1. OSPF (Open Shortest Path First) Single Area Configuration and TestingBy
Nur Wajianto
Collinsvile, Brisbane QD May

2. Link State Routing Protocols
Link-state routing protocols are also known as shortest path first protocols and are built around Edsger Dijkstra's shortest path first (SPF) algorithm. There are two link-state routing protocols for IP :
OSPF(Open Shortest Path First)
IS-IS(Intermediate-System-to-Intermediate-System)

3. Advantages of a Link State Routing Protocol
Each router builds its own topological map of the network to determine the shortest path
Immediate flooding of LSPs achieves faster convergence
LSPs are sent only when there is a change in the topology and contain only the information regarding that change
Hierarchical design used when implementing multiple areas

4. Basic Configuration and Goals
Set the host name, and bring up the interfaces
Configure the OSPF routing protocol
Select the directly connected networks
Display the routing table
Display the OSPF protocol information

5. Configure Routers as the figure below

6. Verify that each router can ping its directly connected neighbors
Queensland#ping
Queensland#ping
Darwin#ping
Adelaide#ping

7. Add OSPF to Queensland use the Process ID number 100
Queensland#config terminal
Queensland(config)#router ospf 100
Queensland(config-router)#network area 0
Queensland(config-router)#network area 0

8. Add OSPF to Darwin use the Process ID number 100
Darwin#config terminal
Darwin(config)#router ospf 100
Darwin(config-router)#network area 0

9. Add OSPF to Adelaide use the Process ID number 100
Adelaide#config terminal
Adelaide(config)#router ospf 100
Adelaide(config-router)#network area 0

10. Test OSPF Routing
OSPF should now be running on all three routers. Press CTRL+Z to exit to privileged mode, and can ping non-directly connected routers. From Darwin, and now be able to ping Adelaide’s serial 0 interface.
Darwin#ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 62/62/63 ms

11. Test OSPF Routing
Connect to Adelaide and ping Darwin’s serial 1 interface. If can ping on both devices, mean its correctly configured routing and otherwise
Adelaide#ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 62/62/63 ms

12. Display the routing table on Darwin’s Router
Darwin#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
Gateway of last resort is not set
/24 is subnetted, 1 subnets
C is directly connected, Serial1/1
/30 is subnetted, 1 subnets
O [110/1562] via , 00:16:14, Serial1/1

13. Display the Specific IP Routing Protocol Information on Darwin’s Router
Darwin#show ip protocols
Routing Protocol is "ospf 100"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Router ID
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Maximum path: 4
Routing for Networks:
area 0
Routing Information Sources:
Gateway Distance Last Update
:17:05
Distance: (default is 110)

14. Display the OSPF Database on Darwin’s Router
Darwin#show ip ospf database
OSPF Router with ID ( ) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
x x00e13b 2
x x00940b 4
x x00ab5d 2

15. Display the all of IP OSPF Neighbors
Darwin#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
FULL/ :00: Serial1/1
Darwin#show ip ospf interface
Serial1/1 is up, line protocol is up
Internet address is /24, Area 0
Process ID 100, Router ID , Network Type POINT-TO-POINT, Cost: 781
Transmit Delay is 1 sec, State POINT-TO-POINT, Priority 0
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:09
Index 1/1, 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
Suppress hello for 0 neighbor(s)

16. Thank You For Your Attention
Ask and Question