Chapter 4: Spanning Tree Protocol (STP)
Exam Objectives
Describing problems related to switching loops and seeing how STP fixes them
Describing STP operation flow, root bridge, and nonroot bridge functions
Managing STP root bridge selection
Managing STP port type assignment
Describing the STP convergence process
Describing the STP port states
Understanding best practices to decrease STP convergence duration
Managing Cisco switch and port configuration options for STP
Describing Rapid Spanning Tree Protocol (RSTP) improvements over STP
Describing and managing EtherChannel
You found out in previous chapters that switches are very often interconnected using redundant links to improve reliability of interswitch links. You also discovered that redundant links can create transmission loops, causing broadcast storms and MAC address table thrashing. Switches need to avoid transmissions loops when they are interconnected using redundant links.
Read this chapter to see how the Spanning Tree Protocol (STP) (IEEE 802.1d) can be used to help Layer 2 switches avoid loops. You see how to configure and manage STP. You are also introduced to STP port types. The convergence process flow is explained, along with some parameters you can set to control STP convergence. Finally, you see how the Rapid Spanning Tree Protocol (RSTP) (IEEE 802.1w) improves STP convergence speed.
Introducing the Spanning Tree Protocol (STP)
Layer 2 switches need to avoid switching loops. Here you see how switches can avoid ...
