CN5E Labs – Instructor README
Dear Instructor:
These labs provide hands–on exercises to deepen students’ understanding of the Internet protocols cov-
ered in a networking course. The Instructor version of the lab bundle contains the following files:
1. Instructor REAME [README–instructor.pdf]. This handout of key information to read first.
2. Lab Handouts for various protocols [lab–xxx.pdf]. The lab handouts for students.
4. Solution Handouts for the labs [solutions–xxx.pdf]. The solution handout for each lab.
6. Source for the solution handouts [solutions–xxx.docs]. To let you customize solutions.
We hope you find them a valuable addition to Computer Networks. Enjoy!
Suggested Usage
You can use the labs as follows:
• As part of traditional lab or recitation sections. You can have students work through the labs in
pairs to gain hands–on experience with real network traffic.
• As part of an instructor demonstration. You can follow selected lab steps yourself to explore
network protocol, letting the students follow along via a remote display.
• As part of homework assignments. You can assign the labs or portions of them for students to
do on their own platform and network as part of a class assignment.
You must decide whether students will collect their own trace, using the instructions provided in the
lab, or load a previously prepared trace; we supply a standard set of traces for this purpose. When it is
feasible, we strongly encourage you to let students collect their own packet traces. Doing so provides a
more engaging experience because students learn about their own network. You should be able to use
this option for any setting in which you have network connectivity and a fairly standard network setup.
In any setting in which students will do the labs, it is important that you or a teaching assistant work
through the labs beforehand to ensure a smooth experience. It is not possible for us to find all issues
because there are many different network and platform settings that continue to evolve. Fortunately,
Platforms, Networks, and Tools
The labs are suited for broad use and can be run on Windows, Mac OS, and Linux platforms. They have
been tested with Windows 7 (Service Pack 1), Mac OS 10.7 (Lion), and Linux Fedora Core 13. We do not
The labs target networks with IPv4 connectivity and work whether or not NAT is used to connect the
To work across platforms, the labs make use of tools that are widely–used and either installed as part
of the operating system or freely–available as downloads. Inevitably, there are differences between
All of the labs use the Wireshark network protocol analyzer to inspect packet traces. Different labs al-
so use different tools depending on their purpose. Each lab begins by listing the tools that it uses, a
Working through the Labs
Each lab covers a different Internet protocol. We suggest you assign them in the following order:
1. Protocol Layers. Text §1.3 and §1.4.This is the introductory lab that comes first.
3. 802.11. Text §4.4.
5. ICMP. Text §5.6.4.
7. DHCP. Text §5.6.4.
9. TCP. Text §6.5.
11. HTTP. Text §7.2.4.
However, the labs are relatively independent, and you may choose different orderings to suit your situa-
tion. Individual labs can be skipped, other than any dependencies noted above. They may also be taken
“top down” instead of “bottom up” after the introductory lab.
Most labs can be completed in a single sitting, though they are rather long to read. To help the reader,
we divide each lab into a series of steps that build on each other and use these formatting conventions:
• Actions that must be taken are given in italics. This is the absolute minimum an experienced lab
taker must read.
Instructor Support
The instructor version of these labs includes brief solution sheets, and the Word source for handouts.
Neither of these resources is included with the student version of the labs, which contains only the PDF
and supplied traces. Our intent is to provide you with added handouts, and to let you customize the lab
Feedback
Please send us tips to streamline these labs for future students based on your experiences. We wel-
come other feedback, whether corrections, constructive suggestions, or ideas for new labs. Send email