step (NQA view)

Function

The step command sets the incremental step for the packet length in a path MTU test.

The undo step command deletes the current incremental step.

By default, the incremental step for the packet length is 10 bytes.

Format

step step

undo step

Parameters

Parameter	Description	Value
step	Specifies the step value of a path MTU.	The value is an integer ranging from 1 to 512, in bytes.

Parameter

Description

Value

step

Specifies the step value of a path MTU.

The value is an integer ranging from 1 to 512, in bytes.

Views

NQA view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
sla	write

Usage Guidelines

Usage Scenario

NQA path MTU test instances are used to check the path MTU. In a path MTU test instance, the initial size of a test packet is 28 bytes (excluding the IP header). If a reply packet is received and the size of the packet does not exceed the specified maximum MTU, a second probe is required. In the second probe, a step is incremented to the packet sent in the first probe so that the size of this test packet is the size of 28 bytes plus a step.

The step command sets the incremental step for the packet length in a path MTU test.

Prerequisites

The incremental step is supported only in path MTU test instances.

Configuration Impact

If you set the step to 1, you can check the maximum MTU from the source to the destination. This process, however, takes a long time.

Precautions

If parameters need to be changed during the running of the test instance, the system prompts you whether to terminate the test instance. Press "Y" or "N" as required.

If you press "Y", the test instance is terminated and parameters changed. The settings take effect after being committed. To restart the test instance, run the start command.
If you press "N", the test instance keeps running, and the parameters fail to be modified.

Example

# Configure a path MTU test instance with the incremental step of 1 byte.

<HUAWEI> system-view
[~HUAWEI] nqa test-instance pathmtu pathmtu
[*HUAWEI-test-pathmtu-pathmtu] test-type pathmtu
[*HUAWEI-test-pathmtu-pathmtu] step 1