and LAN Design
products exceeded router revenues. That event in Cisco's history was significant because
most people in the marketplace thought of Cisco as "that router company" for a long time.
In fact, Cisco would prefer to even shake the reputation as a great router/switch/hub
company and instead be known for empowering the Internet generation, a catch-phrase
from the company's television ads.
certification about routers and routing issues? One issue is that LAN (Layer 2) issues are
inherently less complicated than Layer 3 issues. However, that in no way means that LAN
issues are not complicated; there are simply fewer concepts and issues to consider.
Furthermore, because Layer 3-aware devices, such as routers, make extensive use of Layer
2 features to forward packets, the routing-centric topics can never totally ignore LAN and
WAN Layer 2 concepts. So, this book includes one LAN-specific chapter and one WAN-
specific chapter (Chapter 8, "WAN Protocols and Design"), in addition to the more lengthy
coverage of routing.
Ethernet. This chapter explains bridging and switching, along with some comparisons of
bridging, switching, and routing. This chapter also covers Spanning Tree to a depth beyond
what is probably needed for the exam, but understanding Spanning Tree is very important
to the typical jobs performed by CCNAs. This chapter also covers virtual local-area
networks (VLANs) and offers some switch configuration examples.
the concepts behind them. So, while the concepts in this chapter might in part be review and
in part be new information or a reminder of something you have forgotten, do not neglect
to memorize the LAN standard's names, at least. The concepts are very important to your
success in your job; knowing the names of standards is very important to being able to
communicate about your networks, which is one of Cisco's expectations for CCNAs.
easy reference.