Packet Tracer for CCNA, but not for your future

It is a widely held belief that Packet Tracer is the best tool for CCNA students, however, it is not the best tool for good engineers.

Packet Tracer - Simulation does not equal success

Cisco's Packet Tracer falls under the heading of network simulation, it sits alongside the likes of Boson NetSim. Both are great products; both have had years of development and both are designed to help you learn. The cool thing is that you can even run Packet Tracer on your mobile device (iOS or Android). I started off with Packet Tracer and it is a very easy-to-use product, and I can only assume its become even more impressive since I last used it, many many years ago.
However, there is an inherent issue with any form of simulation.
Network simulation software can only replicate a limited set of commands, being reliant on whatever the developer can write in relation to the demands of the exam they are written for. In this sense they are like a dictionary. They contain a wealth of information, but are limited.
The alternative is network virtualization.

What is Network Virtualization?

Virtualization platforms, such as Dynamips, GNS3 and UNetLab, offer a more flexible approach. To keep with the dictionary analogy, these platforms would be an entire library. Instead of just a dictionary there are books on pretty much everything. Moreover because we are using virtualization, rather than simulation, we increase our scope for learning. Instead of being limited to a subset of commands, we can use proper images (a self-contained environment which is usually Linux based) that support the entire feature set of the device we want to run, such as a Cisco router. These then usually run on a hypervisor such as VMWare, or QEMU.
We can then easily expand our knowledge base. If we start out by using network virtualization, rather than simulation, we can easily add an image for other devices, such as Cisco Nexus, Juniper and Alcatel-Lucent. This exposure to a wider range of devices will make you a better engineer and serve you for longer in your career in networking.
There is a trade-off. Packet Tracer is easy to learn, just download, install and off you go. Virtualization platforms are harder to learn initially. They require time and effort, maybe learning a little Linux, they require time to find, download and install the right images. Far more effort than just running Packet Tracer. The upshot is that there will be a bigger payoff. The wider range of devices you can try out, play with, configure, break and build again will make you a better engineer and quicker.
The networking market is tough, by embracing network virtualization early on you can put yourself ahead of the curve and put yourself in a better position to gain a good job.
I will post an introduction to UNetLab next week explaining how to install it, find and download images and create your first lab.

CCIE #49337, author of CCNA and Beyond, BGP for Cisco Networks, MPLS for Cisco Networks, VPNs and NAT for Cisco Networks.

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November 1, 2016 at 3:20 PM delete

I'm just getting to my studies to renew my CCNA. I've been in the industry for many years, work with many different technologies. Thing is, I need to get back to the basics and refresh those skills. I'm a decent Linux Admin, have fair about of Virtualization Background (have my VCP), and work in the network test and measurement business calling companies such as Cisco my customers. I think I'm over-engineering what I'm trying to do with my labs. I have some old hardware sitting around (2500 and 2621XM series routers, 2950 and 3550 switches), I have Packet Tracer currently up on a Linux host\vm, and I also have GNS3 and IOU setup (have both L2 and L3 images for IOU, as well as IOS 12,x and 15.x images for GNS3 emulated Cisco routers). All of this works great, but not I'm feeling like I've gone too far and not really getting started. I guess my question here is Packet Tracer enough the new CCENT ICND1 and ICND2 (CCNA v3) exams? And any thoughts on what I cannot do in terms of labs\sims based on the lab setups I describe above? Thanks in advance.