© 2016 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public. Page 1 of 4
Packet Tracer – Using File and Data Integrity Checks
Addressing Table
Device
Private IP
Address Public IP Address Subnet Mask Site
FTP/Web Server 10.44.1.254
209.165.201.3
http://www.cisco.corp
255.255.255.0 Metropolis Bank HQ
Backup File
Server
N/A
209.165.201.10
https://www.cisco2.corp
255.255.255.248 Internet
Mike 10.44.2.101 N/A 255.255.255.0 Healthcare at Home
Sally 10.44.1.2 N/A 255.255.255.0 Metropolis Bank HQ
Bob 10.44.1.3 N/A 255.255.255.0 Metropolis Bank HQ
Objectives
Part 1: Download the Client Files to Mike’s PC
Part 2: Download the Client Files from the Backup File Server to Mike’s PC
Part 3: Verify the Integrity of the Client Files using Hashing
Part 4: Verify the Integrity of Critical Files using HMAC
Background
In this activity, you will verify the integrity of multiple files using hashes to ensure files have not been
tampered with. If any files are suspected of being tampered with, they are to be sent to Sally’s PC for further
analysis. The IP addressing, network configuration, and service configurations are already complete. You will
use the client devices in the differing geographic regions to verify and transfer any suspect files.
Part 1: Download the Client Files to Mike’s PC
Step 1: Access the FTP server from Mike’s PC.
a. Click the Gotham Healthcare Branch site and then click the PC Mike.
b. Click the Desktop tab and then click Web Browser.
c. Enter the URL http://www.cisco.corp and click Go.
d. Click the link to download the most current files.
What protocol was used to access this webpage on the backup file server?
Step 2: The file server has been hacked, notify Sally.
a. Within the Gotham Healthcare Branch site, click the PC Mike.
b. Click the Desktop tab and then click Email.
c. Create an email and send it to Sally@cisco.corp
and tell her about the File Server.
Packet Tracer Using File and Data Integrity Checks
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Part 2: Download the Client Files from the Backup File Server to Mike’s PC
Step 1: Access the offsite FTP server from Mike’s PC.
a. Within the Gotham Healthcare Branch site, click the PC Mike.
b. Click the Desktop tab and then click Web Browser.
c. Enter the URL https://www.cisco2.corp and click Go.
d. Click the link to view the most recent files and their hashes.
What protocol was used to access this webpage on the backup file server?
What are the file names and hashes of the client files on the backup server? (copy and paste them below)
Step 2: Download the client files to Mike’s PC.
a. Within the Gotham Healthcare Branch site, click the PC Mike.
b. Click the Desktop tab and then click Command Prompt.
c. Connect to the Backup File server by entering ftp www.cisco2.corp in the command prompt.
d. Enter the username of mike and a password of cisco123.
e. At the ftp> prompt, enter the command dir to view the current files stored on the remote FTP server.
f. Download the six client files (NEclients.txt, NWclients.txt, Nclients.txt, SEclients.txt, SWclients.txt, and
Sclients.txt) to Mike’s PC by entering the command get FILENAME.txt, replace FILENAME with one of
the six client filenames.
ftp> get NEclients.txt
Reading file NEclients.txt from www.cisco2.corp:
File transfer in progress...
[Transfer complete - 584 bytes]
584 bytes copied in 0.05 secs (11680 bytes/sec)
g. After downloading all the files, enter the command quit at the ftp> prompt.
h. At the PC> prompt, enter the command dir and verify the client files are now on Mikes PC.
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Part 3: Verify the Integrity of the Client Files using Hashing
Step 1: Check the hashes on the client files on Mike’s PC.
a. Within the Gotham Healthcare Branch site, click the PC Mike.
b. Click the Desktop tab and then click Text Editor.
c. In the Text Editor window, click File > Open.
d. Click on the first document NEclients.txt and click OK.
e. Copy the entire text document contents.
f. Open a web browser on your personal computer and browse to the website
https://www.tools4noobs.com/online_tools/hash/
g. Click the whitespace and paste in the text document contents. Make sure the algorithm is set to md2.
Click Hash this!.
h. To make sure a file has not been tampered with, you will compare the resulting hash with the
filename/hash information you found in Part 2 Step 1.
i. Repeat Steps d through h for each client file and compare the generated hash with the original hash
shown in Part 2 Step 1.
Which file has been tampered with and has an incorrect hash?
Step 2: Download the suspected file to Sally’s PC.
a. Click the Metropolis Bank HQ site, and then click the PC Sally.
b. Click the Desktop tab and then click Command Prompt.
c. Connect to the Backup File server by entering ftp www.cisco2.corp in the command prompt.
d. Enter the username of sally and a password of cisco123.
e. At the ftp> prompt, enter the command dir to view the current files stored on the remote FTP server.
f. Download the file that was found to have been tampered with in Part 3 Step 1.
g. At the ftp> prompt, enter the command quit.
h. At the PC> prompt, enter the command dir and verify the tampered client file is now on Sally’s PC for
analysis at a later time.
Part 4: Verify the Integrity of Critical Files using HMAC
Step 1: Compute the HMAC of a critical file.
a. Within the Metropolis Bank HQ site, click the PC Bob.
b. Click the Desktop tab and then click Command Prompt.
c. At the PC> prompt, enter the command dir and verify the critical file named income.txt is on Bob’s PC.
d. Within the Desktop tab, click Text Editor.
e. In the Text Editor window, click File > Open.
f. Click the document income.txt and click OK.
g. Copy the entire text document contents.
Packet Tracer Using File and Data Integrity Checks
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h. Open a web browser on your personal computer and browse to the website
http://www.freeformatter.com/hmac-generator.html
i. Click the whitespace and paste in the text document contents. Enter the secret key of cisco123. Make
sure the algorithm is set to SHA1. Click Compute HMAC.
What is the computed HMAC for the contents of the file?
How is using HMAC more secure than general hashing?
Step 2: Verify the computed HMAC.
a. Within the Metropolis Bank HQ site, click the PC Bob.
b. Click the Desktop tab and then click Web Browser.
c. Enter the URL https://www.cisco2.corp and click Go.
d. Click on the link to view the most recent files and their hashes.
Does the HMAC hash for the income.txt file match?
Suggested Scoring Rubric
Activity Section
Question
Location
Possible
Points
Earned
Points
Part 1: Download the client files to Mike’s PC Step 1 2
Part 2: Download the client files from the backup file
server to Mike’s PC
Step 1 2
Step 1 6
Part 3: Verify the integrity of the client files using hashing Step 1 5
Part 4: Verify the integrity of critical files using HMAC Step 1 5
Step 1 5
Step 2 5
Questions 30
Packet Tracer Score 70
Total Score 100