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ipv6 nd hop-limit

Function

The ipv6 nd hop-limit command sets the maximum number of hops on the device.

The undo ipv6 nd hop-limit command restores the default maximum number of hops, namely, 64.

By default, the IPv6 unicast packets sent by the device can pass through 64 hops.

Format

ipv6 nd hop-limit limit

undo ipv6 nd hop-limit

Parameters

Parameter Description Value
limit Specifies the hop limit. It is an integer ranging from 1 to 255. By default, the value is 64.

Views

System view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A hop limit on a routing device can:

  • Limit the number of hops through which IPv6 unicast packets are allowed to travel.

  • Be a parameter in an RA message to help a host automatically configure a hop limit (a limit on the number of hops through which IPv6 unicast packets initially sent by a host are allowed to travel).

Configuration Impact

The hop limit for unicast packets is set using the ipv6 nd hop-limit command in the system view.

The hop limit for RA messages can be set using the ipv6 nd hop-limit command in the system view or the ipv6 nd ra hop-limit command in the interface view.
  • If the hop limit for RA messages is not set in the interface view or in the system view, the hop limit for RA messages is 64 by default.
  • If the hop limit for RA messages is not set in the interface view but the ipv6 nd hop-limit command is run in the system view, the configuration in the system view takes effect.
  • If the ipv6 nd ra hop-limit command is run in the interface view, the configuration in the interface view takes effect, no matter whether the hop limit is set in the system view.

Precautions

The hop limit set for IPv6 unicast packets is the same as that set for RA messages. In the following cases, however, the hop limit for IPv6 unicast packets is 64, whereas the hop limit for RA messages is 0.

  • No hop limit is set for IPv6 unicast packets.
  • The undo ipv6 nd hop-limit command can be run to restore the default hop limit set for IPv6 unicast packets.

After a host receives an RA message with the hop limit of 0, it sets its own hop limit to the default value 64, consistent with the default hop limit on the routing device.

Example

# Set the hop limit for RA packets.

<sysname> system-view
[sysname] ipv6 nd hop-limit 100
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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