Laboratorio de enrutamiento OSPF
Clase de CCNA 2 del 2 de Julio del 2009,
academia Cisco, Rosario
Instructor: Ernesto Vilarrasa
Este escenario para prácticas de Exploration 2,
para prácticas de simulación de una empresa con
dos conexiones a Internet, de las cuales una es
de backup ante la caída de la pricipal.
Se utilzó la redistribución de la ruta por
defecto de OSPF y rutas estáticas con distintas métricas
para que NO realice balance de carga y mantenga
liberado el enlace backup.
Suponemos que por motivos de costo por cantidad
de tráfico o por ancho de banda pobre.
Errata: a partir del 24/7 se corrigió en la configuración
del router Backup la IP 200.45.191.9
por 200.45.191.2 debido a un error de edición.
Dicho error fue encontrado por una alumna de
CCNA 4, muchas gracias por la colaboración.
Diagrama
en Packet Tracer
Diagrama
en pizarrón
Conexiones en el rack:
Desarrollo:
Se configuraron tres routers Cisco 1800 como Cordoba y Borde y Tucuman,
un router Cisco 2501 como ISP y un Cisco 1600 como Backup.
Borde:
!
hostname Borde
!
interface FastEthernet0/0
ip address 172.16.0.1
255.255.255.0
!
interface Serial0/0/0
ip address 190.0.0.2
255.255.255.252
!
router ospf 1
log-adjacency-changes
network
172.16.0.0 0.0.0.255 area 0
default-information
originate
!
ip route 0.0.0.0 0.0.0.0 Serial0/0/0
!
end
Backup:
!
hostname Backup
!
interface Ethernet0
ip address 172.16.0.4
255.255.255.0
!
interface Serial0
ip address 200.45.191.2
255.255.255.252
no ip
mroute-cache
clockrate
64000
!
router ospf 1
network
172.16.0.0 0.0.0.255 area 0
default-information
originate
!
ip classless
ip route 0.0.0.0 0.0.0.0 Serial0 200 <-- Configuración de métrica 200
!
end
Verificamos Gateway en router
backup:
Backup#show ip route
.....
Gateway of last resort is 172.16.0.1 to network
0.0.0.0
200.45.191.0/30
is subnetted, 1 subnets
C
200.45.191.0 is directly connected, Serial0
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
O
172.16.1.32/27 [110/11] via 172.16.0.3, 00:40:13, Ethernet0
C
172.16.0.0/24 is directly connected, Ethernet0
O
172.16.1.0/27 [110/11] via 172.16.0.2, 00:40:13, Ethernet0
ISP:
!
hostname ISP
!
interface FastEthernet0/0
ip address
200.69.216.2 255.255.255.248
!
interface Serial0/0/0
ip address
190.0.0.1 255.255.255.252
clock rate
64000
!
interface Serial0/0/1
ip address
200.45.191.1 255.255.255.252
clock rate
64000
!
ip route 0.0.0.0 0.0.0.0 Serial0/0/0 <-- ruta con
métrica por default (1)
ip route 0.0.0.0 0.0.0.0 Serial0/0/1 2 <-- ruta con métrica 2
!
end
ISP#show ip route
....
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
190.0.0.0/30 is subnetted, 1 subnets
C
190.0.0.0 is directly connected, Serial0/0/0
200.45.191.0/30 is subnetted, 1 subnets
C
200.45.191.0 is directly connected, Serial0/0/1
200.69.216.0/29 is subnetted, 1 subnets
C
200.69.216.0 is directly connected, FastEthernet0/0
Sucursal Tucumán:
!
hostname Tucuman
!
interface FastEthernet0/0
ip address
172.16.0.3 255.255.255.0
!
interface FastEthernet0/1
ip address
172.16.1.33 255.255.255.240
!
router ospf 1
log-adjacency-changes
network
172.16.0.0 0.0.0.255 area 0
network
172.16.1.32 0.0.0.15 area 0
!
end
Sucursal Cordoba:
!
hostname Cordoba
!
interface FastEthernet0/0
ip address
172.16.0.2 255.255.255.0
!
interface FastEthernet0/1
ip address
172.16.1.1 255.255.255.224
!
router ospf 1
log-adjacency-changes
network
172.16.0.0 0.0.0.255 area 0
network
172.16.1.0 0.0.0.31 area 0
!
Verificación:
Desde un PC de
sucursal Córdoba se realiza un traceroute hacia el target 200.69.216.1
y se verifica
el gateway utilizado para alcanzar Internet.
Cordoba# show ip route
.....
172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
O
172.16.1.32/27 [110/2] via 172.16.0.3, 00:08:38, FastEthernet0/0
C
172.16.0.0/24 is directly connected, FastEthernet0/0
C 172.16.1.0/27 is directly connected,
FastEthernet0/1
Realizamos
la prueba con tracert:
C:\>tracert 200.69.216.1
Tracing route to 200.69.216.1 over a maximum of 30
hops:
1 94 ms
46 ms 18 ms
172.16.1.1
2 125 ms
125 ms 125 ms 172.16.0.1
3 156 ms
140 ms 156 ms 190.0.0.1
4 *
188 ms 203 ms 200.69.216.1
Trace complete.
Se simula la
caídadel enlace principal ( se desconectó el cable serial ) y desde un PC de
sucursal
Córdoba
nuevamente se realiza un traceroute hacia el target 200.69.216.1 y se
verifica
el gateway
utilizado para alcanzar Internet.
Borde>
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/0, changed
state to down
00:00:45: %OSPF-5-ADJCHG: Process 1, Nbr 172.16.1.1 on FastEthernet0/0
from LOADING to FULL, Loading Done
00:00:45: %OSPF-5-ADJCHG: Process 1, Nbr 200.45.191.9 on FastEthernet0/0
from LOADING to FULL, Loading Done
00:00:50: %OSPF-5-ADJCHG: Process 1, Nbr 172.16.1.33 on FastEthernet0/0
from LOADING to FULL, Loading Done
En router Cordoba:
00:00:45: %OSPF-5-ADJCHG: Process 1, Nbr 190.0.0.2 on FastEthernet0/0
from LOADING to FULL, Loading Done
00:00:50: %OSPF-5-ADJCHG: Process 1, Nbr 200.45.191.9 on FastEthernet0/0
from LOADING to FULL, Loading Done
Verificamos que
el gateway ahora es:
Cordoba# show ip route
............
172.16.0.0/16
is variably subnetted, 3 subnets, 2 masks
O
172.16.1.32/27 [110/2] via 172.16.0.3, 00:07:33, FastEthernet0/0
C
172.16.0.0/24 is directly connected, FastEthernet0/0
C
172.16.1.0/27 is directly connected, FastEthernet0/1
Realizamos
la prueba con tracert:
C:\>tracert 200.69.216.1
Tracing route to 200.69.216.1 over a maximum of 30
hops:
1 47 ms
46 ms 47 ms 172.16.1.1
2 94 ms
110 ms 111 ms 172.16.0.4
3 125 ms
125 ms 141 ms 200.45.191.1
4 172 ms
187 ms 218 ms 200.69.216.1
Trace complete.
En router Borde:
%LINK-5-CHANGED: Interface Serial0/0/0, changed state
to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface
Serial0/0/0, changed state to up
Cordoba# show ip route
Gateway of last resort is 172.16.0.1 to network
0.0.0.0
172.16.0.0/16
is variably subnetted, 2 subnets, 2 masks
C
172.16.0.0/24 is directly connected, FastEthernet0/0
C
172.16.1.0/27 is directly connected, FastEthernet0/1
O*E2 0.0.0.0/0 [110/1] via 172.16.0.1,
00:00:00, FastEthernet0/0
__________________________________________________________________
Ernesto Vilarrasa ernesto@vilarrasa.com.ar www.vilarrasa.com.ar