RIPv1 extremo !
Clase: 22 de Mayo 2010 (actualizado Septiembre 2012)
Instructor: Ernesto Vilarrasa
Objetivo: llevar a los límites el protocolo RIP v1 mediante la cantidad
máxima de saltos permitidos y observar las falencias de un protocolo de
enrutamiento classfull, mediante VLSM y redes discontiguas.
Escenario: tenemos un panorama de 17 routers en línea que prácticamente rodean el
planeta, mediante líneas point-to-point, superando el límite máximo de RIP de extremo
a extremo. Debemos resolver dicho problema mediante las herramientas disponibles en
el módulo 5 de Exploration 2.
Escenario disponible en ftp.vilarrasa.com.ar user:ccna pass:ccna archivo: rip_extremo.pka
Rosario#sh ip route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 31 subnets
C
172.16.1.0 is directly connected, FastEthernet0/0
C
172.16.2.0 is directly connected, Serial0/0
R 172.16.3.0 [120/1] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.4.0 [120/1] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.5.0 [120/2] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.6.0 [120/2] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.7.0 [120/3] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.8.0 [120/3] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.9.0 [120/4] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.10.0 [120/4] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.11.0 [120/5] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.12.0 [120/5] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.13.0 [120/6] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.14.0 [120/6] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.15.0 [120/7] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.16.0 [120/7] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.17.0 [120/8] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.18.0 [120/8] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.19.0 [120/9] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.20.0 [120/9] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.21.0 [120/10] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.22.0 [120/10] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.23.0 [120/11] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.24.0 [120/11] via 172.16.2.2, 00:00:06, Serial0/0
R 172.16.25.0 [120/12] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.26.0 [120/12] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.27.0 [120/13] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.28.0 [120/13] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.30.0 [120/14] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.31.0 [120/15] via 172.16.2.2,
00:00:06, Serial0/0
R 172.16.32.0 [120/15]
via 172.16.2.2, 00:00:06, Serial0/0
Rosario# (no vemos la red 172.16.33.0)
Rosario#debug ip rip
RIP protocol debugging is on
Rosario#RIP: received v1 update from 172.16.2.2 on
Serial0/0
172.16.3.0 in 1 hops
172.16.4.0 in 1 hops
172.16.5.0 in 2 hops
172.16.6.0 in 2 hops
---resumido---
172.16.30.0 in 14 hops
172.16.31.0 in 15 hops
172.16.32.0 in 15 hops
172.16.33.0
in 16 hops (aquí aparece Wellington)
C:\>tracert
172.16.33.10 (desde PC de Rosario)
Tracing route to 172.16.33.10 over a maximum of 30
hops:
1 31 ms
32 ms 16 ms 172.16.1.1
2 31 ms
* 31 ms 172.16.1.1
3 *
31 ms * Request timed out.
4 31 ms
* 31 ms 172.16.1.1
5
Control-C
^C
C:\> ping 172.16.33.10
Pinging 172.16.33.10 with 32 bytes of data:
Reply from 172.16.1.1: Destination host
unreachable.
Reply from 172.16.1.1: Destination host
unreachable.
Reply from 172.16.1.1: Destination host
unreachable.
Reply from 172.16.1.1: Destination host
unreachable.
Ping statistics for 172.16.33.10:
Packets:
Sent = 4, Received = 0, Lost = 4 (100% loss),
PC>
Solución: Aplicamos en Kinakuta una ruta Quad Zero hacia Internet, luego
la publicamos en RIP:
Kinakuta(config)#ip route 0.0.0.0 0.0.0.0
200.45.0.1
Kinakuta(config)#router rip
Kinakuta(config-router)#redistribute static
Kinakuta(config-router)#end
Kinakuta#
Esto nos dará conectividad hacia Internet en todos los routers, pero
además, nos da un beneficio extra: a travez de la ruta por defecto
alcanzamos las redes que no aparecen en la tabla de enrutamiento ya
que Rosario, al no encontrar la rute mediante RIP, la enviará a esta ruta
que lo llevará a Asunción, y en este router si vemos la red Wellington,
tomemoslo como un "empujón extra".
Asuncion>sh ip route
---resumido---
Gateway of last resort is 172.16.4.2 to network
0.0.0.0
172.16.0.0/24 is subnetted, 32 subnets
R
172.16.1.0 [120/1] via 172.16.2.1, 00:00:12, Serial0/1
---resumido---
R 172.16.32.0 [120/14] via 172.16.4.2,
00:00:23, Serial0/0
R 172.16.33.0 [120/15]
via 172.16.4.2, 00:00:23, Serial0/0
R* 0.0.0.0/0 [120/12] via 172.16.4.2,
00:00:23, Serial0/0
Asuncion>
Verificamos en Rosario:
Rosario#debug ip rip
RIP protocol debugging is on
RIP: received v1 update from 172.16.2.2 on Serial0/0
0.0.0.0
in 14 hops
172.16.3.0 in 1 hops
172.16.4.0 in 1 hops
---resumido---
172.16.28.0 in 13 hops
172.16.30.0 in 14 hops
172.16.31.0 in 15 hops
172.16.32.0 in 15 hops
172.16.33.0
in 16 hops
Rosario#sh ip route (vemos la ruta de último recurso)
Codes: C - connected, S - static, I - IGRP, R - RIP,
M - mobile, B - BGP
---resumido---
Gateway of last resort is 172.16.2.2 to network 0.0.0.0
172.16.0.0/24 is subnetted, 31 subnets
C
172.16.1.0 is directly connected, FastEthernet0/0
C
172.16.2.0 is directly connected, Serial0/0
R 172.16.3.0 [120/1] via 172.16.2.2,
00:00:26, Serial0/0
R 172.16.4.0 [120/1] via 172.16.2.2,
00:00:26, Serial0/0
---resumido---
R 172.16.31.0 [120/15] via 172.16.2.2,
00:00:26, Serial0/0
R 172.16.32.0 [120/15] via 172.16.2.2,
00:00:26, Serial0/0
R* 0.0.0.0/0 [120/14] via 172.16.2.2,
00:00:26, Serial0/0
Rosario#
Verificamos en Rosario desde
un PC:
C:\>tracert 172.16.33.10
Tracing route to 172.16.33.10 over a maximum of 30
hops:
1 51 ms
32 ms 19 ms 172.16.1.1
2 62 ms
47 ms 63 ms 172.16.2.2
3 78 ms
94 ms 78 ms 172.16.4.2
4 78 ms
109 ms 112 ms 172.16.6.2
5 110 ms
140 ms 110 ms 172.16.8.2
6 156 ms
172 ms 157 ms 172.16.10.2
7 203 ms
203 ms 188 ms 172.16.12.2
8 203 ms
158 ms 188 ms 172.16.14.2
9 190 ms
234 ms 234 ms 172.16.16.2
10 203 ms
265 ms 268 ms 172.16.18.2
11 265 ms
265 ms 312 ms 172.16.20.2
12 297 ms
297 ms 266 ms 172.16.22.2
13 281 ms
297 ms 313 ms 172.16.24.2
14 344 ms
359 ms 308 ms 172.16.26.2
15 406 ms
390 ms 375 ms 172.16.28.2
16 375 ms
391 ms 438 ms 172.16.30.2
17 442 ms
438 ms 453 ms 172.16.32.2
18 *
421 ms 469 ms 172.16.33.10
Trace complete.
Problemas de RIPv1 con el classfull y máscaras de subred distintas:
En uno de los enlaces aplicaremos una máscara distinta /30 al resto, verificaremos
la pérdida de redes en la tabla de enrutamiento ya que RIPv1 no soporta VLSM e
interpreta que TODAS las redes deben ser ó /24 ó /30:
Paris(config)#int s0/0
Paris(config-if)#ip add 172.16.16.1 255.255.255.252
Paris(config-if)#^Z
Bruselas(config)#int s0/1
Bruselas(config-if)#ip address 172.16.16.2
255.255.255.252
Bruselas(config-if)#^Z
Paris#sh ip route
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 32 subnets, 2 masks
R 172.16.1.0/24 [120/7] via 172.16.14.1,
00:00:10, Serial0/1
R 172.16.2.0/24 [120/6] via 172.16.14.1,
00:00:10, Serial0/1
---resumido----
R 172.16.13.0/24 [120/1] via 172.16.14.1,
00:00:10, Serial0/1
C
172.16.14.0/24 is directly connected, Serial0/1
C
172.16.15.0/24 is directly connected, FastEthernet0/0
C
172.16.16.0/30 is directly connected, Serial0/0
R
172.16.17.0/30 is possibly down, routing via 172.16.16.2,
Serial0/0
R
172.16.18.0/30 is possibly down, routing via 172.16.16.2,
Serial0/0
---resumido---
luego del temporizador de flush, las sacará de
la tabla
R
172.16.33.0/30 is possibly down, routing via 172.16.16.2,
Serial0/0
Paris#
Bruselas#sh ip route
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 17 subnets, 2 masks
C
172.16.16.0/30 is directly connected, Serial0/1
C
172.16.17.0/24 is directly connected, FastEthernet0/0
C
172.16.18.0/24 is directly connected, Serial0/0
R 172.16.19.0/24 [120/1] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.20.0/24 [120/1] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.21.0/24 [120/2] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.22.0/24 [120/2] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.23.0/24 [120/3] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.24.0/24 [120/3] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.25.0/24 [120/4] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.26.0/24 [120/4] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.27.0/24 [120/5] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.28.0/24 [120/5] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.30.0/24 [120/6] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.31.0/24 [120/7] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.32.0/24 [120/7] via 172.16.18.2,
00:00:07, Serial0/0
R 172.16.33.0/24 [120/8] via 172.16.18.2,
00:00:07, Serial0/0
Bruselas#
Problemas
de RIPv1 con las redes discontiguas:
En uno de los enlaces implementaremos otra dirección de red distinta al resto: 192.168.0.0 /24,
verificaremos las rutas de resumen 172.16.0.0/16 en la depuración, ya que RIPv1 resume por default
con la clase, por lo tanto tendermos redes iguales desde ambas direcciones (172.16.0.0), mostrando
sólo las de mayor concidencia ( máscara más larga ).
Paris#conf t
Paris(config)#int s0/0
Paris(config-if)#ip add 192.168.0.1 255.255.255.252
Paris(config-if)#exit
Paris(config)#router rip
Paris(config-router)#net 192.168.0.0
Paris(config-router)#^Z
Paris#
Bruselas#conf t
Bruselas(config)#int s0/1
Bruselas(config-if)#ip address 192.168.0.2
255.255.255.252
Bruselas(config-if)#exit
Bruselas(config)#router rip
Bruselas(config-router)#net 192.168.0.0
Bruselas(config-router)#^Z
Rosario>sh
ip route (veremos las redes sólo hasta Paris)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 15 subnets
C
172.16.1.0 is directly connected, FastEthernet0/0
C
172.16.2.0 is directly connected, Serial0/0
R 172.16.3.0 [120/1] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.4.0 [120/1] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.5.0 [120/2] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.6.0 [120/2] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.7.0 [120/3] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.8.0 [120/3] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.9.0 [120/4] via 172.16.2.2, 00:00:07,
Serial0/0
R 172.16.10.0 [120/4] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.11.0 [120/5] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.12.0 [120/5] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.13.0 [120/6] via 172.16.2.2, 00:00:07,
Serial0/0
R 172.16.14.0 [120/6] via 172.16.2.2,
00:00:07, Serial0/0
R 172.16.15.0 [120/7] via 172.16.2.2,
00:00:07, Serial0/0
R 192.168.0.0/24 [120/7] via 172.16.2.2,
00:00:07, Serial0/0
Rosario>
Wellington#sh
ip route (veremos las redes sólo hasta Bruselas)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 16 subnets
R
172.16.17.0 [120/8] via 172.16.32.1, 00:00:19, Serial0/1
R 172.16.18.0 [120/7] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.19.0 [120/7] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.20.0 [120/6] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.21.0 [120/6] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.22.0 [120/5] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.23.0 [120/5] via 172.16.32.1, 00:00:19, Serial0/1
R 172.16.24.0 [120/4] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.25.0 [120/4] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.26.0 [120/3] via 172.16.32.1, 00:00:19, Serial0/1
R 172.16.27.0 [120/3] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.28.0 [120/2] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.30.0 [120/1] via 172.16.32.1,
00:00:19, Serial0/1
R 172.16.31.0 [120/1] via 172.16.32.1,
00:00:19, Serial0/1
C
172.16.32.0 is directly connected, Serial0/1
C
172.16.33.0 is directly connected, FastEthernet0/0
R 192.168.0.0/24 [120/8] via 172.16.32.1,
00:00:19, Serial0/1
Wellington#
Paris#debug
ip rip corremos la depuración para observar como propaga
RIP
RIP protocol debugging is on
RIP: sending
v1 update to 255.255.255.255 via Serial0/0 (192.168.0.1)
RIP: build update entries
network
172.16.0.0 metric 1 envía a Bruselas un resumen
clase B
RIP: sending v1 update to 255.255.255.255 via Serial0/1 (172.16.14.2)
RIP: build update entries
network
172.16.15.0 metric 1 envía a Madrid su red local
conectada
network 192.168.0.0 metric 1 envía a Madrid la red clase C
RIP: received v1 update from 172.16.14.1 on
Serial0/1
172.16.1.0
in 7 hops recibe de Madrid las redes (hasta
Rosario)
172.16.2.0 in 6 hops
172.16.3.0 in 6 hops
172.16.4.0 in 5 hops
172.16.5.0 in 5 hops
172.16.6.0 in 4 hops
172.16.7.0 in 4 hops
172.16.8.0 in 3 hops
172.16.9.0
in 3 hops
172.16.10.0 in 2 hops
172.16.11.0 in 2 hops
172.16.12.0 in 1 hops
172.16.13.0 in 1 hops
RIP: received v1 update from 192.168.0.2 on
Serial0/0
172.16.0.0
in 1 hops recibe de Bruselas el resumen clase B
Paris#sh copyright
(2012) smoking chala with uncle Ernst
Rosario,
Argentina
Paris#exit
Connection lost !