Quick Reference Guide

240 IPv6 Addressing
FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\CLI Folders\Ryan - old template\IPv6Addressing.fm
DELL CONFIDENTIAL – PRELIMINARY 5/15/12 – FOR PROOF ONLY
• attempts-number — The number of neighbor solicitation messages. Configuring a value of 0 disables
duplicate address detection processing on the specified interface; a value of 1 configures a single
transmission without follow-up transmissions. (Range: 0 - 600)
Default Configuration
Duplicate address detection on unicast IPv6 addresses with the sending of one (1) neighbor solicitation
message is enabled.
Command Mode
Interface configuration (Ethernet, VLAN, Port-channel). Cannot be configured for a range of interfaces
(range context).
User Guidelines
• Duplicate address detection verifies the uniqueness of new unicast IPv6 addresses before the addresses are
assigned to interfaces (the new addresses remain in a tentative state while duplicate address detection is
performed). Duplicate address detection uses neighbor solicitation messages to verify the uniqueness of
unicast IPv6 addresses.
• 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 is displayed.
• 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).
• Until DAD process is completed, an IPv6 address is in tentative state and can not be used for data transfer.
It is recommended to limit the configured value.
Example
The following example configures the number of consecutive neighbor solicitation messages that are sent on
an interface while duplicate address detection is performed on the unicast IPv6 addresses of the interface to
10.
Console# Console (config)# interface g1
Console (config-if)# ipv6 nd dad attempts 10