Configuring IPv4 Static and Default Routes

Topology

Addressing Table

Device	Interface	IP Address	Subnet Mask	Default Gateway
R1	G0/1	192.168.0.1	255.255.255.0	N/A
	S0/0/1	10.1.1.1	255.255.255.252	N/A
R3	G0/1	192.168.1.1	255.255.255.0	N/A
	S0/0/0 (DCE)	10.1.1.2	255.255.255.252	N/A
	Lo0	209.165.200.225	255.255.255.224	N/A
	Lo1	198.133.219.1	255.255.255.0	N/A
PC-A	NIC	192.168.0.10	255.255.255.0	192.168.0.1
PC-C	NIC	192.168.1.10	255.255.255.0	192.168.1.1

Objectives

Part 1: Set Up the Topology and Initialize Devices

Part 2: Configure Basic Device Settings and Verify Connectivity

Part 3: Configure Static Routes

·         Configure a recursive static route.

·         Configure a directly connected static route.

·         Configure and remove static routes.

Part 4: Configure and Verify a Default Route

Background / Scenario

A router uses a routing table to determine where to send packets. The routing table contains a set of routes that describe which gateway or interface the router uses to reach a specified network. Initially, the routing table contains only directly connected networks. To communicate with distant networks, routes must be specified and added to the routing table.

In this lab, you will manually configure a static route to a specified distant network based on a next-hop IP address or exit interface. You will also configure a static default route. A default route is a type of static route that specifies a gateway to use when the routing table does not contain a path for the destination network.

Note: This lab provides minimal assistance with the actual commands necessary to configure static routing. However, the required commands are provided in Appendix A. Test your knowledge by trying to configure the devices without referring to the appendix.

Note: The routers used with CCNA hands-on labs are Cisco 1941 Integrated Services Routers (ISRs) with Cisco IOS Release 15.2(4)M3 (universalk9 image). The switches used are Cisco Catalyst 2960s with Cisco IOS Release 15.0(2) (lanbasek9 image). Other routers, switches, and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and output produced might vary from what is shown in the labs. Refer to the Router Interface Summary Table at the end of this lab for the correct interface identifiers.

Note: Make sure that the routers and switches have been erased and have no startup configurations. If you are unsure, contact your instructor.

Required Resources

·         2 Routers (Cisco 1941 with Cisco IOS Release 15.2(4)M3 universal image or comparable)

·         2 Switches (Cisco 2960 with Cisco IOS Release 15.0(2) lanbasek9 image or comparable)

·         2 PCs (Windows 7, Vista, or XP with terminal emulation program, such as Tera Term)

·         Console cables to configure the Cisco IOS devices via the console ports

·         Ethernet and serial cables as shown in the topology

Part 1:     Set Up the Topology and Initialize Devices

Step 1:     Cable the network as shown in the topology.

Step 2:     Initialize and reload the router and switch.

Part 2:     Configure Basic Device Settings and Verify Connectivity

In Part 2, you will configure basic settings, such as the interface IP addresses, device access, and passwords. You will verify LAN connectivity and identify routes listed in the routing tables for R1 and R3.

Step 1:     Configure the PC interfaces.

Step 2:     Configure basic settings on the routers.

a.     Configure device names, as shown in the Topology and Addressing Table.

b.    Disable DNS lookup.

c.     Assign class as the enable password and assign cisco as the console and vty password.

d.    Save the running configuration to the startup configuration file.

Step 3:     Configure IP settings on the routers.

a.     Configure the R1 and R3 interfaces with IP addresses according to the Addressing Table.

b.    The S0/0/0 connection is the DCE connection and requires the clock rate command. The R3 S0/0/0 configuration is displayed below.

R3(config)# interface s0/0/0

R3(config-if)# ip address 10.1.1.2 255.255.255.252

R3(config-if)# clock rate 128000

R3(config-if)# no shutdown

Step 4:     Verify connectivity of the LANs.

a.     Test connectivity by pinging from each PC to the default gateway that has been configured for that host.

From PC-A, is it possible to ping the default gateway? __________

From PC-C, is it possible to ping the default gateway? __________

b.    Test connectivity by pinging between the directly connected routers.

From R1, is it possible to ping the S0/0/0 interface of R3? __________

If the answer is no to any of these questions, troubleshoot the configurations and correct the error.

c.     Test connectivity between devices that are not directly connected.

From PC-A, is it possible to ping PC-C? __________

From PC-A, is it possible to ping Lo0? __________

From PC-A, is it possible to ping Lo1? __________

Were these pings successful? Why or why not?

____________________________________________________________________________________

____________________________________________________________________________________

Note: It may be necessary to disable the PC firewall to ping between PCs.

Step 5:     Gather information.

a.     Check the status of the interfaces on R1 with the show ip interface brief command.

How many interfaces are activated on R1? __________

b.    Check the status of the interfaces on R3.  

How many interfaces are activated on R3? __________

c.     View the routing table information for R1 using the show ip route command.

What networks are present in the Addressing Table of this lab, but not in the routing table for R1?

____________________________________________________________________________________

d.    View the routing table information for R3.

What networks are present in the Addressing Table in this lab, but not in the routing table for R3?

____________________________________________________________________________________

Why are all the networks not in the routing tables for each of the routers?

____________________________________________________________________________________

____________________________________________________________________________________

Part 3:     Configure Static Routes

In Part 3, you will employ multiple ways to implement static and default routes, you will confirm that the routes have been added to the routing tables of R1 and R3, and you will verify connectivity based on the introduced routes.

Note: This lab provides minimal assistance with the actual commands necessary to configure static routing. However, the required commands are provided in Appendix A. Test your knowledge by trying to configure the devices without referring to the appendix.

Step 1:     Configure a recursive static route.

With a recursive static route, the next-hop IP address is specified. Because only the next-hop IP is specified, the router must perform multiple lookups in the routing table before forwarding packets. To configure recursive static routes, use the following syntax:

Router(config)# ip route network-address subnet-mask ip-address

a.     On the R1 router, configure a static route to the 192.168.1.0 network using the IP address of the Serial 0/0/0 interface of R3 as the next-hop address. Write the command you used in the space provided.

____________________________________________________________________________________

b.    View the routing table to verify the new static route entry.

How is this new route listed in the routing table?

____________________________________________________________________________________

From host PC-A, is it possible to ping the host PC-C? __________

These pings should fail. If the recursive static route is correctly configured, the ping arrives at PC-C. PC-C sends a ping reply back to PC-A. However, the ping reply is discarded at R3 because R3 does not have a return route to the 192.168.0.0 network in the routing table.

Step 2:     Configure a directly connected static route.

With a directly connected static route, the exit-interface parameter is specified, which allows the router to resolve a forwarding decision in one lookup. A directly connected static route is typically used with a point-to-point serial interface. To configure directly connected static routes with an exit interface specified, use the following syntax:

Router(config)# ip route network-address subnet-mask exit-intf

a.     On the R3 router, configure a static route to the 192.168.0.0 network using S0/0/0 as the exit interface. Write the command you used in the space provided.

____________________________________________________________________________________

b.    View the routing table to verify the new static route entry.

How is this new route listed in the routing table?

____________________________________________________________________________________

c.     From host PC-A, is it possible to ping the host PC-C? __________

This ping should be successful.

Note: It may be necessary to disable the PC firewall to ping between PCs.

Step 3:     Configure a static route.

a.     On the R1 router, configure a static route to the 198.133.219.0 network using one of the static route configuration options from the previous steps. Write the command you used in the space provided.

____________________________________________________________________________________

b.    On the R1 router, configure a static route to the 209.165.200.224 network on R3 using the other static route configuration option from the previous steps. Write the command you used in the space provided.

____________________________________________________________________________________

c.     View the routing table to verify the new static route entry.

How is this new route listed in the routing table?

____________________________________________________________________________________

d.    From host PC-A, is it possible to ping the R1 address 198.133.219.1? __________

This ping should be successful.

Step 4:     Remove static routes for loopback addresses.

a.     On R1, use the no command to remove the static routes for the two loopback addresses from the routing table. Write the commands you used in the space provided.

__________________________________________________________________________________

b.    View the routing table to verify the routes have been removed.

How many network routes are listed in the routing table on R1? __________

Is the Gateway of last resort set? __________

Part 4:     Configure and Verify a Default Route

In Part 4, you will implement a default route, confirm that the route has been added to the routing table, and verify connectivity based on the introduced route.

A default route identifies the gateway to which the router sends all IP packets for which it does not have a learned or static route. A default static route is a static route with 0.0.0.0 as the destination IP address and subnet mask. This is commonly referred to as a “quad zero” route.

In a default route, either the next-hop IP address or exit interface can be specified. To configure a default static route, use the following syntax:

Router(config)# ip route 0.0.0.0 0.0.0.0 {ip-address or exit-intf}

a.     Configure the R1 router with a default route using the exit interface of S0/0/1. Write the command you used in the space provided.

_____________________________________________________________________________

b.    View the routing table to verify the new static route entry.

How is this new route listed in the routing table?

____________________________________________________________________________________

What is the Gateway of last resort?

____________________________________________________________________________________

c.     From host PC-A, is it possible to ping the 209.165.200.225? __________

d.    From host PC-A, is it possible to ping the 198.133.219.1? __________

These pings should be successful.

Reflection

1.     A new network 192.168.3.0/24 is connected to interface G0/0 on R1. What commands could be used to configure a static route to that network from R3?

_______________________________________________________________________________________

_______________________________________________________________________________________

2.     Is there a benefit to configuring a directly connected static route instead of a recursive static route?

_______________________________________________________________________________________

_______________________________________________________________________________________

3.     Why is it important to configure a default route on a router?

_______________________________________________________________________________________

Router Interface Summary Table

Router Interface Summary
Router Model	Ethernet Interface #1	Ethernet Interface #2	Serial Interface #1	Serial Interface #2
1800	Fast Ethernet 0/0 (F0/0)	Fast Ethernet 0/1 (F0/1)	Serial 0/0/0 (S0/0/0)	Serial 0/0/1 (S0/0/1)
1900	Gigabit Ethernet 0/0 (G0/0)	Gigabit Ethernet 0/1 (G0/1)	Serial 0/0/0 (S0/0/0)	Serial 0/0/1 (S0/0/1)
2801	Fast Ethernet 0/0 (F0/0)	Fast Ethernet 0/1 (F0/1)	Serial 0/1/0 (S0/1/0)	Serial 0/1/1 (S0/1/1)
2811	Fast Ethernet 0/0 (F0/0)	Fast Ethernet 0/1 (F0/1)	Serial 0/0/0 (S0/0/0)	Serial 0/0/1 (S0/0/1)
2900	Gigabit Ethernet 0/0 (G0/0)	Gigabit Ethernet 0/1 (G0/1)	Serial 0/0/0 (S0/0/0)	Serial 0/0/1 (S0/0/1)
Note: To find out how the router is configured, look at the interfaces to identify the type of router and how many interfaces the router has. There is no way to effectively list all the combinations of configurations for each router class. This table includes identifiers for the possible combinations of Ethernet and Serial interfaces in the device. The table does not include any other type of interface, even though a specific router may contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation that can be used in Cisco IOS commands to represent the interface.

Appendix A: Configuration Commands for Parts 2, 3, and 4

The commands listed in Appendix A are for reference only. This Appendix does not include all the specific commands necessary to complete this lab.

Basic Device Settings

Configure IP settings on the router.

R3(config)# interface s0/0/0

R3(config-if)# ip address 10.1.1.2 255.255.255.252

R3(config-if)# clock rate 128000

R3(config-if)# no shutdown

Static Route Configurations

Configure a recursive static route.

R1(config)# ip route 192.168.1.0 255.255.255.0 10.1.1.2

Configure a directly connected static route.

R3(config)# ip route 192.168.0.0 255.255.255.0 s0/0/0

Remove static routes.

R1(config)# no ip route 209.165.200.224 255.255.255.224 serial0/0/1

or

R1(config)# no ip route 209.165.200.224 255.255.255.224 10.1.1.2

or

R1(config)# no ip route 209.165.200.224 255.255.255.224

Default Route Configuration

R1(config)# ip route 0.0.0.0 0.0.0.0 s0/0/1