Lesson No. 22 Introduction to the network inter-communication through OSPF.

Description: Open Shortest Path First (OSPF) is a link-state routing protocol for Internet Protocol (IP) networks. It uses a link state routing algorithm and falls into the group of interior routing protocols, operating within a single autonomous system (AS).  Using OSPF, a host that obtains a change to a routing table or detects a change in the network immediately multicasts the information to all other hosts in the network so that all will have the same routing table information. Unlike the RIP in which the entire routing table is sent, the host using OSPF sends only the part that has changed. With RIP, the routing table is sent to a neighbour host every 30 seconds. OSPF multicasts the updated information only when a change has taken place.

Solution: The given topology is:

 

Inter-Communication through OSPF.

Steps:

Configuring steps for router0:

Router0>enable

Router0#config terminal

Router0(config)#interface fa0/0

Router0(config-if)#ip address 192.16.10.3 255.255.255.0

Router0(config-if)#no shutdown

Router0(config-if)#exit

Router0(config)#interface se2/0

Router0(config-if)#ip address 10.0.0.1 255.255.255.0

Router0(config-if)#no shutdown

Router0(config-if)#clock rate 64000

Router0(config-if)#exit

Router0(config-if)#router ospf 100

Router0(config-router)#network 20.0.0.0 0.0.0.255 area 0

Router0(config-router)#network 192.16.12.0 0.0.0.255 area 0

Router0(config-router)#exit

Configuring steps for router1:

Router1>enable

Router1#config terminal

Router1(config)#interface fa0/0

Router1(config-if)#ip address 192.16.12.3 255.255.255.0

Router1(config-if)#no shutdown

Router1(config-if)#exit

Router1(config)#interface se2/0

Router1(config-if)#ip address 20.0.0.2 255.255.255.0

Router1(config-if)#no shutdown

Router1(config-if)#clock rate 64000

Router1(config-if)#exit

Router1(config-if)#router ospf 100

Router1(config-router)#network 192.16.12.0 0.0.0.255 area 0

Router1(config-router)#network 20.0.0.0 0.0.0.255 area 0

Router1(config-router)#exit

Configuring steps for router2:

Router2>enable

Router2#config terminal

Router2(config)#interface fa0/0

Router2(config-if)#ip address 192.16.11.3 255.255.255.0

Router2(config-if)#no shutdown

Router2(config-if)#exit

Router2(config)#interface se2/0

Router2(config-if)#ip address 10.0.0.2 255.255.255.0

Router2(config-if)#no shutdown

Router2(config-if)#exit

Router2(config)#interface se3/0

Router2(config-if)#ip address 20.0.0.1 255.255.255.0

Router2(config-if)#no shutdown

Router2(config-if)#clock rate 64000

Router2(config-if)#exit

Router2(config-if)#router ospf 100

Router2(config-router)#network 20.0.0.0 0.0.0.255 area 0

Router2(config-router)#network 192.16.11.0 0.0.0.255 area 0

Router2(config-router)#network 10.0.0.0 0.0.0.255 area 0

Router2(config-router)#exit

Configuring steps for PC0:

Ip address: 192.16.10.1

Subnet mask: 255.255.255.0

Default gateway: 10.0.0.0.1

Configuring steps for PC1:

Ip address: 192.1.10.2

Subnet mask: 255.255.255.0

Default gateway: 10.0.0.1

Configuring steps for PC2:

Ip address: 192.16.11.1

Subnet mask: 255.255.255.0

Default gateway: 10.0.0.2

Configuring steps for PC3:

Ip address: 192.16.11.2

Subnet mask: 255.255.255.0

Default gateway: 10.0.0.2

Configuring steps for PC4:

Ip address: 192.16.12.2

Subnet mask: 255.255.255.0

Default gateway: 20.0.0.2

Configuring steps for PC5:

Ip address: 192.16.12.1

Subnet mask: 255.255.255.0

Default gateway: 20.0.0.2

Output:

Show ip route command on router 1: