Iphrothokholi ye-PIM iyisethi yezinqubo zokudlulisa ukusakaza okuningi kunethiwekhi phakathi kwamarutha. Ubudlelwano bomakhelwane bakhiwe ngendlela efanayo nasesimweni samaphrothokholi omzila aguqukayo. I-PIMv2 ithumela imilayezo ethi Sawubona njalo ngemizuzwana engu-30 ekhelini lokusakaza okuningi eligodliwe elithi 224.0.0.13 (All-PIM-Routers). Umlayezo uqukethe okuthi Bamba Isikhathi - ngokuvamile esilingana no-3.5*Sawubona Isikhathi, okungukuthi, imizuzwana eyi-105 ngokuzenzakalelayo.
I-PIM isebenzisa izindlela ezimbili zokusebenza eziyinhloko - Imodi Eminyene ne-Sparse. Ake siqale ngemodi Eminyene.
Izihlahla Zokusabalalisa Ezisekelwe Emthonjeni.
Imodi ye-Dense-mode iyancomeka ukuthi isetshenziswe esimweni senombolo enkulu yamakhasimende amaqembu ahlukene okusakaza okuningi. Uma irutha ithola ithrafikhi yokusakaza okuningi, into yokuqala eyenzayo ukuyihlolela umthetho we-RPF. I-RPF - lo mthetho usetshenziselwa ukuhlola umthombo we-multicast ngetafula le-unicast yomzila. Kuyadingeka ukuthi ithrafikhi ifike kusixhumi esibonakalayo ngemuva kwalokho lo msingathi afihlwe ngokuya ngenguqulo yetafula le-unicast. Lo mshini uxazulula inkinga yeluphu eyenzeka ngesikhathi sokusakazwa kwe-multicast.
I-R3 izobona umthombo wokusakaza okuningi (I-IP yomthombo) ovela kumlayezo wokusakaza okuningi futhi ihlole ukugeleza okubili ukusuka ku-R1 no-R2 isebenzisa ithebula layo le-unicast. Ukusakaza okuvela kusixhumi esibonakalayo esikhonjwe yithebula (R1 kuya ku-R3) kuzosatshalaliswa ngokuqhubekayo, futhi ukusakaza okuvela ku-R2 kuzokwehliswa, njengoba ukuze ufinyelele emthonjeni wokusakaza okuningi, udinga ukuthumela amaphakethe nge-S0/1.
Umbuzo uwukuthi, kwenzekani uma unemizila emibili elinganayo enemethrikhi efanayo? Kulokhu, i-router izokhetha i-hop elandelayo kule mizila. Noma ubani onekheli le-IP eliphezulu uyawina. Uma udinga ukushintsha lokhu kuziphatha, ungasebenzisa i-ECMP. Imininingwane eyengeziwe .
Ngemva kokuhlola umthetho we-RPF, i-router ithumela iphakethe le-multicast kubo bonke omakhelwane bayo be-PIM, ngaphandle kwalowo okwamukelwe kuye iphakethe. Amanye amarutha e-PIM aphinda le nqubo. Indlela ethathwe iphakethe le-multicast isuka emthonjeni iye kwabamukeli bokugcina yakha isihlahla esibizwa nge-source-based distribution tree, shortest-path tree (SPT), isihlahla somthombo. Amagama amathathu ahlukene, khetha noma yiliphi.
Indlela yokuxazulula inkinga ukuthi amanye ama-routers awazange ayeke emfuleni othile we-multicast futhi akekho ongayithumela kuye, kodwa i-router ekhuphukayo iyithumela kuye. I-Prune mechanism yasungulelwa lokhu.
Sika umlayezo.
Isibonelo, u-R2 uzoqhubeka nokuthumela i-multicast ku-R3, nakuba u-R3, ngokomthetho we-RPF, uyayiyeka. Kungani ulayisha isiteshi? I-R3 ithumela i-PIM Prune Message futhi i-R2, lapho ithola lo mlayezo, izosusa isixhumi esibonakalayo S0/1 ohlwini oluphumayo lokusebenzelana lwalokhu kugeleza, uhlu lwezindawo lapho le thrafikhi kufanele ithunyelwe khona.
Okulandelayo incazelo esemthethweni yomlayezo we-PIM Prune:
Umlayezo we-PIM Prune uthunyelwa umzila owodwa kumzila wesibili ukuze kubangele umzila wesibili ukuthi ukhiphe isixhumanisi lapho iPrune yamukelwe ku-(S,G) SPT ethile.
Ngemva kokuthola umlayezo Prune, u-R2 usetha isibali sikhathi sePrune sibe yimizuzu emi-3. Ngemva kwemizuzu emithathu, izoqala ukuthumela ithrafikhi futhi ize ithole omunye umlayezo wePrune. Lokhu ku-PIMv1.
Futhi ku-PIMv2 isibali sikhathi sokuvuselela kabusha sezwe sengeziwe (imizuzwana engama-60 ngokuzenzakalelayo). Ngokushesha nje lapho umlayezo wePrune usuthunyelwe usuka ku-R3, lesi sibali sikhathi siqalwa ngo-R3. Uma sesiphelelwe yisikhathi lesi sibali sikhathi, u-R3 uzothumela umlayezo Wokuvuselela Isimo Sezwe, ozosetha kabusha Isibali-sikhathi se-Prune esiyimizuzu emi-3 ku-R2 kuleli qembu.
Izizathu zokuthumela umlayezo wePrune:
- Uma iphakethe le-multicast lehluleka ukuhlola i-RPF.
- Uma engekho amaklayenti axhumene endaweni acele iqembu labalingisi abaningi (I-IGMP Joyina) futhi bengekho omakhelwane be-PIM okungathunyelwa kubo ithrafikhi ye-multicast (I-Non-prune Interface).
Umlayezo we-Graft.
Ake sicabange ukuthi u-R3 wawungafuni izimoto ezivela ku-R2, wathumela uPrune futhi wathola i-multicast evela ku-R1. Kodwa kungazelelwe, isiteshi esiphakathi kuka-R1-R3 siwe kwathi u-R3 wasala ungenayo i-multicast. Ungalinda imizuzu emi-3 kuze kuphele isikhathi I-Prune Timer ku-R2. Imizuzu emi-3 iwukulinda isikhathi eside, ukuze ungalindi, udinga ukuthumela umlayezo ozoletha ngokushesha lesi sixhumi esibonakalayo se-S0/1 sibe ngu-R2 siphume esimweni esithenwe. Lo mlayezo uzoba umlayezo we-Graft. Ngemva kokuthola umlayezo we-Graft, u-R2 uzophendula nge-Graft-ACK.
Prune Override.
Ake sibheke lo mdwebo. I-R1 isakaza ukusakaza okuningi engxenyeni enamarutha amabili. I-R3 yamukela futhi iyasakaza ithrafikhi, i-R2 ithola, kodwa akekho ongasakaza ithrafikhi kuye. Ithumela umlayezo wePrune ku-R1 kule ngxenye. U-R1 kufanele akhiphe u-Fa0/0 ohlwini futhi ayeke ukusakaza kulesi sigaba, kodwa kuzokwenzekani ngo-R3? Futhi u-R3 usesigabeni esifanayo, nawo wathola lo mlayezo ovela kuPrune futhi waqonda usizi lwesimo. Ngaphambi kokuthi i-R1 iyeke ukusakaza, imisa isibali sikhathi semizuzwana emi-3 futhi izoyeka ukusakaza ngemva kwemizuzwana emi-3. 3 imizuzwana - lesi yisikhathi esingakanani u-R3 anaso ukuze angalahlekelwa ukulingisa kwakhe okuningi. Ngakho-ke, u-R3 uthumela umlayezo we-Pim Joyina kuleli qembu ngokushesha okukhulu, futhi u-R1 akasacabangi ukumisa ukusakaza. Mayelana Joyina imilayezo ngezansi.
Umlayezo Wokugomela.
Ake sicabange lesi simo: amarutha amabili asakaza kunethiwekhi eyodwa ngesikhathi esisodwa. Bathola ukusakaza okufanayo okuvela emthonjeni, futhi bobabili bakusakaza kunethiwekhi efanayo ngemuva kwesixhumi esibonakalayo esingu-e0. Ngakho-ke, kufanele banqume ukuthi ngubani ozoba yedwa futhi yedwa umsakazi wale nethiwekhi. Imilayezo yokugomela isetshenziselwa lokhu. Lapho i-R2 ne-R3 ithola ukuphindwaphindwa kwethrafikhi yokusakaza okuningi, okungukuthi, i-multicast ifika ku-R2 naku-R3, yona esakaza yona, ama-routers ayaqonda ukuthi kukhona okungalungile lapha. Kulokhu, amarutha athumela imilayezo ye-Assert, ehlanganisa i-Administrative Distance kanye nemethrikhi yomzila okufinyelelwa ngayo umthombo we-multicast - 10.1.1.10. Owinile unqunywa kanje:
- Lona one-AD ephansi.
- Uma i-AD ilingana, ngabe ubani onemethrikhi ephansi.
- Uma kukhona ukulingana lapha, lowo one-IP ephezulu kunethiwekhi abasakaza kuyo lokhu kusakazwa okuningi.
Owinile kuleli voti uba Umzila Obekiwe. I-Pim Hello isetshenziselwa ukukhetha ama-DR. Ekuqaleni kwesihloko, umlayezo we-PIM Sawubona ubonisiwe, ungabona inkambu ye-DR lapho. Lowo onekheli lasesizindeni se-inthanethi eliphezulu kulesi sixhumanisi uyawina.
Uphawu oluwusizo:
Ithebula le-MROUTE.
Ngemuva kokubheka kokuqala ukuthi iphrothokholi ye-PIM isebenza kanjani, sidinga ukuqonda ukuthi singasebenza kanjani ngetafula lokuzulazula kokusakaza okuningi. Ithebula le-mroute ligcina ulwazi olumayelana nokuthi yikuphi ukusakaza okuceliwe kumakhasimende nokuthi yiziphi izifudlana ezigeleza zisuka kumaseva okusakaza okuningi.
Isibonelo, uma umbiko wobulungu be-IGMP noma Ukujoyina kwe-PIM kwamukelwe esixhumi esibonakalayo, irekhodi lohlobo ( *, G ) liyengezwa kuthebula lomzila:
Lokhu okufakiwe kusho ukuthi isicelo sethrafikhi samukelwe ngekheli elithi 238.38.38.38. Ifulegi le-DC lisho ukuthi ukusakaza okuningi kuzosebenza ngemodi Eminyene futhi u-C usho ukuthi umamukeli uxhumeke ngokuqondile kumzila, okungukuthi, umzila uthole Umbiko Wobulungu be-IGMP kanye Nokujoyina kwe-PIM.
Uma kukhona irekhodi lohlobo (S,G) kusho ukuthi sinokusakazwa kokusakaza okuningi:
Emkhakheni we-S - 192.168.1.11, sibhalise ikheli le-IP lomthombo we-multicast, yilokhu okuzohlolwa umthetho we-RPF. Uma kunezinkinga, into yokuqala okudingeka uyenze ukuhlola ithebula le-unicast ukuze uthole umzila oya emthonjeni. Kunkambu ye-Interface Engenayo, ikhombisa isixhumi esibonakalayo lapho i-multicast yamukelwe khona. Kuthebula le-unicast yomzila, umzila oya emthonjeni kufanele ubhekisele kusixhumi esibonakalayo esicaciswe lapha. I-Outgoing Interface icacisa lapho ukusakaza okuningi kuzoqondiswa kabusha. Uma ingenalutho, khona-ke umzila awukatholi izicelo zale thrafikhi. Ulwazi olwengeziwe mayelana nawo wonke amafulegi lungatholakala .
I-PIM Sparse-mode.
Isu le-Sparse-mode liphambene ne-Dense-mode. Uma i-Sparse-mode ithola ithrafikhi yokusakaza okuningi, izothumela kuphela ithrafikhi ngalezo zindawo lapho bekunezicelo zalokhu kugeleza, isibonelo I-Pim Joyina noma imilayezo ye-IGMP Bika ecela le thrafikhi.
Izinto ezifanayo ze-SM ne-DM:
- Ubudlelwano bomakhelwane bakhiwe ngendlela efanayo naku-PIM DM.
- Umthetho we-RPF uyasebenza.
- Ukukhethwa kwe-DR kuyafana.
- Indlela yokukhipha ama-Prune kanye nemilayezo ye-Assert iyafana.
Ukuze ulawule ukuthi ubani, kuphi futhi hlobo luni lwethrafikhi yokusakaza okuningi edingekayo kunethiwekhi, isikhungo solwazi esivamile siyadingeka. Isikhungo sethu kuzoba yiRendezvous Point (RP). Noma ubani ofuna uhlobo oluthile lwethrafikhi yokusakaza okuningi noma othile waqala ukuthola ithrafikhi yokusakaza okuningi emthonjeni, bese eyithumela ku-RP.
Uma i-RP ithola ithrafikhi yokusakaza okuningi, izoyithumela kulawo marutha aye acela le thrafikhi ngaphambilini.
Ake sicabange nge-topology lapho i-RP ingu-R3. Ngokushesha nje lapho i-R1 ithola ithrafikhi evela ku-S1, ihlanganisa leli phakethe le-multicast ibe umlayezo we-PIM Register ye-unicast bese iwuthumela ku-RP. Wazi kanjani ukuthi ubani u-RP? Kulokhu, ilungiselelwe ngokwezibalo, futhi sizokhuluma ngokucushwa kwe-RP ashukumisayo kamuva.
ip pim rp-ikheli 3.3.3.3
I-RP izobukeka - ingabe belukhona ulwazi oluvela kumuntu ongathanda ukuthola le thrafikhi? Ake sicabange ukuthi bekungenjalo. Bese i-RP izothumela u-R1 umlayezo we-PIM Register-Stop, okusho ukuthi akekho odinga lokhu kusakazwa okuningi, ukubhaliswa kwenqatshwa. I-R1 ngeke ithumele i-multicast. Kodwa umsingathi womthombo we-multicast uzowuthumela, ukuze i-R1, ngemva kokuthola i-Register-Stop, iqale isibali-sikhathi se-Register-Suppression esilingana namasekhondi angu-60. Imizuzwana emi-5 ngaphambi kokuphelelwa yisikhathi kwalesi sibali sikhathi, i-R1 izothumela umlayezo we-Register ongenalutho onebhithi ye-Null-Register (okungukuthi, ngaphandle kwephakethe le-multicast ehlanganisiwe) ubheke ku-RP. I-RP, nayo, izosebenza kanje:
- Uma bekungekho abamukeli, izophendula ngomlayezo othi Bhalisa-Misa.
- Uma abamukeli bevela, ngeke abaphendule nganoma iyiphi indlela. U-R1, njengoba engatholanga ukwenqatshwa kokubhalisa phakathi nemizuzwana emi-5, uzojabula futhi athumele umlayezo Wokubhalisa one-multicast ehlanganisiwe ku-RP.
Kubonakala sengathi sithole ukuthi i-multicast ifinyelela kanjani ku-RP, manje ake sizame ukuphendula umbuzo wokuthi i-RP ihambisa kanjani ithrafikhi kubamukeli. Lapha kuyadingeka ukwethula umqondo omusha - isihlahla se-root-path (RPT). I-RPT isihlahla esinezimpande ku-RP, esikhula sibheke kubamukeli, sihlanganisa umzila ngamunye we-PIM-SM. I-RP iyakha ngokuthola i-PIM Joyina imilayezo bese yengeza igatsha elisha esihlahleni. Futhi ngakho, yonke i-router engezansi iyakwenza. Umthetho ojwayelekile ubukeka kanje:
- Uma irutha ye-PIM-SM ithola umlayezo we-PIM Joyina kunoma yisiphi isixhumi esibonakalayo ngaphandle kwesixhumi esibonakalayo lapho i-RP ifihliwe khona, yengeza igatsha elisha esihlahleni.
- Igatsha liphinde lengezwe lapho irutha ye-PIM-SM ithola umbiko wobulungu be-IGMP kumsingathi oxhumeke ngokuqondile.
Ake sicabange ukuthi sineklayenti le-multicast kumzila we-R5 weqembu 228.8.8.8. Ngokushesha nje lapho u-R5 ethola Umbiko Wobulungu Be-IGMP kumsingathi, u-R5 uthumela I-PIM Joyina ngendlela ye-RP, futhi yona ngokwayo yengeza isixhumi esibonakalayo esihlahleni esibheka umsingathi. Okulandelayo, i-R4 ithola i-PIM Joyina isuka ku-R5, yengeza isixhumi esibonakalayo Gi0/1 esihlahleni bese ithumela i-PIM Joyina ibheke ku-RP. Ekugcineni, i-RP ( R3 ) ithola i-PIM Joyina bese yengeza i-Gi0/0 esihlahleni. Ngakho, umamukeli we-multicast ubhalisiwe. Sakha isihlahla ngempande R3-Gi0/0 β R4-Gi0/1 β R5-Gi0/0.
Ngemva kwalokhu, i-PIM Joyina izothunyelwa ku-R1 futhi u-R1 uzoqala ukuthumela ithrafikhi yokusakaza okuningi. Kubalulekile ukuqaphela ukuthi uma umsingathi ecele ukugcwala ngaphambi kokuba kuqale ukusakazwa kokusakaza okuningi, i-RP ngeke ithumele i-PIM Joyina futhi ngeke ithumele lutho ku-R1 nhlobo.
Uma kungazelelwe ngenkathi kuthunyelwa i-multicast, umsingathi eyeka ukufuna ukuyithola, ngokushesha nje lapho i-RP ithola i-PIM Prune ku-interface ye-Gi0/0, izothumela ngokushesha i-PIM Register-Stop ngqo ku-R1, bese kuba i-PIM Prune. umyalezo nge-interface ye-Gi0/1. I-PIM Register-stop ithunyelwa nge-unicast ekhelini okwavela kulo Irejista ye-PIM.
Njengoba sishilo ekuqaleni, lapho nje irutha ithumela i-PIM Joyina kwenye, isibonelo u-R5 ukuya ku-R4, bese irekhodi lengezwa ku-R4:
Futhi isibali sikhathi siyaqalwa ukuthi i-R5 kumele ihlale isetha kabusha lesi sibali sikhathi se-PIM Joyina imilayezo njalo, ngaphandle kwalokho u-R4 uzokhishwa ohlwini oluphumayo. U-R5 uzothumela yonke imilayezo engu-60 ye-PIM Joyina.
I-Switchover Yesihlahla Esifushane Kakhulu.
Sizokwengeza ukuxhumana phakathi kwe-R1 ne-R5 futhi sibone ukuthi ithrafikhi ihamba kanjani nale topology.
Ake sicabange ukuthi ithrafikhi yathunyelwa futhi yamukelwa ngokohlelo oludala u-R1-R2-R3-R4-R5, futhi lapha sixhume futhi salungisa ukuxhumana phakathi kuka-R1 no-R5.
Okokuqala, kufanele sakhe kabusha itafula le-unicast routing ku-R5 futhi manje inethiwekhi 192.168.1.0/24 ifinyelelwa nge-interface ye-R5 Gi0/2. Manje i-R5, ithola ukusakaza okuningi ku-interface Gi0/1, iyaqonda ukuthi umthetho we-RPF awenelisekanga futhi kungaba okunengqondo kakhulu ukwamukela i-multicast ku-Gi0/2. Kufanele inqamule ku-RPT futhi yakhe isihlahla esifushane esibizwa nge-Shortest-Path Tree (SPT). Ukwenza lokhu, uthumela i-PIM Joyina ku-R0 ukuya ku-Gi2/1 bese u-R1 eqala ukuthumela i-multicast futhi nge-Gi0/2. Manje u-R5 udinga ukuzikhipha ohlwini lwe-RPT ukuze ungatholi amakhophi amabili. Ukwenza lokhu, uthumela u-Prune umlayezo obonisa ikheli le-IP lomthombo bese efaka ibhithi ekhethekile - i-RPT-bit. Lokhu kusho ukuthi awudingi ukungithumelela ithrafikhi, nginesihlahla esingcono lapha. I-RP iphinde ithumele imilayezo ye-PIM Prune ku-R1, kodwa ayiwuthumeli umlayezo we-Register-Stop. Esinye isici: I-R5 manje izothumela ngokuqhubekayo i-PIM Prune ku-RP, njengoba i-R1 iqhubeka nokuthumela i-PIM Register ku-RP njalo ngomzuzu. Kuze kube kungabikho abantu abasha abafuna le traffic, uRP uzokwenqaba. I-R5 yazisa i-RP ukuthi iyaqhubeka nokuthola ukusakaza okuningi nge-SPT.
Usesho lwe-Dynamic RP.
I-Auto-RP.
Lobu buchwepheshe buphathelene ne-Cisco futhi abudumile kakhulu, kodwa busaphila. Ukusebenza kwe-Auto-RP kunezigaba ezimbili eziyinhloko:
1) I-RP ithumela imilayezo ye-RP-Memezela ekhelini eligodliwe - 224.0.1.39, izimemezele ukuthi i-RP yawo wonke umuntu noma amaqembu athile. Lo mlayezo uthunyelwa njalo ngeminithi.
2) Kudingeka i-ejenti yokwenza imephu ye-RP, ezothumela imilayezo ye-RP-Discovery ebonisa ukuthi yimaphi amaqembu okufanele alalelwe i-RP. Kusuka kulo mlayezo lapho amarutha ajwayelekile e-PIM azozinqumela wona i-RP. I-Ejenti Yemephu ingaba irutha ye-RP ngokwayo noma irutha ye-PIM ehlukile. I-RP-Discovery ithunyelwa ku-224.0.1.40 ngesibali sikhathi somzuzu owodwa.
Ake sibheke inqubo ngokuningiliziwe:
Ake silungiselele i-R3 njenge-RP:
ip pim send-rp-annnounce loopback 0 isikophu 10
I-R2 njenge-ejenti yemephu:
ip pim send-rp-discovery loopback 0 isikophu 10
Futhi kubo bonke abanye sizolindela i-RP nge-Auto-RP:
ip pim autop umlaleli
Uma sesilungiselele i-R3, izoqala ukuthumela i-RP-Memezela:
Futhi u-R2, ngemva kokusetha i-ejenti yokwenza imephu, uzoqala ukulinda umlayezo we-RP-Memezela. Kuphela uma ithola okungenani i-RP eyodwa lapho izoqala khona ukuthumela i-RP-Discovery:
Ngale ndlela, ngokushesha nje lapho amarutha avamile (PIM RP Listener) ethola lo mlayezo, azokwazi ukuthi angayibheka kuphi i-RP.
Enye yezinkinga ezinkulu nge-Auto-RP ukuthi ukuze uthole imilayezo ye-RP-Memezela kanye ne-RP-Discovery, udinga ukuthumela i-PIM Joyina ekhelini elithi 224.0.1.39-40, futhi ukuze uthumele, udinga ukwazi ukuthi kuphi I-RP itholakala. Inkinga yenkukhu yama-Classic neqanda. Ukuxazulula le nkinga, i-PIM Sparse-Dense-Mode yasungulwa. Uma i-router ingayazi i-RP, khona-ke isebenza nge-Dense-mode; uma iyazi, kumodi ye-Sparse. Uma i-PIM Sparse-mode kanye nomyalo wesilaleli we-ip pim autorp kulungiselelwa ukuxhumana kwamarutha avamile, umzila uzosebenza ngemodi Eminyene kuphela ekusakazeni okuningi ngokuqondile kuphrothokholi ye-Auto-RP (224.0.1.39-40).
I-BootStrap Router (BSR).
Lo msebenzi usebenza ngokufana ne-Auto-RP. I-RP ngayinye ithumela umlayezo kumenzeli wemephu, oqoqa ulwazi lwemephu bese etshela wonke amanye amarutha. Ake sichaze inqubo ngendlela efanayo ne-Auto-RP:
1) Uma sesilungise i-R3 njengekhandidethi ukuthi ibe yi-RP, ngomyalo:
ip pim rp-candidate loopback 0
Khona-ke u-R3 ngeke enze lutho, ukuze aqale ukuthumela imilayezo ekhethekile, udinga kuqala athole umenzeli wemephu. Ngakho, sidlulela esinyathelweni sesibili.
2) Lungiselela i-R2 njenge-ejenti yemephu:
ip pim bsr-candidate loopback 0
I-R2 iqala ukuthumela imilayezo ye-PIM Bootstrap, lapho iziveza khona njenge-ejenti yokuhlela:
Lo mlayezo uthunyelwa ekhelini elithi 224.0.013, iphrothokholi ye-PIM futhi elisebenzisa kweminye imilayezo yayo. Iwathumela kuzo zonke izinhlangothi ngakho-ke ayikho inkinga yenkukhu neqanda njengoba yayikhona ku-Auto-RP.
3) Ngokushesha nje lapho i-RP ithola umlayezo ovela kumzila we-BSR, izothumela ngokushesha umlayezo we-unicast ekhelini lomzila we-BSR:
Ngemva kwalokho, i-BSR, ngemva kokuthola ulwazi mayelana nama-RPs, izowathumela nge-multicast ekhelini elithi 224.0.0.13, elilalelwa yiwo wonke amarutha we-PIM. Ngakho-ke, i-analogue yomyalo ip pim autop umlaleli kumarutha avamile awekho ku-BSR.
I-Anycast RP ene-Multicast Source Discovery Protocol (MSDP).
I-Auto-RP ne-BSR zisivumela ukuthi sisabalalise umthwalo ku-RP ngendlela elandelayo: Iqembu ngalinye le-multicast line-RP eyodwa kuphela esebenzayo. Ngeke kwenzeke ukusabalalisa umthwalo weqembu elilodwa lokusakaza okuningi ngama-RP ambalwa. I-MSDP yenza lokhu ngokukhipha amarutha e-RP ikheli le-IP elifanayo elinemaski engu-255.255.255.255. I-MSDP ifunda ulwazi isebenzisa enye yezindlela: static, Auto-RP noma BSR.
Esithombeni sinokucushwa kwe-Auto-RP nge-MSDP. Womabili ama-RP amiswe ngekheli le-IP elingu-172.16.1.1/32 kusixhumi esibonakalayo se-Loopback 1 futhi asetshenziselwa wonke amaqembu. Nge-RP-Memezela, womabili amarutha azimemezela ngokubhekisela kuleli kheli. I-ejenti yokwenza imephu ye-Auto-RP, ngemva kokuthola ulwazi, ithumela i-RP-Discovery mayelana ne-RP nekheli elithi 172.16.1.1/32. Sitshela ama-routers mayelana nenethiwekhi 172.16.1.1/32 esebenzisa i-IGP futhi, ngokufanele. Ngakho, amarutha e-PIM acela noma irejista igeleza isuka ku-RP ecaciswe njenge-hop elandelayo emzileni oya kunethiwekhi 172.16.1.1/32. Iphrothokholi ye-MSDP ngokwayo yakhelwe ukuthi ama-RPs ngokwawo ashintshisane ngemilayezo emayelana nolwazi lokusakaza okuningi.
Cabangela le topology:
I-Switch6 isakaza ithrafikhi ekhelini elithi 238.38.38.38 futhi kuze kube manje ngu-RP-R1 kuphela owaziyo ngakho. U-Switch7 kanye no-Switch8 bacele leli qembu. Amarutha u-R5 no-R4 azothumela i-PIM Joyina ku-R1 no-R3, ngokulandelana. Kungani? Umzila oya ku-13.13.13.13 ku-R5 uzobhekisela ku-R1 usebenzisa imethrikhi ye-IGP, njengo-R4.
I-RP-R1 iyazi ngokusakaza futhi izoqala ukuyisakaza iye ku-R5, kodwa u-R4 akazi lutho ngayo, ngoba u-R1 ngeke nje awuthumele. Ngakho-ke i-MSDP iyadingeka. Siyilungiselela ku-R1 naku-R5:
ip msdp peer 3.3.3.3 connect-source Loopback1 ku-R1
ip msdp peer 1.1.1.1 connect-source Loopback3 ku-R3
Bazophakamisa iseshini phakathi komunye nomunye futhi lapho bethola noma yikuphi ukugeleza bayobika kumakhelwane wabo we-RP.
Uma nje i-RP-R1 ithola ukusakaza okuvela ku-Switch6, izothumela ngokushesha umlayezo we-MSDP Source-Active unicast, ozoqukatha ulwazi olufana no-(S, G) - ulwazi olumayelana nomthombo nendawo yokusakaza okuningi. Manje njengoba i-RP-R3 yazi ukuthi umthombo ofana no-Switch6, lapho ithola isicelo esivela ku-R4 salokhu kugeleza, izothumela i-PIM Joyina ibheke ku-Switch6, iqondiswa ithebula lomzila. Ngenxa yalokho, i-R1 ithole i-PIM Join enjalo izoqala ukuthumela ithrafikhi ku-RP-R3.
I-MSDP isebenzisa i-TCP, ama-RPs athumelana imilayezo ebukhoma ukuze ahlole ukuthi uyaphila. Isibali sikhathi siyimizuzwana engama-60.
Umsebenzi wokuhlukanisa ontanga be-MSDP ngezizinda ezihlukene uhlala ungacacile, njengoba imilayezo ye-Keepalive ne-SA ayibonisi ubulungu kunoma yisiphi isizinda. Futhi, kule topology, sihlole ukucushwa okubonisa izizinda ezihlukene - awukho umehluko ekusebenzeni.
Uma noma ubani engacacisa, ngingajabula ukuyifunda kumazwana.
Source: www.habr.com