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 des interaces de tous les routeurs en mode broadcast
R1#conf t
R1(config)#int s0/0
R1(config-if)#ip ospf network broadcast
Dans cette configuration, la découverte de voisins OSPF est automatique
Vérifications:
R1#show ip ospf interface s0/0 Serial0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 64 Transmit Delay is 1 sec, State DR, Priority 255 Designated Router (ID) 1.1.1.1, Interface address 10.1.1.1 No backup designated router on this network Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 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 2 Last flood scan time is 0 msec, maximum is 4 msec Neighbor Count is 3, Adjacent neighbor count is 3 Adjacent with neighbor 2.2.2.2 Adjacent with neighbor 3.3.3.3 Adjacent with neighbor 4.4.4.4 Suppress hello for 0 neighbor(s)
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 0 FULL/DROTHER 00:00:19 10.1.1.2 Serial0/0
3.3.3.3 0 FULL/DROTHER 00:00:15 10.1.1.3 Serial0/0
4.4.4.4 0 FULL/DROTHER 00:00:16 10.1.1.4 Serial0/0
Dans ce mode, les routeurs « spoke » obtiennent les IP des autres « spoke » comme next hop, la configuration frame relay doit permettre d’atteindre tous les next hop
R1#show ip route ospf O 2.0.0.0/8 [110/65] via 10.1.1.2, 00:03:59, Serial0/0 O 3.0.0.0/8 [110/65] via 10.1.1.3, 00:03:59, Serial0/0 O 4.0.0.0/8 [110/65] via 10.1.1.4, 00:03:59, Serial0/0 R2#show ip route ospf O 1.0.0.0/8 [110/65] via 10.1.1.1, 00:07:11, Serial0/0 O 3.0.0.0/8 [110/65] via 10.1.1.3, 00:07:11, Serial0/0 O 4.0.0.0/8 [110/65] via 10.1.1.4, 00:07:11, Serial0/0 R3#show ip route ospf O 1.0.0.0/8 [110/782] via 10.1.1.1, 00:07:29, Serial1/0 O 2.0.0.0/8 [110/782] via 10.1.1.2, 00:07:29, Serial1/0 O 4.0.0.0/8 [110/782] via 10.1.1.4, 00:07:29, Serial1/0 R4#show ip route ospf O 1.0.0.0/8 [110/65] via 10.1.1.1, 00:07:46, Serial0/0 O 2.0.0.0/8 [110/65] via 10.1.1.2, 00:07:46, Serial0/0 O 3.0.0.0/8 [110/65] via 10.1.1.3, 00:07:46, Serial0/0