Configure Dynamic Routing with OSPF (Open Shortest Path First)

R1
Configure Fastethernet:
R1#conf

R1#configure t

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#inte

R1(config)#interface se

R1(config)#interface serial fa

R1(config)#interface fa

R1(config)#interface fastEthernet 0/0

R1(config-if)#inte

R1(config-if)#ip add

R1(config-if)#ip address 192.168.1.1 255.255.255.0

R1(config-if)#no sh

R1(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

Configure Interface:

R1(config)#interface se

R1(config)#interface serial 2/0

R1(config-if)#ip add

R1(config-if)#ip address 192.168.2.1 255.255.255.0

R1(config-if)#no sh

R1(config-if)#no shutdown

%LINK-5-CHANGED: Interface Serial2/0, changed state to down

Its showing down cause we have to configure interface on R2.

 R2

Configure Interface:

Router(config)#interface se

Router(config)#interface serial 3/0

Router(config-if)#ip add

Router(config-if)#ip address 192.168.2.2 255.255.255.0

Router(config-if)#clo

Router(config-if)#clock rat

Router(config-if)#clock rate 64000

Router(config-if)#no sh

Router(config-if)#no shutdown

%LINK-5-CHANGED: Interface Serial3/0, changed state to up

Router(config-if)#

Router#

%SYS-5-CONFIG_I: Configured from console by console

%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/0, changed state to up 

Now on both side ports are up

Now we have to configure second interface which is connected with R3.

R2(config)#interface serial 2/0

R2(config-if)#ip address 192.168.4.1 255.255.255.0

R2(config-if)#no sh

R2(config-if)#no shutdown

%LINK-5-CHANGED: Interface Serial2/0, changed state to down

Configure Fastethernet:

R2(config)#inte

R2(config)#interface fa

R2(config)#interface fastEthernet 3/0

%Invalid interface type and number

R2(config)#interface fastEthernet 0/0

R2(config-if)#ip add

R2(config-if)#ip address 192.168.3.1 255.255.255.0

R2(config-if)#no sh

R2(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

R3

Configure Interface:

R3(config-if)#ip add

R3(config-if)#ip address 192.168.4.2 255.255.255.0

R3(config-if)#clo

R3(config-if)#clock ra

R3(config-if)#clock rate 64000

R3(config-if)#no sh

R3(config-if)#no shutdown

%LINK-5-CHANGED: Interface Serial3/0, changed state to up

Configure Fastethernet:

R3(config)#inte

R3(config)#interface fa

R3(config)#interface fastEthernet 0/0

R3(config-if)#ip add

R3(config-if)#ip address 192.168.5.1 255.255.255.0

R3(config-if)#no sh

R3(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

R3(config-if)#

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

CONFIGURATION OF OSPF:

R1

R1(config)#router ospf 1

R1(config-router)#net

R1(config-router)#network 192.168.1.0 0.0.0.255 are

R1(config-router)#network 192.168.1.0 0.0.0.255 area 0

R1(config-router)#network 192.168.2.0 0.0.0.255 area 0

R1(config-router)#^Z

R1#

R2

R2(config)#router ospf 1

R2(config-router)#network 192.168.2.0 0.0.0.255 area 0

R2(config-router)#network 192.168.3.0 0.0.0.255 area 0

R2(config-router)#network 192.168.4.0 0.0.0.255 area 0

R2(config-router)#^Z

R3

R3(config)#router ospf 1

R3(config-router)#network 192.168.4.0 0.0.0.255 are

R3(config-router)#network 192.168.4.0 0.0.0.255 area 0

R3(config-router)#

02:22:34: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.4.1 on Serial3/0 from LOADING to FULL, Loading Done

R3(config-router)#network 192.168.5.0 0.0.0.255 area 0

R3(config-router)#^Z