🥇 Nga tikanga whakahaere o te kawa BGP

I tenei ra ka titiro tatou ki te kawa BGP. E kore matou e korero mo te wa roa mo te aha me te aha i whakamahia ai hei kawa anake. He maha nga korero mo tenei kaupapa, hei tauira konei.

Na he aha te BGP? Ko te BGP he kawa ararere hihiri, ko ia anake te kawa EGP (External Gateway Protocol). Ka whakamahia tenei kawa ki te hanga ararere i runga ipurangi. Kia titiro tatou ki te hanga i tetahi takiwa i waenga i nga pouara BGP e rua.

Whakaarohia te takiwa i waenga i te Router1 me te Router3. Me whirihora ma te whakamahi i nga whakahau e whai ake nei:

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 10

Ko te noho tata i roto i te punaha motuhake ko te AS 10. Whai muri i te whakauru korero ki runga i te pouara, penei i a Router1, ka ngana taua pouara ki te whakarite hononga tata ki te Router3. Ko te ahua tuatahi ka kore he mea ka puta ka kiia Hapa. Ina whirihorahia te bgp ki Router1, ka tiimata te whakarongo ki te tauranga TCP 179 - ka uru ki te ahua Tūhono, a ka ngana ana ki te whakatuwhera i tetahi huihuinga me Router3, ka uru ki te kawanatanga Hohe.

I muri i te whakaturanga o te huihuinga i waenga i te Router1 me te Router3, ka whakawhitihia nga karere tuwhera. Ina tukuna tenei karere e Router1, ka karangahia tenei ahua Tuwhera Tukua. A, ka tae mai he karere Tuwhera mai i te Router3, ka uru ki te kawanatanga Whakatuwhera Whakaū. Kia ata titiro ki te karere Tuwhera:

Ko tenei karere ka tuku korero mo te kawa BGP ake, ka whakamahia e te pouara. Ma te whakawhiti i nga karere Tuwhera, ka whakawhiti korero a Router1 me Router3 mo o raatau tautuhinga ki a raatau. Kua paahitia nga tawhā e whai ake nei:

putanga: kei roto i tenei ko te putanga BGP e whakamahia ana e te pouara. Ko te putanga o naianei o te BGP ko te putanga 4 e whakaahuatia ana i roto i te RFC 4271. Ka ngana nga kaitarai BGP e rua ki te whiriwhiri i tetahi putanga hototahi, ina he koretake ka kore he huihuinga BGP.

Taku AS: kei roto i tenei ko te nama AS o te pouara BGP, me whakaae nga pouara ki te/tau AS me te tautuhi hoki mena ka whakahaere ratou i te iBGP, eBGP ranei.

Kia Mau te Wa: ki te kore te BGP e whiwhi i nga korero pupuri ora, whakahou ranei i nga karere mai i tera taha mo te roanga o te wa pupuri katahi ka kii atu i tera taha kua 'mate' ka pakaru te wahanga BGP. Ma te taunoa ka whakatauhia te wa pupuri ki te 180 hēkona i runga i nga pouara Cisco IOS, ka tukuna te karere keepalive ia 60 hēkona. Me whakaae nga pouara e rua mo te wa pupuri, karekau he huihuinga BGP.

Kaitohu BGP: koinei te ID pouara BGP rohe kua pootihia pera i ta OSPF:

Whakamahia te pouara-ID i whirihorahia a ringa ki te bgp pouara-id whakahau.

Whakamahia te wāhitau IP teitei i runga i te atanga whakamuri.

Whakamahia te wāhitau IP teitei i runga i te atanga tinana.

Tawhā Kōwhiringa: i konei ka kitea e koe etahi kaha whiriwhiri o te pouara BGP. Kua taapirihia tenei mara kia taea ai te taapiri i nga ahuatanga hou ki te BGP me te kore e hanga he putanga hou. Ko nga mea ka kitea e koe i konei ko:

tautoko mo te MP-BGP (Multi Protocol BGP).

tautoko mo te Whakahou Ara.

tautoko mo nga nama 4 octet AS.

Hei whakarite i tetahi takiwa, me tutuki nga tikanga e whai ake nei:

Tau putanga. Ko te putanga o naianei ko 4.
Me taurite te nama AS ki ta koe i whirihora hoa tata 192.168.13.3 mamao-rite 10.
Me rereke te ID Pouara ki te hoa tata.

Ki te kore tetahi o nga tawhā e tutuki i enei tikanga, ka tukuna e te pouara whakamōhiotanga karere e tohu ana i te hapa. Whai muri i te tuku me te whiwhi i nga karere Tuwhera, ka uru te whanaungatanga tata ki te kawanatanga I WHAKAMAHI. I muri i tenei, ka taea e nga pouara te whakawhiti korero mo nga huarahi me te mahi i tenei ma te whakamahi Whakahōu karere. Koinei te karere Whakahou i tukuna e Router1 ki Router3:

I konei ka kite koe i nga whatunga e whakaatuhia ana e Router1 me nga huanga Ara, he rite ki nga inenga. Ka korero maatau mo nga huanga o te Ara. Ka tukuna ano nga karere Keepalive i roto i te huihuinga TCP. Ka tukuna, ma te taunoa, ia 60 hēkona. Ko te Keepalive Timer tenei. Mena karekau he karere a Keepalive i tae mai i te wa e pupuri ana i te Taima, ka ngaro te korero ki te hoa tata. Ma te taunoa, he rite ki te 180 hēkona.

Tohu whaihua:

Te ahua nei kua maarama taatau me pehea te tuku korero a nga kaitarai ki a raatau ano, inaianei me ngana ki te maarama ki te arorau o te kawa BGP.

Hei panui i tetahi ara ki te tepu BGP, pera i nga tikanga IGP, ka whakamahia te whakahau whatunga, engari he rereke te arorau whakahaere. Mena kei roto i te IGP, i muri i te tohu i te huarahi i roto i te whakahau whatunga, ka tirohia e te IGP ko wai nga atanga no tenei kupenga-roto ka whakauru ki roto i tana ripanga, katahi ka titiro te whakahau whatunga i te BGP ki te ripanga ararere ka rapu tika e ōrite ana ki te ara i roto i te whakahau whatunga. Mena ka kitea, ka puta enei ara ki te ripanga BGP.

Rapua he ara i roto i te ripanga ararere IP o naianei o te pouara e rite ana ki nga tawhā o te whakahau whatunga; mena kei te noho te ara IP, whakauruhia te NLRI rite ki te ripanga BGP rohe.

Inaianei me whakaara ake te BGP ki nga toenga katoa ka kite me pehea te kowhiringa o te huarahi i roto i te AS kotahi. I muri i te whiwhi a te pouara BGP i nga huarahi mai i tona hoa tata, ka tiimata te kowhiri i te huarahi tino pai. I konei me maarama koe he aha te momo noho tata - o roto me waho. Kei te mohio te pouara ma te whirihoranga mehemea kei roto, kei waho ranei te hoa tata kua whirihorahia? Mena kei te roopu:

neighbor 192.168.13.3 remote-as 10

ko te tawhā mamao-rite e whakaatu ana i te AS, kua whirihorahia i runga i te pouara ake i roto i te pouara bgp 10 whakahau. Ko nga huarahi e puta mai ana i te AS o roto ka kiia he roto, ko nga huarahi mai i te AS o waho ka kiia ko waho. A mo ia, he rereke te whakaaro mo te whiwhi me te tuku mahi. Whakaarohia tenei topology:

Kei ia pouara he atanga loopback kua whirihorahia ki te ip: xxxx 255.255.255.0 - kei hea te x te tau pouara. I runga i te Router9 he atanga whakamuri me te wahitau - 9.9.9.9 255.255.255.0. Ka panuitia e matou ma te BGP ka kite i te horapa. Ka tukuna tenei ara ki Router8 me Router12. Mai i te Router8, ka haere tenei ara ki Router6, engari ki te Router5 karekau i te ripanga ararere. I runga ano i te Router12 ka puta tenei ara ki te ripanga, engari i runga i te Router11 kare ano i reira. Kia tamata tatou ki te whakaaro i tenei. Me whakaaro he aha nga raraunga me nga tawhā ka tukuna e Router9 ki ona hoa tata, e whakaatu ana i tenei huarahi. Ka tukuna te paakete i raro nei mai i Router9 ki Router8.

Ko nga korero huarahi kei roto i nga huanga Ara.

Kua wehea nga huanga ara ki nga waahanga e 4:

Ko te whakahau rongonui - Ko nga pouara katoa e whakahaere ana i te BGP me mohio ki enei huanga. Me noho i roto i nga whakahoutanga katoa.
He tohunga mohio - Ko nga pouara katoa e whakahaere ana i te BGP me mohio ki enei huanga. Kei roto pea i nga whakahoutanga, engari kaore e hiahiatia ana to raatau.
Tauwhiro whiriwhiri - kare pea e mohiotia e nga whakatinanatanga BGP katoa. Ki te kore te pouara e mohio ki te huanga, ka tohuhia te whakahou hei waahanga ka tukuna atu ki ona hoa tata, me te penapena i te huanga kore mohio.
Kōwhiringa-kore - kare pea e mohiotia e nga whakatinanatanga BGP katoa. Mena karekau te pouara e mohio ki te huanga, ka warewarehia te huanga ka makahia ina tukuna atu ki nga hoa tata.

Nga tauira o nga huanga BGP:

Ko te whakahau rongonui:
- Ara pūnaha motuhake
- Next-hop
- Origin
He tohunga mohio:
- Manakohanga paetata
- Huinga ngota
Tauwhiro whiriwhiri:
- Kaihuihui
- Nga hapori
Kōwhiringa-kore:
- Whakahāwea maha-putanga (MED)
- ID Taketake
- Rārangi kāhui

I tenei keehi, mo tenei wa ka aro tatou ki te Origin, Next-hop, AS Path. I te mea ka whakawhiti te ara i waenga i te Router8 me te Router9, ara, i roto i te AS kotahi, ka kiia he roto, ka aro atu ki te Origin.

Te huanga takenga - he tohu i te huarahi i whiwhi ai i te whakahou. Uara huanga pea:

0 - IGP: NLRI i whiwhi i roto i te punaha motuhake taketake;
1 - EGP: Ka akohia te NLRI ma te whakamahi i te Kawa Wahowaho (EGP). Tuhinga o mua ki te BGP, kaore i whakamahia
2 - Kare i oti: I akohia te NLRI i etahi atu huarahi

I roto i to maatau, ka kitea mai i te paatete, he rite ki te 0. Ina tukuna tenei ara ki Router12, ka whai waehere 1 tenei waehere.

Next, Next-hop. Te huanga o muri-hop

Koinei te wāhitau IP o te pouara eBGP e haere ai te ara ki te whatunga ūnga.
Ka huri te huanga i te wa e tukuna ana te prefix ki tetahi atu AS.

Mo te iBGP, ara, i roto i te AS kotahi, Next-hop ka tohuhia e te tangata i ako, i korero ranei mo tenei huarahi. Ki ta maatau, ka 192.168.89.9. Engari ka tukuna tenei ara mai i te Router8 ki te Router6, ka huri a Router8 ka whakakapia e ia ki a ia ano. Ko te 192.168.68.8. Na tenei ka arahi tatou ki nga ture e rua:

Mena ka tukuna e te pouara he ara ki tona hoa tata, kaore e huri i te tawhā Next-hop.
Mena ka tukuna e te pouara he ara ki tona hoa tata o waho, ka huri i te Next-hop ki te ip o te atanga ka tukuna e tenei pouara.

Ma tenei ka mohio tatou ki te raru tuatahi - He aha te take karekau he ara i te ripanga ararere i runga i te Router5 me te Router11. Kia ata titiro tatou. Na, i whiwhi a Router6 i nga korero mo te ara 9.9.9.0/24 me te whakauru angitu ki te ripanga ararere:

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>

Ka pera ano te ahuatanga i waenga i te Router11-Router12. Hei karo i tenei ahuatanga, me whirihora e koe te Router6, te Router12 ranei, i te wa e whakawhiti ana i te huarahi ki o ratau hoa noho tata, ki te whakakapi i o raatau wahitau IP hei Next-hop. Ka mahia tenei ma te whakamahi i te whakahau:

neighbor 192.168.56.5 next-hop-self

I muri i tenei whakahau, ka tukuna e te Router6 he karere Whakahou, kei reira te ip o te atanga Gi0/0 Router6 ka tohua hei Next-hop mo nga huarahi - 192.168.56.6, muri iho ka whakauruhia tenei ara ki te ripanga ararere.

Ka anga whakamua kia kite mena ka puta mai tenei ara ki runga Router7 me Router10. Kare i roto i te ripanga ararere ka whakaaro pea tatou he rite tonu te raru ki te tuatahi me te tawhā Next-hop, engari ki te titiro tatou ki te putanga o te whakaaturanga ip bgp whakahau, ka kite tatou ko te karekau te huarahi i tae ki reira ahakoa he he Next-hop, ko te tikanga kaore i tukuna te huarahi. Na tenei ka arahi ia tatou ki te noho o tetahi atu ture:

Ko nga huarahi i whakawhiwhia mai i nga hoa tata o roto kaore e horahia ki etahi atu hoa tata.

I te mea kua whiwhi a Router5 i te ara mai i te Router6, e kore e tukuna ki tetahi atu hoa tata. Kia puta ai te whakawhitinga, me whirihora e koe te mahi Whakaata Ararere, whirihora ranei i nga hononga tata hono katoa (Full Mesh), ara, Router5-7 ka noho tata nga tangata katoa ki te katoa. I tenei keehi ka whakamahi matou i te Whakaata Ara. I runga i te Router5 me whakamahi koe i tenei whakahau:

neighbor 192.168.57.7 route-reflector-client

Ko te Ara-Whakaata ka huri i te whanonga o te BGP ka haere i tetahi ara ki tetahi hoa tata. Mena kua tohua te hoa tata o roto hei huarahi-whakaata-kiritaki, ka panuitia nga huarahi o roto ki enei kiritaki.

Kaore te ara i puta ki Router7? Kaua e wareware ki te Next-hop. Whai muri i enei mahi raweke, me haere ano te ara ki Router7, engari kare e puta. Na tenei ka kawe tatou ki tetahi atu ture:

Ko te ture hou-hop ka mahi mo nga huarahi o waho. Mo nga huarahi o roto, kaore i te whakakapihia te huanga o muri-hop.

A ka whiwhi tatou i tetahi ahuatanga e tika ana ki te hanga i tetahi taiao ma te whakamahi i te ararere pateko, i nga kawa IGP ranei hei whakamohio i nga pouara mo nga huarahi katoa i roto i te AS. Me rehita tatou i nga huarahi pateko i runga i te Router6 me te Router7 a muri iho ka whiwhi tatou i te huarahi e hiahiatia ana i roto i te tepu pouara. I roto i te AS 678, he rereke te mahi - ka rehitatia e matou nga huarahi pateko mo 192.168.112.0/24 i runga i te Router10 me te 192.168.110.0/24 i runga i te Router12. I muri mai, ka whakatauhia e matou te hononga tata i waenga i te Router10 me te Router12. Ka whirihora ano e matou te Router12 ki te tuku i tana-hopi ki Router10:

neighbor 192.168.110.10 next-hop-self

Ko te hua ka riro i a Router10 te ara 9.9.9.0/24, ka riro mai i Router7 me Router12. Kia kite tatou he aha te whiringa a 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 kite ana tatou, e rua nga huarahi me te pere (>) ko te tikanga ka tohua te huarahi ma 192.168.112.12.
Kia kite tatou me pehea te mahi o te huarahi whiriwhiri huarahi:

Ko te mahi tuatahi ina whiwhi huarahi ko te tirotiro i te wateatanga o tana Next-hop. Koia te take, i te wa i whiwhi ai matou i tetahi ara i runga i te Router5 me te kore e tautuhi i te Next-hop-self, kaore tenei huarahi i whakahaerea ano.
Ka whai mai te tawhā Taumaha. Ehara tenei tawhā i te Huanga Ara (PA) karekau i tukuna ki nga karere BGP. Kua whirihorahia i te rohe ki runga i ia pouara, ka whakamahia noa ki te raweke i te kowhiringa ara i runga i te pouara ake. Ka titiro tatou ki tetahi tauira. Kei runga noa atu ka kite koe kua whiriwhiria e Router10 tetahi ara mo 9.9.9.0/24 ma te Router12 (192.168.112.12). Hei huri i te tawhā Wieght, ka taea e koe te whakamahi mapi-ara ki te whakarite i nga huarahi motuhake, te tautapa ranei i te taumaha ki tona hoa tata ma te whakamahi i te whakahau:
```
 neighbor 192.168.107.7 weight 200       
```
Inaianei ka whai taumaha nga huarahi katoa mai i tenei hoa tata. Kia kite tatou me pehea te whakarereketanga o te huarahi i muri i tenei whawhe:
```
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 i
```
Ka taea e koe te kite, ko te huarahi ma Router7 kua tohua inaianei, engari kaore tenei e pa ki etahi atu pouara.

I te turanga tuatoru kei a matou te Manakohanga Rohe. Ko tenei tawhā he huanga whakaaro mohio rongonui, ko te tikanga he mea kowhiria te noho. He tika tenei tawhā i roto i te AS kotahi anake ka pa ki te huarahi whiriwhiri mo nga hoa tata o roto anake. Koinei te take ka tukuna noa i roto i nga karere Whakahoutanga mo te hoa tata. Karekau i roto i nga karere Whakahou mo nga hoa tata o waho. Na reira, i whakarōpūtia hei Whakaaetanga rongonui. Me ngana ki te tono ki runga Router5. I runga i te Router5 me rua nga ara mo 9.9.9.0/24 - kotahi ma Router6 me te tuarua ma Router7.

Ka titiro tatou:

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 i

Engari ka kite tatou i tetahi ara ma Router6. Kei hea te ara ma Router7? Kaore pea a Router7 i a ia ano? Kia titiro tatou:

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 i

He mea whakamiharo, kei te pai nga mea katoa. He aha i kore ai e tukuna ki Router5? Ko te mea ko te BGP he ture:

Ka tukuna e te pouara nga huarahi anake e whakamahia ana e ia.

Ka whakamahi a Router7 i tetahi ara ma Router5, na reira ka kore e tukuna te ara ma Router10. Kia hoki ki te Manakohanga Paetata. Me whakarite te Manakohanga Paetata ki runga Router7 ka kite i te ahua o te Router5 ki tenei:

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>

Na, i hangaia e matou he mapi-ara kei roto nga huarahi katoa me te korero ki a Router7 kia huri i te tawhā Manakohanga Rohe ki te 250 ina tae mai, ko te taunoa ko te 100. Kia kite tatou i te mea i tupu i runga i te 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 i

Kei te kite tatou inaianei ko te Router5 e pai ana ki te huarahi ma Router7. Ko taua pikitia ano kei runga i te Router6, ahakoa he pai ake mo ia te kowhiri i tetahi ara ma Router8. Ka tapiritia ano e matou ko te whakarereke i tenei tawhā me whakaara ano te takiwa kia whai mana ai te huringa. Panui konei. Kua tohua e matou te Manakohanga Paetata. Me neke atu ki te tawhā e whai ake nei.

Me pai ake te ara me te tawhā Panuku-hop 0.0.0.0, ara, ara rohe, whakahiato ranei. Ko enei ara ka tautapa aunoatia he tawhā Taumaha e rite ana ki te morahi—32678—i muri i te whakaurunga ki te whakahau whatunga:

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

Te ara poto rawa atu ma AS. Kua tohua te tawhā AS_Path poto rawa atu. Ko te iti ake o nga AS e haere ana tetahi ara, ka pai ake. Whakaarohia te ara ki te 9.9.9.0/24 i te 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 i

Ka taea e koe te kite, i whiriwhiria e Router10 te huarahi ma te 192.168.112.12 na te mea mo tenei ara ko te AS_Path tawhā kei roto anake te 45, me tetahi atu keehi 123 me te 45. He maamaa te maarama.

Ko te tawhā e whai ake nei ko Origin. He pai ake te IGP (ara i whiwhi ma te BGP) i te EGP (ara i whiwhi ma te whakamahi i mua o BGP, kare e whakamahia ana), he pai ake te EGP i te Inooti? (i riro mai i etahi atu tikanga, hei tauira ma te tohatoha ano).
Ko te tawhā e whai ake nei ko MED. I a matou a Wieght i mahi noa i te rohe i runga i te pouara. He Manakohanga Paetata, i mahi i roto i te punaha motuhake kotahi. Kei te whakaaro koe, ko te MED he tawhā ka tukuna i waenga i nga punaha motuhake. Tino pai tuhinga mo tenei tawhā.

Ka kore e whakamahia nga huanga, engari mena he rite nga huanga e rua, ka whakamahia nga ture e whai ake nei:

Tīpakohia te ara i roto i te tata IGP tata.
Tīpakohia te ara tawhito mo te ara eBGP.
Tīpakohia te ara ma te hoa tata me te ID pouara BGP iti rawa.
Kōwhiria he ara i roto i te hoa tata me te wahitau IP iti rawa.

Inaianei me titiro ki te take o te whakakotahitanga BGP.

Kia kite tatou ka aha mena ka ngaro a Router6 te ara 9.9.9.0/24 ki te Router9. Kia whakakorehia te atanga Gi0/1 o Router6, ka mohio tonu kua mutu te huihuinga BGP me Router8 ka ngaro te hoa tata, ko te tikanga kaore i te tika te huarahi i whakawhiwhia mai. Ka tukuna tonu e Router6 nga karere Whakahou, kei reira e tohu ana i te whatunga 9.9.9.0/24 i roto i te mara o nga huarahi kua tangohia. Ka tae mai he karere pera a Router5, ka tukuna atu ki Router7. Engari i te mea he huarahi a Router7 i roto i te Router10, ka whakautu tonu me te Whakahou me te huarahi hou. Mena kaore e taea te kite i te hinga o tetahi hoa noho i runga i te ahua o te atanga, katahi koe ka tatari kia puhipuhi te Timer pupuri.

Huihuinga.

Mena ka mahara koe, i korero matou mo te meka me whakamahi koe i tetahi topology honohono katoa. Na te maha o nga pouara i roto i te AS kotahi ka raru pea tenei, hei karo i tenei me whakamahi koe i nga hononga. Kua wehea tetahi AS ki etahi waahanga iti-AS, ka taea e raatau te mahi me te kore e hiahiatia he topology honohono katoa.

Anei he hononga ki tenei pukua konei whirihoranga mo GNS3.

Hei tauira, me tenei topology me hono tatou i nga pouara katoa i roto i te AS 2345 ki tetahi ki tetahi, engari ma te whakamahi i te Confederation, ka taea e tatou te whakarite hononga tata ki waenga i nga pouara e hono tika ana ki a raatau. Me korero maatau mo tenei. Mena he AS 2345 noa ta tatou, na laForge kua riro mai he hikoi mai Picard ka korero ki nga pouara Raraunga и Worf, engari kaore ratou e korero ki te pouara mo taua mea Pakaru . Ko nga huarahi ka tohatohahia e te pouara ake laForge, kaore i whakawhitia Pakaru kore Worf-Aue, kahore Raraunga.

Me whirihora e koe he Rote-Reflector, he hononga hono tata ranei. Ma te wehewehe i tetahi AS 2345 ki te 4 sub-AS (2,3,4,5) mo ia pouara, ka mutu he rereke te arorau whakahaere. Ko nga mea katoa ka tino whakaahuahia konei.

Kaupapa:

CCIE Routing and Switching v5.0 Official Cert Guide, Volume 2, Fifth Edition, Narbik Kocharians, Terry Vinson.
paetukutuku xgu.ru
paetukutuku GNS3Vault.

Source: will.com

Me pehea te mahi a BGP

Tāpiri i te kōrero whakakore whakautu