stp max-hops

Function

The stp max-hops command sets the maximum hops of a spanning tree in a MST region.

The undo stp max-hops command restores the default maximum hops of a spanning tree.

By default, the maximum hops are 20 in an MST region.

Format

stp max-hops hop

undo stp max-hops

Parameters

Parameter	Description	Value
hop	Specifies the maximum hops.	The value is an integer ranging from 1 to 40.

Parameter

Description

Value

hop

Specifies the maximum hops.

The value is an integer ranging from 1 to 40.

Views

System view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mstp	write

Usage Guidelines

Usage Scenario

The 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.
The number of remaining hops in a BPDU sent by the root device is the maximum number of hops.
The number of remaining hops in a BPDU sent by a non-root device equals the maximum number of hops minus the number of hops from the non-root device to the root device.
If a device receives a BPDU in which the number of remaining hops is 0, the device discards the BPDU.
The maximum number of hops of a spanning tree in an MST region determines the network scale. To set the maximum number of hops in an MST domain, run the stp max-hops command to control the network scale of a spanning tree.

Precautions

In an MST region, the maximum number of hops set on the root device in a Common and Internal Spanning Tree (CIST) or an MSTI is the maximum number of hops in the CIST or Multiple Spanning Tree instance (MSTI).

Example

# Set the maximum hops in an MST region to 35.

<HUAWEI> system-view
[~HUAWEI] stp max-hops 35