Chapter 12: Spanning Tree Protocol; Stp Modes - Cisco SF220-24 Administration Manual

Spanning Tree Protocol

STP Modes

Cisco 220 Series Smart Switches Administration Guide Release 1.1.0.x
The Spanning Tree Protocol (STP) (IEEE802.1D and IEEE802.1Q) is enabled by
default, set to Classic STP mode.
This chapter describes how to configure STP and contains the following topics:
• STP Modes
• Configuring STP Status and Global Settings
• Configuring STP Interface Settings
• Configuring RSTP Interface Settings
• Configuring Multiple Spanning Tree
STP protects a Layer 2 Broadcast domain from Broadcast storms by selectively
setting links to standby mode to prevent loops. In standby mode, these links
temporarily stop transferring user data. After the topology changes so that the
data transfer is made possible, the links are automatically re-activated.
Loops occur when alternate routes exist between hosts. Loops in an extended
network can cause switches to forward traffic indefinitely, resulting in increased
traffic and reduced network efficiency.
STP provides a tree topology for any arrangement of switches and
interconnecting links, creating a unique path between end stations on a network,
eliminating loops.
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