H3C Technologies H3C SecPath F1000-E - Manual (Page 85)

2
Basic Concepts
DHCPv6 multicast address
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.
DUID
A DHCP unique identifier (DUID) uniquely identifies a DHCPv6 device (DHCPv6 client, server, or relay
agent).
Figure 7 Format of DUID-LL
Currently, a DUID based on link-layer address (DUID-LL) defined in RFC 3315 is used to identify a
DHCPv6 device.
Figure 7 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.
IA
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.
IAID
An IAID uniquely identifies an IA. It is chosen by the client and must be unique among the IAIDs on the
client.
PD
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 creation time, and the IPv6 address of the requesting client.
Prefix Selection Process
Upon receiving a request, the DHCPv6 server selects the prefix and other configuration parameters from
the address pool that is applied to the interface receiving the request. An address pool may contain the