Ingabe i-VPNv4 idinga i-MPLS emgodini? Akudingeki
I-BGP VPNv4 ixoxa ngomongo wokusabalalisa imizila, hhayi indlela yokudlulisa. Hlukanisa ukungenisa, ukuxazululwa kwesinyathelo esilandelayo kanye ne-encapsulation ongayisebenzisa.
Ukuvula umndeni wamakheli we-VPNv4 phakathi kwamarouta amabili kwakha umongo wokusabalalisa imizila kuphela futhi akukho okunye. Akufaki indlela yokudlulisa futhi akusho ukuthi iyiphi i-encapsulation ezothwala iphakethe lekhasimende iye endaweni yokugcina ekude. Lapho la maqiniso amabili ehlukaniswa, umbuzo othi «ingabe lokhu kudinga i-MPLS emgodini» uba umbuzo omncane futhi ongaphendulwa mayelana nendlela yedatha esekelwa yipulatifomu.
Yini umndeni wamakheli oxoxa ngayo ngempela
I-BGP yamaphrothokholi amaningi ithwala ulwazi lokufinyeleleka koshevu lwenethiwekhi lwe-VPNv4 ngaphansi kwe-AFI 1 ne-SAFI 128, futhi umbhalo ngamunye uhlanganisa isihlukanisi somzila nekhompiyutha nophawu. Iseshini ixoxa ukuthi izinhlangothi zombili zingakwazi ukubhala nokufunda lolo lwazi. Engayixoxi indlela yedatha. Konke ngemva kwalesi sigaba kumayelana nokudlulisa, futhi akukho kwakho okunqunywa ukuphakama kweseshini.
Ngakho-ke iseshini ephumelelayo iwubufakazi bekhono lendlela yokulawula, hhayi lokudlulisa. Irouta ingagcina izinkulungwane zamabhodi e-VPNv4 futhi isilahle iphakethe ngalinye lekhasimende, futhi yingakho lezi zigaba ezimbili zokwehluleka zixutshwa kusukela ekuqaleni.
Qaphela uphawu oluku-NLRI. Luyiphawu lesevisi, liboshelwe ekhompiyutha ngaphakathi kwe-VRF, futhi linendima yokudlulisa lapho iphakethe lifika endaweni yokuphuma. Ukuthi ngabe idivayisi ethile yokudlula iyalifunda noma cha kuyisinqumo esihlukile somklamo.
Ukuthola, ukungenisa nokudlulisa kuyizinyathelo ezintathu
Ukuthola umzila, ukuvunyelwa ukuwusebenzisa kanye nekhono lokudlulisa ngawo kwenziwa izingxenye ezihlukene zedivayisi. I-BGP igcina ekuzwayo; inqubomgomo yokungenisa nokufana kwethagethi yomzila kunquma ukuthi iyiphi i-VRF engawucabangela; bese kudingeka indlela yokudlulisa ixazulule isinyathelo esilandelayo esimemezelwe ibe yinto engayikhipha ngempela ocingweni.
| Step in the chain | What has to be true | How it fails quietly |
|---|---|---|
| NLRI exchange | Both speakers negotiate the VPNv4 capability | Session stays up while the family is never activated |
| Import eligibility | A route target on the received route matches the VRF import policy | The route exists in the table but never enters the VRF |
| Next-hop resolution | The advertised next hop resolves to a usable tunnel or label path | Best path is selected, then marked unreachable or unusable |
| Encapsulation | The egress endpoint can decapsulate what the ingress produced | Packets arrive and are discarded for a format mismatch |
Kukulesi sinyathelo saphakathi lapho kuhlala khona ukwehluleka okumangaza kakhulu. Umzila ungaba khona kuthebula le-BGP, uvumelekile futhi ube ngcono kakhulu, kuyilapho ithebula lemizila le-VRF lihlala lingenalutho ngoba akukho thagethi yomzila efane ngohlu lokungenisa. Akukho okubhala iphutha lephrothokholi, ngoba akukho phutha lephrothokholi elenzekile.
Isinyathelo sokugcina yindawo lapho ukusekelwa kwepulatifomu kubonakala khona. Isinyathelo esilandelayo esifinyeleleka engxenyeni engezansi asixazululeki ngokuzenzakalela njengokuthutha kwesevisi ye-VPN, futhi idivayisi ingase idinge uhlobo oluthile lweshubhu, umsebenzi othile wophawu noma kokubili. Ukufunda isimo sokuxazulula kunolwazi oluningi kunokufunda inani lemizila.
Umongo we-IP ungathwala isitaki engasishintshi
Umehluko ofanele ugcinwe uphakathi kokuthi «umongo awusebenzisi i-MPLS» nokuthi «awukho uphawu ndawo yonke kusevisi». Lokhu kuyizitatimende ezihlukene, futhi eyokuqala kuphela ekhuluma ngamadivayisi okudlula. I-RFC 4023 ichaza ukuthwala i-MPLS ngeziteshi ze-IP noma ze-GRE, futhi yiyo le ndlela eyenza isitatimende sesibili sibe nokwenzeka emgodini we-IP kuphela.
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 meaningfulAmarouta okudlula adlulisa ngokwesikhombisi se-IP sangaphandle futhi awadingi iziqalo zekhasimende noma ukushintshwa kophawu kwemvelo. Ekugcineni okukude kususwa ishubhu langaphandle futhi uphawu lwesevisi luqhubeka nomsebenzi wabo. Umongo wahambisa umthwalo ongabonakali, futhi yilokho kanye i-IP network eyikwenzayo kahle.
Lokho lo mklamo ongakuniki isiqinisekiso esisemhlabeni wonke. Akubona ubufakazi bokuthi yonke irouta ixazulula yonke isinyathelo esilandelayo se-VPNv4 kunoma iyiphi i-interface ye-GRE, futhi akusona isizathu sokususa ukucushwa kwe-MPLS kwemvelo okusebenzayo. Kuwuphawu oluphambene nesitatimende esisemhlabeni wonke, futhi umbuzo ongokoqobo uhlala uyingxenye yepulatifomu. Bhala lowo mbuzo njengomkhawulo wepulatifomu hhayi njengomthetho wephrothokholi.
Hamba ngeketango ebhokisini ize iphuke
Qala kumzila otholiwe futhi ume esinyathelweni sokuqala esihlulekayo, ngoba izinyathelo ezilandelayo azikwazi ukuxilongwa ngenkathi esedlule uphukile. Imiyalo emine ihlanganisa iningi lalokho ekusetshenzisweni okujwayelekile.
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_AZifunde njengokulandelana hhayi njengezihlolo ezine ezizimele. Eyokuqala iqinisekisa ukuthi umndeni uyasebenza nokuthi uzakwethu ushintshana ngemizila; eyesibili ikhombisa ukuthi ikhompiyutha yafika nesinyathelo esilandelayo esisebenzisekayo yini; eyesithathu ifakazela ukufaneleka kokungenisa; eyesine ikhombisa ukuthi indlela yokudlulisa yayihlanganisa uphawu noma ishubhu kuyo yini.
Bese uhlola indlela yomthwalo womsebenzi kuzo zombili izinhlangothi, nge-MTU ebekezelela i-encapsulation. I-GRE yengeza amabhayithi ekhanda, futhi indlela edlula izivivinyo ezincane ingase ihluleke emaphaketheni anosayizi ogcwele ohlangothini olulodwa kuphela, okubonakala njengokwehluleka kohlelo lokusebenza hhayi kokuthutha.
Amanothi amabili okusebenza avaliwe umjikelezo. I-GRE iyi-encapsulation, hhayi imfihlo, ngakho-ke inethiwekhi yokudlula engathenjwa idinga ukuhlelwa kokuphepha okusekelwayo phezulu hhayi ukucabanga. Futhi bhala ukuthi iyiphi i-encapsulation esekelwa ngempela yipulatifomu ngaphambi kokubuyekezwa komklamo, ngoba leyo mpendulo eyodwa inquma ukuthi umongo we-IP kuphela uyisinqumo esivumelekile noma uhlelo olungeke lukwazi ukudlulisa.