- Technical Summary
This document specifies the way in which DHCPv4 clients should
identify themselves. DHCPv4 client implementations that conform to
this specification use a DHCPv6-style DHCP Unique Identifier (DUID)
encapsulated in a DHCPv4 client identifier option. This supersedes
the behavior specified in RFC2131 and RFC2132.
The reason for making this change is that as we make the transition
from IPv4 to IPv6, there will be network devices that must use both
DHCPv4 and DHCPv6. Users of these devices will have a smoother
network experience if the devices identify themselves consistently,
regardless of the version of DHCP they are using at any given
moment. Most obviously, DNS updates made by the DHCP server on
behalf of the client will not be handled correctly. This change
also addresses certain limitations in the functioning of
RFC2131/2132-style DHCP client identifiers.
This document first describes the problem to be solved. It then
states the new technique that is to be used to solve the problem.
Finally, it describes the specific changes that one would have to
make to RFC2131 and RFC2132 in order for those documents not to
contradict what is described in this document.
This document updates RFC2131 and RFC2132. DHCPv4 server
implementations SHOULD conform to this document. DHCPv4 clients on
network devices that are expected to support DHCPv6 in the future
SHOULD conform to this document. This document makes no changes to
the behavior of DHCPv6 clients or servers.
DHCPv4 clients and servers that are implemented according to this
document should be implemented as if the changes specified in
section 4.3 and 4.4 have been made to RFC2131 and RFC2132.
- Working Group Summary
The WG has given this document careful review, It has been discussed
extensively at WG meetings and on the WG mailing list. There was
substantive discussion during the WG last call.
- Protocol Quality
The WG has given this document careful review. It extends the
client-identifier option defined in RFC 2131 and RFC 2132 based on the
definition of the DUID in DHCPv6. The extension is necessary for
interoperability in hosts that use both DHCPv4 and DHCPv6. The
document includes text changes for RFC 2131 that will be incorporated
into the DHCP specification when it is revised for Full Standard.