Lab 17 OSPF Single Area

Objective

To be able to configure OSPF in single area network environment.

Topology

Basic Setting

IPs for computers and routers have been set up.

Requirements

• Configure OSPF in area 0
• Check the routing table.
• Check the convergence for OSPF.

Steps

On Router2

Router>en
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.0 0.0.0.3 area 0
Router(config-router)#network 172.16.0.0 0.0.255.255 area 0
Router(config-router)#
OR
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.1 0.0.0.0 area 0
Router(config-router)#network 172.16.0.1 0.0.0.0 area 0
Router(config-router)#

On Route0

Router>en
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.0 0.0.0.3 area 0
Router(config-router)#network 192.168.0.4 0.0.0.3 area 0
Router(config-router)#network 192.168.0.12 0.0.0.3 area 0
Router(config-router)#ex

On Router1

Router>en
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.0 0.0.0.255 area 0

On Router4

Router>en
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.0 0.0.0.255 area 0
Router(config-router)#network 172.18.0.0 0.0.255.255 area 0

On Router3

Router>en
Router#config t
Router(config)#router ospf 1
Router(config-router)#network 192.168.0.0 0.0.0.255 area 0
Router(config-router)#network 172.17.0.0 0.0.255.255 area 0
Router(config-router)#

Check the routing table

On Router3

Router#show 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
O 172.16.0.0/16 [110/1563] via 192.168.0.13, 00:01:15, Serial2/0
C 172.17.0.0/16 is directly connected, FastEthernet0/0
O 172.18.0.0/16 [110/782] via 192.168.0.17, 00:01:15, Serial3/0
192.168.0.0/30 is subnetted, 5 subnets
O 192.168.0.0 [110/1562] via 192.168.0.13, 00:01:15, Serial2/0
O 192.168.0.4 [110/1562] via 192.168.0.13, 00:01:15, Serial2/0
O 192.168.0.8 [110/1562] via 192.168.0.17, 00:01:15, Serial3/0
C 192.168.0.12 is directly connected, Serial2/0
C 192.168.0.16 is directly connected, Serial3/0
Router#

Check OSPF neighbors

Router#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.0.13 1 FULL/- 00:00:39 192.168.0.13 Serial2/0
192.168.0.17 1 FULL/- 00:00:35 192.168.0.17 Serial3/0
Router#

Check OSPF database

Router#show ip ospf database
OSPF Router with ID (192.168.0.18) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
192.168.0.1 192.168.0.1 673 0x80000005 0x0082b6 3
192.168.0.9 192.168.0.9 317 0x80000004 0x004015 4
192.168.0.17 192.168.0.17 219 0x80000005 0x00dc82 5
192.168.0.13 192.168.0.13 214 0x80000006 0x00fbd0 6
192.168.0.18 192.168.0.18 200 0x80000005 0x0093be 5

Test OSPF convergence speed

On PC0

PC>tracert 172.17.0.2
Tracing route to 172.17.0.2 over a maximum of 30 hops:
1 6 ms 8 ms 7 ms 172.16.0.1
2 12 ms 11 ms 11 ms 192.168.0.2
3 13 ms 18 ms 15 ms 192.168.0.14
4 25 ms 28 ms 29 ms 172.17.0.2
Trace complete.
PC>
Package path : Router2=>Router0=>Router3

On Router3

Router>en
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface serial 2/0
Router(config-if)#shutdown

On PC0

PC>tracert 172.17.0.2
Tracing route to 172.17.0.2 over a maximum of 30 hops:
1 9 ms 6 ms 7 ms 172.16.0.1
2 15 ms 11 ms 13 ms 192.168.0.2
3 14 ms 14 ms 16 ms 192.168.0.6
4 19 ms 22 ms 15 ms 192.168.0.10
5 26 ms 25 ms 29 ms 192.168.0.18
6 29 ms 30 ms 36 ms 172.17.0.2
Trace complete.
Package path: Router2=>Router0=>Router1=>Router4=>Router3