TEACHING TCP/IP NETWORKING USING HANDS-ON LABORATORY EXPERIENCE

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1 TEACHING TCP/IP NETWORKING USING HANDS-ON LABORATORY EXPERIENCE N.I. Sarkar School of Computer and Information Sciences, Auckland University of Technology Private Bag 2, Auckland, New Zealand Nabeel A. Y. Al-Qirim College of Information Technology, United Arab Emirates University P.O Box Al Ain, United Arab Emirates [email protected] ABSTRACT This paper reports on the development of new laboratory material that gives students hands-on learning experience in TCP/IP networking. The lab exercises are designed around Linux and are suitable for classroom use in introductory level courses in TCP/IP networking. The effectiveness of these lab exercises has been evaluated both formally by students (student evaluation forms) and informally through discussion within the teaching team. The feedback from students indicates that both the development and implementation of the lab exercises were successful. This paper describes the details of the lab exercises completed to date, their overall effectiveness and our plans for future projects. The impact of the hands-on lab exercises on students learning and comprehension is also discussed. Keywords: Computer education, Evaluation, Linux, TCP/IP networking. 1. INTRODUCTION Transmission Control Protocol/Internet Protocol (TCP/IP) networking is often included in computer science, engineering, information technology, and business courses as TCP/IP is a fundamental component of Internet protocol suite. It is believed that incorporating practical demonstrations into these courses, thereby illustrating theoretical concepts and providing opportunity for hands-on learning experiences, significantly enhances student learning about TCP/IP networking. This view is frequently supported in the educational literature [1]-[2]. Yet, despite the Chinese adage, attributed to Confucius ( BC), I hear, I know. I see, I remember. I do, I understand, only a limited amount of material designed to supplement the teaching of TCP/IP networking is publicly available, as a search of the Computer Science Teaching Center [] and SIGCSE Education Links [4] sites reveals. We strongly believe, as do many others [5]-[8], that students learn more effectively from courses that provide for active involvement in hands-on practical activities. Students gain first-hand experiences in TCP/IP networking by hands-on practical work (e.g. setting up a TCP/IP network, installing and configuring a server, IP subnet addressing, TCP/IP connectivity, Telnet, anonymous FTP, name resolution, etc.). Towards that end, we have prepared a series of lab exercises and materials that facilitate an interactive, hands-on learning experience in TCP/IP networking. These lab exercises are designed around Redhat Linux (version 8), and can be used either in the classroom, as a demonstration, to enhance the lecture environment, or in the computer laboratory to provide hands-on learning experience at an introductory level. TCP/IP networking is described in many textbooks e.g. []-[1], and IP network performance is discussed extensively in the networking literature e.g. [11]. Sloan [] describes TCP/IP labs 1

2 which may be suitable for practical work in the laboratory. However, the lab exercises are still in work-in-progress. A number of sophisticated network simulators exist for building a variety of TCP/IP network models [1]-[]. Nevertheless, by configuring a TCP/IP network the students gain a hands-on experience, which are not observed in computer simulation and modeling. To date, the authors have focused on developing lab exercises to support teaching and learning traditional TCP/IP networking at introductory level. Such an innovative hands-on learning approach to teaching and learning TCP/IP networking has been successfully applied for two years now in the Networking and Telecommunications course at the Auckland University of Technology (AUT). The course covers the main aspects of TCP/IP networking, including client-server networking, LAN administration and management. The practical lab material and exercises have been revised annually by incorporating feedback from both students and staff. The final version of the lab exercises is reported in this paper. These lab exercises are described in some detail in section 2 along with our plans for future projects. The remainder of this paper is organised as follows. Section 2 describes the lab materials completed to date and plans for future projects. Section highlights the main benefits of hands-on lab exercises. A customised TCP/IP network environment is discussed in section 4. The effectiveness of the lab exercises is evaluated and interpreted in section 5. The impact of lab exercises on student performance is discussed in section, and section 7 concludes the paper. 2. LAB EXERCISE DETAILS Table 1 lists the six lab exercises that have been developed to date and have trialed over two years in our undergraduate course Networking & Telecommunications. This course is at level or second year degree level (5 class contact hours) at AUT [1]-[17]. Each lab is conducted as a two-hour session, held weekly in a network laboratory at AUT. Lab exercises Networking concepts 1. Redhat Linux installation Network installation and administration 2. Logon to the host and network administration Network mask, IP address, broadcast address, MAC address, configuration table. Linux configuration Host configuration, administration and management 4. IP subnet addressing Classes of IP networks; subnet mask and network subnetting. 5. TCP/IP connectivity 1 TCP/IP connectivity and practical exercises. TCP/IP connectivity 2 Client-server architecture; telnet; ftp; domain name server; name resolution Table 1: Lab exercises and related networking concepts. Lab 1: Linux Installation This Linux lab exercise shows students how to install a Linux host. Students (in pairs) install the Linux 8 (from a CD) onto a removable hard disk (see section 4 for more about removable hard disk). Like NetWare server, students are asked to keep a journal of the major steps of Linux host installation, including problems and possible solutions. The learning outcomes include: (1) prepare Linux installation boot disk; (2) partition the removable hard disk for Linux installation; () configure the network; (4) set up the root password; (5) add a user account; () configure 2

3 password authentication; and (7) install various software packages. After successful installation, students must reboot the machine to verify that the host is up and running as expected. Lab 2: Logon to the host and network administration This lab exercise shows students how to login to the newly installed Linux host (described in Lab 1) as root user first and then carry out various practical activities related to network administration. The learning outcomes include: (1) use various commands such as ifconfig, arp, route, and hostname to investigate the network status of the host machine; (2) check the network connectivity of the machine using the loopback interface; () change the network configuration of the host; (4) check the network connectivity of the host machine within and outside the classroom; (5) observe and record the entries in the network interfaces configuration table; and () use an appropriate command to find the following: network mask, IP address, broadcast address, and MAC address for each interface. Lab : Linux host configuration In this lab, students further extend their knowledge about Linux host configuration gained in Lab 8. The learning outcomes include: (1) develop an understanding of the meaning of the parameters in some of the network configuration files; (2) identify the model of the network card; () assign superuser rights to a user; (4) use Linux commands (e.g., cat) to display the contents of files; (5) check and interpret the content of various files; and () experiment with various network configurations of the host machine. After completing this lab exercise students will gain sound knowledge and skills in client-server configuration and LAN administration. Lab 4: IP subnet addressing The basic concepts of a TCP/IP network including various classes of IP addresses, subnet mask, and network subnetting are introduced during lectures where students are also given a handout on TCP/IP networking. This Linux lab exercise shows students how to configure (with IP addresses) two sub-networks. Students gain a sound knowledge and understanding of IP subnet addressing by working through a problem based on a small business case scenario as follows. An organization has been assigned a class B address: You are given the task to configure (with IP addresses) the two subnetworks, each has 1 hosts and a router connects them. The network mask used by the organization is Assign a valid IP address to each network interface and show the broadcast address and the subnet ID for each subnetwork. Lab 5: TCP/IP connectivity 1 This Linux lab exercise provides students a step-by-step guided tour to explore TCP/IP connectivity. Students are given a set of exercises on TCP/IP connectivity to test their knowledge and understanding about the topic under study. Examples of exercises are: (1) determine the appropriate bandwidth needed for the connection from the Auckland University of Technology to the Internet; (2) if a router can connect up to K networks, how many routers (R) are needed to connect to N networks? Write an equation that gives R in terms of N and K; () let us assume that 5 million new computers are added to the Internet in a nine month period. If computers are added at a uniform rate, how much time elapses between two additions; and (4) draw up a TCP/IP network diagram that consists of two subnetworks connected by a router. Show a computer attached to each network, and the protocol stack used on both the computer and the router. Lab : TCP/IP connectivity 2 This Linux lab exercise shows students how to create TCP/IP connectivity and interoperability using telnet and ftp. The basic concepts of telnet ftp and DNS (domain name server) are introduced in the lab session. Students are given a set of practical exercises on TCP/IP networking which require them to explore TCP/IP connectivity (both intranet and the Internet) and interoperability using telnet, ftp and anonymous ftp, and to perform name resolution without using DNS.

4 Additional projects The following lab exercises are being considered: Static and dynamic routings: The learning activities include configuring static routing, routing table information, configuring RIP (routing information protocol) and IGRP (interior gateway routing protocol) routings. TCP/IP security: The learning activities include wireless access to campus network, server, and the Internet. Students can experiment with a wireless access point and observe communication traffic as the access point is notified and user data is transmitted. Open A category for student-suggested projects.. BENEFITS OF TCP/IP LAB EXERCISES The lab exercises (described in section 2) provide the following main benefits: Hands-on: The proposed lab exercises and materials facilitate an interactive, hands-on learning experience in TCP/IP networking. Reusability: Students can reuse their removable hard disks for other courses. Economical: Setting up a client-server network by students onto removable hard disks is inexpensive compared to setting up network onto networked PCs in the laboratory. Easy to use: The lab exercises are easy to use and set up for demonstrations. Usefulness: The lab exercises reported in this paper can be used either in the classroom, as demonstrations to enhance traditional lecture environments, or in the computer laboratory to provide hands-on learning experience. Challenging: The hands-on lab exercises provide an environment for students to test their knowledge about TCP/IP networking. 4. LAB ENVIRONMENT There are 25 computers (networked PC; MS Windows XP client) in a typical network laboratory at AUT, which allows us to accommodate up to 24 students in a laboratory (one PC is used for lab tutor s demonstration) for practical work. These computers can use removable hard disk drives so that students can install different operating systems, and to modify various system settings without changing the standard classroom disk image for other users. At the beginning of the lab sessions, we provide each student with a removable hard disk (hard disk cost is included in the course fee and the students are allowed to take away their disks at the end of the course). Students can use the same disk for other courses e.g., NetWare, web development. Figure 1 illustrates how a customized TCP/IP network can be set up in a typical network laboratory at AUT. At the beginning of each lab session, each student use gets a PC in the lab and using it by inserting a removable hard disk into the drive bay. 4

5 Figure 1: A customized TCP/IP network in a typical network laboratory at AUT Students are well disciplined in the laboratory and quickly get used to follow some basic rules and regulations. For example, at the end of each lab session, students must return their removable hard disks to their lab tutor. They also need to ensure that all PCs are reconnected to the AUT network and the orange sheets (i.e., log sheets) are signed off. Students can further explore the TCP/IP lab exercises outside the scheduled laboratory time by booking a time slot with their lab tutor/lecturer. 5. EVALUATION BY STUDENT FEEDBACK To assess the educational value of the lab exercises (described in section 2), they have been evaluated extensively both formally by students (student evaluation forms) and informally through discussion within the teaching team. The formal evaluation of the lab exercises was conducted in the classroom by a member of the teaching team, and anonymity of the respondents was protected. As part of the formal evaluation process students were asked to complete a questionnaire. They were asked the following six questions: Prior knowledge: How well did you understand TCP/IP networking concepts before entering this course? Easy to follow: How easy (overall) did you find the TCP/IP lab exercises to use and follow? Measure of success: How effective were the lab exercises in helping you to improve your understanding of TCP/IP networking? Hands-on: Would you like to have more lab exercises of this kind as part of your course? Time to explore: Would you like to have an extra time (apart from schedule lab time) to further explore the lab exercises? Learning a new OS: Would you prefer to learn TCP/IP networking with another operating system (OS) such as MS Windows 2? 5

6 Prior knowledge (1= poor; 5= excellent) (i) Measure of success (1= poor; 5= excellent) (iii) Time to explore (1= no; 5= yes) Easy to follow (1= poor; 5= excellent) (ii) Hands-on (1= no; 5= yes) (iv) Learning a new OS (1= no; 5= yes) (v) Figure 2: Student response. Graphs illustrating the number of respondents in each category for each of the six questions in the questionnaire. (vi)

7 A Likert scale with 5 points (1-5) was used in the questionnaire. For questions (i) - (iii): 1= poor; 5 =excellent; for questions (iv) - (vi): 1=no, 5=yes. 4 undergraduate students (about % male and 4% female) from Networking & Telecommunications course completed the questionnaire and their responses are plotted in Fig. 2. The responses were interpreted as follows: (i) About 75% of the students have indicated that they had no prior knowledge of TCP/IP networking before entering this course. About 7.5% of the students had basic knowledge of TCP/IP networking whereas the rest (17.5%) were neutral (see Fig. 2(i)). (ii) The lab exercises were found to be reasonably easy to use and follow. About 7% of the students were satisfied with the current version of the lab materials and hands-on experience. About 5% of the students expressed some concern and the rest (25%) were neutral (see Fig. 2(ii)). (iii) About 82.5% of the students indicated that the lab exercises had clearly assisted them in developing a better understanding of the concepts of TCP/IP networking. However, 2.5% of the students indicated that they were not totally satisfied with the current lab materials, and the rest (%) were neutral (see Fig. 2(iii)). (iv) About 77.5% of the students indicated that they would like to have more hands-on lab exercises in the course. About 2.5% of the students were not very interested in trying more lab exercises, and the rest (2%) were neutral (see Fig. 2(iv)). (v) About 8% of the students indicated that they need extra time outside the scheduled lab time to further explore practical activities. About 1% of the students indicated that the scheduled lab time was adequate to explore hands-on activities, and the rest (1%) were neutral (see Fig. 2(v)). (vi) About 55% of the students indicated that they would like to try another network operating system to learn TCP/IP networking. About 25% of the students were not very interested in trying another network operating system, and the rest (2%) were neutral (see Fig. 2(vi)).. IMPACT OF HANDS-ON LAB EXERCISES ON STUDENT PERFORMANCE As mentioned in section, the proposed lab exercises (based on Linux 8), have been used in the undergraduate course Networking & Telecommunications over the last two years, and the experience of the author is very positive. Students are highly motivated in learning TCP/IP networking by doing hands-on practical activities, a fact also confirmed by student feedback (see Fig. 2iii). In contrast to the experience of former approaches carried out during 21 and 22 at AUT, in which only occasional computer simulation and animation were used to reinforce the theoretical concepts. However, a deeper knowledge on a customized TCP/IP networking has been achieved by students who completed hands-on lab exercises. Particular topics in which students learning and comprehension has been improved are: TCP/IP network design and configuration IP subnet addressing TCP/IP connectivity Network administration and management. Hands-on experience of using Linux network operating system. To estimate (quantitatively) the impact of hands-on lab exercises on student performance, an analysis of the student grades in the written exam for the last four years (21-24) has been conducted. Students performance in the final exam with and without hands-on learning experience is shown in Table 2 7

8 Semester Year of study With hands-on lab exercises Without hands-on lab exercises Student pass rate (%) Table 2: Comparison of student performance in the final exam with and without hands-on learning experience. As seen in Table 2, the overall student pass rate in the final exam in both 2 and 24 is higher compared to students in 21 and 22. It is considered that much of this difference can be accounted for by the fact that the students in 2 and 24 used the hands-on lab exercises whereas the students in 21 and 22 did not get an opportunity to use the lab exercises at all. One could argue whether the results of the written final exam precisely reflect laboratory work. It should be noted that the final exam (closed book) was comprehensive and covered the material taught throughout the semester (i.e., 14 weeks). Theory presented in lectures is enhanced via laboratory demonstrations, and practical lab exercises. By inspecting Table 2, one can observed that the students have done slightly better in 24 compared to 2. This is probably due to the lab materials being refined to eliminate points of confusion for the students and also the lab tutor building up a knowledge base of common laboratory problems. CONCLUSION A series of innovative new laboratory materials has been developed, which can be used either in the classroom for class demonstrations, to enhance the traditional lecture environment, or in the computer laboratory for hands-on practical work at an introductory level. Student responses to the hands-on lab exercises were mostly favourable. The students indicated that they had found the lab exercises easy to use and that they helped them gain understanding of TCP/IP networking. The hands-on lab exercises have had a positive impact on students performance. Results show that the students scored better in the final exam with hands-on learning experience than the students without hands-on experience. More lab exercises such as routing and network security are under development. The lab exercises are freely available to faculty interested in using the lab exercises to supplement teaching their TCP/IP networking courses. More information about hands-on lab exercises can be obtained by contacting the author. 8

9 ACKNOWLEDGEMENT We would like to thank Krassie Petrova for her contribution to the TCP/IP lab exercises and Petteri Kaskenpalo for team-teaching Networking and Telecommunications in recent years. REFERENCES [1] M. F. Young, "Instructional Design for Situated Learning," Educational Technology, vol. 41, pp. 4-58, 1. [2] J. R. Anderson, L. M. Reder, and H. A. Simon, "Situated learning and education," Educational Researcher, vol. 25, pp. 5-11, 1. [] S. Grissom, D. Knox, E. Fox, and R. Heller, "Computer Science Teaching Center (CSTC) [4] Anonymous, "SIGCSE Education Links [5] K. Cannon, Lab Manual for CCNA Guide to Cisco Networking, 2nd ed: Course Technology, 2. [] A. Leva, "A Hands-on Experimental Laboratory for Undergraduate Courses in Automatic Control," IEEE Transactions on Education, vol. 4, pp , 2. [7] N. I. Sarkar and T. M. Craig, "Illustrating Computer Hardware Concepts using PIC-based Projects," presented at thirty-fifth SIGCSE Technical Symposium on Computer Science Education, Norfolk, Virginia, USA, 24. [8] K. Abe, T. Tateoka, M. Suzuki, Y. Maeda, K. Kono, and T. Watanabe, "An Integrated Laboratory for Processor Organization, Compiler Design, and Computer Networking," IEEE Transactions on Education, vol. 47, pp. 11-2, 24. [] B. A. Forouzan, TCP/IP Protocol Suite, 2nd ed: McGraw-Hill, 2. [1] N. Mansfield, Practical TCP/IP - Designing, using, and troubleshooting TCP/IP networks on Linux and Windows: Addison-Wesley, 2. [11] M. Hassan and R. Jain, "High Performance TCP/IP Networking - Concepts, Issues, and Solutions," Pearson Prentice Hall, 24. [] J. D. Sloan, "A Remotely Accessible Network Laboratory - TCP/IP Laboratories [1] K. Fall and K. Varadhan, "The ns Manual," The VINT project. UC Berkeley, LBL, USC/ISI, and Xerox PARC, 2. [14] OPNET, "OPNET Technologies - Commercial Simulation Software," 24. [] X. Zeng, R. Bagrodia, and M. Gerla, "GloMoSim: a library for parallel simulation of largescale wireless networks," presented at Parallel and Distributed Simulation,. PADS 8. Proceedings. Twelfth Workshop on,. [1] N. Sarkar and K. Petrova, "Teaching Computer Networking & Telecommunications: A Network Analysis and Software Development Approach," presented at 14th annual conference of the NACCQ, Napier, New Zealand, 21. [17] N. Sarkar and T. Clear, "Developing a New Course for the Software Development Pathway on the AUT Bachelor of Applied Science Programme," presented at 1th annual conference of the NACCQ, Wellington, New Zealand, 2.