El enigma de la ruta por defecto filtrada en OSPF

Fecha: 6 de noviembre del 2018

 

Escenario

 

Implementando un mecanismo para eliminar rutas innecesarias de una tabla con rutas OSPF, ya que por una limitación

licencias de los routers no podía excederme de las 200 rutas, me encontré que también se eliminaba la ruta por defecto

lo cual puede ocasionar que los usuarios no tengan Facebook ni esas cosas que necesitan para ser felices.

 

Como fiel adepto al método científico, realizo nuevamente la prueba con el mismo resultado, y como obsesivo de los mecanismos

que no entiendo, lo reproduje en un laboratorio para no molestar a los usuarios, y esta vez se comportó como dicen los libros.

 

Entonces, cual es la causa de esto ? espero algún día poder volver a dormir…espero feedback en ernesto@vilarrasa.com.ar

 

Para simplificar el escenario real, las rutas son 10.x.x.x y eliminaremos de la tabla las 10.120.x.x/16 y luego las 10.0.x.x/16, quedando

sólo la red 10.0.16.0/30 como directamente conectada.

 

 

1.- Caso real:

 

1.1.- Verificación inicial:

 

Cisco-2960X#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

 

Gateway of last resort is 10.0.16.2 to network 0.0.0.0

 

O*E2  0.0.0.0/0 [110/1] via 10.0.16.2, 00:00:02, Vlan6

      10.0.0.0/8 is variably subnetted, 67 subnets, 8 masks

O        10.0.10.0/29 [110/14] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.12/30 [110/4] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.48/30 [110/104] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.36/30 [110/15] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.24/30 [110/26] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.12.28/30 [110/116] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.12.32/30 [110/16] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.13.4/30 [110/3] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.14.16/30 [110/126] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.14.28/30 [110/105] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.15.4/30 [110/2] via 10.0.16.2, 00:00:02, Vlan6

C        10.0.16.0/30 is directly connected, Vlan6

L        10.0.16.1/32 is directly connected, Vlan6

O IA     10.120.0.0/24 [110/4] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.1.0/28 [110/14] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.1.16/28 [110/14] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.1.32/28 [110/14] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.8.0/24 [110/126] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.16.0/22 [110/4] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.120.32.0/22 [110/4] via 10.0.16.2, 00:00:02, Vlan6

O E2     10.160.0.2/32 [110/1] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.0.251/32 [110/3] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.0/28 [110/115] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.16/28 [110/115] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.32/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.48/28 [110/14] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.64/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O         10.160.1.80/28 [110/110] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.60.1.96/28 [110/116] via 10.0.16.2, 00:00:12, Vlan6

--- resumido pero son mas de 200 rutas ---

Cisco-2960X#

 

1.2.- Filtro aplicado:

 

Se aplicó un filtro basado en route-map que no limita lo que se aprende por OSPF sino que evita

Instalar determinadas  redes en la tabla de enrutamiento.

 

router ospf 1

 ---omitido---

 distribute-list route-map FILTRO-OSPF in (aplica sólo en actualizaciones entrantes)

!

ip access-list standard FILTRO-OSPF

 permit 10.120.0.0 0.0.255.255  (esto quita de la tabla todas las 120.x.x)

!

route-map FILTRO-OSPF deny 10

 match ip address FILTRO-OSPF (quitará de la tabla lo que aplique aquí)

!

ip access-list standard PERMITE-OSPF

 permit any (esto permite instalar la ruta por defecto)

!

route-map FILTRO-OSPF permit 20

 match ip address PERMITE-OSPF (incluirá en la tabla lo que aplique aquí)

!

 

1.3.- Luego se agrega un rango mas a eliminar:

 

Cisco-2960X(config-std-nacl)# permit 10.0.0.0 0.0.255.255

Cisco-2960X(config-std-nacl)#

 

Nov  6 14:05:53: %PARSER-5-CFGLOG_LOGGEDCMD: User:admin  logged command:permit 10.0.0.0 0.0.255.255

Nov  6 17:05:53.812: RT: delete route to 0.0.0.0/0

Nov  6 17:05:53.812: RT: default path has been cleared

Nov  6 17:05:53.812: RT: delete route to 10.0.10.0/29

Nov  6 17:05:53.812: RT: delete route to 10.0.10.12/30

Nov  6 17:05:53.812: RT: delete route to 10.0.10.48/30

Nov  6 17:05:53.812: RT: delete route to 10.0.10.36/30

Nov  6 17:05:53.812: RT: delete route to 10.0.10.24/30

Nov  6 17:05:53.812: RT: delete route to 10.0.10.24/30

Nov  6 17:05:53.812: RT: delete route to 10.0.12.28/30

Nov  6 17:05:53.812: RT: delete route to 10.0.12.32/30

Nov  6 17:05:53.812: RT: delete route to 10.0.13.4/30

Nov  6 17:05:53.812: RT: delete route to 10.0.14.16/30

Nov  6 17:05:53.812: RT: delete route to 10.0.14.28/30

Nov  6 17:05:53.812: RT: delete route to 10.0.15.4/30

--- resumido ---

Nov  6 17:05

 

1.4.- Verificación:

 

Cisco-2960X#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

 

Gateway of last resort is not set  (no está la ruta por defecto)

 

            10.0.0.0/8 is variably subnetted, 55 subnets, 8 masks (no están las rutas 10.0.x.x filtradas)

C        10.0.16.0/30 is directly connected, Vlan6

L        10.0.16.1/32 is directly connected, Vlan6

O E2     10.160.0.2/32 [110/1] via 10.0.16.2, 00:00:08, Vlan6  (no están las rutas 10.120.x.x filtradas)

O IA     10.160.0.251/32 [110/3] via 10.0.16.2, 00:00:08, Vlan6

O IA     10.160.1.0/28 [110/115] via 10.0.16.2, 00:00:08, Vlan6

O IA     10.160.1.16/28 [110/115] via 10.0.16.2, 00:00:08, Vlan6

O IA     10.160.1.32/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.48/28 [110/14] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.64/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O         10.160.1.80/28 [110/110] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.60.1.96/28 [110/116] via 10.0.16.2, 00:00:12, Vlan6

--- resumido ---

Cisco-2960X#

 

1.5.- Se realiza un rollback:

 

Cisco-2960X#conf t

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

Cisco-2960X(config)#ip access-list standard FILTRO-OSPF

Cisco-2960X(config-std-nacl)#no permit 10.0.0.0 0.0.255.255

Cisco-2960X(config-std-nacl)#^Z

Cisco-2960X#

 

Nov  6 14:07:48: %PARSER-5-CFGLOG_LOGGEDCMD: User:admin  logged command:no permit 10.0.0.0 0.0.255.255

Nov  6 17:01:56.728: RT: updating ospf 0.0.0.0/0 (0x0)  :

    via 10.0.16.2 Vl6  0 1048578

--- omitido agrega las rutas 10.0.x.x/30 ---

Nov  6 17:01:56.728: RT: add 0.0.0.0/0 via 10.0.16.2, ospf metric [110/1]

Nov  6 17:01:56.728: RT: default path is now 0.0.0.0 via 10.0.16.2

 

1.6.- Nueva verificación:

 

Cisco-2960X#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

 

Gateway of last resort is 10.0.16.2 to network 0.0.0.0

 

O*E2  0.0.0.0/0 [110/1] via 10.0.16.2, 00:00:02, Vlan6

      10.0.0.0/8 is variably subnetted, 67 subnets, 8 masks

O        10.0.10.0/29 [110/14] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.12/30 [110/4] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.48/30 [110/104] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.36/30 [110/15] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.10.24/30 [110/26] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.12.28/30 [110/116] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.12.32/30 [110/16] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.13.4/30 [110/3] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.14.16/30 [110/126] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.14.28/30 [110/105] via 10.0.16.2, 00:00:02, Vlan6

O        10.0.15.4/30 [110/2] via 10.0.16.2, 00:00:02, Vlan6

C        10.0.16.0/30 is directly connected, Vlan6

L        10.0.16.1/32 is directly connected, Vlan6

O E2     10.160.0.2/32 [110/1] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.0.251/32 [110/3] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.0/28 [110/115] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.16/28 [110/115] via 10.0.16.2, 00:00:02, Vlan6

O IA     10.160.1.32/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.48/28 [110/14] via 10.0.16.2, 00:00:12, Vlan6

O IA     10.160.1.64/28 [110/115] via 10.0.16.2, 00:00:12, Vlan6

O        10.610.1.80/28 [110/110] via 10.60.0.9, 00:00:12, Vlan1600

O IA     10.160.1.96/28 [110/116] via 10.0.16.2, 00:00:12, Vlan6

--- resumido ---

Cisco-2960X#

 

1.7.- Verificación de la versión de IOS:

 

Cisco-2960X #sh ver

Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E6, RELEASE SOFTWARE (fc1)

--- omitido ---

System image file is "flash:/c2960x-universalk9-mz.152-2.E6/c2960x-universalk9-mz.152-2.E6.bin"

Last reload reason: power-on

 

--- omitido ---

 

Switch Ports Model                            SW Version   SW Image          

------     -----   ---------------------------    ----------------   ----------        

*    1     28    WS-C2960XR-24TS-I    15.2(2)E6      C2960X-UNIVERSALK9-M

 

Configuration register is 0xF

 

Cisco-2960X#

 

Cisco-2960X #sh license

Index 1 Feature: iplite

              Period left: Life time

              License Type: Permanent

              License State: Active, In Use

              License Priority: Medium

              License Count: Non-Counted

 

Cisco-2960X #

 

2.- Pruebas de laboratorio:

 

2.1.- Verificación inicial:

 

Cisco-1841#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, + - replicated route

 

Gateway of last resort is 10.0.0.1 to network 0.0.0.0

 

O*E2  0.0.0.0/0 [110/1] via 10.0.0.1, 00:00:12, GigabitEthernet0/1

      10.0.0.0/8 is variably subnetted, 4 subnets, 3 masks

C        10.0.0.0/30 is directly connected, GigabitEthernet0/1

L        10.0.0.2/32 is directly connected, GigabitEthernet0/1

O        10.0.10.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.30.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.50.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.60.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.70.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.80.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

O        10.0.90.0/30 [110/2] via 10.0.0.1, 00:00:09, GigabitEthernet0/1

C        10.0.100.0/24 is directly connected, GigabitEthernet0/0

L        10.0.100.1/32 is directly connected, GigabitEthernet0/0

Cisco-1841

 

2.2.- Implementación del filtro:

 

Cisco-1841#conf t

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

Cisco-1841(config)#ip access-list standard FILTRO-OSPF

Cisco-1841(config-std-nacl)# permit 10.0.0.0 0.0.255.255

Cisco-1841(config-std-nacl)#exit

Cisco-1841(config)#ip access-list standard PERMITE-OSPF

Cisco-1841(config-std-nacl)# permit any

Cisco-1841(configstd-nacl)#exit

Cisco-1841(config)#route-map FILTRO-OSPF deny 10

Cisco-1841(config-route-map)# match ip address FILTRO-OSPF

Cisco-1841(config-route-map)# exit

Cisco-1841(config)#route-map FILTRO-OSPF permit 20

Cisco-1841(config-route-map)# match ip address PERMITE-OSPF

Cisco-1841(config-route-map)# exit

Cisco-1841(config)#router ospf 1

Cisco-1841(config-router)#distribute-list route-map FILTRO-OSPF in

Cisco-1841(config-router)#end

Cisco-1841#

 

2.3.- Verificación:

 

Cisco-1841#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, + - replicated route

 

Gateway of last resort is 10.0.0.1 to network 0.0.0.0

 

O*E2  0.0.0.0/0 [110/1] via 10.0.0.1, 00:00:06, GigabitEthernet0/1

      10.0.0.0/8 is variably subnetted, 4 subnets, 3 masks

C        10.0.0.0/30 is directly connected, GigabitEthernet0/1

L        10.0.0.2/32 is directly connected, GigabitEthernet0/1

C        10.0.100.0/24 is directly connected, GigabitEthernet0/0

L        10.0.100.1/32 is directly connected, GigabitEthernet0/0

Cisco-1841#

 

2.4.- Se modifica el filtro para permitir una red en particular:

 

Con esto alteramos la tabla en busca de “provocar” un cambio que filtre la ruta por defecto.

 

Cisco-1841#conf t

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

Cisco-1841(config)#ip access-list standard FILTRO-OSPF

Cisco-1841(config-std-nacl)# 5 deny 10.0.10.0 0.0.0.3

Cisco-1841(config-std-nacl)# end

Cisco-1841#

 

Nov  5 19:22:02.771: RT: delete route to 0.0.0.0/0

Nov  5 19:22:02.771: RT: default path has been cleared

Nov  5 19:22:02.775: RT: updating ospf 10.0.90.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.80.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.70.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.60.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.50.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.40.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.30.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.20.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: rib update return code: 3

Nov  5 19:22:02.775: RT: updating ospf 10.0.10.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: add 10.0.10.0/30 via 10.0.0.1, ospf metric [110/2]

Nov  5 19:22:02.775: RT: updating ospf 0.0.0.0/0 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:02.775: RT: add 0.0.0.0/0 via 10.0.0.1, ospf metric [110/1]

Nov  5 19:22:02.775: RT: default path is now 0.0.0.0 via 10.0.0.1

 

2.5.- Verificación:

 

Cisco-1841#sh ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, + - replicated route

 

Gateway of last resort is 10.0.0.1 to network 0.0.0.0

 

O*E2  0.0.0.0/0 [110/1] via 10.0.0.1, 00:00:11, GigabitEthernet0/1

      10.0.0.0/8 is variably subnetted, 5 subnets, 3 masks

C        10.0.0.0/30 is directly connected, GigabitEthernet0/1

L        10.0.0.2/32 is directly connected, GigabitEthernet0/1

O        10.0.10.0/30 [110/2] via 10.0.0.1, 00:00:11, GigabitEthernet0/1

C        10.0.100.0/24 is directly connected, GigabitEthernet0/0

L        10.0.100.1/32 is directly connected, GigabitEthernet0/0

Cisco-1841#

 

2.6.- Hacemos la contraprueba:

 

Quitamos la entrada anterior para tratar de que no se actualice la ruta por defecto, sin resultados…

 

Cisco-1841#conf t

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

Cisco-1841(config)#ip access-list standard FILTRO-OSPF

Cisco-1841(config-std-nacl)#no 5

Cisco-1841(config-std-nacl)#end

Cisco-1841#

 

Nov  5 19:22:28.567: RT: delete route to 0.0.0.0/0

Nov  5 19:22:28.567: RT: default path has been cleared

Nov  5 19:22:28.567: RT: delete route to 10.0.10.0/30

Nov  5 19:22:28.567: RT: updating ospf 10.0.90.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.567: RT: rib update return code: 3

Nov  5 19:22:28.567: RT: updating ospf 10.0.80.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.567: RT: rib update return code: 3

Nov  5 19:22:28.567: RT: updating ospf 10.0.70.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.567: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.60.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.50.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.40.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.30.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.20.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 10.0.10.0/30 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: rib update return code: 3

Nov  5 19:22:28.571: RT: updating ospf 0.0.0.0/0 (0x0) via 10.0.0.1 Gi0/1

Nov  5 19:22:28.571: RT: add 0.0.0.0/0 via 10.0.0.1, ospf metric [110/1]

Nov  5 19:22:28.571: RT: default path is now 0.0.0.0 via 10.0.0.1

Cisco-1841#

 

Detalle: La taza es un regalo de Adrián Trombetta J

 

 

(2018) OSPF and me

Rosario, Argentina