Zyxel OLT2412 [78/326] Dhcpv6

Chapter 8 IPv6

OLT2412 User’s Guide

EUI-64

The EUI-64 (Extended Unique Identifier) defined by the IEEE (Institute of Electrical and Electronics

Engineers) is an interface ID format designed to adapt with IPv6. It is derived from the 48-bit (6-

byte) Ethernet MAC address as shown next. EUI-64 inserts the hex digits fffe between the third and

fourth bytes of the MAC address and complements the seventh bit of the first byte of the MAC

address. See the following example.

Stateless Autoconfiguration

With stateless autoconfiguration in IPv6, addresses can be uniquely and automatically generated.

Unlike DHCPv6 (Dynamic Host Configuration Protocol version six) which is used in IPv6 stateful

autoconfiguration, the owner and status of addresses don’t need to be maintained by a DHCP

server. Every IPv6 device is able to generate its own and unique IP address automatically when

IPv6 is initiated on its interface. It combines the prefix and the interface ID (generated from its own

Ethernet MAC address, see Interface ID and EUI-64) to form a complete IPv6 address.

When IPv6 is enabled on a device, its interface automatically generates a link-local address

(beginning with fe80).

When the interface is connected to a network with a router and the ipv6 address autoconfig

command is issued on the OLT, it generates

another address which combines its interface ID and

global and subnet information advertised from the router. This is a routable global IP address.

DHCPv6

The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, RFC 3315) is a server-client protocol

that allows a DHCP server to assign and pass IPv6 network addresses, prefixes and other

configuration information to DHCP clients. DHCPv6 servers and clients exchange DHCP messages

using UDP.

Each DHCP client and server has a unique DHCP Unique IDentifier (DUID), which is used for

identification when they are exchanging DHCPv6 messages. The DUID is generated from the MAC

address, time, vendor assigned ID and/or the vendor's private enterprise number registered with

the IANA. It should not change over time even after you reboot the device.

Identity Association

An Identity Association (IA) is a collection of addresses assigned to a DHCP client, through which

the server and client can manage a set of related IP addresses. Each IA must be associated with

exactly one interface. The DHCP client uses the IA assigned to an interface to obtain configuration

from a DHCP server for that interface. Each IA consists of a unique IAID and associated IP

information.

The IA type is the type of address in the IA. Each IA holds one type of address. IA_NA means an

identity association for non-temporary addresses and IA_TA is an identity association for temporary

Table 33

MAC 00 : 13 : 49 : 12 : 34 : 56

Table 34

EUI-64 02 :13 :49 :FF :FE :12 : 34 :56

1. In IPv6, all network interfaces can be associated with several addresses.