IPv6 address/prefix allocation sequence

The DHCPv6 server selects an IPv6 address/prefix for a client in the following sequence:

1. IPv6 address/prefix statically bound to the client's DUID and IAID and expected by the client.

2. IPv6 address/prefix statically bound to the client's DUID and IAID.

3. IPv6 address/prefix statically bound to the client's DUID and expected by the client.

4. IPv6 address/prefix statically bound to the client's DUID.

5. IPv6 address/prefix that was ever assigned to the client.

6. EUI-64 IPv6 address generated based on the client MAC address if EUI-64 address allocation is enabled.

7. Assignable IPv6 address/prefix in the address pool/prefix pool expected by the client.

8. Assignable IPv6 address/prefix in the address pool/prefix pool.

9. IPv6 address/prefix that was a conflict or passed its lease duration. If no IPv6 address/prefix is assignable, the server does not respond.

If a client moves to another subnet, the DHCPv6 server selects an IPv6 address/prefix from the address pool that matches the new subnet.

Conflicted IPv6 addresses can be assigned to other DHCPv6 clients only after the addresses are in conflict for one hour.