SGS-6341-Series User Manual

Chapter 32 DHCPv6 Configuration
32.1 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.
Reply (Unicast)
Request (Multicast)
Advertise (Unicast)
Solicit (Multicast)
DHCPv6 SERVER
DHCPv6 CLIENT
Figure 32
-1: DHCPv6 negotiation
When a DHCPv6 client tries to req
uest 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
broadcasting a SOLICIT packet to all the DHCP delay delegation and server with
broadcast address as FF02::1:2.
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User’s Manual of SGS-6341 series