Netgear M4200-10MG-PoE+ (GSM4210P) - Multigigabit Managed Switch with 8*2.5G and 2x10G SFP+ Layer 3 Administrator's Guide

Dynamic Host Configuration Protocol version 6 (DHCPv6) for IPv6 is used to assign IPv6 
addresses statefully and distribute other configuration information such as domain name or 
DNS server.

DHCPv6 supports stateful address allocation, prefix delegation, and stateless services. This 
chapter describes how to configure the prefix delegation mode using a DHCPv6 pool. When 
you create a DHCPv6 pool, you need to assign a prefix to the client DHCP unique identifier 
(DUID).

DUID is used to identify the client’s unique DUID value. The format is xx:xx:xx:xx:xx:xx. 
RFC3315 defines three types:

Link-layer address plus time:

00:01:hardware type:time:link-layer address

Hardware type - 16 bit hardware type reserved by IANA. 1 means an Ethernet device.

Time: 32-bit unsigned integer. The time in seconds when this DUID was generated 
since 00:00:00 1/1/2000.

Link-layer address - The link layer address of a device generating the DUID.

Vendor-assigned unique ID based on Enterprise Number:

00:02:enterprise-number:identifier

Enterprise-number - 32-bit integer reserved by IANA.

Identifier - Variable length data for each vendor

Link-layer address:

00:03:hardware type:link-layer address

Hardware type - 16 bit hardware type reserved by IANA. 1 means an Ethernet device.

Link-layer address - The link layer address of a device generating the DUID. 

In the following case, the CPE router requests prefix from the PE router. The PE router 
chooses prefix (2001:1::/64) for delegation, and responds with the prefix to the requesting 
CPE router. The CPE router subnets the prefix and assigns the longer prefixes to links in the 
user’s network. The CPE router is then responsible to assign the 2001:1:1::/96 to one user’s 
network and 2001:1:2::/96 to another user’s network.