ipv6 icmp send

Function

The ipv6 icmp send command enables the system to send ICMPv6 messages.

The undo ipv6 icmp send command disables the system from sending ICMPv6 messages.

The clear ipv6 icmp send command clears the configurations of the ipv6 icmp send and undo ipv6 icmp send commands.

By default, the system is enabled to send ICMPv6 messages.

Format

ipv6 icmp hop-limit-exceeded send

ipv6 icmp host-unreachable send

ipv6 icmp port-unreachable send

clear ipv6 icmp port-unreachable send

clear ipv6 icmp host-unreachable send

clear ipv6 icmp hop-limit-exceeded send

undo ipv6 icmp hop-limit-exceeded send

undo ipv6 icmp host-unreachable send

undo ipv6 icmp port-unreachable send

Parameters

Parameter	Description	Value
host-unreachable	Enables the interface to send ICMP host-unreachable packets.	-
port-unreachable	Enables the interface to send ICMP port-unreachable packets.	-
hop-limit-exceeded	Enables the interface to send ICMP hop-limit packets.	-

Parameter

Description

Value

host-unreachable

Enables the interface to send ICMP host-unreachable packets.

port-unreachable

Enables the interface to send ICMP port-unreachable packets.

hop-limit-exceeded

Enables the interface to send ICMP hop-limit packets.

Views

100ge sub-interface view, 100GE interface view, 10GE sub-interface view, 10GE interface view, 200GE sub-interface view, 25GE sub-interface view, 25GE interface view, 400GE sub-interface view, 400GE interface view, 40GE sub-interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk sub-interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE sub-interface view, GE interface view, GE electrical interface view, Global VE sub-interface view, PW-VE sub-interface view, PW-VE interface view, Tunnel interface view, VBDIF interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
ip-stack	write

Usage Guidelines

Usage Scenario

On a normal network, a device can correctly send or receive ICMPv6 messages; however, when network traffic load is heavy, host unreachable or port unreachable events frequently occur and routers need to send a large number of ICMPv6 messages, which burdens the network and degrades the performance of the routers. In addition, attackers usually use ICMPv6 error messages to probe the internal network topology illegitimately.To improve network performance and security, you need to run the undo ipv6 icmp send command to disable the system from sending ICMPv6 Echo-Reply messages, Host -Unreachable messages, and Port-Unreachable messages.

If you want to restore the default configuration and the display this command output does not contain the ipv6 icmp send or undo ipv6 icmp send command configuration, run the clear icmp send command.

Configuration Impact

After the system is disabled from sending ICMPv6 Echo-Reply messages, Host -Unreachable messages, and Port-Unreachable messages, the system counts only the number of discarded messages instead of the number of sent Echo-Reply messages, Host -Unreachable messages, and Port-Unreachable messages.

Precautions

By default, a device can respond to ICMPv6 TTL timeout packets. Other devices may obtain the IP address of the local device through traceroute. To disable this function, run the icmp name ttl-exceeded send command.

Example

# Enable a device to send ICMPv6 hop-limit-exceeded messages on an interface.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/1
[~HUAWEI-GigabitEthernet0/1/1] ipv6 enable
[*HUAWEI-GigabitEthernet0/1/1] ipv6 icmp hop-limit-exceeded send

# Clear the configuration of sending ICMPv6 hop-limit-exceeded messages on an interface.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/1
[~HUAWEI-GigabitEthernet0/1/1] ipv6 enable
[*HUAWEI-GigabitEthernet0/1/1] clear ipv6 icmp hop-limit-exceeded send