I kēia lā e nānā mākou i ka protocol BGP. ʻAʻole mākou e kamaʻilio lōʻihi e pili ana i ke kumu a me ke kumu i hoʻohana ʻia ai ʻo ia wale nō ka protocol. Nui ka ʻike e pili ana i kēia kumuhana, no ka laʻana .
No laila he aha ka BGP? ʻO ka BGP kahi protocol routing dynamic a ʻo ia wale nō ka protocol EGP (External Gateway Protocol). Hoʻohana ʻia kēia protocol e kūkulu i ke ala ala ma ka Pūnaewele. E nānā kākou pehea i kūkulu ʻia ai kahi kaiāulu ma waena o ʻelua mau mea hoʻokele BGP.
E noʻonoʻo i ke kaiāulu ma waena o Router1 a me Router3. E hoʻonohonoho kākou iā lākou me ka hoʻohana ʻana i kēia mau kauoha:
router bgp 10
network 192.168.12.0
network 192.168.13.0
neighbor 192.168.13.3 remote-as 10
router bgp 10
network 192.168.13.0
network 192.168.24.0
neighbor 192.168.13.1 remote-as 10ʻO ke kaiāulu i loko o kahi ʻōnaehana kūʻokoʻa hoʻokahi he AS 10. Ma hope o ka hoʻokomo ʻana i ka ʻike ma kahi alalai, e like me Router1, hoʻāʻo kēlā mea hoʻokele e hoʻonohonoho i kahi pilina pili me Router3. Kāhea ʻia ke kūlana mua inā ʻaʻohe mea i hana ʻia Kūkā. Ke hoʻonohonoho ʻia ʻo bgp ma Router1, e hoʻomaka ia e hoʻolohe i ke awa TCP 179 - e hele i ka mokuʻāina. hoʻohui, a i ka wā e hoʻāʻo ai e wehe i kahi hālāwai me Router3, e hele ia i ka mokuʻāina ʻeleu.
Ma hope o ka hoʻokumu ʻia ʻana o ke kau ma waena o Router1 a me Router3, ua hoʻololi ʻia nā memo Open. Ke hoʻouna ʻia kēia memo e Router1, e kāhea ʻia kēia mokuʻāina Wehe Hoʻouna ʻia. A i ka loaʻa ʻana o kahi leka wehe mai Router3, e hele ia i ka mokuʻāina Wehe Hōʻoia. E nānā pono kākou i ka memo Open:
Hāʻawi kēia memo i ka ʻike e pili ana i ka protocol BGP ponoʻī, kahi e hoʻohana ai ke alalai. Ma ka hoʻololi ʻana i nā memo Open, ke kamaʻilio nei ʻo Router1 a me Router3 i ka ʻike e pili ana i kā lākou hoʻonohonoho ʻana i kekahi i kekahi. Ua hala kēia mau ʻāpana:
- Version: aia kēia me ka mana BGP e hoʻohana nei ke alalai. ʻO ka mana o kēia manawa o ka BGP he mana 4 ia i wehewehe ʻia ma RFC 4271. E hoʻāʻo ʻelua mau mea hoʻokele BGP e kūkākūkā i kahi mana kūpono, ke loaʻa kahi mismatch a laila ʻaʻohe hālāwai BGP.
- ʻO kaʻu AS: aia kēia me ka helu AS o ka mea hoʻokele BGP, pono e ʻae nā mea hoʻokele i ka helu (s) AS a wehewehe pū ia inā e holo ana lākou i ka iBGP a i ʻole eBGP.
- Paʻa Manawa: inā ʻaʻole loaʻa iā BGP kekahi mau memo keepalive a i ʻole nā mea hou mai kēlā ʻaoʻao no ka lōʻihi o ka manawa paʻa a laila e haʻi ʻo ia i ka ʻaoʻao ʻē aʻe 'make' a e wāwahi ʻo ia i ke kau BGP. Ma ka maʻamau, ua hoʻonohonoho ʻia ka manawa paʻa i 180 kekona ma nā mea hoʻokele Cisco IOS, hoʻouna ʻia ka leka keepalive i kēlā me kēia 60 kekona. Pono nā mea ala ʻelua e ʻae i ka manawa paʻa a i ʻole he kau BGP.
- BGP Identifier: ʻo ia ka ID router BGP kūloko i koho ʻia e like me kā OSPF:
- E hoʻohana i ka router-ID i hoʻonohonoho lima ʻia me ke kauoha bgp router-id.
- E hoʻohana i ka helu IP kiʻekiʻe loa ma ka loopback interface.
- E hoʻohana i ka helu IP kiʻekiʻe loa ma kahi kikowaena kino.
- Nā ʻāpana koho: ma aneʻi e ʻike ʻoe i kekahi mau mana koho o ka router BGP. Ua hoʻohui ʻia kēia kahua i hiki ke hoʻohui ʻia nā hiʻohiʻona hou i ka BGP me ka ʻole e hana i kahi mana hou. ʻO nā mea āu e ʻike ai ma aneʻi:
- kākoʻo no MP-BGP (Multi Protocol BGP).
- kākoʻo no ka Route Refresh.
- kākoʻo no nā helu 4-octet AS.
No ka hoʻokumu ʻana i kahi kaiāulu, pono e hoʻokō ʻia kēia mau kūlana:
- Helu helu. ʻO ka mana o kēia manawa he 4.
- Pono ka helu AS e like me kāu i hoʻonohonoho ai hoalauna 192.168.13.3 mamao-e like me 10.
- Pono ʻokoʻa ka ID Alaula mai ka hoalauna.
Inā ʻaʻole i hoʻokō kekahi o nā ʻāpana i kēia mau kūlana, e hoʻouna ke alalai Hōʻike memo e hōʻike ana i ka hewa. Ma hope o ka hoʻouna ʻana a me ka loaʻa ʻana o nā memo Open, komo ka pilina kaiāulu i ka mokuʻāina Kukuluia. Ma hope o kēia, hiki i nā mea ala ke hoʻololi i ka ʻike e pili ana i nā ala a hana i kēia me ka hoʻohana ʻana Kiʻi hou nā memo. ʻO kēia ka memo Update i hoʻouna ʻia e Router1 iā Router3:
Maanei hiki iā ʻoe ke ʻike i nā pūnaewele i hōʻike ʻia e Router1 a me nā ʻano ala, e like me nā metric. E kamaʻilio mākou e pili ana i nā ʻano Path i nā kikoʻī hou aku. Hoʻouna pū ʻia nā memo Keepalive i loko o kahi kau TCP. Hoʻouna ʻia lākou, ma ka maʻamau, i kēlā me kēia 60 kekona. ʻO kēia kahi Keepalive Timer. Inā ʻaʻole i loaʻa kahi leka Keepalive i ka wā Hold Timer, ʻo ia ke ʻano o ka nalowale o ke kamaʻilio ʻana me ka hoalauna. Ma ka maʻamau, ua like ia me 180 kekona.
Hoailona pono:
Me he mea lā ua noʻonoʻo mākou pehea e hoʻouna ai nā mea ala i ka ʻike i kekahi i kekahi, i kēia manawa e hoʻāʻo mākou e hoʻomaopopo i ka loiloi o ka protocol BGP.
No ka hoʻolaha ʻana i kahi ala i ka papa BGP, e like me nā protocols IGP, hoʻohana ʻia ke kauoha pūnaewele, akā ʻokoʻa ka loiloi hana. Inā ma IGP, ma hope o ka wehewehe ʻana i ke ala i ke kauoha pūnaewele, nānā ka IGP i nā mea pili i kēia subnet a hoʻokomo iā lākou i kāna papaʻaina, a laila ʻo ke kauoha pūnaewele ma BGP e nānā i ka papa kuhikuhi a nānā iā ia. kikoʻī pili i ke ala ma ke kauoha pūnaewele. Inā loaʻa kēlā, e ʻike ʻia kēia mau ala i ka papa BGP.
E ʻimi i kahi ala ma ka papa kuhikuhi IP o kēia manawa e pili pono ana i nā ʻāpana o ke kauoha pūnaewele; inā loaʻa ke ala IP, e hoʻokomo i ka NLRI like i loko o ka papa BGP kūloko.
I kēia manawa, e hoʻokiʻekiʻe mākou i ka BGP i nā mea i koe a ʻike i ke koho ʻana o ke ala i loko o hoʻokahi AS. Ma hope o ka loaʻa ʻana o nā alahele BGP mai kona hoalauna, hoʻomaka ʻo ia e koho i ke ala kūpono loa. Maanei pono ʻoe e hoʻomaopopo i ke ʻano o nā hoalauna e hiki ai - i loko a i waho. Hoʻomaopopo anei ka mea alalai ma ka hoʻonohonoho ʻana inā ʻo loko a i waho paha ka hoalauna i hoʻonohonoho ʻia? Inā ma kahi hui:
neighbor 192.168.13.3 remote-as 10 ʻO ka mamao-e like me ka hoʻohālikelike e hōʻike ana i ka AS, i hoʻonohonoho ʻia ma ka router pono'ī ma ke kauoha bgp 10. ʻO nā ala e hele mai ana mai loko mai o AS e manaʻo ʻia i loko, a ʻo nā ala mai ka AS waho i manaʻo ʻia ma waho. A no kēlā me kēia, he loiloi ʻokoʻa o ka loaʻa ʻana a me ka hoʻouna ʻana i nā hana. E noʻonoʻo i kēia topology:
Loaʻa i kēlā me kēia mea alalai ka loopback interface i hoʻonohonoho ʻia me ka ip: xxxx 255.255.255.0 - kahi x ka helu router. Ma Router9 loaʻa iā mākou kahi loopback interface me ka helu wahi - 9.9.9.9 255.255.255.0. E hoʻolaha mākou ma o BGP a ʻike i ka laha ʻana. E hoʻouna ʻia kēia ala iā Router8 a me Router12. Mai Router8, e hele kēia ala i Router6, akā i Router5 ʻaʻole ia ma ka papa kuhikuhi. Ma Router12 e ʻike ʻia kēia ala ma ka papaʻaina, akā ma Router11 ʻaʻole ia ma laila. E ho'āʻo kākou e noʻonoʻo i kēia. E noʻonoʻo kākou i ka ʻikepili a me nā ʻāpana e hoʻouna ʻia e Router9 i kona mau hoalauna, e hōʻike ana i kēia ala. E hoʻouna ʻia ka ʻeke ma lalo mai Router9 a i Router8.
Aia ka ʻike ala ala i nā ʻano ala.
Hoʻokaʻawale ʻia nā ʻano ala i 4 mau ʻāpana:
- Pono ʻike ʻia - Pono nā mea ala āpau e holo ana i ka BGP i kēia mau ʻano. Pono e loaʻa i nā mea hou a pau.
- Kaulana kaulana - Pono nā mea ala āpau e holo ana i ka BGP i kēia mau ʻano. Aia paha lākou i nā mea hou, akā ʻaʻole koi ʻia ko lākou hele ʻana.
- Transive koho - ʻaʻole ʻike ʻia e nā hoʻokō BGP āpau. Inā ʻaʻole ʻike ka mea alalai i ke ʻano, hōʻailona ʻo ia i ka hōʻano hou ma ke ʻano he hapa a hoʻouna ʻia i kona mau hoalauna, e mālama ana i ka ʻano ʻike ʻole.
- ʻAʻole-transitive koho - ʻaʻole ʻike ʻia e nā hoʻokō BGP āpau. Inā ʻaʻole ʻike ka mea alalai i ke ʻano, a laila e nānā ʻole ʻia ka ʻano a hoʻolei ʻia ke hāʻawi ʻia i nā hoalauna.
Nā laʻana o nā ʻano BGP:
- Pono ʻike ʻia:
- Alanui ʻōnaehana autonomous
- Next-hop
- Kinohi
- Kaulana kaulana:
- Manaʻo kūloko
- ʻAtomic aggregate
- Transive koho:
- Mea houluulu
- kaiaulu
- ʻAʻole-transitive koho:
- Mea hoʻokae lehulehu-puka (MED)
- ID kumu
- Papa helu hui
I kēia hihia, i kēia manawa e makemake mākou iā Origin, Next-hop, AS Path. No ka mea e hoʻouna ʻia ke ala ma waena o Router8 a me Router9, ʻo ia hoʻi, i loko o hoʻokahi AS, ua manaʻo ʻia i loko a e hoʻolohe mākou i ka Origin.
ʻAno kumu - hōʻike i ke ala i loaʻa ai ke ala i ka hoʻonui. Nā waiwai waiwai kūpono:
- 0 - IGP: Loaʻa ka NLRI i loko o ka ʻōnaehana autonomous mua;
- 1 - EGP: Aʻo ʻia ʻo NLRI me ka hoʻohana ʻana i ka Exterior Gateway Protocol (EGP). ʻAʻole i hoʻohana mua ʻia i ka BGP
- 2 - ʻAʻole i pau: Ua aʻo ʻia ʻo NLRI ma kekahi ʻano ʻē aʻe
I kā mākou hihia, e like me ka mea i ʻike ʻia mai ka ʻeke, ua like ia me 0. Ke hoʻouna ʻia kēia ala i Router12, loaʻa i kēia code ke code o 1.
Next, Next-hop. ʻAno hop aʻe
- ʻO kēia ka IP address o ka eBGP router kahi e hele ai ke ala i ka pūnaewele huakaʻi.
- Hoʻololi ke ʻano ke hoʻouna ʻia ka prefix i kekahi AS.
Ma ka hihia o iBGP, ʻo ia hoʻi, i loko o hoʻokahi AS, Next-hop e hōʻike ʻia e ka mea i aʻo a haʻi paha e pili ana i kēia ala. I kā mākou hihia, ʻo ia ka 192.168.89.9. Akā ke hoʻouna ʻia kēia ala mai Router8 a i Router6, e hoʻololi ʻo Router8 a hoʻololi iā ia me kāna ponoʻī. ʻO ka hope-hop ʻo 192.168.68.8. Ke alakaʻi nei kēia iā mākou i ʻelua mau lula:
- Inā hoʻouna ka mea alalai i kahi ala i kona hoalauna kūloko, ʻaʻole ia e hoʻololi i ka hoʻohālikelike Next-hop.
- Inā hoʻouna ka mea alalai i kahi ala i kona hoalauna waho, hoʻololi ia i ka Next-hop i ka ip o ka interface kahi e hoʻouna ai kēia router.
ʻO kēia ke alakaʻi iā mākou e hoʻomaopopo i ka pilikia mua - No ke aha e loaʻa ʻole ai ke ala ma ka papa kuhikuhi ma Router5 a me Router11. E nānā pono kākou. No laila, ua loaʻa iā Router6 ka ʻike e pili ana i ke ala 9.9.9.0/24 a ua hoʻohui maikaʻi ʻia i ka papa kuhikuhi.
Router6#show ip route bgp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
Gateway of last resort is not set
9.0.0.0/24 is subnetted, 1 subnets
B 9.9.9.0 [20/0] via 192.168.68.8, 00:38:25<source>
Теперь Router6 передал маршрут Router5 и первому правилу Next-hop не изменил. То есть, Router5 должен добавить <b>9.9.9.0 [20/0] via 192.168.68.8</b> , но у него нет маршрута до 192.168.68.8 и поэтому данный маршрут добавлен не будет, хотя информация о данном маршруте будет храниться в таблице BGP:
<source><b>Router5#show ip bgp
BGP table version is 1, local router ID is 5.5.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
* i 9.9.9.0/24 192.168.68.8 0 100 0 45 i</b>E like nō ke kūlana ma waena o Router11-Router12. No ka pale ʻana i kēia kūlana, pono ʻoe e hoʻonohonoho i ka Router6 a i ʻole Router12, i ka wā e hele ai i ke ala i ko lākou mau hoalauna kūloko, e hoʻololi i kā lākou IP IP e like me Next-hop. Hana ʻia kēia me ke kauoha:
neighbor 192.168.56.5 next-hop-selfMa hope o kēia kauoha, e hoʻouna ʻo Router6 i kahi memo Update, kahi e kuhikuhi ʻia ai ka ip o ka interface Gi0/0 Router6 e like me Next-hop no nā ala - 192.168.56.6, a laila e hoʻokomo ʻia kēia ala i ka papa kuhikuhi.
E hele hou a ʻike inā ʻike ʻia kēia ala ma Router7 a me Router10. ʻAʻole ia ma ka papa kuhikuhi a manaʻo paha mākou ua like ka pilikia me ka mea mua me ka hoʻohālikelike Next-hop, akā inā mākou e nānā i ka hopena o ka hōʻike ip bgp kauoha, e ʻike mākou i ka ʻAʻole i loaʻa ke ala ma laila me ka Next-hop hewa, ʻo ia hoʻi ʻaʻole i hoʻouna ʻia ke ala. A e alakaʻi kēia iā mākou i ke ola ʻana o kahi lula ʻē aʻe:
ʻAʻole hoʻolaha ʻia nā ala i loaʻa mai nā hoalauna kūloko i nā hoalauna kūloko ʻē aʻe.
Mai ka loaʻa ʻana o ka Router5 i ke ala mai Router6, ʻaʻole ia e hoʻouna ʻia i kona hoalauna kūloko. I mea e hiki ai ke hoʻololi, pono ʻoe e hoʻonohonoho i ka hana , a i ʻole e hoʻonohonoho i nā pilina pili pili piha (Full Mesh), ʻo ia hoʻi, ʻo Router5-7 e lilo nā mea a pau i hoalauna no kēlā me kēia. I kēia hihia, e hoʻohana mākou i Route Reflector. Ma Router5 pono ʻoe e hoʻohana i kēia kauoha:
neighbor 192.168.57.7 route-reflector-clientHoʻololi ʻo Route-Reflector i ke ʻano o ka BGP i ka wā e hele ai i kahi ala i kahi hoalauna kūloko. Inā hōʻike ʻia ka hoalauna kūloko e like me ala-hōʻike-mea kūʻai, a laila e hoʻolaha ʻia nā ala kūloko i kēia mau mea kūʻai aku.
ʻAʻole i ʻike ʻia ke ala ma Router7? Mai poina e pili ana i Next-hop kekahi. Ma hope o kēia mau manipulations, e hele pū ke ala i Router7, akā ʻaʻole hiki kēia. Lawe kēia iā mākou i kahi kānāwai ʻē aʻe:
Hoʻohana wale ka lula hope-hop no nā ala waho. No nā ala kūloko, ʻaʻole i hoʻololi ʻia ke ʻano hop aʻe.
A loaʻa iā mākou kahi kūlana e pono ai e hana i kahi kaiapuni me ka hoʻohana ʻana i ka static routing a i ʻole IGP protocols e hoʻomaopopo i nā mea ala e pili ana i nā ala āpau i loko o ka AS. E hoʻopaʻa inoa i nā ala paʻa ma Router6 a me Router7 a ma hope e loaʻa iā mākou ke ala i makemake ʻia ma ka papa ʻaina. Ma AS 678, e hana ʻokoʻa mākou - e hoʻopaʻa inoa mākou i nā ala paʻa no 192.168.112.0/24 ma Router10 a me 192.168.110.0/24 ma Router12. A laila, e hoʻokumu mākou i ka pilina kaiāulu ma waena o Router10 a me Router12. E hoʻonohonoho pū mākou iā Router12 e hoʻouna i kāna hope-hop iā Router10:
neighbor 192.168.110.10 next-hop-selfʻO ka hopena e loaʻa iā Router10 ke ala 9.9.9.0/24, e loaʻa iā ia mai Router7 a me Router12. E ʻike kākou i ke koho ʻana o Router10:
Router10#show ip bgp
BGP table version is 3, local router ID is 6.6.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*>i 9.9.9.0/24 192.168.112.12 0 100 0 45 i
192.168.107.7 0 123 45 i
E like me kā mākou e ʻike ai, ʻelua ala a me kahi pua (>) ʻo ia ka mea i koho ʻia ke ala ma 192.168.112.12.
E ʻike kākou pehea e hana ai ke kaʻina koho ala:
- ʻO ka hana mua i ka wā e loaʻa ai kahi ala e nānā i ka loaʻa o kāna Next-hop. ʻO ia ke kumu, i ka wā i loaʻa ai iā mākou kahi ala ma Router5 me ka ʻole o ka hoʻonohonoho ʻana iā Next-hop-self, ʻaʻole i hana hou ʻia kēia ala.
- ʻO ka mea aʻe e hele mai ana ka ʻāpana Weight. ʻAʻole kēia ʻāpana he Path Attribute (PA) a ʻaʻole hoʻouna ʻia i nā leka BGP. Hoʻonohonoho ʻia ia ma ka ʻāina ma kēlā me kēia alalai a hoʻohana wale ʻia e hoʻoponopono i ke koho ala ma ke alalai ponoʻī. E nānā kākou i kekahi laʻana. Ma luna aʻe hiki iā ʻoe ke ʻike ua koho ʻo Router10 i kahi ala no 9.9.9.0/24 ma o Router12 (192.168.112.12). No ka hoʻololi ʻana i ka palena Wieght, hiki iā ʻoe ke hoʻohana i ka palapala ʻāina e hoʻonohonoho i nā ala kikoʻī, a i ʻole e hāʻawi i kahi kaumaha i kona hoalauna e hoʻohana ana i ke kauoha:
neighbor 192.168.107.7 weight 200I kēia manawa e loaʻa kēia kaumaha nā ala āpau mai kēia hoalauna. E ʻike kākou pehea e hoʻololi ai ke koho ʻana i ke ala ma hope o kēia hana ʻana:
Router10#show bgp *Mar 2 11:58:13.956: %SYS-5-CONFIG_I: Configured from console by console BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 192.168.107.7 200 123 45 i * i 192.168.112.12 0 100 0 45 iE like me kāu e ʻike ai, ua koho ʻia ke ala ma o Router7, akā ʻaʻohe hopena o kēia i nā mea ala ʻē aʻe.
- Ma ke kolu o ke kūlana, loaʻa iā mākou ka makemake kūloko. ʻO kēia ʻāpana he hiʻohiʻona hoʻokaʻawale kaulana, ʻo ia hoʻi he koho kona hele ʻana. Pono kēia ʻāpana i loko o hoʻokahi AS a pili i ke koho o ke ala no nā hoalauna kūloko. ʻO ia ke kumu i hoʻouna ʻia i nā memo Update i manaʻo ʻia no ka hoalauna kūloko. ʻAʻole i loaʻa i nā memo Update no nā hoalauna waho. No laila, ua helu ʻia ʻo ia ʻo Well-known discretionary. E ho'āʻo kākou e hoʻohana ia mea ma ka Router5. Ma Router5 pono mākou i ʻelua ala no 9.9.9.0/24 - hoʻokahi ma Router6 a ʻo ka lua ma Router7.
Nānā mākou:
Router5#show bgp BGP table version is 2, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 iAkā ke ʻike nei mākou i kahi ala ma o Router6. ʻAuhea ke ala ma o Router7? ʻAʻole paha i loaʻa iā Router7? E nānā kākou:
Router#show bgp BGP table version is 10, local router ID is 7.7.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 i 192.168.107.10 0 678 45 iKahaha, ua maikaʻi nā mea a pau. No ke aha ʻaʻole i hoʻouna ʻia i Router5? ʻO ka mea he kānāwai ko BGP:
Hoʻouna ka mea alalai i kēlā mau ala e hoʻohana ai.
Hoʻohana ʻo Router7 i kahi ala ma o Router5, no laila ʻaʻole e hoʻouna ʻia ke ala ma o Router10. E hoʻi kāua i ka Manaʻo Kūloko. E hoʻonoho kāua i ka Local Preference ma Router7 a ʻike i ka pane ʻana o Router5 i kēia:
route-map BGP permit 10 match ip address 10 set local-preference 250 access-list 10 permit any router bgp 123 neighbor 192.168.107.10 route-map BGP in</b>No laila, ua hana mākou i kahi palapala ʻāina i loaʻa nā ala āpau a haʻi iā Router7 e hoʻololi i ka koho Local Preference i 250 i ka wā i loaʻa ai, ʻo 100 ka paʻamau. E ʻike kākou i ka mea i hana ʻia ma Router5:
Router5#show bgp BGP table version is 8, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.57.7 0 250 0 678 45 iE like me kā mākou e ʻike ai i kēia manawa makemake ʻo Router5 i ke ala ma o Router7. Aia ke kiʻi like ma Router6, ʻoiai ʻoi aku ka maikaʻi o ke koho ʻana i kahi ala ma o Router8. Hoʻohui pū mākou i ka hoʻololi ʻana i kēia ʻāpana e pono ai ka hoʻomaka hou ʻana o ke kaiāulu no ka hoʻololi ʻana i ka hopena. Heluhelu . Ua hoʻokaʻawale mākou i ka makemake kūloko. E neʻe kākou i ka ʻāpana aʻe.
- Koho i ke ala me ka Next-hop parameter 0.0.0.0, ʻo ia hoʻi, nā ala kūloko a i ʻole nā ala i hōʻuluʻulu ʻia. Hāʻawi ʻia kēia mau ala i kahi ʻāpana Weight e like me ka palena kiʻekiʻe-32678-ma hope o ke komo ʻana i ke kauoha pūnaewele:
Router#show bgp BGP table version is 2, local router ID is 9.9.9.9 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 0.0.0.0 0 32768 i - ʻO ke ala pōkole loa ma o AS. Ua koho ʻia ka ʻāpana AS_Path pōkole loa. ʻO ka liʻiliʻi o nā AS e hele ai kahi ala, ʻoi aku ka maikaʻi. E noʻonoʻo i ke ala i 9.9.9.0/24 ma Router10:
Router10#show bgp BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path * 9.9.9.0/24 192.168.107.7 0 123 45 i *>i 192.168.112.12 0 100 0 45 iE like me kāu e ʻike ai, ua koho ʻo Router10 i ke ala ma o 192.168.112.12 no ka mea no kēia ala i ka AS_Path parameter aia wale nō 45, a ma kekahi hihia 123 a me 45. Intuitively maopopo.
- ʻO ka ʻāpana aʻe ʻo Origin. ʻOi aku ka maikaʻi o IGP (alanui e hoʻohana ana i ka BGP) ma mua o EGP (alanui i loaʻa me ka hoʻohana mua ʻana o BGP, ʻaʻole i hoʻohana hou ʻia), a ʻoi aku ka maikaʻi o ka EGP ma mua o Incomplete? (loaʻa ʻia e kekahi ʻano hana ʻē aʻe, no ka laʻana ma ka hāʻawi hou ʻana).
- ʻO MED ka palena aʻe. Loaʻa iā mākou ʻo Wieght i hana wale ma ka ʻāina ma ke alalai. Loaʻa ka Manaʻo Kūloko, i hana i loko o hoʻokahi ʻōnaehana kūʻokoʻa. E like me kāu e koho ai, ʻo MED kahi ʻāpana e hoʻouna ʻia ma waena o nā ʻōnaehana autonomous. Maikaʻi loa e pili ana i kēia ʻāpana.
ʻAʻole e hoʻohana hou ʻia nā ʻano, akā inā loaʻa nā ʻano ʻelua i nā ʻano like, a laila e hoʻohana ʻia kēia mau lula:
- E koho i ke ala ma o ka hoalauna IGP kokoke loa.
- E koho i ke ala kahiko loa no ke ala eBGP.
- E koho i ke ala ma o ka hoalauna me ka BGP router ID liʻiliʻi loa.
- E koho i ke ala ma o ka hoalauna me ka helu IP haʻahaʻa.
I kēia manawa, e nānā kākou i ka pilikia o ka convergence BGP.
E ʻike kākou i ka hopena inā nalowale ʻo Router6 i ke ala 9.9.9.0/24 ma o Router9. E hoʻopau i ka interface Gi0/1 o Router6, e hoʻomaopopo koke ʻia ua hoʻopau ʻia ka hālāwai BGP me Router8 a ua nalowale ka hoalauna, ʻo ia hoʻi ʻaʻole kūpono ke ala i loaʻa mai ia. Hoʻouna koke ʻo Router6 i nā memo Hoʻohou, kahi e hōʻike ai i ka pūnaewele 9.9.9.0/24 ma ke kahua ʻo Withdrawn Routes. Ke loaʻa koke iā Router5 i kēlā memo, e hoʻouna iā ia i Router7. Akā, no ka loaʻa ʻana o kahi ala ʻo Router7 ma o Router10, e pane koke ia me kahi Update me kahi ala hou. Inā ʻaʻole hiki ke ʻike i ka hāʻule ʻana o kahi hoalauna e pili ana i ke kūlana o ka interface, a laila pono ʻoe e kali i ke ahi ʻo Hold Timer.
Huihui.
Inā hoʻomanaʻo ʻoe, ua kamaʻilio mākou e pili ana i ka ʻoiaʻiʻo e hoʻohana pinepine ʻoe i kahi topology pili pono. Me ka nui o nā mea hoʻokele i hoʻokahi AS hiki i kēia ke kumu i nā pilikia nui, e pale aku i kēia pono ʻoe e hoʻohana i nā confederations. Hoʻokaʻawale ʻia kekahi AS i kekahi mau sub-AS, kahi e hiki ai iā lākou ke hana me ke koi ʻole o kahi topology pili pono.
Eia kahi loulou i kēia a me ka hoʻonohonoho no GNS3.
No ka laʻana, me kēia topology pono mākou e hoʻopili i nā mea ala āpau ma AS 2345 i kekahi i kekahi, akā me ka hoʻohana ʻana i ka Confederation, hiki iā mākou ke hoʻokumu i nā pilina pili ma waena o nā mea hoʻokele pili pono kekahi i kekahi. E kamaʻilio pū kākou e pili ana i kēia. Inā loaʻa iā mākou ka AS 2345, a laila laForge i loaa mai ka huakai mai ʻO Picard e haʻi aku i nā mea hoʻokele 'Ikepili и Worf, akā ʻaʻole lākou e haʻi i ke alalai no ia mea Hoʻopili . ʻO nā alahele hoʻi i puʻunaue ʻia e ka router ponoi laForge, ʻaʻole i hoʻoili ʻia Hoʻopili ʻaʻole hoʻi Worf-ʻaʻole 'Ikepili.
Pono ʻoe e hoʻonohonoho i kahi Route-Reflector a i ʻole kahi pilina pili kaiāulu. Ma ka hoʻokaʻawale ʻana i hoʻokahi AS 2345 i 4 sub-AS (2,3,4,5) no kēlā me kēia router, hoʻopau mākou i kahi loiloi hana ʻokoʻa. Ua wehewehe pono ʻia nā mea a pau .
Nā kumuhana:
- CCIE Routing and Switching v5.0 Official Cert Guide, Volume 2, Fifth Edition, Narbik Kocharians, Terry Vinson.
- paena
- paena .
Source: www.habr.com