H3C WA Series, Configuration Manual

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Within an MST region, MSTP generates different MSTIs for different VLANs based on the
VLAN-to-instance mappings. MSTP performs a separate calculation process, which is similar to
spanning tree calculation in STP, for each spanning tree. For details, refer to
How STP works .
In MSTP, a VLAN packet is forwarded along the following paths:
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Within an MST region, the packet is forwarded along the corresponding MSTI.
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Between two MST regions, the packet is forwarded along the CST.
Implementation of MSTP on network devices
MSTP is compatible with STP and RSTP. STP and RSTP protocol packets can be recognized by
network devices running MSTP and used for spanning tree calculation.
In addition to basic MSTP functions, many special functions are provided for ease of management, as
follows:
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Root bridge hold
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Root bridge backup
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Root guard
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BPDU guard
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Loop guard
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TC-BPDU guard
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Support for hot swapping of interface cards and active/standby changeover.
Protocols and Standards
MSTP is documented in:
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IEEE 802.1d: Spanning Tree Protocol
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IEEE 802.1w: Rapid Spanning Tree Protocol
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IEEE 802.1s: Multiple Spanning Tree Protocol
Configuration Task List
Before configuring MSTP, you need to know the role of each bridge in each MSTI: root bridge or leaf
node. In each MSTI, only one bridge acts as the root bridge, while all others act as leaf nodes.
Complete these tasks to configure MSTP:
Task Remarks
Configuring an MST Region Required
Configuring the Root Bridge or a Secondary Root Bridge Optional
Configuring the MSTP Work Mode of the AP Optional
Configuring the Priority of the AP Optional
Configuring the Maximum Hops of an MST Region Optional
Configuring the Network Diameter of a Switched Network Optional
Configuring Timers of MSTP Optional
Configuring the Timeout Factor Optional
Configuring the Maximum Port Rate Optional
Configuring the
root bridge
Configuring Ports as Edge Ports Optional