Configuring Static Routes on Routers

Nerd Cafe

Introduction

Static routing is a method where a network administrator manually configures routing entries in the router’s routing table. Unlike dynamic routing, static routing is straightforward and does not consume extra CPU or bandwidth. It is often used in small networks or as a backup for dynamic routing.

Scenario: Configuring Static Routes Between Two Networks

Imagine we have two branch offices connected through routers, and we need to configure static routes to ensure communication between them.

Topology

• Router1 (R1)

  • LAN Network: 192.168.1.0/24

  • Interface to R2: 10.0.0.1/30

• Router2 (R2)

  • LAN Network: 192.168.2.0/24

  • Interface to R1: 10.0.0.2/30

Objective

• Configure static routes on R1 to reach 192.168.2.0/24 via R2.

• Configure static routes on R2 to reach 192.168.1.0/24 via R1.

Step 1: Configure IP Addresses

On R1

R1#configure terminal
R1(config)#interface fastEthernet 0/0
R1(config-if)#ip address 192.168.1.1 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 3/0
R1(config-if)#ip address 10.0.0.1 255.255.255.252
R1(config-if)#clock rate 64000
R1(config-if)#no shutdown

On R2

R2#configure terminal
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 192.168.2.1 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit                                                                                    et0/0, changed state to up
R2(config)#interface serial 3/0
R2(config-if)#ip address 10.0.0.2 255.255.255.252
R2(config-if)#no shutdown

On PC1

PC1> ip 192.168.1.100/24 192.168.1.1
Checking for duplicate address...
PC1 : 192.168.1.100 255.255.255.0 gateway 192.168.1.1

PC1> show ip

NAME        : PC1[1]
IP/MASK     : 192.168.1.100/24
GATEWAY     : 192.168.1.1
DNS         :
MAC         : 00:50:79:66:68:05
LPORT       : 20018
RHOST:PORT  : 127.0.0.1:20019
MTU         : 1500

PC1> save
Saving startup configuration to startup.vpc
.  done

PC1>

On PC2

PC2> ip 192.168.2.100/24 192.168.2.1
Checking for duplicate address...
PC2 : 192.168.2.100 255.255.255.0 gateway 192.168.2.1

PC2> show ip

NAME        : PC2[1]
IP/MASK     : 192.168.2.100/24
GATEWAY     : 192.168.2.1
DNS         :
MAC         : 00:50:79:66:68:00
LPORT       : 20020
RHOST:PORT  : 127.0.0.1:20021
MTU         : 1500

PC2> save
Saving startup configuration to startup.vpc
.  done

PC2>

Step 3: Configure Static Routes

Now, we need to inform R1 and R2 about each other’s LAN networks.

On R1 (Route to 192.168.2.0/24 via R2)

R1(config)#ip route 192.168.2.0 255.255.255.0 10.0.0.2

On R2 (Route to 192.168.1.0/24 via R1)

R2(config)#ip route 192.168.1.0 255.255.255.0 10.0.0.1

Step 4: Verify the Configuration

Check Routing Table

• On R1:

R1#show ip rou
R1#show ip route
Codes: L - local, C - connected, S - static, 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
       i - IS-IS, su - IS-IS summary, 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, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.0.0.0/30 is directly connected, Serial3/0
L        10.0.0.1/32 is directly connected, Serial3/0
      192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.1.0/24 is directly connected, FastEthernet0/0
L        192.168.1.1/32 is directly connected, FastEthernet0/0
S     192.168.2.0/24 [1/0] via 10.0.0.2
R1#

• On R1:

R2#show ip route
Codes: L - local, C - connected, S - static, 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
       i - IS-IS, su - IS-IS summary, 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, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.0.0.0/30 is directly connected, Serial3/0
L        10.0.0.2/32 is directly connected, Serial3/0
S     192.168.1.0/24 [1/0] via 10.0.0.1
      192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.2.0/24 is directly connected, FastEthernet0/0
L        192.168.2.1/32 is directly connected, FastEthernet0/0
R2#

Test Connectivity

PC1> ping 192.168.2.100

84 bytes from 192.168.2.100 icmp_seq=1 ttl=62 time=83.568 ms
84 bytes from 192.168.2.100 icmp_seq=2 ttl=62 time=22.819 ms
84 bytes from 192.168.2.100 icmp_seq=3 ttl=62 time=41.801 ms
84 bytes from 192.168.2.100 icmp_seq=4 ttl=62 time=23.112 ms
^C
PC1>

Keywords

Static routing, routing table, IP route, Cisco routers, manual routing, network topology, router configuration, LAN network, subnet mask, routing protocol, default route, static route configuration, IP address assignment, routing entry, routing protocol, command-line interface, router interfaces, router connectivity, packet forwarding, network communication, troubleshooting, سیسکو