Este documento describe cómo configurar Border Gateway Protocol (BGP) utilizando números AS de 32 bits. En BGP, cada dominio de ruteo es un dominio administrativo único y tiene un número AS único asignado a él, y se opera dentro de un conjunto uniforme de políticas de ruteo. También mantiene el ruteo interdominio.
En este documento, el peering BGP se configura entre los routers BGP de 16 bits y 32 bits que hablan. El nuevo modo AS de 32 bits es compatible con el modo AS de 16 bits. Los peers BGP que pueden funcionar en el modo de 32 bits responden positivamente a la nueva capacidad, y esa sesión funciona en el nuevo modo. Por otra parte, los peers BGP de 32 bits cuando se comunican con los altavoces BGP de 16 bits, los routers de habla de 16 bits ignoran esta nueva capacidad y operan su sesión BGP en modo de 16 bits.
Cisco recomienda que tenga conocimiento básico de BGP.
Las configuraciones en este documento se basan en el Cisco 7200 Series Router con Cisco IOS® Software Release 15.0(1).
En este ejemplo, los routers R1 y R3 están configurados para estar en AS 100 formando una relación iBGP usando el modo AS de 16 bits. Los routers R2 y R4 se configuran en AS 10.1 y forman el peering iBGP usando el modo AS de 32 bits. Los routers R1 y R2 se ejecutan y el protocolo IGP, en este ejemplo OSPF entre sí y también forman un vecino eBGP entre ellos.
Nota: Use la Command Lookup Tool (sólo para clientes registrados) para encontrar más información sobre los comandos usados en este documento.
En este documento, se utiliza esta configuración de red:
En este documento, se utilizan estas configuraciones:
Router R1 |
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R1#show run Building configuration... ! version 15.0 ! hostname R1 ! ip cef ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Loopback10 ip address 192.168.100.1 255.255.255.0 ! interface Loopback20 ip address 192.168.200.1 255.255.255.0 ! interface FastEthernet1/0 ip address 192.168.10.1 255.255.255.0 duplex auto speed auto ! interface Serial2/0 ip address 10.10.100.1 255.255.255.0 serial restart-delay 0 ! router ospf 1 log-adjacency-changes network 1.1.1.1 0.0.0.0 area 0 network 10.10.100.0 0.0.0.255 area 0 ! router bgp 100 !--- BGP is configured using 16-bit AS number no synchronization bgp router-id 10.10.10.10 bgp asnotation dot !--- This command change the default asplain notation to dot notation. !--- Note that without this command the AS number will treated as asplain notation i.e. 10.1 will be displayed as 655361 bgp log-neighbor-changes network 192.168.100.0 network 192.168.200.0 neighbor 2.2.2.2 remote-as 10.1 !--- The AS number of the eBGP peer in 32-bit neighbor 2.2.2.2 ebgp-multihop 255 neighbor 2.2.2.2 update-source Loopback0 neighbor 192.168.10.2 remote-as 100 neighbor 192.168.10.2 next-hop-self no auto-summary ! end |
Router R2 |
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R2#show run ! version 15.0 ! hostname R2 ! ip cef ! interface Loopback0 ip address 2.2.2.2 255.255.255.0 ! interface Loopback10 ip address 10.1.1.1 255.255.255.255 ! interface Loopback20 ip address 20.1.1.1 255.255.255.255 ! interface FastEthernet1/0 ip address 172.16.10.1 255.255.255.0 duplex auto speed auto ! interface Serial2/0 ip address 10.10.100.2 255.255.255.0 serial restart-delay 0 ! ! router ospf 1 log-adjacency-changes network 2.2.2.2 0.0.0.0 area 0 network 10.10.100.0 0.0.0.255 area 0 ! router bgp 10.1 !--- BGP is configured using 32-bit AS number no synchronization bgp router-id 20.20.20.20 bgp asnotation dot bgp log-neighbor-changes network 10.1.1.1 mask 255.255.255.255 network 20.1.1.1 mask 255.255.255.255 neighbor 1.1.1.1 remote-as 100 neighbor 1.1.1.1 ebgp-multihop 255 neighbor 1.1.1.1 update-source Loopback0 neighbor 172.16.10.2 remote-as 10.1 neighbor 172.16.10.2 next-hop-self no auto-summary ! end |
Router R3 |
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R3#show run Building configuration... ! version 15.0 ip cef ! interface Loopback0 ip address 30.30.30.30 255.255.255.255 ! interface FastEthernet1/0 ip address 192.168.10.2 255.255.255.0 duplex auto speed auto ! router bgp 100 no synchronization bgp router-id 3.3.3.3 bgp log-neighbor-changes network 30.30.30.30 mask 255.255.255.255 neighbor 192.168.10.1 remote-as 100 neighbor 192.168.10.1 next-hop-self no auto-summary !--- iBGP peering is formed between routers R1 and R3 using 16-bit AS number. ! end |
Router R4 |
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R4#show run Building configuration... ! version 15.0 ip cef ! interface Loopback0 ip address 40.40.40.40 255.255.255.255 ! interface FastEthernet1/0 ip address 172.16.10.2 255.255.255.0 duplex auto speed auto ! router bgp 10.1 no synchronization bgp router-id 4.4.4.4 bgp asnotation dot bgp log-neighbor-changes network 40.40.40.40 mask 255.255.255.255 neighbor 172.16.10.1 remote-as 10.1 no auto-summary ! end !--- iBGP peering is formed between routers R2 and R4 using 32-bit AS number. |
Utilize esta sección para confirmar que su configuración funcione correctamente.
La herramienta Output Interpreter Tool (clientes registrados solamente) (OIT) soporta ciertos comandos show. Utilize el OIT para ver una análisis de la salida del comando show.
Para verificar que BGP pueda soportar el ASN de 32 bits, utilice el comando show ip bgp neighbor.
show ip bgp neighbor |
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En el router R1 R1#show ip bgp neighbor 2.2.2.2 BGP neighbor is 2.2.2.2, remote AS 10.1, external link BGP version 4, remote router ID 20.20.20.20 BGP state = Established, up for 03:28:22 Last read 00:00:41, last write 00:00:29, hold time is 180, keepalive interval is 60 seconds Neighbor sessions: 1 active, is multisession capable Neighbor capabilities: Route refresh: advertised and received(new) Four-octets ASN Capability: advertised and received Address family IPv4 Unicast: advertised and received Multisession Capability: advertised and received Message statistics, state Established: InQ depth is 0 OutQ depth is 0 Sent Rcvd Opens: 1 1 Notifications: 0 0 Updates: 3 3 Keepalives: 229 230 Route Refresh: 0 0 Total: 233 234 !--- Output omitted---! |
Para mostrar las entradas en la tabla de ruteo BGP, utilice el comando show ip bgp.
show ip bgp |
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En el router R1 R1#sh ip bgp BGP table version is 13, local router ID is 10.10.10.10 Status codes: s suppressed, d damped, h history, * valid, > best, I - internal, r RIB-failure, S Stale Origin codes: I - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 10.1.1.1/32 2.2.2.2 0 0 10.1 I *> 20.1.1.1/32 2.2.2.2 0 0 10.1 I *>i30.30.30.30/32 192.168.10.2 0 100 0 I *> 40.40.40.40/32 2.2.2.2 0 10.1 I *> 192.168.100.0 0.0.0.0 0 32768 I *> 192.168.200.0 0.0.0.0 0 32768 I !--- Note that the routes highlighted are received from the eBGP peer router R2 which is in 32-bit AS 10.1. In router R3 R3#sh ip bgp BGP table version is 11, local router ID is 3.3.3.3 Status codes: s suppressed, d damped, h history, * valid, > best, I - internal, r RIB-failure, S Stale Origin codes: I - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *>i10.1.1.1/32 192.168.10.1 0 100 0 655361 I *>i20.1.1.1/32 192.168.10.1 0 100 0 655361 I *> 30.30.30.30/32 0.0.0.0 0 32768 I *>i40.40.40.40/32 192.168.10.1 0 100 0 655361 I *>i192.168.100.0 192.168.10.1 0 100 0 I *>i192.168.200.0 192.168.10.1 0 100 0 I !--- The router R3 does not have bgp asnotation dot configured in it. Therefore, the route received from the router in 32-bit AS AS 10.1 is displayed as 655361. In router R4 R4#sh ip bgp BGP table version is 7, local router ID is 4.4.4.4 Status codes: s suppressed, d damped, h history, * valid, > best, I - internal, r RIB-failure, S Stale Origin codes: I - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *>i10.1.1.1/32 172.16.10.1 0 100 0 I *>i20.1.1.1/32 172.16.10.1 0 100 0 I *>i30.30.30.30/32 172.16.10.1 0 100 0 100 I *> 40.40.40.40/32 0.0.0.0 0 32768 I *>i192.168.100.0 172.16.10.1 0 100 0 100 I *>i192.168.200.0 172.16.10.1 0 100 0 100 I !--- The above output shows the entries in BGP routing table of router R4. |
Para verificar el alcance entre los routers, utilice el comando ping.
ping |
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Desde el router R3 R3#ping 40.40.40.40 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 40.40.40.40, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 68/101/148 msDesde el router R4 R4#ping 30.30.30.30 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 30.30.30.30, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 56/89/112 ms !--- The above output shows that End to End connectivity is established between R3 and R4, where R3 is AS 100(16-bit AS) and router R4 is in AS 10.1(32-bit AS). |
Revisión | Fecha de publicación | Comentarios |
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1.0 |
25-Jun-2012 |
Versión inicial |