PT Activity 7.4.3: Troubleshooting DHCP and NAT (Instructor)
Topology Diagram
Addressing Table
Device
R1
R2
ISP
Interface
IP Address
Subnet Mask
S0/0/0
172.16.0.1
255.255.255.252
Fa0/0
172.16.10.1
255.255.255.0
Fa0/1
172.16.11.1
255.255.255.0
S0/0/0
172.16.0.2
255.255.255.252
S0/0/1
209.165.201.1
255.255.255.252
Fa0/0
172.16.20.1
255.255.255.0
S0/0/1
209.165.201.2
255.255.255.252
Learning Objectives
Upon completion of this lab, you will be able to:

Find and correct network errors.

Document the corrected network.
All contents are Copyright © 2007-2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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CCNA Exploration
Accessing the WAN: IP Addressing Services
PT Activity 7.4.3: Troubleshooting DHCP and NAT
Scenario
The routers at your company were configured by an inexperienced network engineer. Several errors in
the configuration have resulted in connectivity issues. Your boss has asked you to troubleshoot and
correct the configuration errors and document your work. Using your knowledge of DHCP, NAT, and
standard testing methods, find and correct the errors. Make sure all clients have full connectivity. The
user EXEC password is cisco, and the privileged EXEC password is class.
Task 1: Find and Correct Network Errors
Step 1. Troubleshoot and correct all errors.
Use troubleshooting commands to discover errors and then correct them. When all errors are corrected,
you should be able to ping from PC1 and PC2 to ISP. ISP should be able to ping the inside web server at
its public IP address.
The following errors are in the activity:

R1 is missing the no shutdown command on the serial 0/0/0 interface.

The ACL on R2 is missing a permit statement for the .11 network.

R2 is missing the ip nat inside command on the serial 0/0/0 interface.

R2 is missing the default-information originate command in the RIP configuration.
Step 2. Check results.
After correcting all errors, your completion percentage should be 100%.
Task 2: Document the Corrected Network
On each router, issue the show run command and capture the configurations.
All contents are Copyright © 2007-2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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