HP (Hewlett-Packard) 2900 Switch User Manual


 
4-20
IPv6 Addressing Configuration
Duplicate Address Detection (DAD)
Operating Notes
A verified link-local unicast address must exist on a VLAN interface before
the switch can run DAD on other addresses associated with the interface.
If a previously configured unicast address is changed, a neighbor adver-
tisement (an all-nodes multicast message--ff02::1) is sent to notify other
devices on the VLAN and to perform duplicate address detection.
IPv6 addresses on a VLAN interface are assigned to multicast address
groups identified with well- known prefixes. For more on this topic, refer
to “Multicast Application to IPv6 Addressing” on page 3-21.
DAD is performed on all stateful, stateless, and statically configured
unicast addresses, but not on Anycast addresses.
Neighbor solicitations for DAD do not cause the neighbor cache of
neighboring switches to be updated.
If a previously configured unicast address is changed, a neighbor adver-
tisement is sent on the VLAN to notify other devices, and also for duplicate
address detection.
If DAD is disabled when an address is configured, the address is assumed
to be unique and is assigned to the interface.