Pruebas con OSPF virtual link
Fecha: 1 de septiembre
del 2023
Escenario
Este laboratorio es otro de los que quería
realizar hace años (digamos sin exagerar, unos 20)
y que entre una cosa fueron quedando, hasta que
retomé el sendero del OSPF para adultos.
Leyendo de que Packet Tracer lo soportaba decidí
hacerlo en el simulador, pero como era de
esperar siempre lo termino verificando en equipos
reales para poder realizar captura.
Esta vez el objetivo es “ver que hay en un
paquete de un virtual link OSPF”. Vamos a ello…
El libro CCNP Routing que compré en 2002 cuando
“quería saberlo todo” y que todavía me sigue enseñando.
1.- Verificación inicial:
1.1.- Verificamos vecinos
OSPF en Sitio-A:
Sitio-A#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address
Interface
10.2.0.1
1 FULL/DROTHER 00:00:34
10.2.0.2 Vlan20 (router Sitio-B)
10.3.0.1
1 FULL/DR 00:00:33 10.2.0.3 Vlan20 (router Sitio-C)
Sitio-A#
1.2.- Verificamos vecinos
OSPF en Sitio-B:
Sitio-B#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address
Interface
10.1.0.1
1 FULL/BDR 00:00:30 10.2.0.1 Vlan20 (router Sitio-A)
10.3.0.1
1 FULL/DR 00:00:37 10.2.0.3 Vlan20 (router Sitio-C)
Sitio-B#
1.3.- Verificamos vecinos
OSPF en Sitio-C:
Sitio-C#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address Interface
10.2.0.1
1 FULL/DROTHER 00:00:37
10.2.0.2 Vlan20 (router Sitio-B)
10.1.0.1
1 FULL/BDR 00:00:39 10.2.0.1 Vlan20 (router Sitio-A)
Sitio-C#
1.4.- Verificamos rutas en
Sitio-A:
Sitio-A#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 6 subnets
C
10.1.0.0 is directly connected, Vlan10
C
10.1.1.0 is directly connected, Vlan11
C
10.1.2.0 is directly connected, Vlan12
C 10.1.3.0
is directly connected, Vlan13
C
10.1.4.0 is directly connected, Vlan14
C
10.2.0.0 is directly connected, Vlan20 (area 2 OSPF)
Sitio-A#
1.5.- Verificamos rutas en
Sitio-B:
Sitio-B#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 1 subnets
C
10.2.0.0 is directly connected, Vlan20 (area 2 OSPF)(no vemos rutas del area 0 OSPF)
Sitio-B#
1.6.- Verificamos rutas en
Sitio-C:
Sitio-C#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 6 subnets
C
10.2.0.0 is directly connected, Vlan20 (area 2 OSPF)
C
10.3.0.0 is directly connected, Vlan30
C
10.3.1.0 is directly connected, Vlan31
C
10.3.2.0 is directly connected, Vlan32
C
10.3.3.0 is directly connected, Vlan33
C
10.3.4.0 is directly connected, Vlan34
Sitio-C#
1.7.- Se quita el vecino
Sitio-C para tener un solo acceso al area 0:
Sitio-B#sh cdp nei
Capability Codes: R - Router, T - Trans Bridge, B
- Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID
Local Intrfce Holdtme Capability
Platform Port ID
Sitio-A
Gig 1/0/24 152 3650 Gig 1/0/24
Sitio-C
Gig 1/0/23 169 3650 Gig 1/0/24
Sitio-B#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Sitio-B(config)#int Gig 1/0/23
Sitio-B(config-if)#shut
Sitio-B(config-if)#^C
%LINK-5-CHANGED: Interface GigabitEthernet1/0/23,
changed state to administratively down
%LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet1/0/23, changed state to down
00:47:41: %OSPF-5-ADJCHG: Process 1, Nbr 10.3.0.1
on Vlan20 from FULL to DOWN, Neighbor Down: Dead timer expired
00:47:41: %OSPF-5-ADJCHG: Process 1, Nbr 10.3.0.1
on Vlan20 from FULL to DOWN, Neighbor Down: Interface down or detached
Sitio-B#
1.8.- Verificamos si vemos
rutas del area 0 en Sitio-B:
Sitio-B#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 1 subnets
C 10.2.0.0
is directly connected, Vlan20 (no vemos rutas del area 0 OSPF)
Sitio-B#
1.9.- Reiniciamos el OSPF en
Sitio-B como último recurso:
Sitio-B#clear ip ospf process
Reset ALL OSPF processes? [no]: y
Sitio-B#
00:48:19: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.0.1
on Vlan20 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
00:48:19: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.0.1
on Vlan20 from FULL to DOWN, Neighbor Down: Interface down or detached
00:48:23: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.0.1
on Vlan20 from LOADING to FULL, Loading Done
Sitio-B#
1.10.- Verificamos si con un
solo vecino en area 0 vemos las rutas:
Sitio-B#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 1 subnets
C 10.2.0.0
is directly connected, Vlan20
Sitio-B#
1.11.- Reiniciamos todos los
equipos:
1.12.- Verificamos luego del
power cicle:
Sitio-B#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 11 subnets
O IA 10.1.0.0
[110/2] via 10.2.0.1, 00:00:01, Vlan20 (rutas del
area 0 OSPF)
O IA
10.1.1.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.2.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.3.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.4.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
C
10.2.0.0 is directly connected, Vlan20 (red loca en el area 2 OSPF)
O IA
10.3.0.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20 (rutas del area 0 OSPF)
O IA
10.3.1.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.2.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.3.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.4.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
Sitio-B#
2.- Implementamos
virtual-link:
Interconectamos ambas area 0 con un virtual link,
que basicamente en un punto a punto unicast entre
las IP que conectan ambos router-id declarados en
la configuración.
2.1.- Configuramos VL en
Sitio-A:
Sitio-A#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Sitio-A(config)#router ospf 1
Sitio-A(config-router)#area 2 virtual-link 10.3.0.1
Sitio-A(config-router)#end
Sitio-A#
2.2.- Configuramos VL en
Sitio-A:
Sitio-C#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Sitio-C(config)#router ospf 1
Sitio-C(config-router)#area 2 virtual-link 10.1.0.1
Sitio-C(config-router)#end
Sitio-C#
2.3.- Verificamos adyacencia
en Sitio-A:
Sitio-A#
00:13:58: %OSPF-5-ADJCHG: Process 1, Nbr 10.3.0.1
on OSPF_VL0 from LOADING to FULL, Loading Done
Sitio-A#sh ip ospf neighbor
Neighbor ID
Pri State Dead Time Address
Interface
10.3.0.1 0
FULL/ - 00:00:32 10.2.0.3 OSPF_VL0
10.2.0.2
1 FULL/DROTHER 00:00:31
10.2.0.2 Vlan20
10.3.0.1
1 FULL/DR 00:00:30 10.2.0.3 Vlan20
Sitio-A#
2.4.- Verificamos adyacencia
en Sitio-C:
Sitio-C#
00:13:58: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.0.1
on OSPF_VL0 from LOADING to FULL, Loading Done
Sitio-C#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address Interface
10.1.0.1 0
FULL/ - 00:00:33 10.2.0.1 OSPF_VL0
10.2.0.2
1 FULL/DROTHER 00:00:30
10.2.0.2 Vlan20
10.1.0.1
1 FULL/BDR 00:00:39 10.2.0.1 Vlan20
Sitio-C#
2.5.- Verificamos rutas en
Sitio-A:
Sitio-A#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 11 subnets
C
10.1.0.0 is directly connected, Vlan10
C
10.1.1.0 is directly connected, Vlan11
C
10.1.2.0 is directly connected, Vlan12
C
10.1.3.0 is directly connected, Vlan13
C
10.1.4.0 is directly connected, Vlan14
C
10.2.0.0 is directly connected, Vlan20 (red de area 2)
O
10.3.0.0 [110/2] via 10.2.0.3, 00:01:49, Vlan20 (rutas de area 0 via virtual-link)
O
10.3.1.0 [110/2] via 10.2.0.3, 00:01:49, Vlan20
O
10.3.2.0 [110/2] via 10.2.0.3, 00:01:49, Vlan20
O 10.3.3.0
[110/2] via 10.2.0.3, 00:01:49, Vlan20
O
10.3.4.0 [110/2] via 10.2.0.3, 00:01:49, Vlan20
Sitio-A#
2.6.- Verificamos rutas en
Sitio-B:
Sitio-B#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 11 subnets
O IA
10.1.0.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.1.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.2.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.3.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
O IA
10.1.4.0 [110/2] via 10.2.0.1, 00:00:01, Vlan20
C
10.2.0.0 is directly connected, Vlan20 (red de area 2)
O IA
10.3.0.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.1.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.2.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.3.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
O IA
10.3.4.0 [110/2] via 10.2.0.3, 00:00:11, Vlan20
Sitio-B#
2.7.- Verificamos rutas en
Sitio-C:
Sitio-C#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i -
IS-IS, 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
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 11 subnets
O
10.1.0.0 [110/2] via 10.2.0.1, 00:02:04, Vlan20 (rutas de area0 via virtual-link)
O
10.1.1.0 [110/2] via 10.2.0.1, 00:02:04, Vlan20
O
10.1.2.0 [110/2] via 10.2.0.1, 00:02:04, Vlan20
O
10.1.3.0 [110/2] via 10.2.0.1, 00:02:04, Vlan20
O
10.1.4.0 [110/2] via 10.2.0.1, 00:02:04, Vlan20
C
10.2.0.0 is directly connected, Vlan20 (red de area 2)
C
10.3.0.0 is directly connected, Vlan30
C
10.3.1.0 is directly connected, Vlan31
C
10.3.2.0 is directly connected, Vlan32
C
10.3.3.0 is directly connected, Vlan33
C
10.3.4.0 is directly connected, Vlan34
Sitio-C#
2.8.- Verificamos virtual
link en Sitio-A:
Sitio-A#sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 10.3.0.1 is up
Run as
demand circuit
Transit area 2, via interface Vlan20, Cost of using 1
Transmit
Delay is 1 sec, State POINT_TO_POINT,
Timer
intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello
due in 00:00:02
Adjacency State FULL
Index
1/2, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
Sitio-A#
2.9.- Verificamos virtual
link en Sitio-C:
Sitio-C#sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 10.1.0.1 is up
Run as
demand circuit
Transit area 2, via interface Vlan20, Cost of using 1
Transmit
Delay is 1 sec, State POINT_TO_POINT,
Timer
intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello
due in 00:00:01
Adjacency State FULL
Index
1/2, retransmission queue length 0, number of retransmission 0
First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last
retransmission scan length is 0, maximum is 0
Last retransmission scan time is 0 msec, maximum is 0 msec
Sitio-C#
3.- Pruebas con equipos
reales:
Aquí es donde intentaremos capturar el tráfico
del virtual link, para diferenciarlo del resto del tráfico OSPF le configuramos
autenticación MD5 (no es encriptación sino que va
firmado con un hash). Por simplicidad omitimos el router Sitio-B.
3.1.- Verificamos configuración OSPF en Sitio-A:
Sitio-A#sh runn | sec ospf
router ospf 1
router-id
10.1.0.1
area 2
virtual-link 10.3.0.1 authentication message-digest authentication-key MD5-VL
network
10.1.0.0 0.0.0.255 area 0
network
10.1.1.0 0.0.0.255 area 0
network
10.1.2.0 0.0.0.255 area 0
network
10.1.3.0 0.0.0.255 area 0
network
10.1.4.0 0.0.0.255 area 0
network
10.2.0.0 0.0.0.255 area 2
3.2.- Verificamos configuración OSPF en Sitio-B:
Sitio-C#sh runn | sec ospf
router ospf 1
router-id
10.3.0.1
log-adjacency-changes
area 2
virtual-link 10.1.0.1 authentication message-digest authentication-key MD5-VL
network
10.2.0.0 0.0.0.255 area 2
network
10.3.0.0 0.0.0.255 area 0
network
10.3.1.0 0.0.0.255 area 0
network
10.3.2.0 0.0.0.255 area 0
network
10.3.3.0 0.0.0.255 area 0
network
10.3.4.0 0.0.0.255 area 0
3.3.- Verificamos adyacencia
en Sitio-A:
Sitio-A#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address
Interface
10.3.0.1
0 FULL/ -
00:00:37 10.2.0.3 OSPF_VL0
10.3.0.1
1 FULL/DR 00:00:36 10.2.0.3 Vlan20
Sitio-A#
3.4.- Verificamos adyacencia
en Sitio-B:
Sitio-C#sh ip ospf nei
Neighbor ID
Pri State Dead Time Address
Interface
10.1.0.1
0 FULL/ -
00:00:38 10.2.0.1 OSPF_VL1
10.1.0.1
1 FULL/BDR 00:00:39 10.2.0.1 Vlan20
Sitio-C#
3.5.- Verificamos virtual
link en Sitio-A:
Sitio-A#sh ip ospf virtual-links
Virtual Link OSPF_VL1 to router 10.3.0.1 is up
Run as
demand circuit
DoNotAge
LSA allowed.
Transit area 2, via interface Vlan20
Topology-MTID Cost
Disabled Shutdown Topology Name
0 1 no no Base
Transmit
Delay is 1 sec, State POINT_TO_POINT,
Timer
intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello
due in 00:00:07
Adjacency State FULL (Hello suppressed)
Index
1/2, retransmission queue length 0, number of retransmission 0
First
0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last
retransmission scan length is 0, maximum is 0
Last
retransmission scan time is 0 msec, maximum is 0 msec
Sitio-A#
3.6.- Verificamos virtual
link en Sitio-B:
Sitio-C#sh ip ospf virtual-links
Virtual Link OSPF_VL1 to router 10.1.0.1 is up
Run as
demand circuit
DoNotAge
LSA allowed.
Transit area 2, via interface Vlan20
Topology-MTID Cost
Disabled Shutdown Topology Name
0 1 no no Base
Transmit
Delay is 1 sec, State POINT_TO_POINT,
Timer
intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello
due in 00:00:08
Adjacency State FULL (Hello suppressed)
Index 1/2,
retransmission queue length 0, number of retransmission 0
First
0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
Last
retransmission scan length is 0, maximum is 0
Last
retransmission scan time is 0 msec, maximum is 0 msec
Sitio-C#
3.7.- Verificamos tráfico
del virtual-link:
Inicialmente vemos los hello multicast iniciales
hasta realizar la convergencia, luego son unicast entre
las IP de ambos routers de borde (ABR).
Frame 3: 130 bytes on wire
(1040 bits), 130 bytes captured (1040 bits) on interface id 0
Ethernet II, Src: cc:46:d6:2b:5a:54, Dst:
70:81:05:b5:77:82
Internet Protocol Version 4, Src: 10.2.0.1, Dst: 10.2.0.3
Open Shortest Path First
OSPF
Header
Version: 2
Message Type: Hello Packet (1)
Packet Length: 44
Source OSPF Router: 10.1.0.1
Area ID: 0.0.0.0 (Backbone)
Checksum: 0x0000 (None)
Auth Type: Cryptographic (2)
Auth Crypt Key id: 0
Auth
Crypt Data Length: 16
Auth Crypt Sequence Number: 1693772095
Auth Crypt Data: 09a868e831fe34bb064c2ec08325a2a5
OSPF
Hello Packet
OSPF
LLS Data Block
Frame 4: 130 bytes on
wire (1040 bits), 130 bytes captured (1040 bits) on interface id 0
Ethernet II, Src: 70:81:05:b5:77:82, Dst:
cc:46:d6:2b:5a:54
Internet Protocol Version 4, Src: 10.2.0.3, Dst: 10.2.0.1
Open Shortest Path First
OSPF
Header
Version: 2
Message Type: Hello Packet (1)
Packet Length: 44
Source OSPF Router: 10.3.0.1
Area ID: 0.0.0.0 (Backbone)
Checksum: 0x0000 (None)
Auth Type: Cryptographic (2)
Auth Crypt Key id: 0
Auth Crypt Data Length: 16
Auth Crypt Sequence Number: 2085893823
Auth Crypt Data: 1a58197503fb23803a27faacb82366b0
OSPF
Hello Packet
OSPF
LLS Data Block
Frame 13: 190 bytes on
wire (1520 bits), 190 bytes captured (1520 bits) on interface id 0
Ethernet II, Src: 70:81:05:b5:77:82, Dst:
cc:46:d6:2b:5a:54
Internet Protocol Version 4, Src: 10.2.0.3, Dst: 10.2.0.1
Open Shortest Path First
OSPF
Header
Version: 2
Message Type: LS Update (4)
Packet Length: 140
Source OSPF Router: 10.3.0.1
Area ID: 0.0.0.0 (Backbone)
Checksum: 0x0000 (None)
Auth Type: Cryptographic (2)
Auth Crypt Key id: 0
Auth Crypt Data Length: 16
Auth Crypt Sequence Number: 2085893823
Auth Crypt Data: 3613894d9c1ae4b22c4dcbec137e3942
LS Update Packet
Number of LSAs: 2
LSA-type 1 (Router-LSA), len 84
.000 0000 0011 0010 = LS Age (seconds): 50
1... .... .... .... = Do Not Age Flag: 1
Options: 0x22, (DC) Demand Circuits, (E) External Routing
LS Type: Router-LSA (1)
Link State ID: 10.3.0.1
Advertising Router: 10.3.0.1
Sequence Number: 0x80000003
Checksum: 0xf092
Length: 84
Flags: 0x01, (B) Area border router
0... .... = (H) flag: No
...0 .... = (N) flag: No
.... 0... = (W) Wild-card multicast receiver: No
.... .0.. = (V) Virtual link endpoint: No
.... ..0. = (E) AS boundary router: No
.... ...1 = (B) Area border router: Yes
Number of Links: 5
Type: Stub
ID: 10.3.4.0 Data:
255.255.255.0 Metric: 1
Type: Stub ID: 10.3.3.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.3.2.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.3.1.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.3.0.0 Data: 255.255.255.0 Metric: 1
LSA-type 3 (Summary-LSA (IP network)), len 28
.000 0000 0010 1000 = LS Age (seconds): 40
1... .... .... .... = Do Not Age Flag: 1
Options: 0x22, (DC) Demand Circuits, (E) External Routing
LS Type: Summary-LSA (IP network) (3)
Link State ID: 10.2.0.0
Advertising Router: 10.3.0.1
Sequence Number: 0x80000001
Checksum: 0x80a1
Length: 28
Netmask: 255.255.255.0
TOS: 0
Metric: 1
Frame 15: 190 bytes on
wire (1520 bits), 190 bytes captured (1520 bits) on interface id 0
Ethernet II, Src: cc:46:d6:2b:5a:54, Dst:
70:81:05:b5:77:82
Internet Protocol Version 4, Src: 10.2.0.1, Dst: 10.2.0.3
Open Shortest Path First
OSPF
Header
Version: 2
Message Type: LS Update (4)
Packet Length: 140
Source OSPF Router: 10.1.0.1
Area ID: 0.0.0.0 (Backbone)
Checksum: 0x0000 (None)
Auth Type: Cryptographic (2)
Auth
Crypt Key id: 0
Auth Crypt Data Length: 16
Auth Crypt Sequence Number: 1693772095
Auth Crypt Data: afb4fc78ee02862b9e929b59062b8dbc
LS Update Packet
Number of LSAs: 2
LSA-type 1 (Router-LSA), len 84
.000 0000 0011 0010 = LS Age (seconds): 50
1... .... .... .... = Do Not Age Flag: 1
Options: 0x22, (DC) Demand Circuits, (E) External Routing
LS Type: Router-LSA (1)
Link State ID: 10.1.0.1
Advertising Router: 10.1.0.1
Sequence Number: 0x80000003
Checksum: 0xe8a7
Length: 84
Flags: 0x01, (B) Area border router
0... .... = (H) flag: No
...0 .... = (N) flag: No
.... 0... = (W) Wild-card multicast receiver: No
.... .0.. = (V) Virtual link endpoint: No
.... ..0. = (E) AS boundary router: No
.... ...1 = (B) Area border router: Yes
Number of Links: 5
Type: Stub ID: 10.1.4.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.1.3.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.1.2.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.1.1.0 Data: 255.255.255.0 Metric: 1
Type: Stub ID: 10.1.0.0 Data: 255.255.255.0 Metric: 1
LSA-type 3 (Summary-LSA (IP network)), len 28
.000 0000 0010 1000 = LS Age (seconds): 40
1... .... .... .... = Do Not Age Flag: 1
Options: 0x22, (DC) Demand Circuits, (E) External Routing
LS Type: Summary-LSA (IP network) (3)
Link State ID: 10.2.0.0
Advertising Router: 10.1.0.1
Sequence Number: 0x80000001
Checksum: 0x9093
Length: 28
Netmask: 255.255.255.0
TOS: 0
Metric: 1
(2023) Una red sin
OSPF son sólo cables
Rosario, Argentina