PE biyu, prefix ɗaya: me ya sa RD ke ƙayyade ganuwa
Routan gefe biyu da ke sanar da prefix ɗaya suna raba manufa ɗaya sai dai idan route distinguisher ɗinsu ya bambanta. Raba da gangan, sannan duba VRF.
Routan gefe biyu da ke sanar da prefix ɗaya na abokin ciniki suna bayyana manufa ɗaya ta VPNv4 har sai wani abu ya raba su, kuma mai raba shi ne route distinguisher. Yana cancantar prefix ɗin; ba ya ƙayyade wanda zai shigo da sakamakon, aikin route target ne. Raba RD daga jerin hanyoyin da dole su kasance masu bambanta a kowace yanki inda waɗannan sanarwar za su iya haɗuwa, ba daga tsarin fayil na akwati ɗaya ba. Lambar da ka zaɓa ita ce asalin da sake dubawa na gaba za su dogara da shi, don haka ya kamata ya kasance cikin lissafin kaya kafin ya shiga tsarin saiti.
RD tare da prefix manufa ɗaya ne
RD tare da prefix na IPv4 suna samar da manufar VPNv4 da matakin sarrafawa ke kwatanta. Ba PE biyu prefix ɗaya don abokan ciniki daban-daban kuma, ba tare da RD daban-daban ba, suna sanar da hanyoyi zuwa manufa ɗaya. Babu abin da ke kan allo da zai gaya maka cewa wannan haɗawar ba daidai ba ce, domin dandamali yana yin daidai abin da asalin ya faɗa. Canza RD a ɗayansu kuma an janye tsohon sanarwar yayin da wani sabo ya bayyana ƙarƙashin wani asali. Duk abin da ke ƙasa da ya dogara da tsohon asalin, daga zaɓin hanya har zuwa tacewar ma'aikaci da aka adana, yanzu yana nuni ga wani abu da ba ya wanzu.
Hanyoyi da yawa ga manufa ɗaya ɗabi'a ce ta BGP, ba alama ba. Mai magana na iya riƙe hanyoyin da aka karɓa da yawa yayin da yake zaɓin hanya mafi kyau don turawa, kuma tazarar da ke tsakanin karɓa da zaɓaɓɓe ita ce inda tambayoyin ganuwa suke. Idan wata hanya ta yi kamar ta ɓace, tabbatar ko asalin da ta ke nasa yana nan kafin ka duba zaman.
RD ɗaya, manufa ɗaya, hanyoyi daban-daban
Aika RD ɗaya da prefix ɗaya daga routa biyu a madadin sabis ɗaya kuma dukansu suna ba da hanyoyi zuwa manufa ɗaya, yawanci da tsalle-tsalle na gaba daban-daban. Wanne daga cikinsu mai nuna hanya zai wuce shi shawara ce game da mai nuna hanya: zaɓin hanyarsa, iyawar sanarwarsa, da duk wata manufa da aka ɗora a kai. Babu ɗaya daga cikin routan gefen da ke sarrafa wannan zaɓi. Ba sanarwar biyu RD daban-daban kuma kowace ta zama nata manufar, ta yadda dukansu za su iya tsira a matakin sarrafawa wanda in ba haka ba yana ɗauke da zaɓaɓɓiyar hanya ga asali ɗaya.
Ganuwa da hanyoyi da yawa suna haɗuwa a cikin VRF mai karɓa, amma ba shawara ɗaya ba ne, kuma mai nuna hanya da ke ɗauke da asali biyu bai saita hanya ta biyu da aka girka ba. VRF yana girka abin da manufar shigo da shi ta yarda da abin da saitinsa na iyakar hanyoyi ya yarda. Duba wannan saitin daban idan kana son a yi amfani da hanya ta biyu ba kawai a gan ta ba.
Ƙa'idar keɓantaka ta gida ba manufa ba ce
Ba kowace PE da kowace misalin turawa nata RD wata al'ada ce mai kyau: tana ambaton asalin, tana hana sabis ɗin da ba su da alaƙa yin karo a kan asali ɗaya, kuma tana ba lissafin kaya maɓalli mai tsayawa. Wasu dandamali suna buƙatar keɓantaka a cikin akwati kawai kuma suna ba da izini a fili ga routa su raba RD ɗaya don misalin VPN ɗaya. Wannan izni ƙuntatawar aiwatarwa ce, ba ƙa'idar tsakanin cibiyoyin sadarwa da za ka iya ba da ita ga mai kaya ba. Idan yankin ya ratsa ƙungiyoyi, ka rubuta manufar rabawa da kanka.
Memba ba ya zuwa daga lambobi. Tsari kamar 65000:12 ga PE ɗaya da 65000:13 ga wani al'ada ce, yayin da maƙasudin fitarwa da shigo da suka dace kamar 65000:112 su ne ke sanya hanya cikin VRF. Ɗauki RD a matsayin asalin hanya da route target a matsayin iznin da ke ɗauke ta cikin VRF.
Tabbatar da canjin a kan VRF, ba a kan allon ba
Kafin ka taɓa RD, rubuta abubuwa huɗu: abin da PE ke sanarwa yau, abin da mai nuna hanya ke nunawa, abin da VRF mai karɓa ke shigo da shi, da wace hanya take zaɓa. Sabon RD yana janye sanarwa ɗaya kuma yana gabatar da wata, don haka canjin yana bayyana a ɓangarorin biyu na zaman kuma yana da sauƙin karantawa ba daidai ba idan ka kalli ɓangaren sanarwa kawai. Karɓuwa ya kamata ya dogara da isar da kake so, ba da wani layi na ƙari da ya bayyana a jerin prefix ba. Jadawalin da ke ƙasa yana hana alamomin uku haɗuwa yayin wannan bita.
| Identifier | Question it answers | What breaks when it is confused with another |
|---|---|---|
| Route distinguisher | Which route identity is this? | Two services collapse into one destination, so one advertisement withdraws the other |
| Route target | Who is allowed to import it? | Routes arrive in a VRF that should not have them, or never arrive at all |
| VRF import policy | What does this instance accept and install? | The route is visible on the PE but never selected in the VRF |
Fara daga PE mai sanarwa ka kwatanta asalin biyu don prefix ɗaya kafin ka cire wani abu. Umarnin IOS da ke ƙasa suna amsa tambayoyi uku a jere: shin tsohon sanarwar yana nan har yanzu, shin sabon asalin yana ganuwa ga mai nuna hanya, kuma shin VRF yana zaɓin prefix ɗin.
show bgp vpnv4 unicast rd 65000:12 203.0.113.0/24 show bgp vpnv4 unicast rd 65000:13 203.0.113.0/24 show ip route vrf CUSTOMER-A 203.0.113.0/24
Wasu dandamali suna buga wannan bayanin da wani tsari, kuma tambayoyin suna wanzuwa bayan wannan canji. Idan sabon asalin ya ɓace a wurin mai nuna hanya yayin da PE ke lissafa shi a matsayin sanarwa, manufar mai nuna hanya ko iyawar sanarwarsa ce farkon wanda ake zargi, ba lambobi ba.
Yi rikodin PE, misali, RD, maƙasudin fitarwa da shigo da mallakar prefix a wuri ɗaya, domin rabawa na gaba bincike ne ba hasashe ba kawai idan wannan rikodin ya kasance. Riƙe tsohon RD har sabon asalin ya zama ganuwa a cikin VRF mai karɓa, sannan ka janye shi a mataki na biyu domin kowane mataki ya kasance mai iya juyawa.