Network Switching Overview

Question 1

The Switch

Answer 1

• Forward or drop frames
  
  • Based on the destination MAC address

• Gather a constantly updating list of MAC addresses
• Builds the list based on the source MAC address of
incoming traffic

• Maintain a loop-free environment
  
  • Using Spanning Tree Protocol (STP)

Question 2

Learning the MACs

Answer 2

• Switches examine incoming traffic
  
  • Makes a note of the source MAC address

• Adds unknown MAC addresses to the MAC address
table
• Sets the output interface to the received interface

Question 3

Flooding for unknown Macs

Answer 3

• The switch doesn’t always have a MAC address in the
table

• When in doubt, send the frame to everyone

Question 4

Address Resolution Protocol

Answer 4

• Determine a MAC address based on an IP address
  
  • You need the hardware address to communicate
• arp -a
  
  • View local ARP table