SLAAC Duplicate Address Detection

• Dummy
• If no other devices respond with a Neighbor Advertisement (NA) message, then the address is virtually guaranteed to be unique and can be used by the host
• If an NA is received by the host, then the address is not unique, and the host must generate a new interface ID to use

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The SLAAC Duplicate Address Detection process:

• The host sends an ICMPv6 Neighbor Solicitation (NS) message with a specially constructed solicited-node multicast address containing the last 24 bits of IPv6 address of the host

Duplicate Address Detection (DAD) is really not required because a 64-bit interface ID provides 18 quintillion possibilities, So the chance of a duplicate address is remote

However, the Internet Engineering Task Force recommends that DAD is used. So DAD is performed on all IPv6 unicast addresses, regardless of how the address is configured