Daarida qoyska cinwaanka VPNv4 ee u dhexeeya laba router waxay abuurtaa oo kaliya macnaha qaybinta waddooyinka iyo wax kale ma aha. Ma rakibto waddo gudbin, mana sheegto isku-duubiddee ayaa u qaadi doonta baakada macmiilka ilaa barta ugu dambeysa ee fog. Marka labadan xaqiiqo la kala sooco, su'aasha «ma u baahan tahay tan MPLS xudunta» waxay noqotaa mid cidhiidhi ah oo laga jawaabi karo oo ku saabsan diyaaradda xogta ee ay taageerto madal.

Waxa ay qoyska cinwaanku dhab ahaan ka wada-hadasho

BGP borotokoolo badan waxay qaadaa macluumaadka gelitaanka lakabka shabakada VPNv4 ee hoos yimaada AFI 1 iyo SAFI 128, iyo gelitaan kastaa waxay isku xirtaa kala-soocaha waddada iyo horudhac iyo calaamad. Fadhiga waxa uu ka wada-hadlaa in labada dhinac ay karti u leeyihiin in ay codeeyaan oo decodeeyaan macluumaadkaas. Waxa aanu ka wada-hadlin waa diyaaradda xogta. Wax kasta oo ka dambeeya cutubkan waxay khuseeyaan gudbinta, oo midkoodna laguma xalliyo fadhiga oo kaca.

Marka fadhi guul leh waa caddayn awoodda diyaaradda kontoroolka, ma aha gudbinta. Router waxa uu hayn karaa kumanaan gelitaan VPNv4 oo wali tuuri karaa baakad kasta oo macmiil, taasina waa sababta labada nooc ee guuldarada loo khaldaa bilowga.

Fiiri calaamadda ku jirta NLRI. Waa calaamad adeeg, oo ku xiran horudhac gudaha VRF, oo waxay leedahay door gudbin marka baakadu gaarto barta ugu dambeysa ee bixitaanka. Hadday qalab kasta oo gudbinta akhriyo iyo haddayna akhrin waa go'aan naqshadeed gooni ah.

Helitaanka, import-ka iyo gudbinta waa saddex tallaabo

Helitaanka waddo, fasaxa in la isticmaalo iyo awoodda lagu gudbiyo waxaa sameeya qaybo kala duwan oo qalabka. BGP waxa uu kaydiyaa waxa uu maqlo; siyaasadda import-ka iyo iswaafajinta bartilmaameedka waddada ayaa go'aamiya VRF kee ayaa tixgelin kara; ka dib diyaaradda gudbinta waa in ay xalliso tallaabada xigta ee lagu dhawaaqay wax ay dhab ahaan ku riixi karto silig.

Step in the chainWhat has to be trueHow it fails quietly
NLRI exchangeBoth speakers negotiate the VPNv4 capabilitySession stays up while the family is never activated
Import eligibilityA route target on the received route matches the VRF import policyThe route exists in the table but never enters the VRF
Next-hop resolutionThe advertised next hop resolves to a usable tunnel or label pathBest path is selected, then marked unreachable or unusable
EncapsulationThe egress endpoint can decapsulate what the ingress producedPackets arrive and are discarded for a format mismatch

Tallaabada dhexe ayaa ku nool guuldarada ugu yaabka badan. Waddo waxa ay ku jiri kartaa shaxda BGP, ansax ah oo xitaa ugu fiican, halka shaxda waddooyinka VRF ay madhan tahay sababtoo ah ma jirin bartilmaameed waddo oo la mid ah liiska import-ka. Waxba ma diiwaangeliyaan khalad borotokool, sababtoo ah khalad borotokool ma dhicin.

Tallaabada ugu dambeysa waa halka taageerada madasha ay muuqato. Tallaabada xigta ee laga gaari karo lakabka hoose si otomaatig ah looguma xalliyo sidii gaadiidka adeegga VPN, qalabkuna waxa uu u baahan karaa nooc tunnel gaar ah, hawlgalka calaamad gaar ah ama labadaba. Akhrinta xaaladda xallinta ayaa ka macluumaad badan akhrinta tirada waddooyinka.

Xudunta IP waxay qaadi kartaa isku-duubid aan waligeed beddelin

Kala duwanaanshaha mudan in la hayo waa inta u dhaxaysa «xuduntu ma shaqeyso MPLS» iyo «meel kasta oo adeegga ka mid ah calaamad ma jirto». Kuwani waa sheegashooyin kala duwan, oo kaliya tan koowaad ayaa ku saabsan qalabka gudbinta. RFC 4023 waxa uu qeexayaa qaadista MPLS iyada oo loo marayo tunnel IP ama GRE, taasina waa habka uu sheegashada labaad suurtogal uga dhigayo xudun IP ah oo dhan.

customer packet + service label
  encapsulated in GRE, addressed to the egress tunnel endpoint
  forwarded by ordinary IP routers on the outer header
  decapsulated at the endpoint, label still meaningful

Router-yada gudbinta waxay ku gudbaan bartilmaameedka IP ee dibadda mana u baahna horudhacyada macmiilka ama beddelka calaamadda asalka ah. Dhinaca fog tunnel-ka dibadda waa la saaraa calaamadda adeegguna waxay dib u bilowdaa shaqadeeda. Xuduntu waxay dhaqaajisay culeys aan caddayn, taasina waa si sax ah waxa shabakad IP ay ku fiican tahay.

Waxa aan naqshaddan ku siinayn waa dammaanad caalami ah. Ma aha caddayn in router kastaa xalliyo tallaabada xigta VPNv4 kasta iyada oo loo marayo interface GRE kasta, mana aha sabab lagu tirtiro qaabeynta MPLS asalka ah ee shaqeynaysa. Waa tusaale lid ku ah sheegashada caalamiga ah, su'aasha waxqabadkuna waxay ku sii socotaa gudaha madasha. Su'aashaas u qor sida xaddidaad madal ah ee ma aha sida qaanuun borotokool.

Silsiladda ku soco sanduuqa ilaa ay jabto

Ka bilow waddada la helay oo ku joogso tallaabada koowaad ee guuldareysata, sababtoo ah tallaabooyinka dambe lama ogaan karo inta tan hore ay jaban tahay. Afar amarro ayaa daboolaya inta badan taas fulin caadi ah.

show bgp vpnv4 unicast all summary
show bgp vrf CUSTOMER_A ip route 198.51.100.0/24
show ip route vrf CUSTOMER_A 198.51.100.0
show mpls forwarding-table vrf CUSTOMER_A

U akhri sida isku xigxiga ee ma aha sida afar hubin oo madaxbannaan. Tan koowaad waxay xaqiijinaysaa in qoysku firfircoon yahay iyo in saaxiibku waddooyin isweydaarsanayo; tan labaad waxay muujinaysaa haddii horudhacu yimid isagoo wata tallaabo xigta oo la isticmaali karo; tan saddexaad waxay caddaynaysaa u-qalmitaanka import-ka; tan afraad waxay muujinaysaa haddii diyaaradda gudbinta ay ku xirtay calaamad ama tunnel.

Ka dib tijaabi waddada culeyska shaqada labada jiho, iyada oo la adeegsanayo MTU ka adkaysan karta isku-duubidda. GRE waxay ku dartaa baytamada madaxa, waddo dhaafsanaya tijaabooyin yaryarna waxay ku guuldareysan kartaa baakadaha cabbirka buuxa hal jiho oo keliya, taasina waxay u ekaanaysaa cillad barnaamij ee ma aha cillad gaadiid.

Laba qoraal hawlgal ah ayaa xidha wareegga. GRE waa isku-duubid, ma aha qarsoodi, sidaas darteed shabakad gudbin aan la aamini karin waxay u baahan tahay hab amni oo la taageeray oo korka saaran halkii ay ka ahaan lahayd malo. Oo qor isku-duubiddee ay madashu dhab ahaan taageerto ka hor dib-u-eegista naqshadda, sababtoo ah jawaabtaas keliya ayaa go'aamisa haddii xudun IP-keli ah ay tahay doorasho ansax ah ama qorshe aan gudbin karin.

Maqaallo la xiriira