Ddns client configuration task list, Configuring parameters for ra messages – H3C Technologies H3C S12500 Series Switches User Manual

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To set the hop limit:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Set the Hop Limit field in
the IP header.

ipv6 hop-limit value

The default setting is 64.

267B

Configuring parameters for RA messages

You can enable an interface to send RA messages, and configure the interval for sending RA messages

and parameters in RA messages. After receiving an RA message, a host can use these parameters to

perform corresponding operations.

775H

Table 9

describes the configurable parameters in an RA message.

Table 9 Parameters in an RA message and their descriptions

Parameter Description

Hop Limit

Maximum number of hops in RA messages. A host receiving the RA message fills the
value in the Hop Limit field of sent IPv6 packets.

Prefix information

After receiving the prefix information, the hosts on the same link can perform
stateless autoconfiguration.

MTU

Guarantees that all nodes on the link use the same MTU.

M flag

Determines whether a host uses stateful autoconfiguration to obtain an IPv6
address.
If the M flag is set to 1, the host uses stateful autoconfiguration (for example, from a
DHCPv6 server) to obtain an IPv6 address. Otherwise, the host uses stateless

autoconfiguration to generate an IPv6 address according to its link-layer address

and the prefix information in the RA message.

O flag

Determines whether a host uses stateful autoconfiguration to obtain configuration
information other than IPv6 address.
If the O flag is set to 1, the host uses stateful autoconfiguration (for example, from a

DHCPv6 server) to obtain configuration information other than IPv6 address.
Otherwise, the host uses stateless autoconfiguration.

Router Lifetime

Tells the receiving hosts how long the advertising router can live. If the lifetime of a
router is 0, the router cannot be used as the default gateway.

Retrans Timer

If the device does not receive a response message within the specified time after
sending an NS message, it retransmits the NS message.

Reachable Time

If the neighbor reachability detection shows that a neighbor is reachable, the
device considers the neighbor reachable within the specified reachable time. If the

device needs to send a packet to the neighbor after the specified reachable time

expires, the device reconfirms whether the neighbor is reachable.

Router Preference

Specifies the router preference in a RA message. A host selects a router as the
default gateway according to the router preference. If router preferences are the
same, the host selects the router from which the first RA message is received.

The maximum interval for sending RA messages should be less than (or equal to) the router lifetime in RA

messages so the router can be updated by an RA message before expiration.

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