Configuring Interfaces and Static Routes on Cisco Routers (R1, R2, R3)

This example shows the command‑line configuration of three Cisco routers (R1, R2, R3) to create a simple static routing topology.

Step 1: Configure interfaces on R1

Router(config)#interface fastEthernet 0/0
R1(config-if)#ip address 192.168.1.254 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface fastEthernet 0/1
R1(config-if)#ip address 192.168.2.1 255.255.255.0
R1(config-if)#no shutdown

Step 2: Configure interfaces on R2

R2(config)#interface f0/1
R2(config-if)#ip address 192.168.2.2 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 192.168.3.1 255.255.255.0
R2(config-if)#no shutdown

Step 3: Configure interfaces on R3

R3(config)#interface fastEthernet 0/1
R3(config-if)#ip address 192.168.3.2 255.255.255.0
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface fastEthernet 0/0
R3(config-if)#ip address 192.168.4.254 255.255.255.0
R3(config-if)#no shutdown

Step 4: Add static routes

R1(config)#ip route 192.168.3.0 255.255.255.0 192.168.2.2
R1(config)#ip route 192.168.4.0 255.255.255.0 192.168.2.2
R2(config)#ip route 192.168.1.0 255.255.255.0 192.168.2.1
R2(config)#ip route 192.168.4.0 255.255.255.0 192.168.3.2
R3(config)#ip route 192.168.1.0 255.255.255.0 192.168.3.1
R3(config)#ip route 192.168.2.0 255.255.255.0 192.168.3.1

After configuring the interfaces and static routes, you can view the routing tables with show ip route on each router to confirm that the routes are correctly installed.

The included diagram (image) illustrates the resulting network topology and the flow of traffic between the subnets.