OSPF Sim Example

OSPF is configured on routers Amani and Lynaic. Amani’s S0/0 interface and Lynaic’s S0/1 interface are in Area 0. Lynaic’s Loopback0 interface is in Area 2.

Your task is to configure the following:

Portland’s S0/0 interface in Area 1
Amani’s S0/1 interface in Area 1
Use the appropriate mask such that ONLY Portland’s S0/0 and Amnani’s S0/1 could be in Area 1.
Area 1 should not receive any external or inter-area routes (except the default route).
Penjelasan

• Di cek di router Portland, apakah OSPF sudah jalan dan cek interface-nya
  
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  Portland#sh ip pro   Portland#sh ip route 192.168.4.0/30 is subnetted, 1 subnets C 192.168.4.4 is directly connected, Serial0/0 Portland#sh ip int br Interface IP-Address OK? Method Status Protocol FastEthernet0/0 unassigned YES NVRAM administratively down down Serial0/0 192.168.4.5 YES NVRAM up up FastEthernet0/1 unassigned YES NVRAM administratively down down Serial0/1 unassigned YES NVRAM administratively down down

• Setting IP address untuk OSPF area 1 dan konfigurasi area 1 sebagai stub
  Dari IP address bisa diketahui kalau subnetnya adalah 192.168.4.4/30 (192.168.4.4 – 192.168.4.7).Jadi commandnya untuk area 1 adalah 192.168.4.4 0.0.0.3 area 1. Command ini diletakkan di router Portland dan Amani dibawah statement router ospf.Dari pertanyaannya diminta agar area 1 tidak menerima external atau inter-area route kecuali via default route. Jika tidak ingin menerima external route, kita blok LSA type 5, untuk inter-area route, kita blok LSA type 3. Jadi konfigurasi area 1 sebagai area totally stub. Caranya dengan menambahkan dibawah router ospf command area 1 stub di Portland, dan area 1 stub no-summary di router Amani (ABR area 1).
  
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  Portland#conf t Portland(config)#router ospf 1 Portland(config-router)#network 192.168.4.4 0.0.0.3 area 1 Portland(config-router)#area 1 stub Portland(config-router)#end

• Cek di router dan Amani, apakah OSPF sudah jalan, cek interface dan catat OSPF process-nya
  
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  Amani #sh ip int br Interface IP-Address OK? Method Status Protocol FastEthernet0/0 unassigned YES NVRAM administratively down down Serial0/0 192.168.72.6 YES NVRAM up up FastEthernet0/1 unassigned YES NVRAM administratively down down Serial0/1 192.168.4.6 YES NVRAM up up

  
  Interface yang terhubung ke router Portland adalah 192.168.4.6, sudah satu subnet dengan interface di router Portland
  
  
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  Amani#sh ip pro 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 192.168.72.6 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: 192.168.72.4 0.0.0.3 area 0 Reference bandwidth unit is 100 mbps Routing Information Sources: Gateway Distance Last Update 192.168.72.6 110 00:01:10 10.239.239.239 110 00:01:00 Distance: (default is 110)

• Konfig router Amani ke area 1 dan sebagai stub area
  
  
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  Amani#conf t Amani(config)#router ospf 1 Amani(config-router)#network 192.168.4.4 0.0.0.3 area 1 Amani(config-router)#area 1 stub no-summary Amani(config-router)#exit

• Periksa routing table Portland dan Amani
  
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  Portland#sh ip route   Gateway of last resort is 192.168.4.6 to network 0.0.0.0   192.168.4.0/30 is subnetted, 1 subnets C 192.168.4.4 is directly connected, Serial0/0 O*IA 0.0.0.0/0 [110/65] via 192.168.4.6, 00:00:48, Serial0/0   Amani#sh ip route   192.168.72.0/30 is subnetted, 1 subnets C 192.168.72.4 is directly connected, Serial0/0 192.168.4.0/30 is subnetted, 1 subnets C 192.168.4.4 is directly connected, Serial0/1 10.0.0.0/32 is subnetted, 1 subnets O IA 10.239.239.239 [110/65] via 192.168.72.5, 00:00:28, Serial0/0