Roteadores utilizando OSPF em diferentes áreas com a utilização de link virtual
Como visto na descrição do teste do OSPF em várias áreas, normalmente toda informação é concentrada no backbone, também chamado de área 0 e daí repassada para outras áreas, que têm que ser fisicamente conectadas a ele.
Mas podemos ter áreas que não estam diretamente conectadas a área 0. Neste caso temos que criar uma conecção virtual entre esta área e a área 0. Esta conecção chamada de virtual link, é criada entre dois roteadores ABR, onde um dos roteadores faz parte da área 0 e de uma área intermediaria e o outro faz parte da intermediaria e da área isolada.
No nosso caso precisamos conectar a área 0 e a área 2 através da área 1, que é a área intermediaria. Para isso criamos um virtual link entre os roteadores cisco1 e cisco2.
Comandos para os roteadores 4000, cisco1, cisco2 e cisco3
Configuração de uma interface serial:
<4000>#
<4000>#conf t
Enter configuration commands, one per line. End with CNTL/Z.
<4000>(config)#int s1
<4000>(config-if)#ip address 192.80.209.14 255.255.255.0
<4000>(config-if)#clock rate 800000
<4000>(config-if)#
Configuração de uma interface ethernet:
<4000>#
<4000>#conf t
Enter configuration commands, one per line. End with CNTL/Z.
<4000>(config)#int e0
<4000>(config-if)#ip address 192.80.100.1 255.255.255.0
<4000>(config-if)#
Configuração de uma interface loopback:
<4000>#conf t
Enter configuration commands, one per line. End with CNTL/Z.
<4000>(config)#int lo0
<4000>(config-if)#ip address 200.20.6.1 255.255.255.0
<4000>(config-if)#
Habilitação do proocolo OSPF:
<4000>#conf t
Enter configuration commands, one per line. End with CNTL/Z.
<4000>(config)#router ospf 1
<4000>(config-router)#
Anúncio das redes pelo OSPF:
cisco1#
cisco1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cisco1(config)#router ospf 1
cisco1(config-router)#network 192.80.209.13 0.0.0.255 area 0
cisco1(config-router)#network 200.156.10.1 0.0.0.255 area 0
cisco1(config-router)#network 200.20.94.81 0.0.0.255 area 1
cisco1(config-router)#
cisco2#
cisco2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cisco2(config)#router ospf 1
cisco2(config-router)#network 200.20.94.1 0.0.0.255 area 1
cisco2(config-router)#network 200.20.3.1 0.0.0.255 area 2
cisco2(config-router)#network 200.20.4.1 0.0.0.255 area 2
cisco2(config-router)#
cisco3#
cisco3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cisco3(config)#router ospf 1
cisco3(config-router)#network 200.20.4.2 0.0.0.255 area 2
cisco3(config-router)#network 139.82.10.1 0.0.0.255 area 2
cisco3(config-router)#
cisco3#
<4000>#conf t
Enter configuration commands, one per line. End with CNTL/Z.
<4000>(config)#router ospf 1
<4000>(config-router)#network 192.80.209.14 0.0.0.255 area 0
<4000>(config-router)#network 192.80.100.1 0.0.0.255 area 0
<4000>(config-router)#network 200.20.6.1 0.0.0.255 area 0
<4000>(config-router)#
Descobrindo o Router ID:
cisco1#
cisco1#show ip ospf 1
Routing Process "ospf 1" with ID 200.156.10.1
Supports only single TOS(TOS0) routes
It is an area border and autonomous system boundary router
Summary Link update interval is 00:30:00 and the update due in 00:17:37
External Link update interval is 00:30:00 and the update due in 00:16:16
Redistributing External Routes from,
rip
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Number of DCbitless external LSA 0
Number of DoNotAge external LSA 0
Number of areas in this router is 2. 2 normal 0 stub 0 nssa
Area BACKBONE(0)
Number of interfaces in this area is 2
Area has no authentication
SPF algorithm executed 73 times
Area ranges are
Link State Update Interval is 00:30:00 and due in 00:16:59
Link State Age Interval is 00:20:00 and due in 00:16:59
Number of DCbitless LSA 1
Number of indication LSA 1
Number of DoNotAge LSA 0
Area 1
Number of interfaces in this area is 1
Area has no authentication
SPF algorithm executed 64 times
Area ranges are
Link State Update Interval is 00:30:00 and due in 00:17:35
Link State Age Interval is 00:20:00 and due in 00:17:35
Number of DCbitless LSA 1
Number of indication LSA 1
Number of DoNotAge LSA 0
cisco1#
cisco2#sh ip ospf
Routing Process "ospf 1" with ID 200.20.3.1
Supports only single TOS(TOS0) routes
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Number of DCbitless external LSA 0
Number of DoNotAge external LSA 0
Number of areas in this router is 2. 2 normal 0 stub 0 nssa
Area BACKBONE(0) (Inactive)
Number of interfaces in this area is 0
Area has no authentication
SPF algorithm executed 1 times
Area ranges are
Link State Update Interval is 00:30:00 and due in 00:00:00
Link State Age Interval is 00:20:00 and due in 00:04:44
Number of DCbitless LSA 1
Number of indication LSA 1
Number of DoNotAge LSA 0
Area 2
Number of interfaces in this area is 2
Area has no authentication
SPF algorithm executed 5 times
Area ranges are
Link State Update Interval is 00:30:00 and due in 00:11:50
Link State Age Interval is 00:20:00 and due in 00:11:50
Number of DCbitless LSA 1
Number of indication LSA 0
Number of DoNotAge LSA 0
Criando o link virtual:
cisco1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cisco1(config)#router ospf 1
cisco1(config-router)#area 1 virtual-link 200.20.3.1
cisco1(config-router)#
cisco2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cisco2(config)#router ospf 1
cisco2(config-router)#area 1 virtual-link 200.156.10.1
cisco2(config-router)#
Salvando as configurações:
<4000>#
<4000>#copy running-config startup-config
Building configuration...
[OK]
<4000>#
Obs: para o cisco3 usar o comando 'write'
cisco3#
cisco3#write
#####[OK]
cisco3#
SHOW RUNNING -CONFIG Este comando é utilizado para verificar a configuração do roteador. Observar se a interface está UP/DOWN, quais os IPs de cada interface, que redes são anunciadas por OSPF com suas respectivas áreas e o vitual link criado para interligar a área 2 à área 0. Resultados 4000 <4000># <4000>#show running-config Building configuration... Current configuration: ! version 11.3 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname <4000> ! ! ! ! ! interface Loopback0 ip address 200.20.6.1 255.255.255.0 ! interface Ethernet0 ip address 192.80.100.1 255.255.255.0 ! interface Ethernet1 no ip address shutdown ! interface Serial0 no ip address no ip mroute-cache shutdown no fair-queue ! interface Serial1 ip address 192.80.209.14 255.255.255.0 clockrate 800000 ! interface Serial2 ip address 192.80.150.1 255.255.255.0 shutdown clockrate 800000 ! interface Serial3 no ip address shutdown ! router ospf 1 network 192.80.100.0 0.0.0.255 area 0 network 192.80.209.0 0.0.0.255 area 0 network 200.20.6.0 0.0.0.255 area 0 ! ip classless ! ! ! line con 0 line aux 0 line vty 0 4 login ! end <4000># Resultados cisco1 cisco1# cisco1#show running-config Building configuration... Current configuration: ! version 11.2 service timestamps debug uptime service timestamps log uptime service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname cisco1 ! enable password 7 06100E324F41 ! ip subnet-zero no ip source-route no ip domain-lookup ! interface Loopback0 ip address 200.156.10.1 255.255.255.0 ! interface Ethernet0 ip address 200.20.94.81 255.255.255.0 ! interface Serial0 ip address 192.80.209.13 255.255.255.0 ! interface Serial1 no ip address shutdown ! router ospf 1 network 192.80.209.0 0.0.0.255 area 0 network 200.156.10.0 0.0.0.255 area 0 network 200.20.94.0 0.0.0.255 area 1 area 1 virtual-link 200.20.3.1 ! ip classless ! ! line con 0 exec-timeout 0 0 password 7 060C0E2F494208 login line aux 0 line vty 0 4 password 7 000E120801570A login ! end cisco1# Resultados cisco2 cisco2# cisco2#show running-config Building configuration... Current configuration: ! version 11.2 service password-encryption no service udp-small-servers no service tcp-small-servers ! hostname cisco2 ! enable secret 5 $1$jibr$cTHEQancHt3LUqhsNxGXG0 ! no ip domain-lookup ! interface Loopback0 ip address 200.20.3.1 255.255.255.0 ! interface Ethernet0 ip address 200.20.94.1 255.255.255.0 no ip directed-broadcast ! interface Serial0 ip address 192.80.209.125 255.255.255.252 no ip directed-broadcast ip ospf network point-to-multipoint shutdown clockrate 800000 ! interface Serial1 ip address 200.20.4.1 255.255.255.0 no ip directed-broadcast ! router ospf 1 network 200.20.3.0 0.0.0.255 area 2 network 200.20.4.0 0.0.0.255 area 2 network 200.20.94.0 0.0.0.255 area 1 area 1 virtual-link 200.156.10.1 ! ip classless ! ! line con 0 password 7 0501070124404F line aux 0 password 7 0501070124404F line vty 0 1 password 7 0501070124404F login line vty 2 password 7 082B4D400C1504 login line vty 3 4 password 7 044904131B245E login ! end cisco2# Resultados cisco3 cisco3# cisco3#show configuration Using 444 out of 32762 bytes ! version 10.2 ! hostname cisco3 ! ! ! interface Loopback0 ip address 139.82.10.1 255.255.255.0 ! interface Ethernet0 ip address 192.80.100.1 255.255.255.0 shutdown ! interface Serial0 ip address 200.20.5.1 255.255.255.0 shutdown ! interface Serial1 ip address 200.20.4.2 255.255.255.0 clockrate 800000 ! router ospf 1 network 200.20.4.0 0.0.0.255 area 2 network 139.82.10.0 0.0.0.255 area 2 ! ! line con 0 line aux 0 line vty 0 4 login ! end cisco3#
Neste ítem serão mostrados dois comandos que são fundamentais para
que possamos tirar nossas conclusões.
São eles: show ip route e traceroute.
O primeiro nos mostra por qual interface e por qual protocolo o roteador
aprende as outras redes, já o segundo nos mostra os roteadores percorridos
até o endereço de destino.
4000
<4000>#
<4000>#show 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, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is 192.80.209.13 to network 0.0.0.0
C 192.80.209.0/24 is directly connected, Serial1
O IA 200.20.4.0/24 [110/138] via 192.80.209.13, 00:02:25, Serial1
C 200.20.6.0/24 is directly connected, Loopback0
139.82.0.0/32 is subnetted, 1 subnets
O IA 139.82.10.1 [110/138] via 192.80.209.13, 00:02:25, Serial1
200.20.3.0/32 is subnetted, 1 subnets
O IA 200.20.3.1 [110/75] via 192.80.209.13, 00:02:25, Serial1
C 192.80.100.0/24 is directly connected, Ethernet0
200.156.10.0/32 is subnetted, 1 subnets
O 200.156.10.1 [110/65] via 192.80.209.13, 00:02:25, Serial1
O IA 200.20.94.0/24 [110/74] via 192.80.209.13, 00:02:25, Serial1
Verificamos que o roteador 4000 aprende as outras redes por OSPF através da interface Serial1,
via 192.80.209.13 (interface Serial0 do cisco1).
É importante notar que as redes que possuem ao lado IA, 200.20.4.0, 139.82.10.1, 200.20.3.1,
200.20.94.1 fazem parte de áreas diferentes, por isso o nome de inter-área.
<4000>#
<4000>#traceroute 139.82.10.1
Type escape sequence to abort.
Tracing the route to 139.82.10.1
1 192.80.209.13 4 msec 0 msec 0 msec
2 200.20.94.1 8 msec 4 msec 4 msec
3 200.20.4.2 8 msec 4 msec *
<4000>#
Com o comando traceroute, confirmamos o caminho que o pacote percorre
até a interface 139.82.10.1 (Loopback0 do cisco3).
cisco1
cisco1#
cisco1#show 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, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
C 192.80.209.0/24 is directly connected, Serial0
C 200.156.10.0/24 is directly connected, Loopback0
C 200.20.94.0/24 is directly connected, Ethernet0
O IA 200.20.4.0/24 [110/74] via 200.20.94.1, 00:00:36, Ethernet0
139.82.0.0/32 is subnetted, 1 subnets
O IA 139.82.10.1 [110/74] via 200.20.94.1, 00:00:36, Ethernet0
200.20.6.0/32 is subnetted, 1 subnets
O 200.20.6.1 [110/65] via 192.80.209.14, 00:00:36, Serial0
200.20.3.0/32 is subnetted, 1 subnets
O IA 200.20.3.1 [110/11] via 200.20.94.1, 00:00:36, Ethernet0
O 192.80.100.0/24 [110/74] via 192.80.209.14, 00:00:36, Serial0
Verificamos que o roteador cisco1 aprende as outras redes por OSPF através de suas interfaces
Serial0, via 192.80.209.14 (Serial1 4000) e Ethernet0 via 200.20.94.1 (Ethernet0 cisco2).
É importante notar que as redes que possuem ao lado IA, 200.20.4.0, 139.82.10.1, 200.20.3.1,
fazem parte de áreas diferentes, por isso o nome de inter-área.
cisco1#
cisco1#traceroute 139.82.10.1
Type escape sequence to abort.
Tracing the route to 139.82.10.1
1 200.20.94.1 4 msec 4 msec 4 msec
2 200.20.4.2 8 msec * 4 msec
cisco1#traceroute 192.80.100.5
Type escape sequence to abort.
Tracing the route to 192.80.100.5
1 192.80.209.14 0 msec 4 msec 4 msec
2 192.80.100.5 4 msec 4 msec 4 msec
cisco1#
Com o comando traceroute confirmamos o caminho que o pacote percorre
até a 139.82.10.1 (Loopback0 do cisco3) e até o PC 192.80.100.5.
cisco2
cisco2#
cisco2#show 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, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
O 192.80.209.0/24 [110/74] via 200.20.94.81, 00:00:03, Ethernet0
200.156.10.0/32 is subnetted, 1 subnets
O 200.156.10.1 [110/11] via 200.20.94.81, 00:00:03, Ethernet0
C 200.20.94.0/24 is directly connected, Ethernet0
C 200.20.4.0/24 is directly connected, Serial1
139.82.0.0/32 is subnetted, 1 subnets
O 139.82.10.1 [110/64] via 200.20.4.2, 00:00:03, Serial1
200.20.6.0/32 is subnetted, 1 subnets
O 200.20.6.1 [110/75] via 200.20.94.81, 00:00:03, Ethernet0
C 200.20.3.0/24 is directly connected, Loopback0
O 192.80.100.0/24 [110/84] via 200.20.94.81, 00:00:03, Ethernet0
Verificamos que o roteador cisco2 aprende as outras redes por OSPF através de suas interfaces
Serial1, via 200.20.4.2 (Serial1 cisco3) e Ethernet0 via 200.20.94.81 (Ethernet0 cisco1).
É importante notar que nenhuma das rotas possuem ao lado IA. Isso se deve ao fato de termos um
virtual link interligando a área2 à área0.
cisco2#
cisco2#traceroute 192.80.100.5
Type escape sequence to abort.
Tracing the route to 192.80.100.5
1 200.20.94.81 4 msec 4 msec 4 msec
2 192.80.209.14 4 msec 4 msec 4 msec
3 192.80.100.5 4 msec 4 msec 8 msec
cisco2#
cisco2#traceroute 139.82.10.1
Type escape sequence to abort.
Tracing the route to 139.82.10.1
1 200.20.4.2 4 msec * 4 msec
cisco2#
Com o comando traceroute confirmamos o caminho que o pacote percorre
até a 139.82.10.19 (Loopback0 do cisco3) e até o PC 192.80.100.5.
cisco3
cisco3#
cisco3#show 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
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, * - candidate default
Gateway of last resort is not set
O IA 192.80.209.0 [110/1636] via 200.20.4.1, 00:09:38, Serial1
200.156.10.0 is subnetted (mask is 255.255.255.255), 1 subnets
O IA 200.156.10.1 [110/1573] via 200.20.4.1, 00:09:38, Serial1
O IA 200.20.94.0 [110/1572] via 200.20.4.1, 16:21:34, Serial1
C 200.20.4.0 is directly connected, Serial1
139.82.0.0 is subnetted (mask is 255.255.255.0), 1 subnets
C 139.82.10.0 is directly connected, Loopback0
200.20.6.0 is subnetted (mask is 255.255.255.255), 1 subnets
O IA 200.20.6.1 [110/1637] via 200.20.4.1, 00:09:39, Serial1
200.20.3.0 is subnetted (mask is 255.255.255.255), 1 subnets
O 200.20.3.1 [110/1563] via 200.20.4.1, 16:21:34, Serial1
O IA 192.80.100.0 [110/1646] via 200.20.4.1, 00:09:39, Serial1
Verificamos que o roteador cisco3 aprende as outras redes por OSPF através da interface Serial1,
via 200.20.4.1 (interface Serial1 do cisco2).
É importante notar que as redes que possuem ao lado IA, 192.80.209.0, 192.80.100.0, 200.20.156.0,
200.20.94.0, 200.20.6.0 fazem parte de áreas diferentes, por isso o nome de inter-área.
cisco3#
cisco3#trace ip 192.80.100.5
Type escape sequence to abort.
Tracing the route to 192.80.100.5
1 200.20.4.1 4 msec 4 msec 4 msec
2 200.20.94.81 4 msec 4 msec 4 msec
3 192.80.209.14 8 msec 4 msec 4 msec
4 192.80.100.5 8 msec 8 msec 4 msec
cisco3#
Com o comando traceroute confirmamos o caminho que o pacote percorre
até o PC 192.80.100.5.
Voltar