Cisco ASR 9000 Series Command Reference Manual page 369

Neighbor Discovery Commands
Use the ipv6 nd ns-interval command to configure the interval between neighbor solicitation messages that
are sent during duplicate address detection.
Duplicate address detection is suspended on interfaces that are administratively down. While an interface is
administratively down, the unicast IPv6 addresses assigned to the interface are set to a pending state. Duplicate
address detection is automatically restarted on an interface when the interface returns to being administratively
up.
For BNG, ensure you run this command in the dynamic template configuration mode. To enter the dynamic
template configuration mode, run dynamic-template command in the Global Configuration mode.
Note An interface returning to administratively up restarts duplicate address detection for all of the unicast IPv6
addresses on the interface. While duplicate address detection is performed on the link-local address of an
interface, the state for the other IPv6 addresses is still set to tentative. When duplicate address detection
is completed on the link-local address, duplicate address detection is performed on the remaining IPv6
addresses.
When duplicate address detection identifies a duplicate address, the state of the address is set to duplicate and
the address is not used. If the duplicate address is the link-local address of the interface, the processing of
IPv6 packets is disabled on the interface and an error message similar to the following is issued:
ipv6_nd[145]: %IPV6_ND-3-ADDRESS_DUPLICATE : Duplicate address 111::1 has been detected
If the duplicate address is a global address of the interface, the address is not used and an error message similar
to the following is issued:
%IPV6-4-DUPLICATE: Duplicate address 3000::4 on GigabitEthernet
All configuration commands associated with the duplicate address remain as configured while the state of the
address is set to duplicate.
If the link-local address for an interface changes, duplicate address detection is performed on the new link-local
address and all of the other IPv6 address associated with the interface are regenerated (duplicate address
detection is performed only on the new link-local address).
Task ID
Task ID
ipv6
config-services
Examples
This example (not applicable for BNG) shows how to set the number of consecutive neighbor solicitation
messages for interface 0/2/0/1 to 1 and then display the state (tentative or duplicate) of the unicast IPv6 address
configured for an interface:
RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# interface gigabitethernet 0/2/0/1
RP/0/RSP0/CPU0:router(config-if)# ipv6 nd dad attempts 1
RP/0/RSP0/CPU0:router(config-if)# Uncommitted changes found, commit them before
exiting(yes/no/cancel)? [cancel]:y
Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Command Reference, Release
ipv6 nd dad attempts (BNG)
Operations
read, write
read, write
5.2.x
355