Introduction (3.0.1.1)
Network redundancy is a key to maintaining network reliability. Multiple physical links between devices provide redundant paths. The network can then continue to operate when a single link or port has failed. Redundant links can also share the traffic load and increase capacity.
Multiple paths need to be managed so that Layer 2 loops are not created. The best paths are chosen, and an alternate path is immediately available in case a primary path fails. Spanning Tree Protocol (STP) is used to create one path through a Layer 2 network.
This chapter focuses on the protocols used to manage these forms of redundancy. It also covers some of the potential redundancy problems and their symptoms.
Class Activity 3.0.1.2: Stormy Traffic
Refer to Scaling Networks v6 Labs & Study Guide and the online course to complete this activity.
It is your first day on the job as a network administrator for a small to medium-sized business. The previous network administrator left suddenly after a network upgrade took place for the business.
During the upgrade, a new switch was added. Since the upgrade, many employees have complained that they are having trouble accessing the Internet and servers on the network. In fact, most of them cannot access the network at all. Your corporate manager asks you to immediately research what could be causing these connectivity problems and delays.
So you take a look at the equipment operating on the network at your main distribution facility in the building. You notice that the network topology seems to be visually correct and that cables have been connected correctly, routers and switches are powered on and operational, and switches are connected together to provide backup or redundancy.
However, you notice that all of your switches’ status lights are constantly blinking at a very fast pace, to the point that they almost appear solid. You think you have found the problem with the connectivity issues your employees are experiencing.
Use the Internet to research STP. As you research, take notes and describe:
Broadcast storm
Switching loops
The purpose of STP
Variations of STP
Complete the reflection questions that accompany the PDF file for this activity. Save your work and be prepared to share your answers with the class.