Configuration très simple en mode « point à point »
- Tous les réseaux sont annoncés dans l’Area OSPF 0
- R1 a une ip secondary sur fa0/0 : 10.2.2.2 /24
- R3 a une ip secondary sur fa0/0 : 10.3.3.3 /24
- la commande « router ospf » n’est pas nécessaire
- la commande « network » n’est pas nécessaire
- en mode point à point, l’élection du DR n’aura pas lieu
Configurations
R1#conf t R1(config)#int s0/0.12 R1(config-subif)#ip ospf network point-to-point R1(config-subif)#ip ospf 1 area 0 R1(config-if)#int lo0 R1(config-if)#ip ospf network point-to-point R1(config-if)#ip ospf 1 area 0
R2#conf t
R2(config)#int s0/0.21
R2(config-subif)#ip ospf network point-to-point
R2(config-subif)#ip ospf 1 area 0
R2(config)#int lo0
R2(config-if)#ip ospf network point-to-point
R2(config-if)#ip ospf 1 area 0
R2(config)#int fa0/0
R2(config-if)#ip ospf 1 area 0
R3#conf t
R3(config)#int fa0/0
R3(config-if)#ip ospf 1 area 0
R3(config)#int loopback 0
R3(config-if)#ip ospf network point-to-point
R3(config-if)#ip ospf 1 area 0
Vérifications:
R1#show ip route C 1.0.0.0/8 is directly connected, Loopback0 O 2.0.0.0/8 [110/65] via 10.1.12.2, 00:14:41, Serial0/0.12 O 3.0.0.0/8 [110/66] via 10.1.12.2, 00:14:41, Serial0/0.12 10.0.0.0/24 is subnetted, 4 subnets C 10.1.12.0 is directly connected, Serial0/0.12 O 10.3.3.0 [110/66] via 10.1.12.2, 00:14:41, Serial0/0.12 O 10.2.2.0 [110/65] via 10.1.12.2, 00:14:41, Serial0/0.12 O 10.1.23.0 [110/65] via 10.1.12.2, 00:14:41, Serial0/0.12
R2#show ip protocols Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID 2.2.2.2 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: Routing on Interfaces Configured Explicitly (Area 0): FastEthernet0/0 Loopback0 Serial0/0.21 Routing Information Sources: Gateway Distance Last Update 3.3.3.3 110 00:15:14 1.1.1.1 110 00:15:14 2.2.2.2 110 00:15:14 Distance: (default is 110)
Ne pas annoncer les IP secondary
R2(config)#int fa0/0
R2(config-if)#ip ospf 1 area 0 secondaries none
R3(config)#int fa0/0
R3(config-if)#ip ospf 1 area 0 secondaries none
Vérifications:
R1#show ip route C 1.0.0.0/8 is directly connected, Loopback0 O 2.0.0.0/8 [110/65] via 10.1.12.2, 00:00:12, Serial0/0.12 O 3.0.0.0/8 [110/66] via 10.1.12.2, 00:00:12, Serial0/0.12 10.0.0.0/24 is subnetted, 2 subnets C 10.1.12.0 is directly connected, Serial0/0.12 O 10.1.23.0 [110/65] via 10.1.12.2, 00:00:12, Serial0/0.12
Annoncer correctement le sub-net mask des loopback
Par défaut, les interfaces loopback sont annoncées avec une masque en /32
R1#show ip route ospf 2.0.0.0/32 is subnetted, 1 subnets O 2.2.2.2 [110/65] via 10.1.12.2, 00:03:22, Serial0/0.12 3.0.0.0/32 is subnetted, 1 subnets O 3.3.3.3 [110/66] via 10.1.12.2, 00:03:22, Serial0/0.12 10.0.0.0/24 is subnetted, 3 subnets O 10.1.23.0 [110/65] via 10.1.12.2, 00:03:22, Serial0/0.12 O 10.1.34.0 [110/846] via 10.1.12.2, 00:03:22, Serial0/0.12
Configuration en mode point à point
R2#conf t
R2(config)#int lo0
R2(config-if)#ip ospf network point-to-point
R3#conf t
R3(config)#int lo0
R3(config-if)#ip ospf network point-to-point
Vérifications:
R1#show ip route ospf O 2.0.0.0/8 [110/65] via 10.1.12.2, 00:00:01, Serial0/0.12 O 3.0.0.0/8 [110/66] via 10.1.12.2, 00:00:01, Serial0/0.12 10.0.0.0/24 is subnetted, 3 subnets O 10.1.23.0 [110/65] via 10.1.12.2, 00:00:01, Serial0/0.12 O 10.1.34.0 [110/846] via 10.1.12.2, 00:00:01, Serial0/0.12