Escenario homenaje Alemania – Brasil

Fecha: 8 de julio del 2014

 

Escenario

 

Este escenario reproduce en forma simbólica el toqueteo de Alemania contra Brasil, en el que terminó 7 a 1.

El fútbol no me interesa pero durante la clase miramos el partido y me inspiró para llevarlo como un juego al ámbito del enrutamiento.

 

Objetivo: La jugada (el tracert) arranca desde el arco de Neuer, Lahm, Khedira, Kross, Schweinsteiger, Müller, klose entra al área 0 y al arco.

 

El término “entra al área 0” inplica utilizar OSPF, como este busca la ruta mas corta (o la más rápida) no es posible el “toqueteo” de Alemania,

por lo tanto habrá que jugar con los anchos de banda o los costos OSPF.

 

                Solución

 

Una vez configurados todos los routers, primero hay que verificar que el tracert “llegue al arco” por la vía mas corta (SPF).

 

PC>tracert 192.168.2.1

 

Tracing route to 192.168.2.1 over a maximum of 30 hops:

 

1 0 ms 0 ms 0 ms 192.168.1.254 (Lahm)

2 0 ms 0 ms 0 ms 10.0.0.2 (Boateng)

3 0 ms 1 ms 0 ms 10.0.0.10 (Khedira)

4 0 ms 0 ms 0 ms 10.0.0.18 (Schweinsteiger)

5 0 ms 0 ms 0 ms 10.0.0.62 (Klose)

6 0 ms 0 ms 0 ms 192.168.2.1 (Julio César)

 

Trace complete.

 

PC>

 

Una vez completados los bandwidth o ip ospf cost verificamos:

 

PC>tracert 192.168.2.1

 

Tracing route to 192.168.2.1 over a maximum of 30 hops:

 

1 1 ms 0 ms 0 ms 192.168.1.254 (Lahm)

2 0 ms 0 ms 0 ms 10.0.0.26 (Kedira)

3 0 ms 0 ms 0 ms 10.0.0.38 (Kross)

4 0 ms 0 ms 0 ms 10.0.0.42 (Schweinsteiger)

5 0 ms 0 ms 0 ms 10.0.0.50 (Müller)

6 0 ms 0 ms 0 ms 10.0.0.54 (Klose)

7 0 ms 0 ms 0 ms 192.168.2.1 (Julio César)

 

Trace complete.

 

PC>

 

Cabe detallar lo siguiente: al seleccionar el camino del tracert (o de la pelota), debemos jugar con el

bandwidth o el costo OSPF, pero, en Packet Tracert es una cosa o la otra y BW le gana al costo OSPF:

 

Lahm#sh runn

Building configuration...

 

Current configuration : 827 bytes

!

version 12.2

---resumido---

!

hostname Lahm

!

!

interface FastEthernet0/0

 ip address 192.168.1.254 255.255.255.0

 duplex auto

 speed auto

!

interface GigabitEthernet1/0

 bandwidth 8000 (costo OSPF: 12)

 ip address 10.0.0.5 255.255.255.252

!

interface GigabitEthernet2/0

 bandwidth 8000 (costo OSPF: 12)

 ip address 10.0.0.1 255.255.255.252

!

interface GigabitEthernet3/0 (bandwidth por defecto, o sea 1 Gbps, o sea costo OSPF: 1)

 ip address 10.0.0.25 255.255.255.252

!

---resumido---

!

end

 

Lahm#sh ip ospf int Gi3/0 (verificamos)

GigabitEthernet3/0 is up, line protocol is up

  Internet address is 10.0.0.25/30, Area 0

  Process ID 1, Router ID 192.168.1.254, Network Type BROADCAST, Cost: 1

  Transmit Delay is 1 sec, State DR, Priority 1

  Designated Router (ID) 192.168.1.254, Interface address 10.0.0.25

  Backup Designated Router (ID) 10.0.0.58, Interface address 10.0.0.26

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

    Hello due in 00:00:03

  Index 4/4, flood queue length 0

  Next 0x0(0)/0x0(0)

  Last flood scan length is 1, maximum is 1

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 1, Adjacent neighbor count is 1

    Adjacent with neighbor 10.0.0.58  (Backup Designated Router)

  Suppress hello for 0 neighbor(s)

Lahm#

 

Si configuramos el ancho de banda real:

 

Lahm(config)#interface GigabitEthernet3/0

Lahm(config-if)#band 2000

 

Lahm#sh int Gi3/0 (verificamos)

GigabitEthernet3/0 is up, line protocol is up (connected)

  Hardware is Lance, address is 00d0.d3e7.0cab (bia 00d0.d3e7.0cab)

  Internet address is 10.0.0.25/30

  MTU 1500 bytes, BW 2000 Kbit, DLY 10 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  ---resumido---

Lahm#sh ip ospf int Gi3/0 (verificamos que cambia el costo)

GigabitEthernet3/0 is up, line protocol is up

  Internet address is 10.0.0.25/30, Area 0

  Process ID 1, Router ID 192.168.1.254, Network Type BROADCAST, Cost: 50

  Transmit Delay is 1 sec, State DR, Priority 1

  ---resumido---

Lahm#

 

Modificamos el costo:

 

Lahm(config-if)#ip ospf cost 1 (para que le gane al costo  12 de las otras interfaces)

Lahm(config-if)#

 

Lahm#sh ip ospf int Gi3/0 (verificamos)

GigabitEthernet3/0 is up, line protocol is up

  Internet address is 10.0.0.25/30, Area 0

  Process ID 1, Router ID 192.168.1.254, Network Type BROADCAST, Cost: 50 (no cambia)

  Transmit Delay is 1 sec, State DR, Priority 1

  ---resumido---

Lahm#

 

Prueba en un equipo real:

 

C1841#sh ip ospf int fa0/0 (verificamos costo 1)

FastEthernet0/0 is up, line protocol is up

  Internet Address 192.168.0.1/24, Area 0

  Process ID 1, Router ID 192.168.72.253, Network Type BROADCAST, Cost: 1

  Transmit Delay is 1 sec, State WAITING, Priority 1

  ---resumido---

C1841#conf t (modificamos BW, del costo cambiaría a 10^8/2.000.000=50)

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

C1841(config)#int fa0/0

C1841(config-if)#band 2000

C1841(config-if)#^Z

C1841#sh ip ospf int fa0/0 (verificamos costo)

FastEthernet0/0 is up, line protocol is up

  Internet Address 192.168.0.1/24, Area 0

  Process ID 1, Router ID 192.168.72.253, Network Type BROADCAST, Cost: 50 (OK)

  Transmit Delay is 1 sec, State DR, Priority 1

  ---resumido---

C1841#conf t

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

C1841(config)#int fa0/0 (modificamos costo sin alterar el BW)

C1841(config-if)#ip ospf cost 1

C1841(config-if)#^Z

C1841#sh ip ospf int fa0/0

FastEthernet0/0 is up, line protocol is up

  Internet Address 192.168.0.1/24, Area 0

  Process ID 1, Router ID 192.168.72.253, Network Type BROADCAST, Cost: 1

  Transmit Delay is 1 sec, State DR, Priority 1

  ---resumido---

C1841#sh int fa0/0 (verificamos BW alterado por el costo)

FastEthernet0/0 is up, line protocol is up

  Hardware is Gt96k FE, address is 001f.9ec9.0b16 (bia 001f.9ec9.0b16)

  Internet address is 192.168.0.1/24

  MTU 1500 bytes, BW 2000 Kbit/sec, DLY 100 usec, (no cambia, sólo sucede en Packet Tracer)

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Full-duplex, 100Mb/s, 100BaseTX/FX

  ---resumido---

C1841#

 

C1841#sh runn

Building configuration...

 

Current configuration : 827 bytes

!

version 12.4

---resumido---

!

hostname C1841

!

interface FastEthernet0/0

 ip address 192.168.1.254 255.255.255.0

 duplex auto

 speed auto

!

interface GigabitEthernet1/0

 bandwidth 8000 (costo OSPF: 12)

 ip address 10.0.0.5 255.255.255.252

!

interface GigabitEthernet2/0

 bandwidth 8000 (costo OSPF: 12)

 ip address 10.0.0.1 255.255.255.252

!

interface GigabitEthernet3/0

bandwidth 2000

 ip address 10.0.0.25 255.255.255.252

ip ospf cost 1

!

---resumido---

!

end

 

De la currícula Exploration 2:

 

 

 

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Rosario, Argentina