CLI Reference Guide-R04

Table Of Contents
Chapter 31
| IP Interface Commands
IPv6 Interface
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ipv6 nd dad attempts This command configures the number of consecutive neighbor solicitation
messages sent on an interface during duplicate address detection. Use the no form
to restore the default setting.
Syntax
ipv6 nd dad attempts count
no ipv6 nd dad attempts
count - The number of neighbor solicitation messages sent to determine
whether or not a duplicate address exists on this interface. (Range: 0-600)
Default Setting
1
Command Mode
Interface Configuration (VLAN)
Command Usage
Configuring a value of 0 disables duplicate address detection.
Duplicate address detection determines if a new unicast IPv6 address already
exists on the network before it is assigned to an interface.
Duplicate address detection is stopped on any interface that has been
suspended (see the vlan command). While an interface is suspended, all unicast
IPv6 addresses assigned to that interface are placed in a “pending” state.
Duplicate address detection is automatically restarted when the interface is
administratively re-activated.
An interface that is re-activated restarts duplicate address detection for all
unicast IPv6 addresses on the interface. While duplicate address detection is
performed on the interface’s link-local address, the other IPv6 addresses remain
in a “tentative” state. If no duplicate link-local address is found, duplicate
address detection is started for the remaining IPv6 addresses.
If a duplicate address is detected, it is set to “duplicate” state, and a warning
message is sent to the console. If a duplicate link-local address is detected, IPv6
processes are disabled on the interface. If a duplicate global unicast address is
detected, it is not used. All configuration commands associated with a
duplicate address remain configured while the address is in “duplicate” state.
If the link-local address for an interface is changed, duplicate address detection
is performed on the new link-local address, but not for any of the IPv6 global
unicast addresses already associated with the interface.