stp max-hops (MSTP process view)

Function

The stp max-hops command sets the maximum hops of a spanning tree in a Multiple Spanning Tree (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

MSTP process 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 Multiple Spanning Tree Protocol (MSTP) communicate with each other by exchanging Multiple Spanning Tree (MST) Bridge Protocol Data Units (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 MSTP process 1 to 35.

<HUAWEI> system-view
[~HUAWEI] stp process 1
[~HUAWEI-mst-process-1] stp max-hops 35