Concepts

The multicast address FF05::1:3 identifies all DHCPv6 servers on the site-local network. The multicast address FF02::1:2 identifies all DHCPv6 servers and relay agents on the link-local link.

A DHCP unique identifier (DUID) uniquely identifies a DHCPv6 device (DHCPv6 client, server, or relay agent).

A DUID based on link-layer address (DUID-LL) defined in RFC 3315 is used to identify a DHCPv6 device. Figure 66 shows the DUID-LL format, where:

• DUID type—The device supports DUID-LL as the DUID type with the value of 0x0003.

• Hardware type—The device supports Ethernet as the hardware type with the value of 0x0001.

• Link layer address—Its value is the bridge MAC address of the device.

Identified by an IAID, an Identity Association (IA) provides a construct through which the obtained addresses, prefixes, and other configuration parameters assigned from a server to a client are managed. A client can maintain multiple IAs, each of which is configured on an interface to manage the addresses, prefixes, and other configuration parameters obtained by that interface.

An IAID uniquely identifies an IA. It is chosen by the client and must be unique among the IAIDs on the client.

The Prefix Delegation (PD) is the lease record created by the DHCPv6 server for each assigned prefix. The PD contains information such as the IPv6 prefix, client DUID, IAID, valid lifetime, preferred lifetime, lease expiration time, and the IPv6 address of the requesting client.