Unlike Token Ring and FDDI, which for the most part are defunct, Ethernet technology is alive and very well. 10 Gigabit Ethernet has been introduced and is being deployed in the cores of large networks. It is important to have a solid understanding of some of the basic principles involved with this technology.

This chapter explored numerous Ethernet technologies and architectures. It investigated the importance and functions of CSMA/CD used in shared medium. The chapter also discussed autonegotiation and its specific components as well as the importance of where autonegotiation should be implemented and on which devices.

Transparent bridging solves the issue of too many collisions on a LAN segment by breaking the segment into two or more, with fewer devices to compete for the access on each segment. The limitations of transparent bridging in reference to loops and the repercussions involved were also discussed. Along with redundancy comes some of the potential problems of bridging. Spanning tree ensures a loop-free topology on the network. The chapter also included some of the rudimentary components of spanning tree, such as packet types, timers, and types of decision processes involved.