Duplicate address detection (DAD)

Duplicate Address Detection verifies that a configured unicast IPv6 address is unique before it is assigned to an interface. When the Owner router fails, the backup VRRP router assumes the Master role. When the Owner router becomes operational, DAD will fail because a backup VRRP router is in the Master role that responds to the DAD request. To avoid this, on virtual routers that are in owner mode (priority = 255) DAD needs to be disabled for the interface on which the owner VR is configured.