Chapter 6: Local-Area Networks (LANs)
Exam Objectives
Identifying and choosing Ethernet LAN type, duplex mode, and speed
Identifying and choosing Ethernet cabling and connectors
Describing collision domains and their impact on network performance
Describing how collision domains relate to CSMA/CD
Identifying and choosing methods to minimize collision domains
Identifying Ethernet operations at the data link layer
Identifying Ethernet operations at the physical layer
On the CCNA exam, local-area networks are related to Ethernet, Layer 2 switches, and cabling. Read this chapter to find out about Ethernet and related standards and technologies, including cabling and an introduction to Layer 2 switching. The exam asks about the CSMA/CD protocol, and about the distinction between half-duplex and full-duplex transmission modes in Ethernet. It also expects you to know about the IEEE 802.X Ethernet standards. In this chapter, you discover CSMA/CD and half- and full-duplex transmission modes. This chapter shows how Ethernet operates at both the data link and physical layers.
Introduction to Local-Area Networks
Local-area networks, known as LANs, interconnect host devices over short distances. LANs can support high speed and a fairly large bandwidth. LAN traffic can be controlled with bridges and switches. Hubs are also used to interconnect hosts in a LAN.