3com 4210 PWR 9-Port 3CR17341-91-ME User Manual

C

HAPTER

 14: MSTP C

ONFIGURATION

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MSTP supports mapping VLANs to MST instances by means of a 
VLAN-to-instance mapping table. MSTP introduces "instance" (integrates 
multiple VLANs into a set) and can bind multiple VLANs to an instance, thus 
saving communication overhead and improving resource utilization.

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MSTP divides a switched network into multiple regions, each containing 
multiple spanning trees that are independent of one another.

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MSTP prunes a ring network into a network with tree topology, preventing 
packets from being duplicated and forwarded in a network endlessly. 
Furthermore, it offers multiple redundant paths for forwarding data, and thus 
achieves load balancing for forwarding VLAN data.

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MSTP is compatible with STP and RSTP.

Figure 49 illustrates basic MSTP terms (assuming that MSTP is enabled on each 
switch in this figure).

Figure 49   Basic MSTP terminologies

A multiple spanning tree region (MST region) comprises multiple 
physically-interconnected MSTP-enabled switches and the corresponding network 
segments connected to these switches. These switches have the same region 
name, the same VLAN-to-MSTI mapping configuration and the same MSTP 
revision level.