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Zombie and Non-Zombie Technologies and What We Should Be Teaching in Basic Networking Classes

- October 16, 2015 - 3 Comments

In the networking field, there are a number of technologies that should be dead but that still linger on, at least in our folklore and training, if not actually installed in modern networks. There are also concepts and technologies that are extensively used in modern networks, but that aren’t taught in most basic networking classes.

zombie tech

In this short blog, I would like to distinguish zombie from non-zombie technologies, and make a call to action to ensure that relevant, modern topics are taught in training classes and at universities.

Zombie Technologies

This is an abbreviated list of technologies that we still love to talk about and teach in our classes, even though we need to move on.

  • Hubs. Why do basic networking classes still talk about hubs? I guess maybe it’s necessary in order to explain that switches are better, but I doubt it. I think hubs need to be put in their grave.
  • ISDN. Even when ISDN was marginally popular, people said the acronym stood for, “I still don’t need it.” But for some reason, basic networking classes still cover ISDN. Perhaps ISDN helps present the concept of multiplexing? But there must be better ways to get that concept across.
  • Frame Relay. This one is debatable, but do we really still need to teach a technology that was invented around the same time as the 128-K Macintosh?
  • AppleTalk. Speaking of Apple, I may be unique in this, but I still love to talk about AppleTalk. There are many reasons to respect AppleTalk. Long before Zero Configuration or even before DHCP, AppleTalk nodes could automatically determine the network addressing scheme and update the distributed name space. In addition, AppleTalk really did have seven layers, unlike the TCP/IP stack that for years has been coerced into seven layers by network training classes.
  • OSI. Speaking of seven layers, can we please finally stop talking about the OSI model? The concept of layering is important, but the mythical seven layers were never accurately portrayed and networking classes should let them stay dead.

Non-Zombie Technologies

With all the time saved in networking classes by not covering zombies, we can now teach more modern topics. I surveyed a few people who joined the networking field relatively recently, and here are some topics that they wish they had learned better in class:

  • Tunneling. Some recent college graduates told me that it wasn’t until they got into the real world that they realized that network traffic is often tunneled inside other traffic. They learned the basics of hop-by-hop routing but didn’t consider that packets could be just along for the ride en route from one edge of the network to another. Plus, they didn’t learn Generic Routing Encapsulation (GRE) even though they now need to know it in their work.
  • Virtualization. In hands-on classes, students often take advantage of virtualization, but they don’t actually learn about it. Someone else sets up the virtual lab for them. Students should learn virtualization and hypervisor theory, and how to set up and configure virtual machines.
  • Security. Every networking class should teach network security concepts and best practices. This should go beyond convincing students to disable Telnet for router and switch access. It should include IPsec.
  • Storage. High-level theory about enterprise storage is an important topic. In addition, anybody who will deal with storage in midsize to large businesses needs to know how Fibre Channel works.
  • MPLS. A colleague recently admitted to me that he thought his coworkers were referring to Minneapolis instead of Multiprotocol Label Switching when he first saw MPLS on network diagrams. I’m glad to see that Cisco requires CCNA candidates to learn some basic MPLS.
  • IPv6. With the depletion of IPv4 prefixes, this is no longer optional. I talked to one network manager who said that he would not hire a network engineer who didn’t have at least some solid lab experience with IPv6.
  • Software Defined Networking. Arguably, network administrators, technicians, and installers don’t need to learn about SDN. However, anyone who plans to be a network engineer should learn SDN. In addition, DevOps and network programmers should study SDN.
  • RF. A basic understanding of how radio signals propagate and reflect, frequencies, wavelengths, antennas, and signal loss should be a prerequisite for entering the networking field.
  • Linux. Students should gain practical experience using Linux.
  • Hexadecimal. Students need to learn how to convert between hex and decimal. 0xB00!

What am I missing? Can you think of any other zombie technologies that are still wandering among us? What new technologies should be taught instead? When you entered the workforce, what do you wish you had learned better in your training classes?


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  1. Non-Zombie How mobile (GPRS, UMTS and LTE-A) network works! Some basic join-dots stuff, like the different between a public APN and private APN. Amount of time I spend tell network engineers, this sort of stuff is mind blowing!

  2. Zombie technology: classful addressing concepts. Please, Cisco, stop teaching classful thinking in intro classes. It just confuses people and is a stumbling block to understanding subnetting. I die a little inside every time I read a question that mentions address classes.

    Nice summary. To add to the zombie technologies: ATM To add to Tunneling: Should also learn VXLAN To add to the Must Understand technologies: Network Programmability, automation and orchestration (or some basic Python for network automation).