Accton Technology ES3552XA, ES3526XA manual Displaying Global Settings, For this Region

Spanning Tree Algorithm Configuration 3

MSTP then builds a Internal Spanning Tree (IST) for the Region containing all commonly configured MSTP bridges.

IST	MST 1
(for this Region)

Region R

MST 2

An MST Region consists of a group of interconnected bridges that have the same MST Configuration Identifiers (including the Region Name, Revision Level and Configuration Digest – see “Configuring Multiple Spanning Trees” on page 3-132). An MST Region may contain multiple MSTP Instances. An Internal Spanning Tree (IST) is used to connect all the MSTP switches within an MST region. A Common Spanning Tree (CST) interconnects all adjacent MST Regions, and acts as a virtual bridge node for communications with STP or RSTP nodes in the global network.

	Region 1			Region 1
CIST			CST
IST	Region 4			Region 4
Region 2		Region 3	Region 2	Region 3

MSTP connects all bridges and LAN segments with a single Common and Internal Spanning Tree (CIST). The CIST is formed as a result of the running spanning tree algorithm between switches that support the STP, RSTP, MSTP protocols.

Displaying Global Settings

You can display a summary of the current bridge STA information that applies to the entire switch using the STA Information screen.

Field Attributes

•Spanning Tree State – Shows if the switch is enabled to participate in an STA-compliant network.

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