Cisco LAN Switching…1999

cat5000I just finished reading Cisco LAN Switching, which was published in 1999 as part of the CCIE Professional Development series. Since this book was published 14 years ago, quite a bit of it can be considered out of date now (such as the extensive coverage on Token Ring networks and flat campus-wide Layer-2 topologies). However, I found this book to be very interesting and it has provided me both a history lesson as well as reinforcing fundamentals that are still used in networks today, such as the usage of Spanning Tree Protocol.

Another interesting thing about this book is that all of the command-line examples are done in CatOS, which I have never worked with. Any Cisco switch I have ever touched has always run native IOS, even if they were 10 years old (well, the 2950 is the oldest switch I’ve worked with so far).

The beginning of this book also made me question just how much innovation Cisco has done itself as a company. It seems that almost every major product line in the company has its roots in corporate acquisitions. Some company invents something really useful, then Cisco buys them out and relabels the product. I understand that they have been instrumental in helping to develop several protocols that we take for granted today, but as far as product lines are concerned, it made me wonder. 🙂

Cisco IOS is a wonderfully-deep network operating system with a very large hierarchy of commands; a good portion of which I imagine I will never touch. However, seeing some of the terms with regards to deprecated technologies like Token Ring made me realize that many of those commands are still present in IOS. For example, if you configure a VLAN, you can assign it the properties of Token Ring and FDDI networks. In some strange way, this makes IOS seem just a little bit smaller to me, which is a good thing. Since the commands are mostly hierarchical, knowing which sections of commands I will never need to touch is nice and makes navigating to the other commands a little easier.

Yet another interesting thing in reading this book is how certain standards that are now a standard part of Cisco curricula (and have been for several years) were either not yet developed or in their infancy when this book was published, such as 802.1s, Multiple Spanning Tree. Likewise, I think newer textbooks leave a little to be desired with regards to information on things like UplinkFast and Backbone fast. Maybe this isn’t true for CCIE material (I don’t know yet), but for current CCNA/CCNP material, I feel like they don’t do a particularly good job of explaining those two technologies. This book straightened that out for me and explained fully how each technology would be used.

The aspect of the book that I think I found the most interesting, due to having completed the CCDA certification, is that many of the design topologies that seemed like a good idea at the time due to the nature of the existing technology are no longer applicable in today’s networks. The biggest example is the campus-wide flat Layer-2 topology instead of the hierarchical Layer-3 designs present in today’s networks. This book emphasized that many networks were still designed that way (in 1999), but that the industry trend is moving away from that. By having a 2013 set of networking knowledge and reading a 1999 set of knowledge, I could more easily see where we came from and why things progressed the way they did. A large part of it was due to the speed and functionality of routers and switches in 1999. Hardware Layer-3 switching was a pretty new concept then, but it is commonplace now, and the design of the access, distribution and core layers of the network have changed over time to reflect this. For example, the book highly emphasized using a Layer-2 core, but I don’t believe this would ever be done today.

Overall, a very good, useful read. 🙂