Huawei AR530 Series - Setting the Maximum Number of Hops in an MST Region

1. Run:
system-view
The system view is displayed.
2. Run:
interface interface-type interface-number
The view of the Ethernet interface that participates in spanning tree calculation is
displayed.
3. (Optional) Run:
stp edged-port enable
The port is configured as an edge port.
By default, all ports are non-edge ports.
4. Run:
stp bpdu-filter enable
The port is configured as a BPDU filter port.
By default, a port is a non-BPDU filter port.
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7.6.2.9 Setting the Maximum Number of Hops in an MST Region
Context
Switching devices on a Layer 2 network running MSTP communicate with each other by
exchanging MST BPDUs. An MST BPDU has a field that indicates the number of remaining
hops.
l The number of remaining hops in a BPDU sent by the root switching device equals the
maximum number of hops.
l The number of remaining hops in a BPDU sent by a non-root switching device equals the
maximum number of hops minus the number of hops from the non-root switching device
to the root switching device.
l If a switching device receives a BPDU in which the number of remaining hops is 0, the
switching device will discard the BPDU.
Therefore, the maximum number of hops of a spanning tree in an MST region determines the
network scale. The stp max-hops command can be used to set the maximum number of hops
in an MST domain so that the network scale of a spanning tree can be controlled.
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Run:
stp max-hops hop
The maximum number of hops in an MST region is set.
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
7 MSTP Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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