ADTRAN AOS Version R10.1.0 Command Reference Manual page 1665

Command Reference Guide Ethernet Interface Command Set
Technology Review
DHCPv6, like DHCP in IPv4, is used in IP networks to supply hosts with IP addresses and other
networking information. DHCPv6, however, functions slightly differently than DHCPv4 by providing relay
agents with the ability to send relay-forward and relay-reply messages. In addition, in DHCPv4, when
DHCP messages are sent to a DHCP server whose address is not known, the IPv4 client uses the
broadcast address. In DHCPv6, the IPv6 client sends messages using the link-scoped mulitcast address.
This address is the All DHCP Relay Agents and Servers link, designated as FF02::1:2.
In AOS, DHCPv6 relay agents are used when the DHCP server is not on the same link as the DHCP client.
The relay is typically a router on the same link as the client, which acts as an intermediary to help the
client's DHCP messages reach the DHCP server. DHCPv6 relay agents operate transparently to the
DHCP client, and can be configured in chains, meaning that information about each agent encountered is
encapsulated into the relay message. Relay agents add fields to the DHCP message as they send these
messages to the server, thus providing a method to properly manage the DHCP client.
For more information about DHCPv6 functionality in AOS, refer to the configuration guide Using IPv6 in
AOS, available online at https://supportforums.adtran.com (article number 3505).
60000CRG0-35E Copyright © 2012 ADTRAN, Inc. 1665