The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

Chapter 14. LAN Security^[]

^[] Hmmm — did you just read that right? It can't be right, it must be a typo! With all of the advancements in network security, why the fuss about Layer 2 security? It is non-existent ... or is it?

Data communication has experienced a tremendous growth through both technological leaps as well as the physical size of LANs in place today. In the early 1990s, most computer networks were a series of dumb terminals operating off of a centralized storage and processing medium. As we have discussed throughout this book, the LANs of today connect users in large numbers to one another, as well as connecting them to a potpourri of shared devices that are in place to make information transfer quick and easy. These advancements do not come cheap. The cost of acquiring, implementing, and maintaining the nodes in the LAN require an ongoing investment, but it does not stop there! Securing the network is as important (if not more important) than ensuring the data is transferring at optimum expectations.

History has repeatedly shown that there are unscrupulous individuals who will exploit any situation for personal gain, amusement, or both. From the elementary schoolyard bully and prankster to the thief trying to make a quick buck, there's undoubtedly a need to be on the lookout to protect your interests — and the same is true when dealing with your networks.

Corporate LANs have a very real (and very critical) need to secure the data in their networks. Any lapse in security ...