H3C Technologies H3C S12500 Series Switches - Manual (Page 178)

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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 addresses to specific hosts, thus facilitating network
management.
• Assign prefixes to devices, thus facilitating automatic configuration and management of the entire
network.
• Assign configuration parameters to hosts, such as the DNS server address or domain name.
Basic concepts
DHCPv6 multicast addresses
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 (Relay agent or server), and is
used for authentication between DHCPv6 devices.
Figure 65 DUID-LL format
There are many types of DUID. The device only supports the DUID that is based on link-layer address
(DUID-LL) defined in RFC 3315. The DUID-LL format is shown in Figure 65 , where:
• DUID type—The value 0x0003 indicates that the DUID type is DUID-LL.
• Hardware type—The switch supports Ethernet as the hardware type with the value of 0x0001.
• Link layer address—Its value is the bridge MAC address of the switch.