Network simulation tools allow students (e.g people studying for Cisco Exams) to easily learn the core concepts of computer networking and TCP/IP in general. Even professionals could benefit from these tools by simulating network environments and get an idea of how a network will work before actual implementation.
Moreover, system administrators could use them as testing grounds for new network topologies and system testing. The simulation environment allows specialists to try out ideas with no harm to existing networks.
If this is the kind of functionality you are looking for, then in this article you will find 18 suggestions of network simulation tools below.
Some of them are great for people studying for network certification exams (such as Cisco CCNA, CCNP etc) but you will find also other options for general networking simulations and research.
Cisco’s Packet Tracer is perhaps the most famous of all network simulation tools, especially for practicing on Cisco CCNA certification.
It is functional, easy to use, and is accessible for educational institutions or for people who enrolled in Cisco’s Net Academy (free of charge).
The highlight of the Packet Tracer is its drag-and-drop user interface. To start testing network topologies, you simply choose a network device from the bottom panel and drop it into the building area. Packet Tracer offers several categories of devices, such as routers, switches, computers, servers, and more.
The drag-and-drop UI is complemented by a command line interface. Although you can do much of the setup in the visual editor, the command line provides you with full access to all features of the Packet Tracer, including TCP/IP settings of network devices, routing protocols supports, Layer 2 features etc.
With that said, Cisco Packet Tracer has some limitations. Among other things, it’s proprietary and only simulates Cisco devices. Also, it does not support all the features available on actual devices.
Still, Cisco Packet Tracer is fairly intuitive and is a great tool for students and experienced network specialists alike. It lets you easily build super-complex network topologies to test out ideas or to allow you to better understand networking concepts.
GNS3 is quite a bit different from Cisco Packet Tracer. Although GNS3 is perhaps more difficult to set up, it offers more flexibility than the Packet Tracer. It’s all in all more advanced and allows you to do more (if you have the knowledge).
The most important advantage of GNS3 over the Packet Tracer is that GNS3 is open-source and supports more device options as emulated devices.
If needed, you could dive into its source code to extend its base functionality. Most people probably won’t benefit from the open-source license of GNS3, but it’s still nice to have.
Another nice thing about GNS3 is that it runs real Cisco IOS images in an emulated virtual environment (more close to the real device), whereas the Packet Tracer merely simulates IOS and does not support all the features available in real devices.
Among other things, this allows GNS3 to integrate with real, physical network devices.
Aside from IOS, GNS3 supports other vendors as well, such as Arista or Mikrotik.
What’s also great about GNS3 is that it’s completely free, though the customer support is limited.
3. Cisco VIRL
Many people think that Cisco Packet Tracer is good only for testing high-level ideas. Well, if you want something more advanced, Cisco VIRL may be the right choice.
VIRL is notorious for its resource management and complexity issues, but it’s way more functional than Packet Tracer. It features the latest versions of Cisco IOS as well.
What’s also nice about VIRL is that it can create automated bootstrap configurations with one click thanks to AutoNetkit.
After AutoNetkit is done, it presents graphical representations of network topology and allows you to customize routing protocols, IP addresses, and more.
One thing to note with VIRL is that the more RAM your machine has, the better. VIRL hogs computer resources like there’s no tomorrow, so a powerful machine is a must.
EVE-NG is available in free and paid editions with vastly different features. Although the free version comes with all the basics of this tool, it lacks some things such as Docker container support, NAT clouds, or Wireshark integrations.
What’s also particularly notable about EVE-NG is that it is clientless. Basically, this means that you only need to deploy the server through a virtual machine, and that you don’t need to install separate tools to visualize and connect network devices. Network setup is done via HTML5, which is fairly convenient.
Like GNS3, EVE-NG also allows you to modify network topologies while they are running, which makes it a little more time-efficient.
5. Boson NetSim
NetSim is an excellent solution for preparing for CCNA, ENCOR, and ENARSI exams. Each subscription of NetSim covers 1 exam in its respective category as well, so you don’t need to dedicate money to it separately.
The core of NetSim is the Network Designer – a tool that allows you to create intuitive topologies with ease. Among the things that the Network Designer lets you do is aligning elements, annotating topologies, and easily identifying active or inactive connections.
NetSim allows you to share your own labs, lab packs, and network topologies with others as well. Likewise, you may view labs and topologies of other NetSim users, which may give you an edge in education.
Mininet is yet another open-source network simulation solution. This thing works best with Linux machines since you may install it natively without any VMs. However, you could use Mininet on Mac and Windows as well if you have something like Virtual Box or VMWare.
As an open-source network simulator, Mininet provides excellent flexibility for setup, though it also requires more technical knowledge.
It’s not as functional as GNS3 or VIRL, but it’s certainly a good pick for testing ideas or learning. Mininet is based on OpenFlow as well, so it’s particularly good for building OpenFlow solutions.
Common Open Research Emulator, or CORE, has been originally developed by a Network Technology research group at Boeing Research and Technology. Now, the U.S. Naval Research Laboratory is supporting the further development of CORE.
As an open-source network simulation solution, CORE is highly customizable. Maintained by the U.S. Navy, it’s reliable and frequently updated as well. CORE is efficient and scalable too, and it also allows you to run real-time connections to live networks.
IMUNES is based on the Linux and FreeBSD kernel. The kernel has been divided into smaller virtual nodes that can be connected with each other to form complex network topologies.
This tool may simulate or emulate IP networks at gigabit speeds in real time, with hundreds and thousands of nodes running on a single physical machine. INUMES is scalable as well, allowing you to perform large-scale experiments.
Completely open-source and free, IMUNES is remarkably customizable too. And what’s also notable is that IMUNES is currently used for general-purpose network testing at Ericsson Nikola Tesla and learning at the University of Zagreb.
Cloonix comprises a server subset of virtual machines and a client subset of virtual machines providing distant server’s control.
Primarily, Cloonix is aimed at “the coherent usage” of open-source software solutions such as openswitch, qemu-kvm, and dpdk.
Cloonix emulates 3 cable types too – socket, vhost-ovs, and dpdk-ovs. Aside from that, this network emulation tool provides easy access to the virtual machines managed by it.
When it comes to the easiness of use, Cloonix is intended for more advanced users (though if you are interested in networking, you should be “advanced” anyway). It’s open-source and free as well, allowing for great customizability.
The Paessler Multi Server Simulator is specifically designed for large-scale network testing. Among the protocols this thing supports are HTTP, FTP, SMTP, and DNS – all the essential and basic stuff you would want for testing.
What’s also notable about the Multi Server Simulator is that it allows you to simulate recurrent downtimes for each device – intervals can be set by the user. And thanks to the detailed logs for each simulated server, keeping an eye on the network is very easy.
Cisco Modeling Labs Personal allows you to prepare for Cisco Expert, Professional, or Associate certifications via its accurately simulated network environments.
Modeling Labs Personal uses real Cisco IOS images for simulation, allowing you to model real Cisco switches and routers. Aside from that, Cisco Modeling Labs Personal allows you to create what-if scenarios and models of real-world networks, connect virtual and physical environments, and work with up to 20 simulated nodes.
If 20 doesn’t seem quite enough for your needs, then you could get Modeling Labs Personal Plus with up to 40 concurrent nodes.
Cisco CCIE Lab Builder is recommended by Cisco for those who have passed the CCIE Routing and Switching Written Exam, as well as for those who are preparing for expert written labs and exams.
The virtual lab environment in Cisco CCIE Lab Builder provides access to features that are tested during the CCIE Routing and Switching Version 5 Lab Exam.
The CCIE Lab Builder lets you configure topologies with up to 20 nodes, while the drag-and-drop builder with minimal reload times ensures an environment for efficient learning.
ns-3 is licensed under the GNU GPLv2 license and is available for research, development, and educational use for free.
Remarkably, ns-3 has been used in hundreds of research publications, some of which have been published in Google Scholar, the ACM digital library, and the IEEE digital library.
What’s also nice about ns-3 is that it has quite an expansive Wiki documentation to assist first-time users with setup. ns-3 requires some technical knowledge, but it’s fairly intuitive even for beginners.
ns-3 works with a wide range of platforms as well – most notably, IDEs such as Eclipse or NetBeans, though these aren’t supported officially.
Kathara is a Python implementation of Netkit. Advertised to be 10 times faster than Netkit, Kathara allows for the deployment of arbitrary network topologies running on SND, NFV, BGP, or OSPF.
Kathara perhaps isn’t very well-known, but it’s currently being used by students at Roma Tre University. Aside from that, Kathara has been used to write a number of research papers that demonstrated the capabilities of Kathara itself, among other things.
VNX is a Linux-based, general-purpose network virtualization tool. Among the highlights of VNX is the automatic deployment of network scenarios that comprise virtual machines of different types, such as Windows, FreeBSD, or Linux. Aside from that, VNX may be deployed on hundreds of virtual machines at a time.
Designed by the Telematics Engineering Department of the Technical University of Madrid, VNX allows organizations to test network topologies of different scales, as well as may be used for education.
16. VR Network Lab
VR Network Lab has been developed for the TeraStream project at Deutsche Telekom for testing the company’s network provisioning system. It has been made available for students and network specialists via GitHub for free use as well.
This network simulation tool supports devices from multiple vendors – most notably, Arista, Cisco, Juniper, and Nokia. VR Network Lab is also intended to be run with KVM enabled for hardware-assisted virtualization, though it may work without it as well.
The OPNET network simulator is an open-source piece of software with pre-built models of protocols and devices, allowing you to create a wide range of network topologies. Aside from that, it incorporates a large number of project scenarios.
The user interface of OPNET is quite nice and simple. It’s functional too – once you create or import a network topology for simulation, you may create traffic, select statistics for tracking, and view results. After that, you may make changes to the topology to hopefully come up with a more efficient solution.
One thing to note with OPNET is that you can’t create new protocols or modify existing ones. Still, what comes out of the box should be more than enough for most use cases.
The QualNet Network Simulator is wonderfully scalable, supporting thousands of nodes for building and testing network topologies.
Thanks to its efficiency, the Network Simulator is well-optimized and isn’t exorbitantly hungry for resources like some other network simulation tools out there.
Network Simulator tools allow you to quickly and intuitively design network topologies, analyze data flow within the network, trace packets, and set up what-if scenarios to see how the network holds up to tests and challenges.
The QualNet Network Simulator is also compatible with Windows and Linux running on 64-bit multiprocessor architectures and can be connected to real networks or third-party visualizations to help you enhance your network model.
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