Datasheet

Lab - Troubleshooting NAT Configurations

 PC-B acts as a host computer and dynamically receives an IP address from the created pool of

addresses called NAT_POOL, which uses the 209.165.200.240/29 range.

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 switch have been erased and have no startup configurations. If you are

unsure, contact your instructor.

Instructor Note: Refer to the Instructor Lab Manual for the procedures to initialize and reload devices.

Required Resources

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

 1 Switch (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: Build the Network and Configure Basic Device Settings

In Part 1, you will set up the network topology and configure the routers with basic settings. Additional NAT-

related configurations are provided. The NAT configurations for the Gateway router contains errors that you

will identify and correct as you proceed through the lab.

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

Step 2: Configure PC hosts.

Step 3: Initialize and reload the switch and routers.

Step 4: Configure basic settings for each router.

a. Disable DNS lookup.

b. Configure device name as shown in the topology.

c. Configure IP addresses as listed in the Address Table.

d. Set the clock rate to 128000 for DCE serial interfaces.

e. Assign cisco as the console and vty password.

f. Assign class as the encrypted privileged EXEC mode password.

g. Configure logging synchronous to prevent console messages from interrupting the command entry.

Step 5: Configure static routing.

a. Create a static route from the ISP router to the Gateway router-assigned public network address range

209.165.200.224/27.

ISP(config)# ip route 209.165.200.224 255.255.255.224 s0/0/0