Configuring IP Floating Static Routes on Cisco Routers

Objective

The objective of this lab exercise is to learn how to implement IP floating static route functionality on a Cisco router.

Purpose

Configuring a floating static route allows your Cisco router to have a backup route to a destination in case the primary route fails. This knowledge is essential for Cisco engineers and is part of the Cisco CCNA exam.

Lab Topology

Use the following topology to complete this lab exercise:

Image 1

Note: Both R2 and R3 connect to the Internet, so R1 has two exit options to the Internet.


Task 1: Configure Hostnames

Objective: Set hostnames on R1, R2, and R3 as illustrated in the topology.

Configuration:

R1#configure terminal
R1(config)#hostname R1
R1(config)#end

R2#configure terminal
R2(config)#hostname R2
R2(config)#end

R3#configure terminal
R3(config)#hostname R3
R3(config)#end

Task 2: Configure IP Addresses

Objective: Configure the IP addresses on the Gig0/0 and Gig0/1 interfaces of R1, R2, and R3 as illustrated in the topology.
Note: R1 will always have the .1 IP in each of its Gig interfaces. R2 and R3 will have the .1 IP on the Gig0/1 interface.

Configuration:

R1#configure terminal
R1(config)#interface gigabitEthernet0/0
R1(config-if)#no shutdown
R1(config-if)#ip address 192.168.10.1 255.255.255.252
R1(config-if)#exit
R1(config)#interface gigabitEthernet0/1
R1(config-if)#no shutdown
R1(config-if)#ip address 192.168.20.1 255.255.255.252
R1(config-if)#end

R2#configure terminal
R2(config)#interface gigabitEthernet0/0
R2(config-if)#no shutdown
R2(config-if)#ip address 192.168.10.2 255.255.255.252
R2(config-if)#exit
R2(config)#interface gigabitEthernet0/1
R2(config-if)#no shutdown
R2(config-if)#ip address 192.168.30.1 255.255.255.252
R2(config-if)#end

R3#configure terminal
R3(config)#interface gigabitEthernet0/0
R3(config-if)#no shutdown
R3(config-if)#ip address 192.168.20.2 255.255.255.252
R3(config-if)#exit
R3(config)#interface gigabitEthernet0/1
R3(config-if)#no shutdown
R3(config-if)#ip address 192.168.40.1 255.255.255.252
R3(config-if)#end

Task 3: Configure Default Static Routes

Objective: Configure two default static routes on R1. The first one (primary) will go to R2 with an administrative distance of 1. The secondary one will go to R3 with an administrative distance of 254. This ensures all traffic to unknown destinations is sent via R2.

Configuration:

R1#configure terminal
R1(config)#ip route 0.0.0.0 0.0.0.0 192.168.10.2
R1(config)#ip route 0.0.0.0 0.0.0.0 192.168.20.2 254
R1(config)#end

Task 4: Test Floating Static Route

Objective: Shut down the interface Gig0/0 of R1 and use show commands to observe how the secondary route activates.

R1#sh 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, 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 192.168.10.2 to network 0.0.0.0

     192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C       192.168.10.0/30 is directly connected, GigabitEthernet0/0
L       192.168.10.1/32 is directly connected, GigabitEthernet0/0
     192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C       192.168.20.0/30 is directly connected, GigabitEthernet0/1
L       192.168.20.1/32 is directly connected, GigabitEthernet0/1
S*   0.0.0.0/0 [1/0] via 192.168.10.2

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#interface gigabitEthernet0/0
R1(config-if)#shutdown
R1(config-if)#end

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, 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 192.168.20.2 to network 0.0.0.0

     192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C       192.168.20.0/30 is directly connected, GigabitEthernet0/1
L       192.168.20.1/32 is directly connected, GigabitEthernet0/1
S*   0.0.0.0/0 [254/0] via 192.168.20.2

R1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0     192.168.10.1    YES manual administratively down down
GigabitEthernet0/1     192.168.20.1    YES manual up                    up
GigabitEthernet0/2     unassigned      YES unset  administratively down down
Vlan1                  unassigned      YES unset  administratively down down

Task 5: Restore Primary Route

Objective: Bring the interface Gig0/0 of R1 up again and verify how it re-establishes the primary route due to the lower administrative distance.

Configuration:

R1#configure terminal
R1(config)#interface gigabitEthernet0/0
R1(config-if)#no shutdown
R1(config-if)#end

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, 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 192.168.10.2 to network 0.0.0.0

     192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C       192.168.10.0/30 is directly connected, GigabitEthernet0/0
L       192.168.10.1/32 is directly connected, GigabitEthernet0/0
     192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C       192.168.20.0/30 is directly connected, GigabitEthernet0/1
L       192.168.20.1/32 is directly connected, GigabitEthernet0/1
S*   0.0.0.0/0 [1/0] via 192.168.10.2

R1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0     192.168.10.1    YES manual up                    up
GigabitEthernet0/1     192.168.20.1    YES manual up                    up
GigabitEthernet0/2     unassigned      YES unset  administratively down down
Vlan1                  unassigned      YES unset  administratively down down

Cisco Packet Tracer file:
Load and open the .pkt Lab file in Cisco Packet Tracer from here: Configuring_IP_Floating_Static_Routes.pkt