Duplicate Address Detection

• Node X is going to assign IP address A on its interface “I”

• Interface “I” joins the multicast groups:

  • FF02::1 (“all nodes”)
  • FF02::1:FF00:0:A' (the solicited-node multicast address «all nodes with IP = A»)

• Is there any NS queries? (dst ip = FF02::1:FF00:0:A, src ip = ::)

• X sends NS query (dst ip = FF02::1:FF00:0:A, src ip = ::)

• Is there any NA (flag S = 0) sent to address FF02::1?

• In case of events 3 or 5 - the address isn't unique!

• Else – the address is unique

Must be performed on all unicast addresses (except for anycast)