A Remotely Accessible Network Laboratory 
Notes on the TCP/IP Laboratories

Laboratory Setup

This project has gone through two stages.  The first was an investigation into possible lab setups and organizations.  In a sense it was a cataloging of techniques and methods that could be used.  As such, the laboratory that was created was fairly expensive and might be beyond the scope of what a number of schools could or would want to do.

The second stage was the development of specific assignments or laboratory exercises.  In developing these labs, the opposite approach was taken.  Of course, the primary goal was to produce useful, meaningful assignments.  But in meeting that goal, a minimalist approach was taken, i.e., no special laboratory features were used that were not pedagogically necessary.

Except as noted below, all of the assignments described here can be completed with a network composed of a couple of computers and a shared-media hub.  Many could be done with a single Unix-based server.  These were developed using a computer (maud) with a current release of FreeBSD but other flavors of Unix could be used with, at most, minor changes.  While it was not the goal of these labs to teach Unix, they do use Unix.  Many of the Unix related issues become much simpler or can be avoided if a GUI interface can be provided.

While some of the labs could be used in isolation or omitted from the sequence, several presuppose concepts introduced in earlier labs.  If you elect to use a subset of the labs, be sure to  verify your students have the appropriate background.

Notes on the Individual Assignments

The first eight labs have been classroom tested.

Lab 1: Connecting to the Networking Laboratory—This lab is basic to all subsequent laboratories.  It introduces the use of TELNET, SSH, and VNC.  Consequently, servers for these need to be installed on the remote host and client software should be available for the workstations used by students.

Lab 2: IP Addresses—This lab is a review of basic configuration parameters related to IP addresses.  The lab centers on interpreting IP address information.  It should be noted that maud is a dual-homed system and the lab reflects this.

Lab 3: tcpdump—This lab introduces the use of tcpdump, capture filters, and decoding packet capture information.  tcpdump must be installed and permissions must be set to allow student access.

Lab 4: Ethereal—This lab is largely a repeat of Lab 3 using Ethereal, a GUI-based capture tool that will fully decode most packets. Use of Ethereal is basic to subsequent laboratories.  Consequently, it must be installed and accessible by students.

Lab 5: ping—This lab introduces the ping utility.  In addition to using ping to investigate connectivity, it is used to estimate the bandwidth of a channel.  The utility pchar is also introduced.  Because of permission problems with ping, (it won't allow unprivileged users to set the packet size), canned data is provided in this lab.  pchar is required for part of this lab.

Lab 6: traceroute—This lab deals with the use of the traceroute utility to create maps of paths through networks.  Ideally, students will be exposed to asymmetric routes and NAT when doing this lab.  However, it could be completed using existing Internet looking-glasses.

Lab 7: ARP—This lab investigates the operation of the Address Resolution Protocol.  It assumes an Ethernet-based network.

Lab 8: Name Resolution—This lab investigates host tables, the Domain Name Services Protocol, and the nslookup utility.  Appropriate tools such as dig must be installed.

The next four labs have not been classroom tested.

Lab 9: Ports—This lab introduces port numbers and their uses.  It also introduces the netstat utility.  An appropriate portscanner will also need to be installed to run this lab.

Lab 10: Email—This lab introduces email protocols.  Both a POP3 and SMTP server-software must be installed on the remote machine.  Students will also need access (and probably experience with) a Unix-based email reader such as pine or xmail.  For inexperienced users, xmail or something similar is probably the best choice.

Lab 11: FTP—This lab introduces the FTP protocol.  An FTP server must be installed.

Lab 12: Routing—This lab introduces route tables.  This is probably the most demanding lab in terms of equipment.  maud is located on a buffer network with two attached routers for this lab.  This arrangement is needed to demonstrate redirects.  And if students are to discover the routing protocol on the network, one must be used.

 

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Comments are encouraged.  Please email: sloanjd@wofford.edu
Last updated: Wednesday, February 25, 2004

Copyright © 2002, Dr. Joseph D. Sloan