ttl (TCP test instance)

Function

The ttl command sets the time to live (TTL) value for the NQA TCP test packets.

The undo ttl command restores the default TTL value.

By default, the TTL value is 30.

Format
Parameters
Views
Default Level
Task Name and Operations
Usage Guidelines
Example

Format

ttl ttlValue

undo ttl

Parameters

Parameter	Description	Value
ttlValue	Specifies the TTL value of test packets.	The value is an integer ranging from 1 to 255.

Parameter

Description

Value

ttlValue

Specifies the TTL value of test packets.

The value is an integer ranging from 1 to 255.

Views

NQA view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
sla	write

Usage Guidelines

Usage Scenario

TTL is an 8-bit field in the IP header. The TTL value is decreased by 1 on each hop. When the TTL value is 0, the sender receives an ICMP Time Exceeded packet.

The ttl command sets the TTL value for test packets so that the test instance is performed within a specified number of hops.

Configuration Impact

If the TTL value has been set for test packets, running the ttl command again overrides the previous configuration.

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

# Set the TTL value for packets in the test instance named user test to 10.

<HUAWEI> system-view
[~HUAWEI] nqa test-instance user test
[*HUAWEI-nqa-user-test] test-type tcp
[*HUAWEI-nqa-user-test] ttl 10