OSPF – Hub and spoke Topology
Dans une architecture « Hub and spoke » Frame relay, les interfaces peuvent être configurées dans 4 modes de communication OSPF :
R1(config)#int s0/0 R1(config-if)#ip ospf network ? broadcast Specify OSPF broadcast multi-access network non-broadcast Specify OSPF NBMA network point-to-multipoint Specify OSPF point-to-multipoint network point-to-point Specify OSPF point-to-point network
Configuration d’une sous interface point à point sur chaque routeur
Configuration de R1 :
interface Serial0/0 no ip address encapsulation frame-relay ! interface Serial0/0.12 point-to-point ip address 10.1.12.1 255.255.255.0 frame-relay interface-dlci 102 ! interface Serial0/0.13 point-to-point ip address 10.1.13.1 255.255.255.0 frame-relay interface-dlci 103 ! interface Serial0/0.14 point-to-point ip address 10.1.14.1 255.255.255.0 frame-relay interface-dlci 104 ! router ospf 1 log-adjacency-changes network 1.1.1.1 0.0.0.0 area 0 network 10.1.12.1 0.0.0.0 area 0 network 10.1.13.1 0.0.0.0 area 0 network 10.1.14.1 0.0.0.0 area 0 !
Vérifications :
R1#show ip ospf int s0/0 %OSPF: OSPF not enabled on Serial0/0
R1#show ip ospf int s0/0.12 Serial0/0.12 is up, line protocol is up Internet Address 10.1.12.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type POINT_TO_POINT, Cost: 64 Transmit Delay is 1 sec, State POINT_TO_POINT, Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:09 Supports Link-local Signaling (LLS) Index 2/2, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 2.2.2.2 Suppress hello for 0 neighbor(s)
R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 4.4.4.4 0 FULL/ - 00:00:36 10.1.14.4 Serial0/0.14 3.3.3.3 0 FULL/ - 00:00:31 10.1.13.3 Serial0/0.13 2.2.2.2 0 FULL/ - 00:00:34 10.1.12.2 Serial0/0.12
R1#show ip route ospf O 2.0.0.0/8 [110/65] via 10.1.12.2, 00:05:20, Serial0/0.12 O 3.0.0.0/8 [110/65] via 10.1.13.3, 00:05:20, Serial0/0.13 O 4.0.0.0/8 [110/65] via 10.1.14.4, 00:05:20, Serial0/0.14
R4#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 1.1.1.1 0 FULL/ - 00:00:30 10.1.14.1 Serial0/0.41
Dans cette configuration, le routage des routeurs « spoke » converge vers le routeur « hub » :
R4#show ip route ospf O 1.0.0.0/8 [110/65] via 10.1.14.1, 00:02:44, Serial0/0.41 O 2.0.0.0/8 [110/129] via 10.1.14.1, 00:02:44, Serial0/0.41 O 3.0.0.0/8 [110/129] via 10.1.14.1, 00:02:44, Serial0/0.41 10.0.0.0/24 is subnetted, 3 subnets O 10.1.13.0 [110/128] via 10.1.14.1, 00:02:44, Serial0/0.41 O 10.1.12.0 [110/128] via 10.1.14.1, 00:02:44, Serial0/0.41