Lecture 21: Link Layer Devices

Using Hubs to form separate collison domains

This lecture will cover a few more details about Ethernet as a link layer. First, a discussion of the Address Resolution Protocol (ARP) will show how addresses from a higher layer (such as IP addresses) get mapped to the link layer address (the MAC address). ARP is a broadcast request/reply protocol, with fairly low complexity. Following the ARP discussion, we will examine various interconnection offerings, such as hubs, switches and routers. As part of that discussion, students will come to recognize how the collision domains are affected by interconnections. We will finish up with a discussion of the spanning tree protocol used by routers for autoconfiguration purposes.

Lesson Objectives

By the end of this lesson, the student will be able to: