H3C Technologies H3C SecPath F1000-E - Manual (Page 118)

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NOTE:
•
The maximum interval for sending RA messages should be less than or equal to the router lifetime in RA
messages.
• The values of the NS retransmission timer and the reachable time configured for an interface are sent to
hosts via RA messages. Furthermore, this interface sends NS messages at the interval of the NS
retransmission timer and considers a neighbor reachable within the reachable time.
Configuring the Maximum Number of Attempts to Send an NS
Message for DAD
An interface sends an NS message for DAD after acquiring an IPv6 address. If the interface does not
receive a response within a specified time (determined by the ipv6 nd ns retrans-timer command),
it continues to send an NS message. If it still does not receive a response after the number of sent attempts
reaches the threshold (specified with the ipv6 nd dad attempts command), the acquired address is
considered usable.
Follow these steps to configure the attempts to send an NS message for DAD:
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure the number of attempts
to send an NS message for DAD
ipv6 nd dad attempts value
Optional
1 by default. When the value
argument is set to 0, DAD is
disabled.
Enabling ND Proxy
NOTE:
ND proxy supports the NS and NA messages only.
Introduction
If a host sends an NS message requesting the hardware address of another host that is isolated from the
sending host at Layer 2, the device in between must be able to forward the NS message to allow Layer
3 communication between the two hosts. This is achieved by ND proxy.
As shown in
Figure 6 , the device connects to two subnets through GigabitEthernet 0/1 and
GigabitEthernet 0/2. The IP addresses of the two interfaces are 4:1::99/64 and 4:2::99/64. Host A
and Host B have the same prefix assigned and are connected to Ethernet 1/1 and Ethernet 1/2,
respectively.