Hnub no peb yuav saib BGP raws tu qauv. Peb yuav tsis tham ntev txog vim li cas nws yog thiab yog vim li cas nws thiaj li siv raws tu qauv nkaus xwb. Muaj ntau cov ntaub ntawv hais txog qhov no, piv txwv li .
Yog li BGP yog dab tsi? BGP yog ib qho kev sib txuas lus dynamic thiab tsuas yog EGP (External Gateway Protocol) raws tu qauv. Cov txheej txheem no yog siv los tsim routing hauv Internet. Cia peb saib yuav ua li cas lub zej zog tsim ntawm ob lub BGP routers.
Xav txog lub zej zog ntawm Router1 thiab Router3. Cia peb teeb tsa lawv siv cov lus txib hauv qab no:
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 10Cov neeg zej zog nyob hauv ib qho kev tswj hwm tus kheej yog AS 10. Tom qab nkag mus rau cov ntaub ntawv ntawm lub router, xws li Router1, tus router sim teeb tsa kev sib raug zoo nrog Router3. Thawj lub xeev thaum tsis muaj dab tsi tshwm sim yog hu ua kaw. Thaum bgp tau teeb tsa ntawm Router1, nws yuav pib mloog TCP chaw nres nkoj 179 - nws yuav nkag mus rau hauv lub xeev. Mus Txuas Lus, thiab thaum nws sim qhib kev sib tham nrog Router3, nws yuav nkag mus rau hauv lub xeev active.
Tom qab kev sib kho yog tsim los ntawm Router1 thiab Router3, Qhib cov lus sib pauv. Thaum cov lus no xa los ntawm Router1, lub xeev no yuav raug hu Qhib Xa. Thiab thaum nws tau txais cov lus qhib los ntawm Router3, nws yuav nkag mus rau hauv lub xeev Qhib Confirm. Cia peb saib ze dua ntawm Cov Lus Qhib:
Cov lus no qhia cov ntaub ntawv hais txog BGP raws tu qauv nws tus kheej, uas lub router siv. Los ntawm kev sib pauv qhib cov lus, Router1 thiab Router3 sib txuas lus cov ntaub ntawv hais txog lawv qhov chaw rau ib leeg. Cov nram qab no tsis dhau:
- version: qhov no suav nrog BGP version uas lub router siv. Tam sim no version ntawm BGP yog version 4 uas tau piav qhia hauv RFC 4271. Ob lub BGP routers yuav sim sib tham txog qhov sib xws, thaum muaj qhov tsis sib haum ces yuav tsis muaj kev sib tham BGP.
- Kuv AS: qhov no suav nrog AS tus lej ntawm BGP router, cov routers yuav tsum pom zoo rau AS tus lej (s) thiab nws kuj txhais tau tias lawv yuav khiav iBGP lossis eBGP.
- Tuav Sij Hawm: Yog tias BGP tsis tau txais cov lus khaws cia lossis hloov kho cov lus los ntawm lwm sab rau lub sijhawm tuav lub sijhawm nws yuav tshaj tawm rau sab nraud 'tuag' thiab nws yuav rhuav tshem BGP kev sib kho. Los ntawm lub neej ntawd lub sijhawm tuav yog teem rau 180 vib nas this ntawm Cisco IOS routers, cov lus khaws cia tau xa txhua 60 vib nas this. Ob lub routers yuav tsum pom zoo rau lub sijhawm tuav lossis yuav tsis muaj kev sib tham BGP.
- BGP ID nkag mus: qhov no yog lub zos BGP router ID uas raug xaiv ib yam li OSPF ua:
- Siv tus router-ID uas tau teeb tsa manually nrog bgp router-id hais kom ua.
- Siv qhov chaw nyob IP siab tshaj plaws ntawm lub voj voog rov qab.
- Siv qhov chaw nyob IP siab tshaj plaws ntawm lub cev interface.
- Xaiv tsis tau: Ntawm no koj yuav pom qee qhov kev xaiv muaj peev xwm ntawm BGP router. Daim teb no tau muab ntxiv kom cov yam ntxwv tshiab tuaj yeem ntxiv rau BGP yam tsis tas yuav tsim ib qho tshiab.Txhua yam koj yuav pom ntawm no yog:
- txhawb MP-BGP (Multi Protocol BGP).
- kev txhawb nqa rau Route Refresh.
- kev txhawb nqa rau 4-octet AS tus lej.
Txhawm rau tsim ib lub zej zog, cov hauv qab no yuav tsum tau ua raws li:
- Tus lej version. Tam sim no version yog 4.
- Tus lej AS yuav tsum phim qhov koj tau teeb tsa neeg zej zog 192.168.13.3 chaw taws teeb-as 10.
- Router ID yuav tsum txawv ntawm tus neeg nyob ze.
Yog tias ib qho ntawm qhov tsis ua raws li cov xwm txheej no, lub router yuav xa Kev ceeb toom lus qhia qhov yuam kev. Tom qab xa thiab tau txais cov lus Qhib, cov kev sib raug zoo hauv zej zog nkag mus rau hauv lub xeev TSHAJ. Tom qab ntawd, routers tuaj yeem pauv cov ntaub ntawv hais txog cov kev thiab ua qhov no siv Hloov tshiab lus. Nov yog cov lus hloov tshiab xa los ntawm Router1 rau Router3:
Ntawm no koj tuaj yeem pom cov tes hauj lwm qhia los ntawm Router1 thiab Path cwj pwm, uas zoo sib xws rau cov ntsuas. Peb mam li tham txog Path cwj pwm nyob rau hauv kom meej ntxiv. Cov lus Keepalive tseem raug xa mus rau hauv kev sib tham TCP. Lawv kis tau los ntawm lub neej ntawd, txhua 60 vib nas this. Nov yog Keepalive Timer. Yog tias tsis tau txais cov lus Keepalive thaum lub sijhawm Tuav Timer, qhov no yuav txhais tau tias tsis muaj kev sib txuas lus nrog cov neeg nyob ze. Los ntawm lub neej ntawd, nws yog sib npaug rau 180 vib nas this.
Cov cim tseem ceeb:
Nws zoo nkaus li peb tau txheeb xyuas seb routers xa cov ntaub ntawv mus rau ib leeg, tam sim no cia peb sim nkag siab txog cov laj thawj ntawm BGP raws tu qauv.
Txhawm rau tshaj tawm txoj hauv kev mus rau BGP lub rooj, xws li hauv IGP cov txheej txheem, cov lus txib hauv lub network tau siv, tab sis kev khiav hauj lwm logic txawv. Yog tias hauv IGP, tom qab qhia meej txog txoj hauv kev hauv lub network hais kom ua, IGP saib cov kev sib txuas ntawm cov subnet no thiab suav nrog lawv hauv nws lub rooj, ces cov lus txib hauv network hauv BGP saib ntawm lub rooj sib tham thiab nrhiav. meej phim txoj kev hauv lub network hais kom ua. Yog tias pom muaj, cov kev no yuav tshwm sim hauv BGP rooj.
Nrhiav ib txoj hauv kev hauv lub router tam sim no IP routing rooj uas raws nraim qhov tsis sib xws ntawm cov lus txib network; yog tias muaj txoj hauv kev IP, muab qhov sib npaug NLRI rau hauv lub rooj BGP hauv zos.
Tam sim no cia peb tsa BGP rau tag nrho cov seem thiab saib seb txoj kev xaiv li cas hauv ib qho AS. Tom qab BGP router tau txais txoj hauv kev los ntawm nws cov neeg nyob ze, nws pib xaiv txoj kev zoo. Ntawm no koj yuav tsum nkag siab tias hom neeg nyob sib ze tuaj yeem muaj - sab hauv thiab sab nraud. Puas yog lub router nkag siab los ntawm kev teeb tsa txawm tias tus neeg nyob ze tau teeb tsa yog sab hauv lossis sab nraud? Yog nyob rau hauv ib pab neeg:
neighbor 192.168.13.3 remote-as 10 tej thaj chaw deb-raws li parameter qhia AS, uas yog configured ntawm lub router nws tus kheej nyob rau hauv lub router bgp 10 hais kom ua. Routes los ntawm lub internal AS yog xam nyob rau hauv, thiab txoj kev los ntawm lub sab nraud AS yog xam sab nraud. Thiab rau txhua tus, qhov sib txawv ntawm kev txais thiab xa cov haujlwm. Xav txog qhov topology no:
Txhua lub router muaj lub voj voog rov qab teeb tsa nrog ip: x.x.x.x 255.255.255.0 - qhov twg x yog tus lej router. Ntawm Router9 peb muaj qhov sib txuas rov qab nrog qhov chaw nyob - 9.9.9.9 255.255.255.0. Peb yuav tshaj tawm nws ntawm BGP thiab saib seb nws kis tau li cas. Txoj kev no yuav raug xa mus rau Router8 thiab Router12. Los ntawm Router8, txoj kev no yuav mus rau Router6, tab sis mus rau Router5 nws yuav tsis nyob rau hauv lub rooj routing. Tsis tas li ntawm Router12 txoj kev no yuav tshwm sim hauv lub rooj, tab sis ntawm Router11 nws yuav tsis nyob ntawd. Cia peb sim ua qhov no. Cia peb xav txog dab tsi cov ntaub ntawv thiab qhov ntsuas Router9 xa mus rau nws cov neeg nyob ze, qhia txog txoj kev no. Cov pob ntawv hauv qab no yuav raug xa los ntawm Router9 rau Router8.
Cov ntaub ntawv txoj kev muaj Path cwj pwm.
Path attributes muab faib ua 4 pawg:
- Zoo-paub yuav tsum - Tag nrho cov routers uas khiav BGP yuav tsum paub txog cov cwj pwm no. Yuav tsum muaj nyob rau hauv txhua qhov kev hloov tshiab.
- Zoo-paub kev txiav txim siab - Tag nrho cov routers uas khiav BGP yuav tsum paub txog cov cwj pwm no. Tej zaum lawv yuav muaj nyob rau hauv kev hloov tshiab, tab sis lawv lub xub ntiag tsis tas yuav tsum muaj.
- Optional transitive - tej zaum yuav tsis raug lees paub los ntawm txhua qhov kev siv BGP. Yog tias lub router tsis paub txog tus cwj pwm, nws cim qhov hloov tshiab raws li ib feem thiab xa mus rau nws cov neeg nyob ze, khaws cov cwj pwm tsis lees paub.
- Optional non-transitive - tej zaum yuav tsis raug lees paub los ntawm txhua qhov kev siv BGP. Yog tias lub router tsis paub tus cwj pwm, ces tus cwj pwm tsis quav ntsej thiab muab pov tseg thaum kis mus rau cov neeg nyob ze.
Piv txwv ntawm BGP tus cwj pwm:
- Zoo-paub yuav tsum:
- Autonomous system txoj kev
- Tom ntej no-hop
- Keeb kwm
- Zoo-paub kev txiav txim siab:
- Local nyiam
- Atomic sib sau ua ke
- Optional transitive:
- agregator
- Cov zej zog
- Optional non-transitive:
- Multi-exit discriminator (MED)
- Keeb kwm ID
- Cov npe pawg
Hauv qhov no, rau tam sim no peb yuav txaus siab rau Keeb Kwm, Next-hop, AS Path. Txij li thaum txoj kev xa tawm ntawm Router8 thiab Router9, uas yog, nyob rau hauv ib qho AS, nws suav hais tias yog sab hauv thiab peb yuav xyuam xim rau Keeb Kwm.
Keeb kwm tus cwj pwm - qhia seb txoj hauv kev hauv qhov hloov tshiab tau txais li cas. Yam khoom muaj nqis:
- 0 - IGP: NLRI tau txais nyob rau hauv thawj qhov kev tswj hwm tus kheej;
- 1 - EGP: NLRI tau kawm siv Exterior Gateway Protocol (EGP). Predecessor rau BGP, tsis siv
- 2 - Tsis tiav: NLRI tau kawm lwm txoj hauv kev
Nyob rau hauv peb cov ntaub ntawv, raws li tau pom los ntawm lub pob ntawv, nws yog sib npaug zos rau 0. Thaum txoj kev no kis mus rau Router12, qhov code no yuav muaj ib tug code ntawm 1.
Tom ntej no, Next-hop. Next-hop attribute
- Qhov no yog qhov chaw nyob IP ntawm eBGP router los ntawm txoj kev mus rau lub hom phiaj network mus.
- Tus cwj pwm hloov thaum lub npe ua ntej xa mus rau lwm tus AS.
Nyob rau hauv cov ntaub ntawv ntawm iBGP, uas yog, nyob rau hauv ib tug AS, Next-hop yuav qhia los ntawm ib tug uas kawm los yog qhia txog txoj kev no. Hauv peb qhov xwm txheej, nws yuav yog 192.168.89.9. Tab sis thaum txoj kev no kis tau los ntawm Router8 mus rau Router6, Router8 yuav hloov nws thiab hloov nws nrog nws tus kheej. Tom ntej-hop yuav yog 192.168.68.8. Qhov no coj peb mus rau ob txoj cai:
- Yog tias lub router xa ib txoj hauv kev mus rau nws cov neeg nyob ze, nws tsis hloov qhov Next-hop parameter.
- Yog tias lub router xa ib txoj hauv kev mus rau nws cov neeg nyob ze sab nraud, nws hloov Next-hop mus rau ip ntawm lub interface uas tus router no xa mus.
Qhov no ua rau peb nkag siab txog thawj qhov teeb meem - Vim li cas yuav tsis muaj txoj hauv kev hauv lub rooj sib tham ntawm Router5 thiab Router11. Cia wb mus saib ntxiv. Yog li, Router6 tau txais cov ntaub ntawv hais txog txoj hauv kev 9.9.9.0/24 thiab ua tiav nws ntxiv rau lub rooj routing:
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>
Π’Π΅ΠΏΠ΅ΡΡ Router6 ΠΏΠ΅ΡΠ΅Π΄Π°Π» ΠΌΠ°ΡΡΡΡΡ Router5 ΠΈ ΠΏΠ΅ΡΠ²ΠΎΠΌΡ ΠΏΡΠ°Π²ΠΈΠ»Ρ Next-hop Π½Π΅ ΠΈΠ·ΠΌΠ΅Π½ΠΈΠ». Π’ΠΎ Π΅ΡΡΡ, Router5 Π΄ΠΎΠ»ΠΆΠ΅Π½ Π΄ΠΎΠ±Π°Π²ΠΈΡΡ <b>9.9.9.0 [20/0] via 192.168.68.8</b> , Π½ΠΎ Ρ Π½Π΅Π³ΠΎ Π½Π΅Ρ ΠΌΠ°ΡΡΡΡΡΠ° Π΄ΠΎ 192.168.68.8 ΠΈ ΠΏΠΎΡΡΠΎΠΌΡ Π΄Π°Π½Π½ΡΠΉ ΠΌΠ°ΡΡΡΡΡ Π΄ΠΎΠ±Π°Π²Π»Π΅Π½ Π½Π΅ Π±ΡΠ΄Π΅Ρ, Ρ
ΠΎΡΡ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΡ ΠΎ Π΄Π°Π½Π½ΠΎΠΌ ΠΌΠ°ΡΡΡΡΡΠ΅ Π±ΡΠ΄Π΅Ρ Ρ
ΡΠ°Π½ΠΈΡΡΡΡ Π² ΡΠ°Π±Π»ΠΈΡΠ΅ 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>Tib qhov xwm txheej yuav tshwm sim ntawm Router11-Router12. Txhawm rau zam qhov xwm txheej no, koj yuav tsum teeb tsa Router6 lossis Router12, thaum dhau txoj kev mus rau lawv cov neeg nyob sib ze, hloov lawv tus IP chaw nyob ua Next-hop. Qhov no yog ua tiav siv cov lus txib:
neighbor 192.168.56.5 next-hop-selfTom qab cov lus txib no, Router6 yuav xa cov lus hloov tshiab, qhov twg ip ntawm interface Gi0/0 Router6 yuav raug teev raws li Next-hop rau txoj kev - 192.168.56.6, tom qab uas txoj kev no twb tau muab tso rau hauv lub rooj routing.
Cia peb mus ntxiv thiab saib seb txoj kev no tshwm sim ntawm Router7 thiab Router10. Nws yuav tsis nyob rau hauv lub rooj routing thiab tej zaum peb yuav xav tias qhov teeb meem yog tib yam li nyob rau hauv thawj ib tug nrog lub Next-hop parameter, tab sis yog hais tias peb saib nyob rau hauv cov zis ntawm lub show ip bgp hais kom ua, peb yuav pom tias tus txoj kev tsis tau txais muaj txawm tias qhov tsis ncaj ncees lawm Next-hop, uas txhais tau hais tias txoj kev tseem tsis tau kis. Thiab qhov no yuav coj peb mus rau lub neej ntawm lwm txoj cai:
Txoj kev tau txais los ntawm cov neeg nyob sib ze tsis tau nthuav tawm mus rau lwm cov neeg nyob sib ze.
Txij li thaum Router5 tau txais txoj kev los ntawm Router6, nws yuav tsis raug xa mus rau nws lwm tus neeg nyob ze. Txhawm rau kom qhov kev hloov pauv tshwm sim, koj yuav tsum teeb tsa txoj haujlwm , lossis teeb tsa kev sib raug zoo hauv zej zog kev sib raug zoo (Full Mesh), uas yog, Router5-7 txhua tus yuav yog ib tus neeg nyob ze rau txhua tus. Hauv qhov no peb yuav siv Route Reflector. Ntawm Router5 koj yuav tsum siv cov lus txib no:
neighbor 192.168.57.7 route-reflector-clientRoute-Reflector hloov tus cwj pwm ntawm BGP thaum hla txoj hauv kev mus rau ib tus neeg nyob ze. Yog hais tias tus neeg zej zog sab hauv tau teev tseg raws li route-reflector-neeg siv, ces cov kev sab hauv yuav raug tshaj tawm rau cov neeg siv khoom no.
Txoj kev tsis tshwm sim ntawm Router7? Tsis txhob hnov ββqab txog Next-hop ib yam. Tom qab cov kev hloov pauv no, txoj hauv kev yuav tsum mus rau Router7, tab sis qhov no tsis tshwm sim. Qhov no coj peb mus rau lwm txoj cai:
Txoj cai tom ntej-hop tsuas yog ua haujlwm rau sab nrauv. Rau kev sab hauv, tus cwj pwm tom ntej-hop tsis hloov.
Thiab peb tau txais ib qho xwm txheej uas tsim nyog los tsim ib qho chaw siv static routing lossis IGP raws tu qauv qhia rau routers txog txhua txoj hauv kev hauv AS. Cia peb sau npe txoj hauv kev zoo li qub ntawm Router6 thiab Router7 thiab tom qab ntawd peb yuav tau txais txoj kev xav tau hauv lub rooj router. Hauv AS 678, peb yuav ua qhov txawv me ntsis - peb yuav sau npe cov kev zoo li qub rau 192.168.112.0/24 ntawm Router10 thiab 192.168.110.0/24 ntawm Router12. Tom ntej no, peb yuav tsim cov zej zog kev sib raug zoo ntawm Router10 thiab Router12. Peb kuj tseem yuav teeb tsa Router12 xa nws qhov txuas ntxiv mus rau Router10:
neighbor 192.168.110.10 next-hop-selfQhov tshwm sim yuav yog tias Router10 yuav tau txais txoj hauv kev 9.9.9.0/24, nws yuav tau txais los ntawm Router7 thiab Router12. Cia peb pom dab tsi xaiv Router10 ua:
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
Raws li peb tuaj yeem pom, ob txoj kev thiab tus xub (>) txhais tau tias txoj kev ntawm 192.168.112.12 raug xaiv.
Cia peb saib seb txoj kev xaiv txoj kev ua haujlwm li cas:
- Thawj kauj ruam thaum tau txais ib txoj kev yog los xyuas qhov muaj ntawm nws Next-hop. Yog li ntawd, thaum peb tau txais txoj hauv kev ntawm Router5 yam tsis tau teeb tsa Next-hop-tus kheej, txoj kev no tsis tau ua tiav ntxiv.
- Tom ntej no los qhov hnyav parameter. Qhov kev ntsuas no tsis yog Path Attribute (PA) thiab tsis raug xa hauv BGP cov lus. Nws tau teeb tsa hauv zos ntawm txhua lub router thiab tsuas yog siv los tswj cov kev xaiv ntawm lub router nws tus kheej. Cia peb saib ib qho piv txwv. Tsuas yog saum toj no koj tuaj yeem pom tias Router10 tau xaiv txoj hauv kev rau 9.9.9.0/24 ntawm Router12 (192.168.112.12). Txhawm rau hloov qhov Wieght parameter, koj tuaj yeem siv txoj hauv kev-daim ntawv qhia kev teeb tsa tshwj xeeb, lossis muab qhov hnyav rau nws cov neeg nyob ze siv cov lus txib:
neighbor 192.168.107.7 weight 200Tam sim no txhua txoj kev los ntawm cov neeg nyob ze no yuav muaj qhov hnyav no. Cia peb saib yuav ua li cas kev xaiv ntawm txoj kev hloov tom qab no manipulation:
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 iRaws li koj tuaj yeem pom, txoj hauv kev los ntawm Router7 tam sim no raug xaiv, tab sis qhov no yuav tsis muaj kev cuam tshuam rau lwm tus routers.
- Hauv peb txoj haujlwm peb muaj Local Preference. Qhov no parameter yog ib tug zoo-paub discretionary cwj pwm, uas txhais tau hais tias nws lub xub ntiag yog nyob ntawm yeem. Qhov kev ntsuas no siv tau tsuas yog nyob rau hauv ib qho AS thiab cuam tshuam rau kev xaiv txoj hauv kev nkaus xwb rau cov neeg nyob sib ze. Tias yog vim li cas nws thiaj kis tau tsuas yog nyob rau hauv Hloov tshiab cov lus npaj rau cov neeg zej zog sab hauv. Nws tsis muaj nyob rau hauv Hloov tshiab cov lus rau cov neeg nyob sib ze. Yog li ntawd, nws tau raug cais raws li Zoo-paub kev txiav txim siab. Cia peb sim siv nws ntawm Router5. Ntawm Router5 peb yuav tsum muaj ob txoj hauv kev rau 9.9.9.0/24 - ib qho dhau ntawm Router6 thiab thib ob los ntawm Router7.
Peb saib:
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 iTab sis raws li peb pom ib txoj hauv kev los ntawm Router6. Txoj kev hla Router7 nyob qhov twg? Tej zaum Router7 tsis muaj nws thiab? Cia peb saib:
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 iQhov txawv, txhua yam zoo li zoo. Vim li cas nws tsis xa mus rau Router5? Qhov tseeb yog tias BGP muaj txoj cai:
Lub router tsuas xa cov kev uas nws siv.
Router7 siv txoj hauv kev los ntawm Router5, yog li txoj kev los ntawm Router10 yuav tsis raug xa mus. Cia peb rov qab mus rau Local Preference. Wb teem Local Preference ntawm Router7 thiab saib yuav ua li cas Router5 reacts rau qhov no:
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>Yog li, peb tsim ib txoj kev-daim ntawv qhia chaw uas muaj tag nrho cov kev thiab hais rau Router7 hloov lub Local Preference parameter rau 250 thaum tau txais, lub neej ntawd yog 100. Cia saib dab tsi tshwm sim ntawm 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 iRaws li peb tuaj yeem pom tam sim no Router5 nyiam txoj hauv kev los ntawm Router7. Tib daim duab yuav nyob ntawm Router6, txawm hais tias nws muaj txiaj ntsig ntau dua rau nws xaiv txoj hauv kev los ntawm Router8. Peb kuj ntxiv tias kev hloov pauv qhov ntsuas no yuav tsum tau rov pib dua ntawm cov zej zog kom qhov kev hloov pauv tau siv. Nyeem . Peb tau txheeb xyuas Local Preference. Cia peb mus rau qhov parameter tom ntej.
- Nyiam txoj kev nrog Next-hop parameter 0.0.0.0, uas yog, hauv zos lossis cov kev sib sau ua ke. Cov kev no tau txais kev tso cai qhov hnyav qhov sib npaug ntawm qhov siab tshaj plaws - 32678 - tom qab nkag mus rau lub network hais kom ua:
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 - Txoj kev luv tshaj dhau AS. Qhov luv tshaj AS_Path parameter raug xaiv. Qhov tsawg dua ASs ib txoj kev dhau mus, qhov zoo dua. Xav txog txoj kev mus rau 9.9.9.0/24 ntawm 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 iRaws li koj tuaj yeem pom, Router10 xaiv txoj hauv kev los ntawm 192.168.112.12 vim tias rau txoj kev no AS_Path parameter tsuas muaj 45, thiab lwm qhov 123 thiab 45. Intuitively meej.
- Tom ntej no parameter yog Keeb Kwm. IGP (txoj kev tau siv BGP) zoo dua li EGP (txoj kev tau siv BGP tus thawj, tsis siv lawm), thiab EGP zoo dua tsis tiav? (tau los ntawm ib co lwm txoj kev, piv txwv li los ntawm redistribution).
- Tom ntej no parameter yog MED. Peb muaj Weight uas tsuas yog ua haujlwm hauv zos ntawm lub router. Muaj Kev Xaiv Hauv Zos, uas tsuas yog ua haujlwm hauv ib qho kev tswj hwm tus kheej xwb. Raws li koj tuaj yeem twv, MED yog qhov ntsuas uas yuav kis tau los ntawm kev tswj hwm tus kheej. Zoo heev txog qhov parameter no.
Tsis muaj cov cwj pwm ntxiv yuav raug siv, tab sis yog tias ob txoj kev muaj cov cwj pwm zoo ib yam, ces cov cai hauv qab no raug siv:
- Xaiv txoj hauv kev los ntawm cov neeg nyob ze IGP ze tshaj plaws.
- Xaiv txoj kev qub tshaj plaws rau txoj kev eBGP.
- Xaiv txoj hauv kev los ntawm cov neeg nyob ze nrog qhov tsawg tshaj plaws BGP router ID.
- Xaiv ib txoj hauv kev los ntawm cov neeg nyob ze nrog qhov chaw nyob IP qis tshaj.
Tam sim no cia saib qhov teeb meem ntawm BGP convergence.
Cia peb saib yuav ua li cas yog Router6 poob txoj kev 9.9.9.0/24 dhau Router9. Cia peb lov tes taw interface Gi0/1 ntawm Router6, uas tam sim ntawd nkag siab tias BGP kev sib ntsib nrog Router8 tau raug txiav thiab cov neeg nyob ze tau ploj mus, uas txhais tau hais tias txoj kev tau txais los ntawm nws tsis siv. Router6 tam sim ntawd xa cov lus hloov tshiab, qhov twg nws qhia txog lub network 9.9.9.0/24 nyob rau hauv qhov chaw rho tawm. Thaum Router5 tau txais cov lus zoo li no, nws yuav xa mus rau Router7. Tab sis txij li thaum Router7 muaj ib txoj hauv kev los ntawm Router10, nws yuav teb tam sim nrog kev hloov tshiab nrog txoj kev tshiab. Yog tias nws tsis tuaj yeem txheeb xyuas lub caij nplooj zeeg ntawm ib tus neeg nyob ze raws li lub xeev ntawm lub interface, ces koj yuav tsum tau tos kom Tuav Timer tua hluav taws.
Confederation.
Yog tias koj nco qab, peb tau tham txog qhov tseeb tias koj feem ntau yuav tsum tau siv tag nrho cov topology txuas. Nrog ntau tus routers hauv ib qho AS qhov no tuaj yeem ua rau muaj teeb meem loj, kom tsis txhob muaj qhov no koj yuav tsum tau siv cov kev sib koom tes. Ib qho AS tau muab faib ua ob peb sub-AS, uas tso cai rau lawv ua haujlwm yam tsis tas yuav tsum muaj kev sib txuas ua ke tag nrho.
Nov yog qhov txuas rau qhov no thiab configuration rau GNS3.
Piv txwv li, nrog cov topology no peb yuav tsum txuas tag nrho cov routers hauv AS 2345 rau ib leeg, tab sis siv Confederation, peb tuaj yeem tsim kev sib raug zoo ntawm cov routers ncaj qha rau ib leeg. Wb tham txog qhov no kom ntxaws. Yog tias peb tsuas muaj AS 2345, ces laForge tau txais lub peb hlis ntuj los ntawm Picard yuav qhia rau cov routers Cov ntaub ntawv ΠΈ Worf, tab sis lawv yuav tsis qhia lub router txog nws Pob Tsuas . Kuj tseem muaj kev faib los ntawm router nws tus kheej laForge, yuav tsis tau pauv Pob Tsuas tsis Worf-aw, no Cov ntaub ntawv.
Koj yuav tau teeb tsa Route-Reflector lossis kev sib raug zoo hauv zej zog. Los ntawm kev faib ib qho AS 2345 rau hauv 4 sub-AS (2,3,4,5) rau txhua tus router, peb xaus nrog kev ua haujlwm sib txawv. Txhua yam tau piav qhia zoo kawg nkaus .
Qhov chaw:
- CCIE Routing and Switching v5.0 Cov Ntawv Qhia Ntawv Pov Thawj, Volume 2, Thib Tsib, Narbik Kocharians, Terry Vinson.
- website
- website .
Tau qhov twg los: www.hab.com