CHAPTER 11 - Configuring Cisco Switches

Abstract

This chapter covers the process of configuring Cisco Catalyst switches. All Cisco Catalyst switches use content-addressable memory (CAM) to store the Media Access Control (MAC) addresses used for switching. When a switch receives a frame, the switch reads the frame and places the source MAC address into the CAM table together with a timestamp. The switch would later use the MAC address table to forward the frame to the correct switchport. A host when moved from one switchport to another then the switch would update only the timestamp, since the MAC address is already listed in the MAC address table. Layer 2 switch operates at the datalink layer, which means the switch forwards traffic based on MAC addresses. When a Layer 2 switch forwards traffic, the switch would not modify the original frame. The only exception is when Quality of Service (QoS) is implemented on a switch. In that case, the switch would modify the Differentiated Services Code Point (DSCP) bits in the Internet Protocol (IP) header. A switch can be configured in several ways such as through Windows HyperTerminal and an alternative to HyperTerminal is Minicom, which is a Linux-based serial communications program.