H3C Technologies H3C S12500 Series Switches - Manual (Page 179)

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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.
Binding
The DHCPv6 server uses bindings to record the configuration information assigned to DHCPv6 clients,
including the IPv6 address/prefix, client DUID, IAID, valid lifetime, preferred lifetime, and lease
expiration time.
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
expiration time, and the IPv6 address of the requesting client.
DHCPv6 address/prefix assignment
A process of DHCPv6 address/prefix assignment involves two or four messages. The following describe
the detailed processes.
Rapid assignment involving two messages
Figure 66 Process of rapid assignment involving two messages
1. The DHCPv6 client sends out a Solicit message that contains a Rapid Commit option, requesting
that rapid assignment of address/prefix and other configuration parameters should be preferred.
2. If the DHCPv6 server supports rapid assignment, it responds with a Reply message containing the
assigned IPv6 address/prefix and other configuration parameters. If the DHCPv6 server does not
support rapid assignment, " Assignment involving four messages " is implemented.