RP kuti ikupitilizabe kulandira ma multicast kudzera pa SPT.
Kusaka kwa Dynamic RP.
Auto-RP.
Tekinoloje iyi ndi ya Cisco ndipo si yotchuka kwambiri, koma ikadali yamoyo. Auto-RP ntchito imakhala ndi magawo awiri akulu:
1) RP imatumiza mauthenga a RP-Lengezani ku adilesi yosungidwa - 224.0.1.39, kulengeza yokha RP kaya aliyense kapena magulu enaake. Uthenga uwu umatumizidwa mphindi iliyonse.
2) Wothandizira mapu a RP akufunika, omwe adzatumiza mauthenga a RP-Discovery osonyeza magulu omwe RP ayenera kumvera. Ndi kuchokera ku uthenga uwu kuti ma routers okhazikika a PIM adziwonetsera okha RP. Wothandizira Mapu atha kukhala rauta ya RP yokha kapena rauta yosiyana ya PIM. RP-Discovery imatumizidwa ku 224.0.1.40 ndi timer ya miniti imodzi.
Tiyeni tiwone ndondomekoyi mwatsatanetsatane:
Tiyeni tikonze R3 ngati RP:

ip pim kutumiza-rp-lengeza loopback 0 kuchuluka 10

R2 ngati wothandizira mapu:

ip pim send-rp-discovery loopback 0 scope 10

Ndipo pa ena onse tidzayembekezera RP kudzera pa Auto-RP:

ip pim autop omvera

Tikakonza R3, iyamba kutumiza RP-Lengezani:

Ndipo R2, mutatha kukhazikitsa wothandizira mapu, idzayamba kuyembekezera uthenga wa RP-Lengezani. Pokhapokha ikapeza RP imodzi yomwe imayamba kutumiza RP-Discovery:

Mwanjira iyi, ma routers okhazikika (PIM RP Listener) akalandira uthengawu, adzadziwa komwe angayang'ane RP.
Imodzi mwamavuto akulu ndi Auto-RP ndikuti kuti mulandire mauthenga a RP-Lengezani ndi RP-Discovery, muyenera kutumiza PIM Join ku ma adilesi 224.0.1.39-40, ndipo kuti mutumize, muyenera kudziwa komwe RP ilipo. Classic nkhuku ndi dzira vuto. Kuti athetse vutoli, PIM Sparse-Dense-Mode idapangidwa. Ngati rauta sakudziwa RP, imagwira ntchito mu Dense-mode; ngati itero, ndiye mu Sparse-mode. Pamene PIM Sparse-mode ndi ip pim autorp omvera lamulo akonzedwa pa ma interfaces a rauta wamba, rauta idzagwira ntchito mu Dense-mode kokha kwa multicasting mwachindunji Auto-RP protocol (224.0.1.39-40).
BootStrap Router (BSR).
Izi zimagwira ntchito mofanana ndi Auto-RP. RP iliyonse imatumiza uthenga kwa wopanga mapu, yemwe amasonkhanitsa zambiri zamapu ndikuuza ma router ena onse. Tiyeni tifotokoze ndondomekoyi mofanana ndi Auto-RP:
1) Tikangokonza R3 ngati ofuna kukhala RP, ndi lamulo:

ip pim rp-candidate loopback 0

Ndiye R3 sangachite kalikonse, kuti ayambe kutumiza mauthenga apadera, choyamba ayenera kupeza wothandizira mapu. Motero, timapita ku sitepe yachiwiri.
2) Konzani R2 ngati chothandizira mapu:

ip pim bsr-candidate loopback 0

R2 imayamba kutumiza mauthenga a PIM Bootstrap, pomwe imadziwonetsa ngati wothandizira mapu:

Uthengawu umatumizidwa ku adilesi 224.0.013, yomwe PIM protocol imagwiritsanso ntchito mauthenga ake ena. Zimawatumiza kumbali zonse choncho palibe vuto la nkhuku ndi dzira monga momwe zinalili mu Auto-RP.
3) RP ikangolandira uthenga kuchokera ku rauta ya BSR, imatumiza uthenga wosasinthika ku adilesi ya rauta ya BSR:

Pambuyo pake, BSR, italandira zambiri za RPs, idzawatumiza ndi multicast ku adilesi 224.0.0.13, yomwe imamvera ndi ma routers onse a PIM. Choncho, analogue ya lamulo ip pim autop omvera kwa ma routers okhazikika osati mu BSR.
Anycast RP yokhala ndi Multicast Source Discovery Protocol (MSDP).
Auto-RP ndi BSR zimatilola kugawa katundu pa RP motere: Gulu lililonse la multicast lili ndi RP imodzi yokha yogwira. Sizingatheke kugawa katundu wa gulu limodzi la multicast pa ma RP angapo. MSDP imachita izi popereka ma rauta a RP adilesi yomweyo ya IP yokhala ndi chigoba cha 255.255.255.255. MSDP imaphunzira zambiri pogwiritsa ntchito njira imodzi: static, Auto-RP kapena BSR.

Pachithunzichi tili ndi kasinthidwe ka Auto-RP ndi MSDP. Ma RP onsewa amapangidwa ndi IP adilesi 172.16.1.1/32 pa mawonekedwe a Loopback 1 ndipo amagwiritsidwa ntchito pamagulu onse. Ndi RP-Lengezani, ma router onse awiri amadzilengeza okha potengera adilesi iyi. Wothandizira mapu a Auto-RP, atalandira zambiri, amatumiza RP-Discovery za RP ndi adilesi 172.16.1.1/32. Timauza ma routers za netiweki 172.16.1.1/32 pogwiritsa ntchito IGP ndipo, molingana. Chifukwa chake, ma routers a PIM amapempha kapena kulembetsa kumayenda kuchokera ku RP komwe kumatchulidwa ngati hop yotsatira panjira yopita ku netiweki 172.16.1.1/32. Protocol ya MSDP yokha idapangidwa kuti ma RP okha azisinthana mauthenga okhudza zambiri zowulutsa.
Taganizirani topology iyi:

Switch6 imawulutsa magalimoto ku adilesi 238.38.38.38 ndipo mpaka pano ndi RP-R1 yokha yomwe ikudziwa za izo. Switch7 ndi Switch8 anapempha gulu ili. Ma routers R5 ndi R4 adzatumiza PIM Join ku R1 ndi R3, motsatana. Chifukwa chiyani? Njira yopita ku 13.13.13.13 ya R5 idzatanthauza R1 pogwiritsa ntchito metric ya IGP, monga ngati R4.
RP-R1 amadziwa za mtsinjewo ndipo ayamba kuyiulutsa ku R5, koma R4 sakudziwa kalikonse za izo, popeza R1 simangotumiza. Chifukwa chake MSDP ndiyofunikira. Timakonza pa R1 ndi R5:

ip msdp peer 3.3.3.3 connect-source Loopback1 pa R1

ip msdp peer 1.1.1.1 connect-source Loopback3 pa R3

Adzakweza gawo pakati pa wina ndi mnzake ndipo akalandira kutuluka kulikonse adzauza oyandikana nawo a RP.
RP-R1 ikangolandira mtsinje kuchokera ku Switch6, idzatumiza mwamsanga uthenga wa MSDP Source-Active, womwe udzakhala ndi chidziwitso cha mtundu (S, G) - zambiri za gwero ndi kopita kwa multicast. Tsopano popeza RP-R3 ikudziwa kuti gwero ngati Switch6, ikalandira pempho kuchokera ku R4 pakuyenda uku, itumiza PIM Join ku Switch6, motsogozedwa ndi tebulo lamayendedwe. Chifukwa chake, R1 italandira PIM Join iyamba kutumiza magalimoto ku RP-R3.
MSDP imayendera TCP, ma RPs amatumizirana mauthenga osunga moyo kuti awone ngati akuyenda. The timer ndi 60 masekondi.
Ntchito yogawa anzawo a MSDP m'magawo osiyanasiyana sichidziwika bwino, popeza mauthenga a Keepalive ndi SA samawonetsa umembala mu domain iliyonse. Komanso, mu topology iyi, tidayesa masinthidwe omwe akuwonetsa madera osiyanasiyana - panalibe kusiyana kwa magwiridwe antchito.
Ngati wina atha kufotokozera, ndingakhale wokondwa kuwerenga mu ndemanga.

Source: www.habr.com