the role of cisco virtual internet routing lab in … role of cisco virtual internet routing lab in...
TRANSCRIPT
The Role of Cisco Virtual
Internet Routing Lab in
network training
environments
Research Proposal
Author
Herbert, Bradley Mark - herbm001
Division
School of Information Technology & Mathematical Sciences Bachelor of Information Technology (Honours)
Supervisors
Wigley, Grant Brian
July 2015
Australia
Version 1.1
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
1 Chapter 1
Contents
1. Introduction ............................................................................. 6
2. Literature Review ..................................................................... 1
2.1 Teaching Methodologies ........................................................................................... 2
2.1.1 The role of practical-based education in networking training ............................ 2
2.1.2 Using Network Simulators for education in networking ..................................... 7
2.2 Networking Learning Platforms ............................................................................ 11
2.2.1 Types of Education Platforms ............................................................................ 11
2.2.2 Physical Equipment ............................................................................................ 13
2.2.2 Cisco Packet Tracer ............................................................................................ 18
2.2.3 GNS3 ................................................................................................................... 27
2.2.5 Common Open Research Emulator (CORE) ....................................................... 29
2.2.6 Miscellaneous Platforms .................................................................................... 32
2.2.7 Cisco Virtual Internet Routing Lab ..................................................................... 34
2.3 Summary .................................................................................................................. 39
3. Methodology ............................................................................ 1
3.1 Outline of Current Research Methodologies .......................................................... 1
3.2 Experimental Design ................................................................................................. 2
3.2.1 Recruitment Procedures ...................................................................................... 2
3.2.2 Overview of the experiment ................................................................................ 4
3.2.3 Implementation ................................................................................................... 5
References ..................................................................................... 6
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
2 Chapter 1
Declaration
I declare that this thesis titled, ‘The Role of Cisco Virtual Internet Routing Lab in network
training environments’ is, to the best of knowledge, original work and that all sources used in
this thesis is acknowledged using IEEE referencing. This thesis, or the research therein has
not been previously submitted by me for any assessment to any educational institution or
university.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
3 Chapter 1
Acronyms
ACRONYM WORD
VIRL Cisco Virtual Internet Routing Lab
STP Spanning Tree Protocol
UNISA University of South Australia
CORE Common Open Research Emulator
RAM Random Access Memory
LTS Long Term Support
OSPF Open Shortest Path First
BGP Border Gateway Protocol
IP Internet Protocol
TCP Transmission Control Protocol
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
4 Chapter 1
Glossary
WORD MEANING
SPANNING-TREE PROTOCOL A network protocol that shutdowns links on
a switch intended to be used as backups to
prevent loops from occurring.
SWITCH A device specially designed to forward
frames on a computer network. A smart
hub.
SWITCHING A switch making decisions on where to
send traffic based on source/destination
MAC addresses.
ROUTING A router making decisions where to send IP
packets based on source/destination IP
addresses. Rewrites MAC addresses.
VIRTUALISATION Virtualisation is the allocation of
computing resources to so-called guest
operating systems to allow multiple
operating systems to run on a single
machine.
EMULATION Software that converts instructions
designed on one type of CPU to that of the
host system, enabling the program to run.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
5 Chapter 1
Abstract
Teaching advanced network concepts is challenging because it often involves teaching
complex concepts not easily understood by students. To help improve students’
understanding, simulators are often used in network training environments but the literature
supports the premise that using simulators can be inadequate to enhance understanding. Three
factors influence this. Firstly, the students’ perception of the simulator. Secondly, the
technical application of the simulator i.e. how good is it at simulating the network? Is it
limited? Thirdly, the use of the simulator and how the learning is assessed or improved.
Cloud computing, decentralised lab environments and virtualisation can reduce costs,
maintenance and enhance student learning of networking. Often, these relied on real
equipment because virtualisation of Cisco devices was poor. The Cisco Virtual Internet
Routing Lab (VIRL) provided the feature set to fill in the limitations in current simulation
tools such as limited functionality and the reliance on physical equipment. While Cisco VIRL
is a useful tool for testing network designs, no research has been done to demonstrate its
effectiveness and role in a networking training environment. A practical approach is
necessary, according to the literature and should be supplemented with a theoretical approach
for understanding. This paper presents current research on simulators and concludes that no
tool is adequate for learning advanced networking and that Cisco VIRL is a possible tool to
address this issue.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
6 Chapter 1
1. Introduction
Cisco Virtual Internet Routing Lab (VIRL) is a new software package released by Cisco in
December 2014 designed to virtualise a networking environment[1] [2]. This is beneficial for
technicians testing a network design before it is rolled out onto a production network1. The
nature of Cisco VIRL gives it potential to be used in training environments by Cisco certified
instructors for teaching advanced networking concepts to students and trainees with diverse
learning needs.
Teaching subjects like networking can be challenging because of the different learning needs
of the students. For example, some students live in remote areas and may not be able to get to
the educational institution to perform hands-on activities, some students have disabilities that
may impact their ability to interact with physical equipment, others become frustrated or lose
focus when doing repetitive tasks such as cabling a physical network every time they do a
practical exercise and some students prefer a theoretical approach. Nevertheless, the current
research demonstrates that there are two forms of learning, essential for learning advanced
networking concepts. Firstly, there is abstract conceptualisation, which is developed through
lecturing and memorising of important concepts. Secondly, there is active experimentation
which is best developed through a practical approach [3].
Delivering the first learning method through lecturing is easily achieved and is tradition in
most universalities worldwide. But delivering the second method is challenging and often
poorly delivered. In third-world countries such as Ethiopia, hands-on practicals are rare
because of insufficient funds and resources[4]. Implementing a practical lab is often
expensive and time-consuming [5]. Use of the equipment is often restricted or shared by a
1 A network that transmits traffic for the operational day-to-day running of a company, government or home.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
7 Chapter 1
number of students. As a result, inexpensive simulation-like tools such as Cisco Packet
Tracer are used as an alternative[4]. But use of simulation tools, such as Packet Tracer may
lead to a perception by students and instructors that students cannot apply the problems to
real-world examples[6]. These simulators also lack a great deal of real-world functionality,
that is, how the software installed on servers behaves in a real environment. This restricts the
student to a narrow subset of networking concepts and, therefore, may fail to provide the
student with a full perspective of how networks operate in reality.
While these problems have been extensively addressed in the literature [6-10], often the
research has only aimed to solve one or two of the aforementioned problems. In the paper
titled, ‘Assessing the Effectiveness of Remote Networking Laboratories’, the role of practical-
based labs in remote educational environments is explored. Now while a remote lab improves
accessibility to the lab environment and enhances realism, it does not solve the financial
problems or the concerns associated with maintenance[5]. Likewise, software tools often lack
realism, degrading a student’s learning experience[9]. Consequently, no solution appears
solve the challenges faced in teaching advanced networking in training environments.
In early 2015, development of Cisco Virtual Internet Routing Lab (or better known as VIRL)
progressed. This new tool not yet explored in the literature offers unique features not
available in previous software based tools. In particular, Cisco VIRL was designed to test
configurations of Cisco equipment in a virtual environment. In simple terms, Cisco VIRL
effectively runs an almost identical version of the operating system found in enterprise Cisco
routers and switches using virtualisation2. In theory, this means that Cisco VIRL offers a
2 Virtualisation is the allocation of computing resources to so-called guest operating systems to allow multiple
operating systems to run on a single machine.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
8 Chapter 1
sense of realism and unlike Packet Tracer is not a cut-down version of the Cisco operating
system.
Unfortunately, although Cisco VIRL has the potential to replicate a real networking
environment, its impact, whether positive or negative on student education is unclear. The
literature does not make any mention of VIRL because it was not released until December
2014. This thesis investigates Cisco Virtual Internet Routing Lab (VIRL) and its application
and role in an academic environment to teach advanced networking concepts. Because
Packet Tracer and physical equipment may not necessarily provide students with a sound
understanding of computer networks, it is important to assess the feasibility and practicality
of using Cisco VIRL for this purpose.
Cisco Virtual Internet Routing Lab is technically better than Packet Tracer in terms of its
functionality and feature set. However, this does not necessarily mean that the students’ and
trainees learning will be improved. This is because a student’s perception of the tool can
negatively impact their education [11].
The following research question is posed and will be investigated:-
“What role does Cisco Virtual Internet Routing Lab play in network
training environments to help students and trainees understand advanced
networking concepts?”
It is hypothesised that Cisco VIRL plays a significant role at enhancing the realism of the
simulated networking environment, increasing engagement and helps students understand the
behaviour of production networks. This hypothesis will be tested by conducting an
experiment on a group of networking students and several staff members enrolled at the
University of South Australia, which aims to test their perceptions of the tool, their use of the
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
9 Chapter 1
tool and to measure their understanding of key networking concepts after they have used the
tool to determine how well the tool has helped develop their learning of networking concepts.
In the next chapter, the arguments and counter-arguments will be examined in light of the
literature available. Chapter 3 specifies the methodology and the processes to be undertaken
to answer the research questions.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
1 Chapter 2
2. Literature Review
This section presents previous research in respect to teaching networking, including; the
importance of a practical learning approach, the weaknesses of relying too much on a
theoretical approach, the student’s perceptions of various simulators, the importance of
developing skills for the workplace, an overview of network simulation tools including how
they should be used to improve learning.
The first section outlines research in respect to the use of a practical teaching method and
why it is essential for student’s learning. The subsection provides an overview of network
simulators, including their benefits and weaknesses and why they fail to improve learning.
The same subsection also outlines the perceptions of using simulators, which although
positive, do not indicate successful learning and understanding. The second part of the
literature review is a comparison of various types of networking simulators, tools and
platforms that could be used to teaching networking and why each solution is inadequate to
achieve this goal. The first subsection briefly lists and categorises the different kinds of
platforms. The second subsection outlines the benefits and weaknesses of using physical
equipment. The third subsection outlines the benefits and weaknesses of using Cisco Packet
Tracer. The fourth subsection outlines GNS3, its benefits and its weaknesses. The fifth
section explores the Common Open Research Emulator, including its weaknesses and
benefits. The sixth section outlines various other platforms and summarises key benefits and
weaknesses of each tool, or why they are not suitable for a training environment. The seventh
section summarises VIRL, including its advantages and disadvantages and how this tool will
be further explored in the research. The third and last major section of this literature review is
a summary that summarises the literature review and emphasises the gap in the literature.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
2 Chapter 2
2.1 Teaching Methodologies
This section presents current research on studies, suggesting that a practical approach is
essential for developing soft skills, such as problem solving. The weaknesses of the
theoretical-only approach will be outlined, as well as the perceived or real learning
difficulties faced by students who are not familiar with a practical environment and how this
may impact their performance in industry. In conclusion, the section will outline why a
combination of both theoretical and practical learning is supported by the literature and
strongly recommended. The drawbacks of relying too much on simulators will also be
addressed in this section.
2.1.1 The role of practical-based education in networking training
This section presents previous research on the effectiveness of the traditional lecturing
approach to teach subjects such as networking and engineering and identifies the weaknesses
of this approach. This subsection also outlines why a practical-based approach needs to be
supplemented with lectures for effective understanding of networking concepts.
A study by Holvikivi, J suggests that undertaking practical exercises are essential for students
to develop motor skills and to enhance the areas of the brain that drives problem solving and
analytical thinking[4]. Unfortunately, practical exercises alone often rely on a student’s
mental model of technology and their imagination[6] [12]. The abstract concepts of
networking have to be understood using imaginative processes or illustrations[6]. This
requires a careful balance between a theoretical and practical approach.
In third-world countries including China and Ethiopia, the money or infrastructure for a
practical lab does not exist. Often, learning networks relies on lectures, exams and limited use
of Packet Tracer. But the effectiveness of Packet Tracer has been questioned by several
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
3 Chapter 2
academics which perceive Packet Tracer of making students too reliant on step-by-step
processes[6]. A comparison between western educational institutions and those in third-world
countries such as China showed interesting trends of vastly different learning methods. In
countries where practical learning is not used, those students would often struggle with
practical-based tasks and would require additional support to get through it, but the students
did perceive practical learning to be beneficial. The study suggested that use of lecturing and
exams without a practical approach may lead to bad learning habits such as rote learning or
failure to apply the content. The study by Holvikivi, J confirmed this hypothesis. When
international students enrolled into an education institution in the United States, interesting
observations were made. For instance, the international students struggled to get started with
the labs and without additional support, would rarely complete them. The study investigated
why this divide existed and found that it is likely due to the absence of technology in the
homes of third-world countries. At a young age, children in western countries learn from
others around them by observing them and using technology such as turning on/off lights and
watching technology work[4]. When children go to school, they use computers and
technology in a lab environment, learning about the technology and becoming familiar with
it. This influences how they think and learn about technical subjects[4]. In comparison,
Ethiopians, for example, do not grow up experiencing technology and consequently this
impacts their understanding of technical subjects i.e. engineering and information technology.
This may lead to them struggling to start the labs. The study also implies that experience in
using technology enhances understanding. In the absence of technology, third-world students
did not have the same experience as western students and this leads to learning difficulties.
Also, lack of practice on the labs may present learning challenges because of less experience.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
4 Chapter 2
Because students not familiar with technology may struggle with practical labs, this possibly
also suggests that they may not be able to apply their skills in the workplace. Therefore, the
study strongly recommends that these international students be given additional practical
experience to give them the level of understanding required[4]. From the study, we can
deduce the following:-
A) South American students are taught networking using a theoretical approach.
B) South American students, according to the study, struggle to apply content to labs.
C) The workplace requires hands-on use of the real equipment
D) Therefore, South American students are not prepared for the workplace.
E) Therefore, this method of training is not effective.
From the study, we also deduce the following:-
A) North American students have grown up experiencing technology.
B) North American students are educated using lectures and labs.
C) North American students easily apply concepts to the labs due to prior experience
with technology.
D) Therefore, they have skills preparing them for the workplace.
E) Therefore, this method of learning is effective
In conclusion, it follows by logical reasoning that both a practical and theoretical approach is
the preferred approach to provide the best learning outcomes. There is another advantage to
practical training as well. Employers are wanting employees with skills in using physical
networking equipment[13].
According to a literature review recorded in a New Zealand paper titled, ‘Does Embedding an
ICT Certification Help Align Tertiary Programs with Industry? A Study of CCNA
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
5 Chapter 2
Perceptions’, the majority of employers believed skills in Cisco were important or beneficial
to have and that CCNA skills had a large impact on successful employment[13]. The same
paper highlights the need for a teaching tool that will allow instructors to focus on key
learning areas perceived as important by industry. However, in many cases, the instructor is
constrained to the labs by Cisco and customising or creating new labs is a challenge[9].
Learning about computer networking using the practical teaching method can also be
beneficial for employers in terms of providing transferrable skills. According to a study cited
in ‘‘Does Embedding an ICT Certification Help Align Tertiary Programs with Industry? A
Study of CCNA Perceptions’, some participates indicated that learning to configure a Cisco
router or switch provided them with the ability to transfer those skills to routers and switches
offered by third-party vendors[13]. Others also made mention of the importance of using
other hardware such as the Cisco ASA Appliance, which is not in the CCNA curriculum[13].
Tools provided by Cisco such as Packet Tracer cannot provide an unlimited array of
simulated hardware devices. Consequently, the literature is suggesting the importance of
functionality that extends beyond the CCNA framework. Troubleshooting skills were also
viewed as very important in the study[13]. However, troubleshooting requires skills that
takes time to develop and usually, this involves practice in a simulated environment.
Interestingly, those in industry, according to the aforementioned study, listed cabling a
network as important, switching, VLANs, wireless LANs and equipment configuration [14].
Some alternative simulation tools that will be discussed further in this chapter do not support
VLANs or switching. The study suggests a perception that having CCNA qualifications may
lead to improve communication with experts in industry and lead to better understanding.
Furthermore, troubleshooting networks leads to improved skills in communication, teamwork
and problem solving[13]. Because of the perceived industry need for networking skills, this
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
6 Chapter 2
motivates the discussion of evaluating a software tool that replicates the behaviour of a
physical network lab and by doing so makes networking courses more accessible and
available.
The study mentioned in ‘From theory to practice: Adopting the engineering approach’[4],
problem solving is considered an important skill in both academia as well as industry that has
to be practiced using a hands-on practical approach[4, 13]. A theoretical approach involving
lecturing and exams is not sufficient for providing real-world problem solving, experience
and transferral skills[4, 13]. Consequently, the graduate is ill-prepared for the workplace
because he fails to fulfil industry expectations.
Therefore, it is clear from the literature that a curriculum that incorporates a practical
component is absolutely essential for the development of in-demand industry skills such as
problem solving and troubleshooting. Unfortunately, implementing a practical lab to provide
the necessary practical is challenging in terms of costs and maintenance[15]. Without prior
experience, students from impoverished nations may not have the sufficient background to do
the practicals without additional support[4]. In the case of networking laboratories, these
cannot be easily modified to support the individual learning needs of the student, creating
additional learning barriers[9]. The current research does not address these issues in sufficient
detail.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
7 Chapter 2
2.1.2 Using Network Simulators for education in networking
This section explores the role of using networking simulators as an education tool in
networking training courses and evaluates the effectiveness of using simulators to help
students and trainees understand advanced networking concepts.
Simulators are frequently used by instructors to demonstrate concepts and to reinforce
concepts taught in lectures[16]. One of the widely used tools in networking education is
Cisco Packet Tracer. This tool, often referred to as a ‘network simulator’[8] is considered by
Frezzo et. al. to not be a complete network simulator because it does not simulate the entire
network stack[15]. The same paper suggests that a simulation environment alone is
inadequate unless the students have a developed way of thinking and an understanding of the
conceptual concepts. A similar view is mentioned in the paper titled, ‘Using a Network
Simulation Tool to engage students in Active Learning enhances their understanding of
complex data communications concepts’. This paper suggests that the simulator must be used
to provide feedback and recognition of mistakes and suggests that use of the simulator for
demonstration purposes is unlikely to improve learning outcomes[16]. The learning outcome
generated by simulators might be perceived and not truly enhancing learning at all. Students
often use simulators to finish the set activity with as least amount of effort as possible. But as
noted in the paper, ‘Using a Network Simulation Tool to engage students in Active Learning
enhances their understanding of complex data communications concepts’, this is not the goal
of the simulator. Instead, the simulator should be used to improve understanding[17]. A
survey was conducted on a number of lecturers at Malaysian Polytechnic Institutions suggests
that, while students can easily follow the lab sheet to complete the assigned tasks, they
struggle with any slight variation to the lab-sheet and struggle to apply what they have
learned[6]. One lecture in the survey commented that it seems that the students learned
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
8 Chapter 2
nothing and the data from the survey suggests that the simulator tool, Packet Tracer, provided
no actual improvement to learning because it was used to complete the tasks and not to
encourage deeper thinking[14, 16].
According to a survey in the paper titled, ‘Survey on the Challenges Faced by the Lecturers
in Using Packet Tracer Simulation in Computer Networking Course’, some of the
interviewed lecturers made some quotes concerning the learning of the students who used the
simulation tool.
“Students are not able to answer the questions or execute any basic
configuration instructions learned at the initial stages of the course; it
seems as if the students have never learned them. It forces us to repeat
and repeat the process, this is time-consuming. Students only manage to
follow laboratory instructions, step-by-step but they fail to understand the
concept or theory used in the laboratory activity. This problem is
prominent for the topics like routing protocol, subnetting and ACL.
Students only memorize the instructions or the theories learned without
really knowing the actual time or circumstances that the instructions or
theories should be applied.” (Polytechnic Lecturer 2: CCNA, Program
Head, Resource Lecturer, in Survey on the Challenges Faced by the
Lecturers in Using Packet Tracer Simulation in Computer Networking
Course, p. 13, emphasis added)[6]
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
9 Chapter 2
The paper, ‘Using a Network Simulation Tool to engage students in Active Learning
enhances their understanding of complex data communications concepts’ emphasises that
getting a student to configure a device will not improve understanding or enhance
learning[16]. Evidence for this seemed was also supported by the statement of the lectures in
the paper, ‘Survey on the Challenges Faced by the Lecturers in Using Packet Tracer
Simulation in Computer Networking’ that suggested that key networking concepts had to be
repeated to students[6]. When the simulator is used for the purposes of illustrating a student’s
lack of understanding, errors, misconceptions and getting them to fix the problems by
applying learned knowledge, a deep understanding was obtained, according to the study[16].
Though the education of networking is not addressed, Dr. Teresa Coffman in the paper titled,
‘Using Simulations to Enhance Teaching and Learning: Encouraging the Creative Process’
suggests that simulation experiences should be realistic to allow the student to apply
knowledge to a given problem or scenario. Simulation experiences, according to Coffman, T,
improves both education and application of knowledge to a specific problem[17]. Students
involved in the simulation should be delegated roles and feel as though they are taking
responsibility for their learning while in that role. Simulations also improve experience,
problem solving skills and improved student awareness[17]. Therefore, it is how the tool is
used rather than what tool is used, that leads to better learning outcomes[16].
Simulators play several roles in the education of networking concepts. Firstly, they mimic, as
close as possible, the behaviour of real networks[5]. Secondly, they provide the tools for
those working in industry to refresh their skills. Thirdly, they provide a platform for students
to troubleshoot networks, problem-solve and to engage in deeper thinking[16] [17]. Fourthly,
they provide (somewhat limited) networking packet and traffic analysis[16]. Fifthly, they
provide a cost effective supplement or alternative to expensive physical labs[5].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
10 Chapter 2
Even though simulators provide a sense of realism and allow traffic analysis, these aims of
the simulators are limited[9]. In general, simulators only replicate a limited number of
features found on physical network devices[18]. Furthermore, as newer technologies become
available, the simulator has to be reprogrammed (or updated) to support the new features[5].
Because networking often incorporates propriety devices such as Cisco, it is not feasible for a
simulator to replicate all the necessary components, resulting in a limited system[18]. As a
result, in terms of realism and network analysis, simulators can only provide a limited
environment. Even a paper, ‘Pedagogical evaluation of simulation tools usage in network
technology education’ states that simulators cannot replace real equipment[5].
The other problems with simulators is that many of them are designed for research purposes
or testing and are not designed for education[5] [9]. Their difficulty makes them an
impractical solution.
Network simulators such as CORE, GNS3, Packet Tracer and even Cisco VIRL [19] [9] [7]
are not merely simulators, though they may appear to be such. Cisco VIRL and GNS3 use
emulation/virtualisation to fully replicate the Cisco IOS, providing a full feature-set[18].
Packet Tracer contains additional features not found in a traditional network simulator and
CORE integrates both emulation and simulation to replicate the networking experience[19].
Because they differ significantly from software-based simulators, they will be discussed in
the next section. It is important to note that emulation and virtualisation helps overcome the
limitations of simulators in terms of realism and functionality. The problem is finding an
emulator or virtualisation solution that replicates routing, switching and which can do such
things lawfully. Prior to 2015, no such solution existed, though Cisco Virtual Internet
Routing Lab potentially supports these features.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
11 Chapter 2
2.2 Networking Learning Platforms
In this section, several networking learning platforms will be discussed and, although they
are used for network training, the limitations of each tool will be outlined.
2.2.1 Types of Education Platforms
The following table is constructed from the data available in the literature.
Tool Category Examples Use Cases Limitations
Physical Lab N/A Full sense of realism Cost / Maintenance
Visualisation Tools Cisco Packet Tracer Practice Networking Limited commands
Software Simulators NS-2 Protocol simulation Difficult to use
Emulation /
Virtualisation
GNS3, Core, VIRL Testing Networks No Switching
Table 1 Network Learning Platforms Comparison
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
12 Chapter 2
Network Simulation tools can be categorised as followed:-
2.2.1.1 Physical Lab
According to the literature, there are two types of physical labs [20]. They are:-
I. Centralised: Students connect to, or use physical equipment at their educational
institution to practice their networking skills and/or to learn networking.
II. Decentralised: Students use their own equipment to practice their networking skills.
2.2.1.2 Software Simulators / Visualisation Tools
Software simulators and/or visualisation tools available include [7] [9] [12]:-
J-SIM
NS
Partov
NetSims
Cisco Packet Tracer (also a visualisation tool)
2.2.1.3 Emulation / Virtualisation
Virtualisation or emulation software is used to replicate the realism of Cisco devices [1] [19]
[21].
Cisco Internet Virtual Routing Lab
GNS3
Common Open Research Emulator (CORE)
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
13 Chapter 2
2.2.2 Physical Equipment
In tertiary education institutions like universities, it is not uncommon for separate physical
networks to be setup to allow students to practice on real-equipment. This greatly enhances
realism and accurately replicates the networking environment. Unfortunately, physical
equipment presents a number of technical and learning challenges. Firstly, the costs to
purchase and maintain physical equipment is high [5]. The hardware becomes out of date
within a few years and constantly needs to be replaced, adding to maintenance and
downtime. Secondly, there is the on-going electricity costs to power a separate physical
network that utilises probably less than 5% of the total resources[18]. The remainder
resources are not used, however, a separate network is necessary for security and stability of
the university’s production network. Due to budget restrictions, many universities often
interconnect the practice networks with real production networks to cut down on costs. This
design decision means that it is difficult to allow the student to practice with key elements of
the network[9]. Thirdly, to save costs, limited equipment is purchased and students work in
teams to configure the network. Now while teamwork provides useful skills, it follows that
some students will get less experience than others[7] [20]. Select students may hog the
equipment and some students may not get the hands on experience they need. Fourthly, using
physical equipment may not lead to understanding. In the paper titled, ‘Design Patterns for
Learning and Assessment: Facilitating the Introduction of a Complex Simulation-Based
Learning Environment into a Community of Instructors’, the author argues that physical
equipment alone is not enough to provide understanding. Therefore, the use of physical
equipment needs to supplemented with a software visualisation tool, for example, Packet
Tracer[15]. Assistant Professor, Sheikh Raashid Javid in his paper, ‘Role of Packet Tracer in
learning Computer Networks’ also argues that Packet Tracer’s features play a key role in the
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
14 Chapter 2
education of students learning computer networking[8]. Therefore, physical equipment must
be supplemented with visualisation tools such as Packet Tracer.
The literature supports the premise that use of physical equipment is necessary for the
education of students learning advanced networking concepts [5, 13, 22]. Furthermore,
experience in using physical equipment is perceived as a useful skill in the workplace and
improves the chance of successful employment[23]. Unfortunately, physical equipment is
both time-consuming and costly to maintain [9] [5] [18] . The author, Woratat
Makasiranondh et. al in the paper, ‘Pedagogical evaluation of simulation tools usage in
network technology education’ gives an illustration of how much it might cost to provide
students access to physical equipment. If a student is supplied with access to one router and
one Cisco switch, the costs could be $50,000 Australian dollars per student. In addition to the
initial purchasing cost, there is also the on-going costs associated with maintenance and
support. It is suggested that practical labs would require at least 20 hours per week of
attention to keep maintained. Wear and tear may result quicker because students are
constantly connecting and disconnecting cables each time a practical exercise is ran and this
increases replacement costs because of higher failure rates. There is also the on-going
demand to keep up with the latest software installed on the router or switch. The IOS needs to
be updated frequently, which adds to costs and administrative overhead. Eventually, the
router or switch may not support the latest version of the IOS and will need to be replaced
[5].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
15 Chapter 2
Setting up the physical equipment in preparation for the lab and cleaning up after the lab
often wastes critical learning time and this degrades a student’s production [24]. There needs
to be a way of managing the equipment and to allow remote access of the equipment[22]. For
example, configurations need to be wiped after each session to provide a fresh configuration
for each exercise. Consequently, management software needs to be configured to allow this
process to occur automatically, adding to the costs.
In many cases, universities use a web-based front-end to physical equipment called NDG
NetLab [22]. This solution provides remote access and management of physical equipment at
any time of the day. After each session, configurations are wiped and/or restored to provide a
fresh environment for each subsequent student [3]. NetLab provides a number of advantages
including; reduced administration of the lab environment, the infrastructure to establish a
virtual network lab hosted in a cloud infrastructure, accessible from anywhere, allocation of
resources only when they are needed and automation of tedious configuration tasks. Student
perceptions of NetLab are also positive with many indicating that it helps improve their
learning [3].
Use of NetLab does have its disadvantages. Firstly, the solution is high-maintenance and
expensive[10]. Secondly, NetLab uses fixed topologies and because physical equipment
topologies cannot be easily redesigned, it is not possible to tailor NetLab to the diverse
learning needs of students [3]. Thirdly, NetLab is not user-friendly for people with special
requirements such as blindness or vision-impairment[10]. Most western countries such as
Australia requires the education institutions to make reasonable adjustments to ensure that
people with disabilities have equal access to the education environment. Fourthly, NetLab has
used the Java runtime to provide access to the underlying technologies. This means that
NetLab cannot be used on tablets or smartphones due to their lack of Java support. Sixthly,
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
16 Chapter 2
because students are not seeing and interacting with the physical equipment, key tasks such
as cabling are not done, resulting in less experience [3]. Therefore, NetLab is not the best
solution for overcoming the technical and financial issues associated with using real
equipment.
In order to provide education support for long-distance education students, physical
equipment must be made remotely accessible. This can be inherently risky in terms of
security and ensuring that the infrastructure cannot be accessed by unauthorised people [3].
Best design practice recommends that production and training networks be separated from
each other to minimise disruption, but this presents management and cost issues.
Furthermore, it is possible that untrained students might damage the equipment, adding to
replacement costs [8] [24]. Another issue that might arise is that students may not be able to
access the remote lab because of a slow Internet connection [20]. Solutions to address these
problems involve spending a lot of money and funding for practical labs from the government
is usually limited[22].
To reduce the purchasing, maintenance and operating costs of a local and/or remote
laboratory, several approaches have been done over the years. One of the approaches is to use
virtualisation to help reduce the actual hardware being used [9] [18] [3] . The issue with
virtualisation, especially in times past, was that it required a platform that would accurately
virtualise Cisco equipment. Until recently, the only viable solution was GNS3. But its lack of
features to support all of the CCNA curriculum meant that he had to be supplemented with
physical equipment and/or Packet Tracer[24]. The second approach outlined in the paper,
‘Exploring virtual environments in a decentralized lab’ also uses virtualisation but uses a
decentralised lab model to reduce the strain of resources on the campus infrastructure[20].
This means that virtual machines are ran on student’s home computers rather than on a
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
17 Chapter 2
remote server at the campus. As a result, the costs are lower because instead of a centralised,
high costing lab, the resources are used on each student’s local computer. Because of recent
advancements in home computing, most computers have sufficient RAM to run the virtual
machines needed to complete the lab exercises. While the virtual machines provide packet
sniffing and intrusion detection tools, the use of VMWare Player or VirtualBox alone is not
enough to virtualise Cisco equipment. A decentralised lab solution also assumes high-end
computer systems to run the virtual machines and additional work by students to setup on the
virtual machines with the added risk of confusion or failure to complete the labs because of
errors. To overcome this problem, the paper used a centralised lab as a backup to provide
students with continuous access. This would lead to reduced costs as the hardware would not
overstressed by many students but only used in the event of a system failure. However,
according to a survey, approximately 89% of all students preferred the decentralised lab
solution, rather than a centralised lab. One of the reasons for the decentralised lab approach
was because of the connection to the campus lab environment was too slow[20].
It is clear that every solution has a trade-off that greatly impacts the learning outcomes of
students.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
18 Chapter 2
2.2.2 Cisco Packet Tracer
Cisco Packet Tracer, a simulation and software visualisation tool, is provided freely by Cisco
to students enrolled in a network academy program [24]. According to a study by Holvikivi,
J, Packet Tracer is sometimes used in improvised nations as a substitute for using real
equipment[4]. This because it uses minimal hardware resources, runs on a variety of
platforms and is very cost effective [7] [15] . Cisco Packet Tracer has an array of advantages
over the use of physical equipment. Firstly, it is easier to install and use of it virtually costs
nothing in contrast to physical equipment that costs thousands [5]. Secondly, unlike
traditional network simulators, Packet Tracer’s visualisation features and simulation mode
greatly helps students visually see the packet movement through the network and this
arguably leads to improved learning [7] [8]. Thirdly, unlike physical equipment, Packet
Tracer requires very little amounts of disk space and RAM because it is only mimicking the
environment. No actual packet transmission is occurring [9]. Fourthly, because Packet Tracer
does not actually use any physical network devices, there is no risk of damage or disruption
occurring to the network [15]. Fifthly, Packet Tracer also provides the tools to allow
instructors to set assessments, assignments, tests and activities. In addition, it is possible to
use Packet Tracer for collaborative projects [8].
As noted in the paper, ‘Pedagogical evaluation of simulation tools usage in network
technology education’, Packet Tracer is virtually free in comparison to local or remote
practical labs that potentially costs thousands of dollars to build and maintain [5].
Furthermore, Packet Tracer is portable3 and can be deployed at home for additional practice.
Packet Tracer is not only a networking simulator. It combines an array of features such as a
3 Portable means that it can be used anywhere and does not have to run on a server or in a lab environment.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
19 Chapter 2
command line interface, visual learning systems and an easy to use graphical user
interface[7].
While Packet Tracer is sometimes used as a substitute for physical equipment, the Cisco
Packet Tracer Datasheet warns that Packet Tracer should never be used to replace physical
equipment[25].
The verbatim quotation from the Packet Tracer Cisco Data Sheet reflects this:-
“Packet Tracer supplements physical equipment in the classroom by
allowing students to create a network with an almost unlimited number of
devices, encouraging practice, discovery, and troubleshooting…” (Cisco
Packet Tracer Data Sheet, emphasis added, p. 1)[25]
A similar quotation in the same data sheet confirms that Packet Tracer is not
designed to replace physical equipment.
“… Although Packet Tracer is not a substitute for real equipment, it
allows students to practice using a command-line interface…” (Packet
Tracer Data Sheet, emphasis added, p. 2)[25]
Despite this, the Cisco Packet Tracer Data Sheet does provide some perceived benefits of
using Packet Tracer, for instance, its ability to use an (almost) unlimited number of devices
for troubleshooting, practice and discovery [25].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
20 Chapter 2
According to a survey undertaken by Mohd Syahrizad Elias and Ahmad Zamzuri Mohamad
Ali, an interviewed senior lecturer who teaches networking at the Malaysian Polytechnic
Institutions was quoted as saying:-
“Students have fun doing the PT Simulation as compared to using the
actual equipment. The former helps in terms of starting the configuration,
but it gets more and more difficult when they reach higher concept levels.
The actual equipment has a better reputation in making students
understand. If they follow the lab sheet they should be able to demonstrate
the effectiveness of the PT simulation through a lot of practices, but they
are not able to do their own troubleshooting. They prefer to ask their
friends or lecturer, rather than thinking about ways to resolve the issue at
hand. The flaw of the PT Simulation is actually very scarce. I think this
issue is more apparent in certain topics like routing protocol, where the
students find it hard to apply what they have learned. ” (Polytechnic
Lecturer 5: CCNA, Senior Lecturer quoted in study in ‘Survey on the
Challenges Faced by the Lecturers in Using Packet Tracer Simulation in
Computer Networking Course’, pp. 13, emphasis added)[6]
Similar views were expressed by other quoted lecturers in the study [6]. It is also mentioned
in the paper, ‘Using a network simulation tool to engage students in active learning enhances
their understanding of complex data communications concepts’ that use of Packet Tracer
alone provides no demonstrated proof that learning is improved, questioning the premise that
the visualisation tools aid in understanding and learning. The paper does, however,
demonstrate that if Packet Tracer is used to encourage deep thinking and learning, then the
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
21 Chapter 2
tool is effective and useful[17]. Assistant Professor at R.K University, India, Sheikh Raashid
Javid has different views, arguing in his paper, ‘The Role of Packet Tracer in learning
computer networks’ that Packet Tracer is necessary for learning computer networks because
it provides; assessment of student activities, visualisation features designed to improve the
learning of students[8] and a cost-effective supplement to physical equipment[8]. Similarly,
the paper, ‘Visual Learning Tools for Teaching/Learning Computer Networks: Cisco
Networking Academy and Packet Tracer’, also supports the premise that Packet Tracer
provides necessary visualisation tools that are required to understand the complex
networking concepts that are not visible on a physical network [7] [24]. Both these papers
recommend the use of Packet Tracer as a supplement to physical equipment and not as a
replacement [7] [8].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
22 Chapter 2
The author took a screenshot of the Packet Tracer user interface. The screenshot provides an
illustration of the visualisation tools in action.
Figure 1 Packet Tracer UI - Simulation Mode
The red cross on the blue envelope indicates a ping failure and the point in the network
where the failure occurred.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
23 Chapter 2
In the survey in the paper titled, ‘Survey on the Challenges Faced by the Lecturers in Using
Packet Tracer Simulation in Computer Networking Course’, the general consensus among
the interviewed lecturers was that Packet Tracer suffices when basic concepts and topologies
are being simulated. But as more advanced concepts are introduced into the course, the labs
become much more difficult when done using Packet Tracer[6]. As outlined in the paper, ‘A
practical study on networking equipment emulation’, a simulation (including Packet Tracer)
is an incomplete model of the real thing and has limited functionality[18]. A number of
commands used on real Cisco equipment do not work properly or at all in Packet Tracer.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
24 Chapter 2
To demonstrate this, the author of this thesis took a still snapshot of the Packet Tracer
interface.
Figure 2 Packet Tracer CLI - No Debug Command
This command, while a valid command on Cisco enterprise routers and switches does not
work on Packet Tracer. As you see in the image above, the command line displays the text,
‘Invalid input detected at ‘^’ marker.’ This indicates that the command, ‘debug dhcp detail’
is not a valid command. This is because this command is not available on Packet Tracer.
Because Packet Tracer has a limited subset of all the Cisco IOS commands, some education
institutions have used an alternative solution, GNS3, to simulate networking using software
virtualisation [9] [26].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
25 Chapter 2
In addition to the technical limitations of Packet Tracer, some studies have indicated a
perception among lecturers that use of Packet Tracer, while fun and convenient for students,
may lead to bad study habits, such as blindly following the steps on the lab sheet, rote-
learning and a failure to apply the material or troubleshooting advanced networking
problems[6]. However, in the same study, one lecturer perceived no difference between a
student using Packet Tracer and using real equipment:-
“There has been no remarkable difference between students’ use of the
PT simulation and the actual equipment. Laboratory activities can be
done well by making reference to the lab sheet provided. Only a number of
students have problems in doing the Skills Test, where they can only do it
if they are helped, in some way. They are able to apply theories and lab
activities but stumble when it comes to perform the troubleshooting; if they
have problems, then normally the problems will be resolved with the
lecturer’s assistance.” (Polytechnic Lecturer 4: CCNA, Senior Lecturer
quoted in study in ‘Survey on the Challenges Faced by the Lecturers in
Using Packet Tracer Simulation in Computer Networking Course’, pp. 13,
emphasis added)[6]
It is clear that there is a perception that using physical equipment is preferred to simulation
tools such as Packet Tracer[6] [9] [5]. One study suggests lack of exposure to the physical
technology may result in learning difficulties in the future and subsequently lead to a lack of
confidence with using physical hardware in the industry[4]. Use of simulation tools also
requires for the learner to have some contextual background of the topic to understand the
concepts. This involves imagination to understand what is really happening[6]. Students who
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
26 Chapter 2
do not have this background may fail to learn anything from the tool[4]. A study by
Armstrong, H and Murray, I at Curtain University, Perth, Australia outlines the challenges
vision-impaired or blind people have with learning information technology courses. In
particular, the research found that Packet Tracer is not usable by vision-impaired students.
Consequently, its visualisation tools are useless [10]. Recent versions of Packet Tracer have
limited screen reader support, but the design of the application fails to address the issues
mentioned in the paper.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
27 Chapter 2
2.2.3 GNS3
GNS3 is network emulation software widely used as a supplementary tool for teaching
advanced networking concepts. It uses the Dynamips emulator to emulate a selected number
of Cisco devices. Dynamips was originally developed by Christophe Fillot [24]. The
advantages of using GNS3 are firstly that it is an open-source project [9] [24] . This means
that it can be used at no cost. Secondly, unlike simulators, GNS3 emulates the Cisco IOS,
creating a complete replication of the functionality of Cisco devices, enhancing realism [9]
[24]. This also enables GNS3 to connect to a physical network, to other virtual machines and
to the host computer, allowing the use of real networking tools like Wireshark or ZenMap to
be used for a full simulation experience [9]. Thirdly, GNS3 runs on a home computer and is
an ideal supplement for students working remotely, or for supporting long-distance education
[9] [20]. Fourthly, all commands available on real equipment is available in the emulated
environment because an actual operating system is being emulated. Fifthly, GNS3 can share
the resources of multiple computers to enhance performance and to support many virtual
routers [24].
Several disadvantages or problems arise when using GNS3. Firstly, it can only emulate select
Cisco devices [24]. The Cisco catalyst switches are not included. Therefore, a student cannot
use GNS3 to learn switching concepts such as spanning-tree or VLANs. This eliminates
almost a quarter of the CCNA curriculum. Secondly, GNS3 is very poor in terms of
performance and requires a lot of hardware resources [24]. However, in the paper titled,
‘Comparison between physical devices and simulator software for Cisco network technology
teaching’, the author suggests that most modern computer should be powerful enough to run
it and that distribution between machines can be used, if necessary [24].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
28 Chapter 2
Thirdly, while GNS3 is open source and free, the software requires a valid Cisco IOS image.
Without it, the software itself is useless. Because of licensing restrictions, GNS3 is
prohibited from including an IOS image with the software. It is also possible that even if a
student has authorisation to download and use a Cisco IOS image, the Cisco licensing
agreement restricts how that image might be used. A quotation of a portion of the software
license agreement implies that it may not be lawful to use the Cisco IOS image with GNS3:-
“… Cisco Systems, Inc. ("Cisco") and its suppliers grant to Customer
("Customer") a nonexclusive and nontransferable license to use the Cisco
software ("Software") in object code form solely on a single central
processing unit owned or leased by Customer or otherwise embedded in
equipment provided by Cisco.” (Cisco Software Licence Agreement, pp. 1,
emphasis added)[27]
It is important to note that Cisco only grants a 'non-exclusive and non-transferrable’ license.
This means that Cisco control how the Cisco IOS is to be used, and it is clear from the text
that the image is not be transferred to someone else, may only be used on customer owned
computers or on Cisco equipment with the software already embedded. There is no
authorisation that permits the use of the software in emulation platforms. Whether or not, the
use of the Cisco IOS with GNS3 is lawful or not is currently a grey area. A discussion of the
issue at The Cisco Learning Network online forums indicated that various people were
divided over the issue [28]. This uncertainty on the legality of using the Cisco IOS with
GNS3 indicates that GNS3 is not a viable alternative to Packet Tracer and/or physical
equipment due to the risk of being sued or prosecuted.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
29 Chapter 2
2.2.5 Common Open Research Emulator (CORE)
The Common Open Research Emulator (CORE) is a freely-available, open-source network
simulator and emulator [19]. According to the paper, ‘Comparison of CORE network
emulation platforms’, CORE is unique in that it is considered both an emulator and
simulator. The software emulates the OSPF, OSPFv3 and BGP routing protocols using a
form of process isolation [19] [29]. Layer-2 protocols are simulated in software and CORE
uses the hardware resources of the operating system to process the network traffic [19]. This
means that CORE may run on low, inexpensive hardware.
Like Packet Tracer, CORE uses a drag and drop graphical user interface where virtual
network devices such as routers and switches are dragged onto the main pane and then
connected using virtual cables.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
30 Chapter 2
The author took a screenshot of the core graphical user interface as a demonstration of what
it looks like:-
Figure 3 CORE GUI - No Nodes Added
CORE also simulates wireless networks, a feature that is commonly unavailable in many
simulation platforms [29] [19]. Unlike Packet Tracer, CORE can also physically connect to a
real network, but a separate network interface has to be reserved for CORE as it is
unavailable for use by the host system [29].
Internally, CORE runs an open-source routing engine called Quagga to provide the router
nodes with the ability to route packets using static routes or select dynamic routing protocols
such as BGP or OSPF [19] [29]. CORE can also use other simulators such as NS by using
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
31 Chapter 2
configurable Python scripting to enhance the functionality of the software [19]. The research
paper emphasises that CORE is ideal for scalability, supporting many nodes and has the
ability for nodes to be distributed across one or more physical machines [19]. Though, the
documentation suggests is that because the nodes are a simulation, the performance of CORE
depends on the amount of traffic being sent or received through it and not the number of
nodes [29]. In an educational environment, the amount of network traffic transmitted in a lab
is very low [18]. CORE is beneficial of helping students draw and understand network
topologies, routing configuration and operation and operation of the IP/TCP stack. The
problem with CORE is that it does not use Cisco devices. Even though the command line for
the routers is very similar to the Cisco IOS, it is not identical. Because EIGRP is a Cisco-
propriety routing protocol, CORE does not support it. A managed switch cannot be setup in
CORE unless CORE is physically connected to an external network where a real (or
virtualised) Cisco switch is installed. Therefore, although CORE has some beneficial
features, it lacks the support for Cisco devices and, therefore, is unlikely to help students
learn networking. Functionality and modelling requires programming knowledge of Python,
resulting in CORE being somewhat complex and not suitable for learning networking
courses [5]. The other problem with CORE is that it may only run on Linux or FreeBSD. It
does not run on Windows [29]. X11 forwarding can be used to access the graphical user
interface running on a remote server, allowing Windows users to use the software [29].
There has been little research on evaluating CORE for use in an academic environment.
Therefore, its effectiveness on student learning outcomes is unclear. Nevertheless, its lack of
support for switching or Cisco devices indicates that it is probably not the most suitable
solution. Interestingly, CORE can be installed on a Cisco VIRL server since the VIRL sever
runs Ubuntu 14.04 LTS, which CORE will run on [29].
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
32 Chapter 2
2.2.6 Miscellaneous Platforms
This section outlines and presents previous research on numerous simulation tools.
2.2.6.1 List of Miscellaneous Simulators
Some examples include:-
NetSims – Used to teach CCNA
iNetSim – An accessibility network simulation tool [10].
2.2.6.2 The Role of Network Simulators
According to the paper, ‘Simulation Tool for Active Learning of Introductory Computer
Networks’, various simulators exist for simulating networks including; Emulab, PlanetLab,
Open Network Lab and IREEL. These simulators often need to be connected to physical
equipment to work effectively and, therefore, are not suitable for use in a training
environment. Similar simulators, such as opnet, ns2, ns3, glomosim, OMMNet++ are
designed for researching network behaviour, rather than device configuration and
troubleshooting. These simulators are also complex because they require extensive
programming knowledge to simulate the network and are not user-friendly [30].
One of the important aspects of learning networking is the use of tools such as Wireshark to
learn and troubleshoot networks [9]. Third-party simulators, cnet and the scale simulation
framework lack the ability to be used with Wireshark.
Boston NetSim is a Windows-based network simulator that, according to K. Wan Mohd
Ghazali and R. Hassan, simulates more functionality than Cisco Packet Tracer. However, the
full version of the software must be purchased at a cost and is not freely provided to students.
This simulator also includes exercises to assist the student with their studies. Unlike both
Packet Tracer and GNS3, Boston NetSims is a Windows application and will not run natively
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
33 Chapter 2
on Linux systems4. The paper, ‘Simulation Tool for Active Learning of Introductory
Computer Networks’ recommends GNS3 and Packet Tracer and implies that these
simulatiors are preferred to the Boston NetSims simulator [30].
Therefore, none of these simulator tools are viable to be used by students for learning
networking because they do not help improve understanding of networking but are more
designed for research purposes [30].
4 It is unclear if it works with Wine / PlayOnLinux. However, this increases the level of difficulty and time
wasted.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
34 Chapter 2
2.2.7 Cisco Virtual Internet Routing Lab
Cisco Virtual Internet Routing Lab (VIRL) is a software tool that simulates computer
networks. Its primary use case, according to the vendor documentation, is to test network
designs prior to the design being rolled out on a real network. Nevertheless, the design of
VIRL is not unlike a simulator which students could potentially use to learn advanced
networking concepts. Virtualisation technologies enable resources to be shared, but
virtualisation of propriety cisco equipment was difficult. GNS3 lacked support for layer-2
switching capabilities, so its application in learning environments was limited. Cisco VIRL
now supports layer-2 switching [1].
The user interface for Cisco VIRL is below. The screenshot was taken by the author on a
Mac computer.
Figure 4 Cisco VIRL Pane
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
35 Chapter 2
In many ways, the interface is similar to Packet Tracer because devices such as routers and
switches can be dragged and dropped onto the main pane and connected using virtual cables
as shown in the figure[2].
Like GNS3, the operating system powering the Cisco devices is virtualised and from the user
perspective appears to be real. In fact, the VIRL topology can be branched out and connected
to a real network[1]. In theory, this means students could use SSH to connect to routers and
switches using a real computer in the lab via the VIRL network.
Cisco VIRL can also support the aims mentioned in the literature. For instance, Cisco VIRL,
by design, can support both a centralised and decentralised lab. This is because routers and
switches created in VIRL can be branched out to an external layer-2 or external layer-3
network [2]. Cisco VIRL is designed to be integrated into a virtualisation infrastructure
powered using VMWare vSphere, though this requires additional configuration [2].
Subsequently, this allows VIRL to be used to set up a laboratory-as-a-service [2] [3].
Because it is running in a cloud environment, this means that VIRL can potentially be used
as a software-cloud service and hosted externally, eliminating the need to maintain physical
servers. Cisco VIRL is powered by OpenStack, the Linux KVM hypervisor and Ubuntu
14.04 LTS, allowing further customisation of the server to support the learning needs of
students. Also, Cisco VIRL replicates all the functionality and commands of physical
equipment.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
36 Chapter 2
To demonstrate this, the author took a screenshot of the VIRL output.
Figure 5 Cisco VIRL - DHCP Debug Command
The output is DHCP client activity debugging is on (detailed)
The command completes successfully.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
37 Chapter 2
However, on Packet Tracer, the command fails.
Figure 6 Debug Command Fails (Packet Tracer)
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
38 Chapter 2
There are some drawbacks with using Cisco VIRL. Some of these will be explored further as
part of the research of this paper. Firstly, the maintenance and cost of setting up the hardware
to host the Cisco VIRL server, though this can be overcome using cloud computing [1] [2]
[3]. Secondly, running a virtual network (known as a ‘simulation’) requires an extensive
amount of resources. The physical hardware alone requires full-blown hardware assisted
virtualisation if VIRL is installed in a virtual environment to function [2] [31].
The recommended minimum RAM for Cisco VIRL is 8GB and 50GB of disk space, but
meeting these requirements does not guarantee VIRL will work because the amount of
computing resources needed to run VIRL depends on the number of simulations running[31].
Assuming that one simulation uses 8GB of RAM to run, a class with 25 students all running
one simulation each would require a server with 200GB of RAM.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
39 Chapter 2
2.3 Summary
Learning computer networking concepts requires both understanding of abstract concepts and
experimentation. Understanding abstract concepts is easily achieved through the traditional
lecturing style of teaching. But developing a student’s experience and soft skills, such as
problem solving and teamwork, requires a hands-on practical approach. As concluded in the
study by Holvikivi, J, a practical approach is necessary to help students develop motor skills
and to apply the theoretical material. Both a theoretical and practical approach to teach
networking concepts. Unfortunately, implementing practical networking equipment costs
thousands of dollars, so is often not affordable by many education institutions. The use of
network simulators, including Packet Tracer helps solve this problem with the trade-off of
reduced functionality and realism. Hardware resources in a lab are underutilised but have to
be separate from production networks for security and safety reasons. Virtualisation
technologies allow resources to be shared but isolated from each other, reducing the overall
costs in terms of purchasing and maintenance. While virtualisation virtualises desktop and
server operating systems quite well, virtualisation of network operating systems such as those
that run on Cisco routers and switches is done very poorly. GNS3, an open source tool, only
emulates select Cisco devices excluding switches and this emulation is very demanding on
hardware resources. The Common Open Research Emulator (CORE) emulates layer-3
protocols but uses operating system resources to maximise efficiency but it accurately
simulate Cisco devices. A decentralised lab approach uses students’ home computers to
provide the hardware resources, reducing costs. Unfortunately, this requires additional work
by students to setup, adding complexity. Furthermore, the virtualisation software lacks the
capability to simulate Cisco routers and switches. Cloud computing technologies enable
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
40 Chapter 2
education institutions to deliver ‘Laboratory-As-A-Service’ to students using NDG NetLab
combined with vSphere. NetLab is costly and does not run on mobile devices easily.
Cisco Virtual Internet Routing Lab (VIRL) provides full virtualisation of Cisco routers and
switches, incorporating the full functionality of a Cisco networking environment. This tool
appears to incorporate the functionality that is missing or poorly implemented in the other
tools analysed and provides a promising solution to teaching networking. However, its role in
a network training environment has not been researched. Neither has the student perceptions
of this new tool been taken into consideration. As a result, this thesis aims to investigate
Cisco VIRL’s role in a network training environment by undertaking research on a number of
select staff and students at UniSA.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
1 Chapter 3
3. Methodology
In this section, the methodology for the experiment will be outlined. The first subsection will
outline the current methodologies and outline why a particular methodology has been chosen
for this research. The second subsection will outline the experimental design, providing
details on the nature of the experiment, the people involved and kind of data collected during
the experiment and the implementation. This subsection will consist of a recruitment
procedures section that will outline how the participates will be chosen, an overview of the
experiment that will provide a summary of the experiment and what will be done and
implementation will provide details such as the location and how it will be implemented. The
experiment has been approved by the UniSA Ethics Committee and may proceed.
3.1 Outline of Current Research Methodologies
The research will consist of both quantitive and qualitive research methods. The form of
research will involve observational methods and evaluation methods. Both the understanding
and perceptions of the participant will need to be gathered to assess the effectiveness of the
tool. In order for the tool to be effective, it must be perceived by students as a useful tool that
helps them learn. This information will be obtained from students through a questionnaire
evaluating their perceptions of the tool. Secondly, perceptions alone do not prove that the
tool actually assisted in developing their learning[16]. Therefore, each participant will be
issued a pre-test to assess their understanding of computer networking concepts. They will
then be given a post test, testing similar concepts to see if the tool has helped them learn.
The exercises undertaken by students will require deep thinking and application of content
used in previous networking courses to help develop deep learning[16]. If deep learning is
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
2 Chapter 3
observed and demonstrated in the tests, then it follows that the tool assisted their learning and
is a promising tool for teaching networking.
Because assessment of theoretical knowledge does not necessarily cover all aspects of
learning, the student will be observed to see how he reacts to mistakes and how they use their
knowledge and experience and the tool to correct the mistakes.
Other forms of research includes; testing their perceptions, testing how many mistakes they
make with the tool, or testing did they complete the lab. However, these research
methodologies do not truly determine if VIRL is a good tool for education. It simply answers
the question that a student can blindly follow instructions. Furthermore, mistakes or slow
reaction times in the application does not imply poor learning or poor understanding. At the
commencement of this project, it was proposed that each student would do one lab but on
three separate platforms. This is not only a slow process but it has the tendency to create a
learning effect that can result in confirmation bias.
3.2 Experimental Design
3.2.1 Recruitment Procedures
Participants will consist of approximately 30-60 people, comprising of both students and
staff at the University of South Australia (UniSA). The students will be selected from a pool
of networking students studying the third year of an undergraduate networking degree. The
staff members will be selected from a pool of staff members that are experienced in teaching
the Cisco Networking Academy program (CNA). Because the students are studying
networking, it is anticipated that they will have some background in computer networking
and will be suitable for the study. A screening test will be unnecessary.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
3 Chapter 3
To minimise possible disruption to staff and students, the experiment will be scheduled
during the students’ routine practical class and held in the practical laboratory on the UniSA
campus.
The participates will be contacted by a recruitment email sent out by the school of
Information Technology & Mathematical Sciences (ITMS) to ask them if they would like to
participate. Those that consent to the experiment will compose of the total sample size for
this experiment.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
4 Chapter 3
3.2.2 Overview of the experiment
The experiment will assess the students’ and staff members learning outcomes of using a
network simulator to complete a series of practicals similar to those done by CCNA Security
students. This will be done using both quantitive and quantitative research methods to assess
the participants’ learning outcomes.
The experiment will be broken down into four sections:-
1) Each participant will complete a preliminary set of multiple choice questions
assessing their understanding of computer networks
2) Each participant will then (attempt) to complete the series of activities using the
network configuration tool. During this time, the investigator will record numerical
data in respect to their performance and this will constitute the quantitative data.
3) Each participant will then complete a series of multiple choice questions to see if the
tool has helped them develop a better understanding of networking.
4) Each participant will fill out a shot questionnaire, evaluating their perceptions of
using the tool. This will constitute the quantitive data.
This experiment has been approved by the UniSA Ethics Committee and complies with
Australian ethics regulations. Although private or personal information will not be collected
during the experiment, the participants’ desktop will be captured using video capture
software so that their activities may be observed by the researcher. All participants will be
made aware of this prior to the start of the experiment.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
5 Chapter 3
3.2.3 Implementation
The experiment will involve each participant filling out printed questionnaires as well as
using a computer to interact with the simulated networking environment. The experiment
will be held in a practical networking lab on a UniSA campus. The experiment is estimated
take between 1-2 hours. A pilot version of the experiment will be ran prior to the experiment
being undertaken to ensure that the experiment is reasonable and can be achieved in the time
allocated.
Except for technical issues, or ambiguity with the questions, the investigator will not provide
any help to any participate, since this will make it too difficult to accurately determine the
learning outcomes.
Practical activities will cover networking topics such as STP, switching, routing protocols
and basic troubleshooting.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
6 Chapter 3
References
[1] Cisco, "Welcome to VIRL," 2015 2015.
[2] Cisco, "VIRL Learning Lab Tutorial," 2015 2015.
[3] R. I. Dinita, G. Wilson, A. Winckles, M. Cirstea, and A.
Jones, "A cloud-based virtual computing laboratory for
teaching computer networks," in Optimization of
Electrical and Electronic Equipment (OPTIM), 2012 13th
International Conference on, 2012, pp. 1314-1318.
[4] J. Holvikivi, "FROM THEORY TO PRACTICE: ADAPTING THE
ENGINEERING APPROACH," in CONFERENCE ON ENGINEERING
EDUCATION 2012, 2012, p. 78.
[5] W. Makasiranondh, S. P. Maj, and D. Veal, "Pedagogical
evaluation of simulation tools usage in network
technology education," Engineering and Technology, vol.
8, pp. 321-326, 2010.
[6] M. S. Elias and A. Z. M. Ali, "Survey on the Challenges
Faced by the Lecturers in Using Packet Tracer Simulation
in Computer Networking Course," Procedia - Social and
Behavioral Sciences, vol. 131, pp. 11-15, 2014.
[7] J. Janitor, F. Jakab, and K. Kniewald, "Visual Learning
Tools for Teaching/Learning Computer Networks: Cisco
Networking Academy and Packet Tracer," 2010.
[8] S. R. Javid, "Role of Packet Tracer in learning Computer
Networks," International Journal of Advanced Research in
Computer and Communication Engineering, vol. 3, 5 May
2014 2014.
[9] P. Gil, G. J. Garcia, A. Delgado, R. M. Medina, A.
Calderon, and P. Marti, "Computer networks virtualization
with GNS3: Evaluating a solution to optimize resources
and achieve a distance learning," in Frontiers in
Education Conference (FIE), 2014 IEEE, 2014, pp. 1-4.
[10] H. Armstrong and I. Murray, "Remote and local delivery of
cisco education for the vision-impaired," presented at
the Proceedings of the 12th annual SIGCSE conference on
Innovation and technology in computer science education,
Dundee, Scotland, 2007.
[11] L. Hsin-Ke and L. Peng-Chun, "Effects of interactivity on
students' intention to use simulation-based learning tool
in computer networking education," in Advanced
Communication Technology (ICACT), 2012 14th International
Conference on, 2012, pp. 573-576.
[12] C. R. M.R, N. M. Chacko, J. Major, and S. D, "A
Comprehensive Overview on Different Network Simulators,"
International Journal of Engineering and Technology, Vol
5, Iss 1, Pp 325-332 (2013), 2013.
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
7 Chapter 3
[13] D. Rajendran, "Does embedding an ICT certification help
align tertiary programs with industry?: A study of CCNA
workplace perceptions," Journal of Applied Computing and
Information Technology, vol. 15, 2011.
[14] !!! INVALID CITATION !!! {}.
[15] D. Frezzo, J. Behrens, and R. Mislevy, "Design Patterns
for Learning and Assessment: Facilitating the
Introduction of a Complex Simulation-Based Learning
Environment into a Community of Instructors," Journal of
Science Education and Technology, vol. 19, pp. 105-114,
2010.
[16] C. Goldstein, S. Leisten, K. Stark, and A. Tickle, "Using
a network simulation tool to engage students in active
learning enhances their understanding of complex data
communications concepts," presented at the Proceedings of
the 7th Australasian conference on Computing education -
Volume 42, Newcastle, New South Wales, Australia, 2005.
[17] T. Coffman, "Using Simulations to Enhance Teaching and
Learning: Encouraging the Creative Process," The VSTE
Journal, vol. 21, pp. 1-7, 2006.
[18] C. Li, J. Pickard, P. Li, T. Mohammed, B. Yang, and K.
Augustus, "A practical study on networking equipment
emulation," Journal of Computing Sciences in Colleges,
vol. 24, pp. 137-143, 2008.
[19] J. Ahrenholz, "Comparison of CORE network emulation
platforms," in Proceedings of IEEE MILCOM Conference,
2010, pp. 864-869.
[20] P. Li, "Exploring virtual environments in a decentralized
lab," SIGITERes. IT, vol. 6, pp. 4-10, 2009.
[21] J. Ahrenholz, C. Danilov, T. R. Henderson, and J. H. Kim,
"CORE: A real-time network emulator," in Military
Communications Conference, 2008. MILCOM 2008. IEEE, 2008,
pp. 1-7.
[22] D. C. Sicker, T. Lookabaugh, J. Santos, and F. Barnes,
"Assessing the Effectiveness of Remote Networking
Laboratories," in Frontiers in Education, 2005. FIE '05.
Proceedings 35th Annual Conference, 2005, pp. S3F-S3F.
[23] T. McGill and M. Dixon, "Information technology
certification: A student perspective," Proceedings of
International Resource Management Association, pp. 302-
306, 2004.
[24] S. Liangxu, W. liansheng, Z. Yujun, and Y. Hang,
"Comparison between physical devices and simulator
software for Cisco network technology teaching," in
Computer Science & Education (ICCSE), 2013 8th
International Conference on, 2013, pp. 1357-1360.
[25] Cisco, "Cisco Packet Tracer Data Sheet."
The Role Of Cisco Virtual Internet Routing Lab In Network Training Environments
Bradley Herbert
8 Chapter 3
[26] D. Dobrilovic, V. Jevtic, and B. Odadzic, "VIRTUALIZATION
TECHNOLOGY IN HIGHER EDUCATION IT COURSES," CORRECTION OF
THE JOURNAL ITRO 2011, p. 66, 2012.
[27] C. Systems, "SOFTWARE LICENSE AGREEMENT."
[28] Cisco, "The Cisco Learning Network," Online Forums, 2010.
[29] "Core Documentation," vol. Release 4.8, pp. 1-43, 5 June
2015 2015.
[30] K. Wan Mohd Ghazali and R. Hassan, "Simulation tool for
active learning of introductory computer network
subjects," 2011.
[31] Cisco, "About Virl."