XGS-5240-Series User Manual

Configuration Guide of XGS-5240-Series
37-1
Chapter 37 DHCPv6 Configuration
37.1 Introduction to DHCPv6
DHCPv6 [RFC3315] is the IPv6 version for Dynamic Host Configuration Protocol (DHCP).
It is a protocol that assigns IPv6 address as well as other network configuration parameters
such as DNS address, and domain name to DHCPv6 client, DHCPv6 is a conditional auto
address configuration protocol relative to IPv6. In the conditional address configuration
process, DHCPv6 server assigns a complete IPv6 address to client, and provides DNS
address, domain name and other configuration information, maybe the DHCPv6 packet can
transmit through relay delegation, at last the binding of IPv6 address and client can be
recorded by DHCPv6 server, all that can enhance the management of network; DHCPv6
server can also provide non state DHCPv6 service, that is only assigns DNS address and
domain name and other configuration information but not assigns IPv6 address, it can solve
the bug of IPv6 auto address configuration in non state; DHCPv6 can provide extend function
of DHCPv6 prefix delegation, upstream route can assign address prefix to downstream route
automatically, that achieve the IPv6 address auto assignment in levels of network environment,
and resolved the problem of ISP and IPv6 network dispose.
There are three entities in the DHCPv6 protocol – the client, the relay and the server. The
DHCPv6 protocol is based on the UDP protocol. The DHCPv6 client sends request messages
to the DHCP server or DHCP relay with the destination port as 547, and the DHCPv6 server
and relay send replying messages with the destination port as 546. The DHCPv6 client sends
solicit or request messages with the multicast address – ff02::1:2 for DHCP relay and server.
Fig 2-1 DHCPv6 negotiation
When a DHCPv6 client tries to request an IPv6 address and other configurations from the
DHCPv6 server, the client has to find the location of the DHCP server, and then request
configurations from the DHCP server.
1. In the time of located server, the DHCP client tries to find a DHCPv6 server by
DHCPv6 CLIENT
DHCPv6 SERVER
Solicit (Muticast)
Advertise (Unicast)
Request (Muticast)
Reply (Unicast)