Laboratorio de enrutamiento OSPF

Clase de CCNA 2 del 25 de Junio del 2009, academia Cisco, Rosario

Instructor: Ernesto Vilarrasa

Escenario/ Topología:

Este escenario para prácticas de Exploration 2, para prácticas de elección de DR/BDR en una

topología multiacceso de backbone con redistribución de la ruta por defecto hacia el ISP y se

generan conflictos de router-id.

Diagrama en Packet Tracer

Diagrama en pizarrón

Conexiones en el rack:

Desarrollo:

Se configuraron tres routers Cisco 1800 como Cordoba y Borde y Mendoza,

un router Cisco 2501 como ISP y un Cisco 1600 como Tucumán.

Borde:

hostname Borde

interface fa0/0

ip address 172.16.0.4 255.255.255.248

exit

interface Serial0/0/0

ip address 10.0.0.1 255.255.255.252

exit

router ospf 1

network 172.16.0.0 0.0.0.7 area 0

default-information originate

ip route 0.0.0.0 0.0.0.0 Serial0/0/0

end

ISP:

conf t

host ISP

ip ro 0.0.0.0 0.0.0.0 s0/0/0

int s0/0/0

ip add 10.0.0.2 255.255.255.252

clock rate 64000

no shut

exit

int loop 0

ip add 200.69.216.1 255.255.255.255

exit

end

Sucursal Mendoza:

conf t

host Mendoza

int fast 0/1

no shut

ip add 192.168.2.1 255.255.255.0

exit

int fast 0/0

no shut

ip add 172.16.0.2 255.255.255.248

exit

router ospf 1

net 172.16.0.0 0.0.0.7 area 0

net 192.168.2.0 0.0.0.255 area 0

end

Sucursal Tucumán:

conf t

host Tucuman

int fast 0/1

no shut

ip add 10.0.1.1 255.255.255.0

exit

int fast 0/0

no shut

ip add 172.16.0.3 255.255.255.248

exit

router ospf 1

net 172.16.0.0 0.0.0.7 area 0

net 10.0.1.0 0.0.0.255 area 0

end

copy ru st

Sucursal Cordoba:

conf t

host Cordoba

int fast 0/1

no shut

ip add 192.168.1.1 255.255.255.0

exit

int fast 0/0

no shut

ip add 172.16.0.1 255.255.255.248

exit

router ospf 1

net 172.16.0.0 0.0.0.7 area 0

net 192.168.2.0 0.0.0.255 area 0

end

Verificación:

Mendoza>sh ip route verificamos convergencia

Gateway of last resort is 172.16.0.4 to network 0.0.0.0

10.0.0.0/24 is subnetted, 1 subnets

O 10.0.1.0 [110/2] via 172.16.0.3, 00:01:44, FastEthernet0/0

172.16.0.0/29 is subnetted, 1 subnets

C 172.16.0.0 is directly connected, FastEthernet0/0

O 192.168.1.0/24 [110/2] via 172.16.0.1, 00:01:44, FastEthernet0/0

C 192.168.2.0/24 is directly connected, FastEthernet0/1

O*E2 0.0.0.0/0 [110/1] via 172.16.0.4, 00:01:44, FastEthernet0/0

Mendoza>

Mendoza>sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

172.16.0.4 1 FULL/DROTHER 00:00:34 172.16.0.4 FastEthernet0/0

172.16.0.3 1 FULL/DROTHER 00:00:34 172.16.0.3 FastEthernet0/0

192.168.1.1 1 FULL/BDR 00:00:34 172.16.0.1 FastEthernet0/0

Mendoza>

Tucuman>sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

172.16.0.4 1 2WAY/DROTHER 00:00:35 172.16.0.4 FastEthernet0/0

192.168.1.1 1 FULL/BDR 00:00:35 172.16.0.1 FastEthernet0/0

192.168.2.1 1 FULL/DR 00:00:35 172.16.0.2 FastEthernet0/0

Tucuman>

Sucursal Mendoza cae:

Tucuman>sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

172.16.0.4 1 FULL/BDR 00:00:37 172.16.0.4 FastEthernet0/0

192.168.1.1 1 FULL/DR 00:00:37 172.16.0.1 FastEthernet0/0

Tucuman#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Tucuman(config)#int loop 0 ahora modificamos el router ID de Tucumán, si el ID no es

el más alto, no es elejido por este método para ser DR

%LINK-5-CHANGED: Interface Loopback0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up

Tucuman(config-if)#ip add 20.1.2.3 255.255.255.255

Tucuman(config-if)#^Z

Tucuman>sh ip ospf int luego de reiniciar el router para cambiar su ID

FastEthernet0/0 is up, line protocol is up

Internet address is 172.16.0.3/29, Area 0

Process ID 1, Router ID 20.1.2.3, Network Type BROADCAST, Cost: 1

Transmit Delay is 1 sec, State DROTHER, Priority 1

Designated Router (ID) 192.168.1.1, Interface address 172.16.0.1

Backup Designated Router (ID) 172.16.0.4, Interface address 172.16.0.4

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

Borde>sh ip ospf neighbor verificamos quién es el DR

Neighbor ID Pri State Dead Time Address Interface

192.168.1.1 1 FULL/DR 00:00:39 172.16.0.1 FastEthernet0/0

20.1.2.3 1 FULL/DROTHER 00:00:39 172.16.0.3 FastEthernet0/0

Borde>

Cordoba#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Cordoba(config)#int loop 0

%LINK-5-CHANGED: Interface Loopback0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up

Cordoba(config-if)#ip add 20.1.2.3 255.255.255.255

Cordoba(config-if)#^Z

Cordoba#copy ru st

Destination filename [startup-config]?

Building configuration...

[OK]

Cordoba#reload

Proceed with reload? [confirm]

Mendoza#sh ip route verificamos la convergencia no se realiza (ver tabla anterior )

Gateway of last resort is 172.16.0.4 to network 0.0.0.0

10.0.0.0/24 is subnetted, 1 subnets

O 10.0.1.0 [110/2] via 172.16.0.3, 00:00:14, FastEthernet0/0

172.16.0.0/29 is subnetted, 1 subnets

C 172.16.0.0 is directly connected, FastEthernet0/0

C 192.168.2.0/24 is directly connected, FastEthernet0/1

O*E2 0.0.0.0/0 [110/1] via 172.16.0.4, 00:00:14, FastEthernet0/0

Mendoza#sh ip ospf nei verificamos vecindario inconsistente:

Neighbor ID Pri State Dead Time Address Interface

20.1.2.3 1 FULL/BDR 00:00:38 172.16.0.3 FastEthernet0/0

172.16.0.4 1 FULL/DR 00:00:38 172.16.0.4 FastEthernet0/0

20.1.2.3 1 2WAY/DROTHER 00:00:32 172.16.0.1 FastEthernet0/0

Mendoza#

Mendoza#conf t generamos un nuevo conflicto

Enter configuration commands, one per line. End with CNTL/Z.

Mendoza(config)#int loop 0

Mendoza(config-if)#ip add 20.1.2.3 255.255.255.255

Mendoza(config-if)#^Z

Mendoza#

Mendoza#copy ru st

Destination filename [startup-config]?

Building configuration...

[OK]

Mendoza#reload

Proceed with reload? [confirm]

Mendoza>sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

20.1.2.3 1 EXSTART/BDR 00:00:30 172.16.0.3 FastEthernet0/0

172.16.0.4 1 FULL/DR 00:00:30 172.16.0.4 FastEthernet0/0

20.1.2.3 1 2WAY/DROTHER 00:00:34 172.16.0.1 FastEthernet0/0

Mendoza>

Borde#conf t ... y otro más ...

Enter configuration commands, one per line. End with CNTL/Z.

Borde(config)#router ospf 1

Borde(config-router)#router-id 20.1.2.3

Borde(config-router)#Reload or use "clear ip ospf process" command, for this to take effect

Borde(config-router)#^Z

Borde#reload

Proceed with reload? [confirm]

Borde>sh ip route ya no existe convergencia

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

10.0.0.0/30 is subnetted, 1 subnets

C 10.0.0.0 is directly connected, Serial0/0/0

172.16.0.0/29 is subnetted, 1 subnets

C 172.16.0.0 is directly connected, FastEthernet0/0

S* 0.0.0.0/0 is directly connected, Serial0/0/0

Borde>

__________________________________________________________________

Ernesto Vilarrasa evilarrasa@centroit.org.ar www.vilarrasa.com.ar