Chapter 15: Spanning Tree; Stp Flavors - Cisco Small Business 200 Series Administration Manual

Spanning Tree
This section describes the Spanning Tree Protocol (STP) (IEEE802.1D and IEEE802.1Q) and covers the
following topics:
•

STP Flavors

• STP Status and Global Settings
• Spanning Tree Interface Settings
• Rapid Spanning Tree Settings
STP Flavors
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 load and reduced network efficiency.
STP provides a tree topology for any arrangement of switches and interconnecting links, by creating a
unique path between end stations on a network, and thereby eliminating loops.
The device supports the following Spanning Tree Protocol versions:
• Classic STP – Provides a single path between any two end stations, avoiding and eliminating loops.
• Rapid STP (RSTP) – Detects network topologies to provide faster convergence of the spanning tree.
This is most effective when the network topology is naturally tree-structured, and therefore faster
convergence might be possible. RSTP is enabled by default.
The 200 series switches do not support MSTP.
NOTE
Cisco Small Business 200 Series Smart Switch Administration Guide
15
198