H3C Technologies H3C S10500 Series Switches - Manual (Page 139)

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DHCPv6 overview
Introduction to DHCPv6
The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) was designed based on IPv6 addressing
scheme and is used for assigning IPv6 prefixes, IPv6 addresses and other configuration parameters to
hosts.
Compared with other IPv6 address allocation methods (such as manual configuration and stateless
address autoconfiguration), DHCPv6 can:
• Record addresses assigned to hosts and assign specific addresses to hosts, thus facilitating network
management.
• Assign prefixes to devices, facilitating automatic configuration and management of the entire
network.
• Assign other configuration parameters, such as DNS server addresses and domain names.
NOTE:
In actual application, whether a DHCPv6 server can assign IPv6 addresses and other configuration
parameters depends on the DHCPv6 server.
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 50 Rapid assignment involving two messages
As shown in Figure 50 , the rapid assignment involving two messages operates in the following steps.
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.