จาก Network Diagram ทำการตั้งค่าบน Router ตามหัวข้อดังต่อไปนี้
1. ทำการ Check Pre-Configure ของ R1, R2 และ R3 พร้อมทั้ง Check ความพร้อมต่างๆ
2. ทำการเพิ่ม Configure OSPF
3. ทำการ Configure virtual link
4. ทำการ Configure OSPF Summarize area
5. ทำการ Configure Generate a default route into OSPF
Task and Configuration
1. ทำการ Check Pre-Configure ของ R1, R2 และ R3 พร้อมทั้ง Check ความพร้อมต่างๆ
1.1 ที่ Router R1
R1#show running-config
hostname R1
!
!
interface Loopback1
description Engineering Department
ip address 10.1.1.1 255.255.255.0
!
interface Loopback30
ip address 172.30.30.1 255.255.255.252
!
interface Ethernet0/0
ip address 10.1.12.1 255.255.255.0
!
!
!
end
R1#
!
R1#show ip interface brief | e un
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 10.1.12.1 YES manual up up
Loopback1 10.1.1.1 YES manual up up
Loopback30 172.30.30.1 YES manual up up
1.2 ที่ Router R2
R2#show running-config
!
hostname R2
!
interface Loopback2
description Marketing Department
ip address 10.1.2.1 255.255.255.0
!
interface Ethernet0/0
ip address 10.1.12.2 255.255.255.0
!
interface Ethernet0/1
ip address 10.1.23.2 255.255.255.0
!
end
R2#show ip interface brief | e un
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 10.1.12.2 YES manual up up
Ethernet0/1 10.1.23.2 YES manual up up
Loopback2 10.1.2.1 YES manual up up1.3 ที่ Router R3
R3#show running-config
hostname R3
!
interface Loopback3
description Accounting Department
ip address 10.1.3.1 255.255.255.0
!
interface Loopback100
ip address 192.168.100.1 255.255.255.0
!
interface Loopback101
ip address 192.168.101.1 255.255.255.0
!
interface Loopback102
ip address 192.168.102.1 255.255.255.0
!
interface Loopback103
ip address 192.168.103.1 255.255.255.0
!
interface Ethernet0/0
no ip address
shutdown
!
interface Ethernet0/1
ip address 10.1.23.3 255.255.255.0
!
end
R3#show ip interface brief | e un
Interface IP-Address OK? Method Status Protocol
Ethernet0/1 10.1.23.3 YES manual up up
Loopback3 10.1.3.1 YES manual up up
Loopback100 192.168.100.1 YES manual up up
Loopback101 192.168.101.1 YES manual up up
Loopback102 192.168.102.1 YES manual up up
Loopback103 192.168.103.1 YES manual up up2. ทำการเพิ่ม Configure OSPF
2.1. ตั้งค่า OSPF process 1 และ OSPF router ID บน router R1 R2 และ R3 โดยการใช้คำสั่ง network และทำการ configure subnet ของ ethernet link ระหว่าง R1 และ R2 ให้อยู่ใน OSPF area 0 แล้วทำการเพิ่ม loopback 1 บน router R1 และ loopback 2 บน router R2 ให้อยู่ใน OSPF area 0 เช่นกัน
ตั้งค่า OSPF process 1 และ OSPF router ID บน router R1
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router ospf 1
R1(config-router)#router-id 1.1.1.1
R1(config-router)#network 10.1.12.0 0.0.0.255 area 0
R1(config-router)#network 10.1.1.0 0.0.0.255 area 0
R1(config-router)#exit
R1(config)#interface loopback 1
R1(config-if)#ip ospf network point-to-point
R1(config-if)#end
2.2. ใช้คำสั่ง show ip ospf เพื่อตรวจสอบ OSPF router ID โดย OSPF router ID จะเป็นค่า 32-bit หากเป็นค่าอื่นๆ ที่ไม่ใช่ค่าที่ได้กำหนดเข้าไป เราสามารถทำการ reset โดยใช้คำสั่ง Cleaar ip ospf pid process
R1#show ip ospf
Routing Process "ospf 1" with ID 1.1.1.1 ----> Router ID คือ 1.1.1.1
Start time: 00:23:13.687, Time elapsed: 00:01:15.158
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Supports NSSA (compatible with RFC 3101)
Supports Database Exchange Summary List Optimization (RFC 5243)
Event-log enabled, Maximum number of events: 1000, Mode: cyclic
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
ตั้งค่า OSPF process 1 และ OSPF router ID บน router R2
R2(config)#router ospf 1
R2(config-router)#router-id 2.2.2.2
R2(config-router)#network 10.1.12.0 0.0.0.255 area 0
R2(config-router)#network 10.1.2.0 0.0.0.255 area 0
R2(config-router)#exit
R2(config)#interface loopback 2
R2(config-if)#ip ospf network point-to-point
R2(config-if)#end
R2#
*Nov 1 18:13:43.670: %SYS-5-CONFIG_I: Configured from console by console
R2#
*Nov 1 18:13:48.996: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Ethernet0/0 from LOADING to FULL, Loading Done
R2#2.3 ทำการตรวจสอบว่าสามารถเห็น Router OSPF เพื่อนบ้านหรือไม่ โดยใช้คำสั่ง show ip ospf neighbor บน router ทั้งสองตัว และใช้คำสั่ง show ip route เพื่อตรวจสอบว่า routing สามารถเห็น loopback ของกันและกันหรือไม่
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 FULL/BDR 00:00:34 10.1.12.2 Ethernet0/0
R1#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
C 10.1.1.0/24 is directly connected, Loopback1
L 10.1.1.1/32 is directly connected, Loopback1
O 10.1.2.0/24 [110/11] via 10.1.12.2, 00:02:32, Ethernet0/0
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.1/32 is directly connected, Ethernet0/0
172.30.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.30.30.0/30 is directly connected, Loopback30
L 172.30.30.1/32 is directly connected, Loopback30
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:33 10.1.12.1 Ethernet0/0
R2#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:03:24, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1
2.4. ทำการเพิ่ม subnet ระหว่าง R2 และ R3 เข้าไปยัง OSPF area 23 โดยใช้คำสั่ง network พร้อมทั้งเพิ่ม Interface loopback 3 บน router R3 เข้าไปยัง area 23
R2(config)#router ospf 1
R2(config-router)#network 10.1.23.0 0.0.0.255 area 23
R3(config)#router ospf 1
R3(config-router)#router-id 3.3.3.3
R3(config-router)#network 10.1.23.0 0.0.0.255 area 23
R3(config-router)#network 10.1.3.0 0.0.0.255 area 23
R3(config-router)#exit
R3(config)#interface loopback 3
R3(config-if)#ip ospf network point-to-point
2.5. ตรวจสอบความสัมพันธ์ระหว่างเพื่อนบ้านด้วยคำสั่ง show ip ospf neighbors
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:34 10.1.12.1 Ethernet0/0
3.3.3.3 1 FULL/BDR 00:00:37 10.1.23.3 Ethernet0/1
ตรวจสอบ Routing Table ที่ Router R3
R3#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O IA 10.1.1.0/24 [110/21] via 10.1.23.2, 00:01:09, Ethernet0/1
O IA 10.1.2.0/24 [110/11] via 10.1.23.2, 00:01:09, Ethernet0/1
C 10.1.3.0/24 is directly connected, Loopback3
L 10.1.3.1/32 is directly connected, Loopback3
O IA 10.1.12.0/24 [110/20] via 10.1.23.2, 00:01:09, Ethernet0/1
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.3/32 is directly connected, Ethernet0/1
192.168.100.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.100.0/24 is directly connected, Loopback100
L 192.168.100.1/32 is directly connected, Loopback100
192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.101.0/24 is directly connected, Loopback101
L 192.168.101.1/32 is directly connected, Loopback101
192.168.102.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.102.0/24 is directly connected, Loopback102
L 192.168.102.1/32 is directly connected, Loopback102
192.168.103.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.103.0/24 is directly connected, Loopback103
L 192.168.103.1/32 is directly connected, Loopback103
R1(config)#interface ethernet 0/0
R1(config-if)#ip ospf network point-to-point
R1(config-if)#
*Nov 1 18:21:43.507: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Ethernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Nov 1 18:21:43.507: %OSPF-4-NET_TYPE_MISMATCH: Received Hello from 2.2.2.2 on Ethernet0/0 indicating a potential
network type mismatch
R1(config-if)#
*Nov 1 18:21:43.508: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Ethernet0/0 from LOADING to FULL, Loading Done
R1(config-if)#
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 0 FULL/ - 00:00:35 10.1.12.2 Ethernet0/0
R1#sh ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C 10.1.1.0/24 is directly connected, Loopback1
L 10.1.1.1/32 is directly connected, Loopback1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.1/32 is directly connected, Ethernet0/0
172.30.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.30.30.0/30 is directly connected, Loopback30
L 172.30.30.1/32 is directly connected, Loopback30
R1#
R2(config)#interface ethernet 0/0
R2(config-if)#ip ospf network point-to-point
R2(config-if)#
*Nov 1 18:23:48.757: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Ethernet0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Nov 1 18:23:48.759: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Ethernet0/0 from LOADING to FULL, Loading Done
R2(config-if)#
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 0 FULL/ - 00:00:34 10.1.12.1 Ethernet0/0
3.3.3.3 1 FULL/BDR 00:00:32 10.1.23.3 Ethernet0/1
R2#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:01:08, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
O 10.1.3.0/24 [110/11] via 10.1.23.3, 00:05:23, Ethernet0/1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1
R1#sh ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
C 10.1.1.0/24 is directly connected, Loopback1
L 10.1.1.1/32 is directly connected, Loopback1
O 10.1.2.0/24 [110/11] via 10.1.12.2, 00:00:50, Ethernet0/0
O IA 10.1.3.0/24 [110/21] via 10.1.12.2, 00:00:50, Ethernet0/0
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.1/32 is directly connected, Ethernet0/0
O IA 10.1.23.0/24 [110/20] via 10.1.12.2, 00:00:50, Ethernet0/0
172.30.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.30.30.0/30 is directly connected, Loopback30
L 172.30.30.1/32 is directly connected, Loopback30 3. ทำการ Configure virtual link
3.1. ประกาศ loopback Interface ตั้งแต่ 100 ถึง 103 บน router R3 ให้อยู่ใน OSPF process 1 area 100 โดยใช้คำสั่ง network และทำการเปลี่ยน network type เป็น network point-to-point
R3(config)#router ospf 1
R3(config-router)#network 192.168.100.0 0.0.3.255 area 100
R3(config-router)#exit
R3(config)#interface loopback 100
R3(config-if)#ip ospf network point-to-point
R3(config-if)#interface loopback 101
R3(config-if)#ip ospf network point-to-point
R3(config-if)#interface loopback 102
R3(config-if)#ip ospf network point-to-point
R3(config-if)#interface loopback 103
R3(config-if)#ip ospf network point-to-point
3.2. ใช้คำสั่ง show ip route บน router R2
R2#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:03:42, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
O 10.1.3.0/24 [110/11] via 10.1.23.3, 00:07:57, Ethernet0/1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1ปรากฎว่าไม่พบ Route ของ Loopback Interface ตั้งแต่ 100 ถึง 103 บน router R3 เนื่องจาก Loopback ดังกล่าถูกประกาศให้อยู่น Area ที่ไม่ได้เชื่อมต่อกับ Backbone Area หรือ Area ซึ่งใน LAB นี้จะแก้ปัญหาด้วยการสร้าง Virtual link ระหว่าง R2 และ R3
3.3. ก่อนที่จะสร้าง virtual link เราจำเป็นต้องระบุ OSPF router ID ให้ router ที่เกี่ยวข้องกัน (R2 และ R3) โดยใช้คำสั่ง show ip ospf, show ip protocols หรือ show ip ospf interface เพื่อตรวจสอบ router ID
R2#show ip ospf
Routing Process "ospf 1" with ID 2.2.2.2
<output omitted>
R3#show ip ospf
Routing Process "ospf 1" with ID 3.3.3.3
<output omitted>3.4. ทำการสร้าง virtual บน R2 และ R3 link ด้วยคำสั่ง area transit_area virtual-link router-id
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router ospf 1
R2(config-router)#area 23 virtual-link 3.3.3.3
R3(config)#router ospf 1
R3(config-router)#area 23 virtual-link 2.2.2.2
R3(config-router)#
*Nov 1 18:34:58.798: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on OSPF_VL0 from LOADING to FULL, Loading Done
R3(config-router)#3.5. ใช้คำสั่ง show ip route บน router R2 และพิจารณาเส้นทางจาก area 100 ทั้งนี้เราสามารถตรวจสอบ virtual link ด้วยการใช้คำสั่ง show ip ospf neighbor และ show ip ospf interface
R2#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:11:42, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
O 10.1.3.0/24 [110/11] via 10.1.23.3, 00:15:57, Ethernet0/1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1
O IA 192.168.100.0/24 [110/11] via 10.1.23.3, 00:00:28, Ethernet0/1
O IA 192.168.101.0/24 [110/11] via 10.1.23.3, 00:00:28, Ethernet0/1
O IA 192.168.102.0/24 [110/11] via 10.1.23.3, 00:00:28, Ethernet0/1
O IA 192.168.103.0/24 [110/11] via 10.1.23.3, 00:00:28, Ethernet0/1
R2# show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/ - - 10.1.23.3 OSPF_VL0
1.1.1.1 0 FULL/ - 00:00:31 10.1.12.1 Ethernet0/0
3.3.3.3 1 FULL/BDR 00:00:35 10.1.23.3 Ethernet0/1
R2#show ip ospf interface
OSPF_VL0 is up, line protocol is up
Internet Address 10.1.23.2/24, Area 0, Attached via Not Attached
Process ID 1, Router ID 2.2.2.2, Network Type VIRTUAL_LINK, Cost: 10
Topology-MTID Cost Disabled Shutdown Topology Name
0 10 no no Base
Configured as demand circuit
Run as demand circuit
DoNotAge LSA allowed
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 00:00:03
<output omitted>
4. ทำการ Configure OSPF Summarize area
4.1. ทำการ configure router R3 (ABR) เพื่อ summarize area โดยใช้คำสั่ง area area range network mask
R3(config)#router ospf 1
R3(config-router)#area 100 range 192.168.100.0 255.255.252.0
4.2. เราสามารถดู summarize route บน router R2 ด้วยคำสั่ง show ip route และ show ip ospf database
R2#show ip route
<output omitted>
10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:21:41, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
O 10.1.3.0/24 [110/11] via 10.1.23.3, 00:25:56, Ethernet0/1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1
O IA 192.168.100.0/22 [110/11] via 10.1.23.3, 00:00:44, Ethernet0/1
R2#
R2#
R2#show ip ospf database
OSPF Router with ID (2.2.2.2) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 1484 0x80000003 0x007141 3
2.2.2.2 2.2.2.2 688 0x80000006 0x008BD1 4
3.3.3.3 3.3.3.3 1 (DNA)0x80000002 0x00DD03 1
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.3.0 2.2.2.2 1608 0x80000001 0x000C10
10.1.3.0 3.3.3.3 6 (DNA) 0x80000001 0x008998
10.1.23.0 2.2.2.2 1674 0x80000001 0x0025E3
10.1.23.0 3.3.3.3 6 (DNA) 0x80000001 0x0007FD
192.168.100.0 3.3.3.3 1 (DNA) 0x80000002 0x00263E
Router Link States (Area 23)
Link ID ADV Router Age Seq# Checksum Link count
2.2.2.2 2.2.2.2 688 0x80000003 0x00F5D4 1
3.3.3.3 3.3.3.3 689 0x80000005 0x007A26 2
Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
10.1.23.2 2.2.2.2 1613 0x80000001 0x009D5C
Summary Net Link States (Area 23)
Link ID ADV Router Age Seq# Checksum
10.1.1.0 2.2.2.2 1353 0x80000001 0x0022FB
10.1.2.0 2.2.2.2 1679 0x80000001 0x00B274
10.1.12.0 2.2.2.2 1679 0x80000001 0x009E75
192.168.100.0 3.3.3.3 102 0x80000002 0x00263E
R2#
4.3. สังเกต router R3 ว่า OSPF ได้สร้าง summary route ที่มีค่าเข้าสู่ Null0 (LAB นี้ไม่ได้อธิบายเหตุผลของ Null0)
R3#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O 10.1.1.0/24 [110/21] via 10.1.23.2, 00:02:56, Ethernet0/1
O 10.1.2.0/24 [110/11] via 10.1.23.2, 00:02:56, Ethernet0/1
C 10.1.3.0/24 is directly connected, Loopback3
L 10.1.3.1/32 is directly connected, Loopback3
O 10.1.12.0/24 [110/20] via 10.1.23.2, 00:02:56, Ethernet0/1
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.3/32 is directly connected, Ethernet0/1
O 192.168.100.0/22 is a summary, 00:02:56, Null0
192.168.100.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.100.0/24 is directly connected, Loopback100
L 192.168.100.1/32 is directly connected, Loopback100
192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.101.0/24 is directly connected, Loopback101
L 192.168.101.1/32 is directly connected, Loopback101
192.168.102.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.102.0/24 is directly connected, Loopback102
L 192.168.102.1/32 is directly connected, Loopback102
192.168.103.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.103.0/24 is directly connected, Loopback103
L 192.168.103.1/32 is directly connected, Loopback1035. ทำการ Configure Generate a default route into OSPF
5.1. ใช้คำสั่ง default-information originate always ที่ router R1 เพื่อสร้าง default route
ทั้งนี้ ถ้าเราไม่ใส่ keyword “always” default route จะถูกสร้างและประกาศยัง OSPF ก็ต่อเมื่อเคยมีอยู่ใน routing table เท่านั้น
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router ospf 1
R1(config-router)#default-information originate alwaysตรวจสอบว่า default route นั้นปรากฎบน router R2 และ R3 หรือไม่ โดยใช้คำสั่ง show ip route
R2#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is 10.1.12.1 to network 0.0.0.0
O*E2 0.0.0.0/0 [110/1] via 10.1.12.1, 00:00:46, Ethernet0/0
10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
O 10.1.1.0/24 [110/11] via 10.1.12.1, 00:26:25, Ethernet0/0
C 10.1.2.0/24 is directly connected, Loopback2
L 10.1.2.1/32 is directly connected, Loopback2
O 10.1.3.0/24 [110/11] via 10.1.23.3, 00:30:40, Ethernet0/1
C 10.1.12.0/24 is directly connected, Ethernet0/0
L 10.1.12.2/32 is directly connected, Ethernet0/0
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.2/32 is directly connected, Ethernet0/1
O IA 192.168.100.0/22 [110/11] via 10.1.23.3, 00:05:28, Ethernet0/1
R3#show ip route
Codes: L - local, C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
Gateway of last resort is 10.1.23.2 to network 0.0.0.0
O*E2 0.0.0.0/0 [110/1] via 10.1.23.2, 00:01:15, Ethernet0/1
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
O 10.1.1.0/24 [110/21] via 10.1.23.2, 00:06:02, Ethernet0/1
O 10.1.2.0/24 [110/11] via 10.1.23.2, 00:06:02, Ethernet0/1
C 10.1.3.0/24 is directly connected, Loopback3
L 10.1.3.1/32 is directly connected, Loopback3
O 10.1.12.0/24 [110/20] via 10.1.23.2, 00:06:02, Ethernet0/1
C 10.1.23.0/24 is directly connected, Ethernet0/1
L 10.1.23.3/32 is directly connected, Ethernet0/1
O 192.168.100.0/22 is a summary, 00:06:02, Null0
192.168.100.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.100.0/24 is directly connected, Loopback100
L 192.168.100.1/32 is directly connected, Loopback100
192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.101.0/24 is directly connected, Loopback101
L 192.168.101.1/32 is directly connected, Loopback101
192.168.102.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.102.0/24 is directly connected, Loopback102
L 192.168.102.1/32 is directly connected, Loopback102
192.168.103.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.103.0/24 is directly connected, Loopback103
L 192.168.103.1/32 is directly connected, Loopback103
5.2. ทำการ ping ไปยัง interface ที่เชื่อมต่อไปยัง internet ที่ R1 จะพบว่าสามารถ ping ได้แม้ว่าจะไม่เคยถูกประกาศเข้าไปใน OSPF เลยก็ตาม
R3#ping 172.30.30.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.30.30.1, timeout is 2 seconds:
!!!!!
Full Configuration
Router R1
R1#show running-config
hostname R1
!
!
interface Loopback1
description Engineering Department
ip address 10.1.1.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback30
ip address 172.30.30.1 255.255.255.252
!
interface Ethernet0/0
ip address 10.1.12.1 255.255.255.0
ip ospf network point-to-point
!
!
router ospf 1
router-id 1.1.1.1
network 10.1.1.0 0.0.0.255 area 0
network 10.1.12.0 0.0.0.255 area 0
default-information originate always
!
End
Router R2
R2#show running-config
hostname R2
!
!
interface Loopback2
description Marketing Department
ip address 10.1.2.1 255.255.255.0
ip ospf network point-to-point
!
interface Ethernet0/0
ip address 10.1.12.2 255.255.255.0
ip ospf network point-to-point
!
interface Ethernet0/1
ip address 10.1.23.2 255.255.255.0
!
!
router ospf 1
router-id 2.2.2.2
area 23 virtual-link 3.3.3.3
network 10.1.2.0 0.0.0.255 area 0
network 10.1.12.0 0.0.0.255 area 0
network 10.1.23.0 0.0.0.255 area 23
!
End
Router R3
R3#show running-config
hostname R3
!
!
interface Loopback3
description Accounting Department
ip address 10.1.3.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback100
ip address 192.168.100.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback101
ip address 192.168.101.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback102
ip address 192.168.102.1 255.255.255.0
ip ospf network point-to-point
!
interface Loopback103
ip address 192.168.103.1 255.255.255.0
ip ospf network point-to-point
!
interface Ethernet0/0
no ip address
shutdown
!
interface Ethernet0/1
ip address 10.1.23.3 255.255.255.0
!
interface Ethernet0/2
no ip address
shutdown
!
interface Ethernet0/3
no ip address
shutdown
!
router ospf 1
router-id 3.3.3.3
area 23 virtual-link 2.2.2.2
area 100 range 192.168.100.0 255.255.252.0
network 10.1.3.0 0.0.0.255 area 23
network 10.1.23.0 0.0.0.255 area 23
network 192.168.100.0 0.0.3.255 area 100
!
!
end
หวังว่าน่าจะได้ความรู้ในส่วนของการตั้งค่า กันไปนะครับ
แล้วเจอกันบทความต่อไปครับ
ขอบคุณแหล่งที่มา www.cisco.com, www.ine.com, และ เอกสาร LAB Cisco Networking Academy