Conversión de anuncios del estado del link estilo Not So Stubby Area (área no exclusiva de rutas internas) del tipo 7 al tipo 5 en OSPF
Contenido
Introducción
Este documento muestra cómo Open Shortest Path First (OSPF) convierte un anuncio de estado de vínculo (LSA) de tipo 7 de Not So Stubby Area (NSSA) en un LSA de tipo 5.
Prerequisites
Requirements
No hay requisitos específicos para este documento.
Componentes Utilizados
Este documento no tiene restricciones específicas en cuanto a versiones de software y de hardware.
Convenciones
Configurar
En esta sección encontrará la información para configurar las funciones descritas en este documento.
Nota: Para encontrar información adicional sobre los comandos usados en este documento, utilice la Command Lookup Tool (sólo clientes registrados) .
Diagrama de la red
Este documento utiliza la configuración de red que se muestra en el siguiente diagrama.
Configuraciones
Este documento usa las configuraciones detalladas aquí.
| Router 1.1.1.1 |
|---|
Current configuration: hostname r1.1.1.1 interface Loopback0 ip address 1.1.1.1 255.0.0.0 interface Serial2/1/0 ip address 5.0.0.1 255.0.0.0 interface Ethernet2/0/0 ip address 4.0.0.1 255.0.0.0 router ospf 4 redistribute static metric 5 metric-type 1 network 5.0.0.0 0.255.255.255 area 1 network 4.0.0.0 0.255.255.255 area 1 area 1 nssa ip route 9.0.0.0 255.0.0.0 4.0.0.2 end |
| Router 2.2.2.2 |
|---|
Current configuration: hostname r2.2.2.2 interface Loopback0 ip address 2.2.2.2 255.0.0.0 interface Serial0/1/0 ip address 5.0.0.2 255.0.0.0 interface ATM1/0.20 ip address 6.0.0.2 255.0.0.0 router ospf 2 network 5.0.0.0 0.255.255.255 area 1 network 6.0.0.0 0.255.255.255 area 0 area 1 nssa end |
| Router 3.3.3.3 |
|---|
Current configuration: hostname r3.3.3.3 interface Loopback0 ip address 3.3.3.3 255.0.0.0 interface ATM2/0.20 point-to-point ip address 6.0.0.3 255.0.0.0 router ospf 2 network 6.0.0.0 0.255.255.255 area 0 end |
Verificación
En esta sección encontrará información que puede utilizar para confirmar que su configuración esté funcionando correctamente.
La herramienta Output Interpreter (sólo para clientes registrados) permite utilizar algunos comandos “show” y ver un análisis del resultado de estos comandos.
-
show ip ospf database —Muestra una lista de los LSAs y los tipea en una base de datos de estado de link. Esta lista muestra solamente la información en el encabezado LSA.
-
show ip ospf database nssa-external: muestra información solamente sobre los LSA externos NSSA.
-
show ip ospf database external: muestra información solamente sobre los LSA externos.
-
show ip ospf database [router] [link-state-id]—Muestra una lista de todos los LSA de un router en la base de datos. Los LSA son producidos por cada router, y estos LSA fundamentales enumeran todos los links, o interfaces de los routers, junto con los estados y los costos de salida de los links. Sólo se inundan dentro de la zona de origen.
-
show ip ospf database summary <link-state id> : muestra los enlaces de resumen del router de borde de área (ABR).
-
show ip route —Muestra el estado actual de la tabla de ruteo.
Examinar la base de datos OSPF
Para ver cómo se ve la base de datos OSPF dado este entorno de red, utilice el comando show ip ospf database.
r2.2.2.2#show ip ospf database
OSPF Router with ID (2.2.2.2) (Process ID 2)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
2.2.2.2 2.2.2.2 1235 0x8000001D 0xD9FF 2
3.3.3.3 3.3.3.3 1100 0x8000000B 0x9455 2
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
4.0.0.0 2.2.2.2 1979 0x80000002 0xFDE7
5.0.0.0 2.2.2.2 1483 0x80000004 0x8864
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 319 0x8000000C 0xAFA8 3
2.2.2.2 2.2.2.2 220 0x8000002F 0xD478 2
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
6.0.0.0 2.2.2.2 1483 0x8000001C 0x7894
Type-7 AS External Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Tag
9.0.0.0 1.1.1.1 334 0x80000005 0xD738 0
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
9.0.0.0 2.2.2.2 1725 0x80000004 0x50C6 0
Para anunciar las rutas externas en un NSSA, el router del límite del sistema autónomo (ASBR) crea LSA externas al nssa (tipo 7).
r2.2.2.2#show ip ospf database nssa-external 9.0.0.0
OSPF Router with ID (2.2.2.2) (Process ID 2)
Type-7 AS External Link States (Area 1)
Routing Bit Set on this LSA
LS age: 381
Options: (No TOS-capability, Type 7/5 translation, DC)
!--- This can be translated into a type 5 LSA by !--- an ABR.
LS Type: AS External Link
Link State ID: 9.0.0.0 (External Network Number )
!--- The ASBR (Router 1.1.1.1) advertises !--- 9.0.0.0/8.
Advertising Router: 1.1.1.1
!--- Router ID of the ASBR.
LS Seq Number: 80000005
Checksum: 0xD738
Length: 36
Network Mask: /8
Metric Type: 1 (Comparable directly to link state metric)
TOS: 0
Metric: 5
Forward Address: 4.0.0.1
!--- Forwarding address is incorrectly specified !--- as an interface on the ASBR.
El ABR convierte los LSA de tipo 7 en LSA de tipo 5 y propaga los LSA de tipo 5 en áreas normales.
r2.2.2.2#show ip ospf database external 9.0.0.0
OSPF Router with ID (2.2.2.2) (Process ID 2)
Type-5 AS External Link States
LS age: 1782
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 9.0.0.0 (External Network Number )
!--- Router 2.2.2.2 advertises 9.0.0.0/8.
Advertising Router: 2.2.2.2
!--- When the conversion is complete, the advertising !--- router ID becomes the ABR router ID !--- because the ABR originates this type 5 LSA.
LS Seq Number: 80000004
Checksum: 0x50C6
Length: 36
Network Mask: /8
Metric Type: 1 (Comparable directly to link state metric)
TOS: 0
Metric: 5
Forward Address: 4.0.0.1
External Route Tag: 0
r2.2.2.2#show ip ospf database router 1.1.1.1
OSPF Router with ID (2.2.2.2) (Process ID 2)
Router Link States (Area 1)
Routing Bit Set on this LSA
LS age: 426
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 1.1.1.1
!--- For router links, Link State ID is always the same !--- as the advertising router (next line).
Advertising Router: 1.1.1.1
LS Seq Number: 8000000C
Checksum: 0xAFA8
Length: 60
AS Boundary Router
!--- Bit E in the router LSA indicates that this router !--- originates from external LSAs.
Number of Links: 3
!--- There are three links in area 1.
Link connected to: a Stub Network
!--- This represents the Ethernet segment 4.0.0.0/8.
(Link ID) Network/subnet number: 4.0.0.0
(Link Data) Network Mask: 255.0.0.0
Number of TOS metrics: 0
TOS 0 Metrics: 10
!--- The OSPF cost of the Ethernet segment.
Link connected to: another Router (point-to-point)
!--- Shows that Router 1.1.1.1 is a neighbor with !--- Router 2.2.2.2.
(Link ID) Neighboring Router ID: 2.2.2.2
(Link Data) Router Interface address: 5.0.0.1
!--- The interface address that connects to Router !--- 2.2.2.2 is 5.0.0.1.
Number of TOS metrics: 0
TOS 0 Metrics: 64
!--- The OSPF cost of the link that connects !--- the two routers.
Link connected to: a Stub Network
!--- This represents the serial link 5.0.0.0/8.
(Link ID) Network/subnet number: 5.0.0.0
(Link Data) Network Mask: 255.0.0.0
Number of TOS metrics: 0
TOS 0 Metrics: 64
!--- The OSPF cost of the serial link.
Puede ver en el resultado bold aquí que aunque el Router 2.2.2.2 no tiene ninguna instrucción redistribute en su configuración, sigue siendo un ASBR porque convierte LSA de tipo 7 en LSA de tipo 5.
r2.2.2.2#show ip ospf database router 2.2.2.2
OSPF Router with ID (2.2.2.2) (Process ID 2)
Router Link States (Area 0)
LS age: 1361
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 2.2.2.2
Advertising Router: 2.2.2.2
LS Seq Number: 8000001D
Checksum: 0xD9FF
Length: 48
Area Border Router
!--- Bit B is set in the router LSA to indicate !--- that this router is an ABR.
AS Boundary Router
!--- Bit E in the router LSA indicates that this router !--- originates from external LSAs.
Number of Links: 2
!--- There are two links in area 0.
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 3.3.3.3
(Link Data) Router Interface address: 6.0.0.2
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: a Stub Network
(Link ID) Network/subnet number: 6.0.0.0
(Link Data) Network Mask: 255.0.0.0
Number of TOS metrics: 0
TOS 0 Metrics: 1
Router Link States (Area 1)
LS age: 346
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 2.2.2.2
Advertising Router: 2.2.2.2
LS Seq Number: 8000002F
Checksum: 0xD478
Length: 48
Area Border Router
AS Boundary Router
Number of Links: 2
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 1.1.1.1
(Link Data) Router Interface address: 5.0.0.2
Number of TOS metrics: 0
TOS 0 Metrics: 64
Link connected to: a Stub Network
(Link ID) Network/subnet number: 5.0.0.0
(Link Data) Network Mask: 255.0.0.0
Number of TOS metrics: 0
TOS 0 Metrics: 64
r2.2.2.2#show ip ospf database router 3.3.3.3
OSPF Router with ID (2.2.2.2) (Process ID 2)
Router Link States (Area 0)
LS age: 1245
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 3.3.3.3
Advertising Router: 3.3.3.3
LS Seq Number: 8000000B
Checksum: 0x9455
Length: 48
Number of Links: 2
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 2.2.2.2
(Link Data) Router Interface address: 6.0.0.3
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: a Stub Network
(Link ID) Network/subnet number: 6.0.0.0
(Link Data) Network Mask: 255.0.0.0
Number of TOS metrics: 0
TOS 0 Metrics: 1
Para anunciar rutas de un área a otra, ABR crea LSA de resumen (tipo 3).
r2.2.2.2#show ip ospf database summary 4.0.0.0
OSPF Router with ID (2.2.2.2) (Process ID 2)
Summary Net Link States (Area 0)
LS age: 172
Options: (No TOS-capability, DC)
LS Type: Summary Links(Network)
Link State ID: 4.0.0.0 (summary Network Number)
!--- The ABR (Router 2.2.2.2) advertises !--- 4.0.0.0/8 into area 0.
Advertising Router: 2.2.2.2
LS Seq Number: 80000003
Checksum: 0xFBE8
Length: 28
Network Mask: /8
TOS: 0 Metric: 74
r2.2.2.2#show ip ospf database summary 5.0.0.0
OSPF Router with ID (2.2.2.2) (Process ID 2)
Summary Net Link States (Area 0)
LS age: 1687
Options: (No TOS-capability, DC)
LS Type: Summary Links(Network)
Link State ID: 5.0.0.0 (summary Network Number)
!--- The ABR (Router 2.2.2.2) advertises !--- 5.0.0.0/8 into area 0.
Advertising Router: 2.2.2.2
LS Seq Number: 80000004
Checksum: 0x8864
Length: 28
Network Mask: /8
TOS: 0 Metric: 64
r2.2.2.2#show ip ospf database summary 6.0.0.0
OSPF Router with ID (2.2.2.2) (Process ID 2)
Summary Net Link States (Area 1)
LS age: 1697
Options: (No TOS-capability, DC)
LS Type: Summary Links(Network)
Link State ID: 6.0.0.0 (summary Network Number)
!--- The ABR (Router 2.2.2.2) advertises !--- 6.0.0.0/8 into area 1.
Advertising Router: 2.2.2.2
LS Seq Number: 8000001C
Checksum: 0x7894
Length: 28
Network Mask: /8
TOS: 0 Metric: 1
Los LSA de resumen ASBR no son necesarios en este caso porque ABR origina el LSA externo y el ABR es accesible dentro del área 0. Compare este ejemplo con una situación en la que el NSSA era un área normal observando el ejemplo de la base de datos Cómo propaga OSPF rutas externas en varias áreas.
Este resultado de la tabla de ruteo muestra los diferentes tipos de rutas OSPF que cada router conoce como 9.0.0.0.
r1.1.1.1#show ip route 9.0.0.0
Routing entry for 9.0.0.0/8
Known via "static", distance 1, metric 0
Redistributing via ospf 4
Advertised by ospf 4 metric 5 metric-type 1
Routing Descriptor Blocks:
* 4.0.0.2
Route metric is 0, traffic share count is 1
r2.2.2.2#show ip route ospf
O 4.0.0.0/8 [110/74] via 5.0.0.1, 01:10:13, Serial0/1/0
O N1 9.0.0.0/8 [110/79] via 5.0.0.1, 01:07:20, Serial0/1/0
R3.3.3.3#show ip route ospf
O IA 4.0.0.0/8 [110/75] via 6.0.0.2, 02:11:14, ATM2/0.20
O IA 5.0.0.0/8 [110/65] via 6.0.0.2, 03:10:41, ATM2/0.20
O E1 9.0.0.0/8 [110/80] via 6.0.0.2, 02:08:11, ATM2/0.20
Troubleshoot
Actualmente, no hay información específica de troubleshooting disponible para esta configuración.
Información Relacionada
Historial de revisiones
| Revisión | Fecha de publicación | Comentarios |
|---|---|---|
1.0 |
10-Aug-2005 |
Versión inicial |
Comentarios