remark ttl

Function

The remark ttl command re-marks the TTL value of IP packets.

The undo remark ttl command cancels the configuration.

By default, the TTL value of IP packets is not re-marked.

Format

remark ttl ttl-value

undo remark ttl [ ttl-value ]

Parameters

Parameter	Description	Value
ttl-value	Specifies the TTL value of IP packets.	The value is an integer ranging from 1 to 255.

Parameter

Description

Value

ttl-value

Specifies the TTL value of IP packets.

The value is an integer ranging from 1 to 255.

Views

Traffic behavior view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
qos	write

Usage Guidelines

Usage Scenario

In most schools, especially in dormitories, many students dial up to go online using IPoE and use the wireless router or adapter to provide Internet services through NAT. This may lead to the following problems:

The school's revenue decreases when students share their monthly-paid Internet services.
The real-name based Internet access is difficult to implement, which troubles network management.
The wireless campus Internet environment deteriorates and is difficult to construct.
To prevent these problems, run the remark ttl command to set the TTL value to 1. The TTL value of a packet decreases by 1 when the packet passes through a router. Once the TTL value is set to 1, the TTL value of the packets that passing through the private router will become 0, causing the packets to be dropped.

Prerequisites

The traffic behavior view has been displayed.

Configuration Impact

If the remark ttl command is run repeatedly in the same traffic behavior view, the latest configuration overrides the previous configuration.

Precautions

A traffic policy containing the remark TTL action is supported only in the outbound direction of an interface.

Example

# Set the TTL value of IP packets to 5.

<HUAWEI> system-view
[~HUAWEI] traffic behavior beh1
[*HUAWEI-behavior-beh1] remark ttl 5