ZyXEL Communications metrogigabit switch Plumbing Product User Manual


 
Chapter 13 Spanning Tree Protocol
MGS3700-12C User’s Guide
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Note: Each port can belong to one STP tree only.
Figure 65 MRSTP Network Example
13.1.5 Multiple STP
Multiple Spanning Tree Protocol (IEEE 802.1s) is backward compatible with STP/
RSTP and addresses the limitations of existing spanning tree protocols (STP and
RSTP) in networks to include the following features:
One Common and Internal Spanning Tree (CIST) that represents the entire
network’s connectivity.
Grouping of multiple bridges (or switching devices) into regions that appear as
one single bridge on the network.
A VLAN can be mapped to a specific Multiple Spanning Tree Instance (MSTI).
MSTI allows multiple VLANs to use the same spanning tree.
Load-balancing is possible as traffic from different VLANs can use distinct paths
in a region.
13.1.5.1 MSTP Network Example
The following figure shows a network example where two VLANs are configured on
the two switches. If the switches are using STP or RSTP, the link for VLAN 2 will be