Cabletron Systems CSX200 User Manual

Also see for SPECTRUM: User guide User guide User guide User guide Guide

Contents

CSX Bridge View3-28The Spanning Tree Protocol WindowIn the Bridge Traffic View, display the Device menu by clicking on the FrontPanel button. Drag down to Find MAC Address.Figure 3-12. Find MAC Address WindowThe Spanning Tree Protocol WindowBridges in a network collectively implement a Spanning Tree Algorithm (STA) todetect and eliminate data loops in a network containing parallel bridges.In a network designed with multiple bridges placed in parallel (i.e., attached tothe same network segment), Spanning Tree selects a controlling Root Bridge andPort for the entire bridged local area network, and a Designated Bridge and Portfor each individual network segment. The Root bridge is the one that selects oneof two or more available bridge paths between two end stations, basing itsdecision on factors associated with each of the bridges in the path. A DesignatedPort/Bridge for a network segment relays frames toward the Root Bridge, or fromthe Root Bridge onto the network segment. When data passes from one endstation to another across a bridged local area network, it is forwarded through theDesignated Bridge/Port for each network segment towards the Root Bridge,which in turn forwards frames towards Designated Bridges/Ports on its oppositeside.During the Root Bridge selection process, all bridges on the networkcommunicate STA information via Bridge Protocol Data Units (BPDUs). It is withBPDUs that the bridges collectively determine the current network topology andensure that all bridges have current topology information.The Spanning Tree Protocol window displays information used by the networkbridges to select the Root Bridge and parameters that affect the bridge’sparticipation in Spanning Tree operations.To open the Spanning Tree Protocol window:1. Click on the Front Panel button.2. Drag down to Spanning Tree and release.2. In the edit box, enter a valid MACaddress and then press theReturn key. If the address is foundin the Filtering Database, its portlocation and status will appear inthe list box. If it is not found, aseparate window will appear witha “Not Found” message.