Dynamic Host Configuration (dhc)

In addition to the charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at: Additional DHC Page

Description of Working Group

The dhc working group (DHC WG) has developed DHCP for automated
allocation, configuration and management of IP addresses and TCP/IP
protocol stack parameters. DHCPv4 is currently a "Draft Standard" and
is documented in RFC 2131 and RFC 2132. DHCPv6 is currently a
"Proposed Standard" and is documented in RFC 3315. Subsequent RFCs
document additional options and other enhancements to the
specifications.

The DHC WG is responsible for reviewing DHCP options or other
extensions (for both IPv4 and IPv6). The DHC WG is expected to review
all proposed extensions to DHCP to ensure that they are consistent
with the DHCP specification and other option formats, that they do not
duplicate existing mechanisms, etc. Generally speaking, the DHC WG
will not be responsible for evaluating the semantic content of
proposed options. Similarly, the ownership of specifications typically
belongs the relevant working group that needs more functionality from
DHCP, not the DHC WG. The DHC WG coordinates reviews of the proposed
options together with those working groups. It is required that those
working groups have consensus to take on the work and that the work is
within their charter. Exceptionally, with AD agreement, this same
process can also be used for Individual Submissions originating
outside WGs.

However, the DHC WG can in some cases develop its own options that
relate to either maintenance of existing specifications or
improvements in the operation of the DHCP infrastructure itself.

The DHC WG has the following main objectives:

* Develop extensions to the DHCP infrastructure as required to meet
new applications and deployments of DHCP. The topics currently
in development are:

- Subnet allocation mechanisms
- Virtual subnet identification option
- Option for passing DNS domain information in DHCPv6
- DHCP relay agent assignment notification in DHCPv6
- Option for DHCPv6 server reply sequence numbers
- Rebinding capability for DHCPv6 Reconfigure messages
- Behavior of layer 2 relay agents

The adoption of new items requires explicit agreement from
the AD or rechartering.

* Write analyses of the DHCPv4 and DHCPv6 specifications,
including RFC 2131, RFC 2132, RFC 3315 and other RFCs defining
additional options, which identifies ambiguities, contradictory
specifications and other obstacles to development of interoperable
implementations. Recommend a process for resolving identified
problems and incorporating the resolutions into the DHCP
specification.

Secondly, advance DHCPv4 (RFC 2131 and RFC 2132) and DHCPv6 (RFC
3315) in IETF Standards Track.

Thirdly, specify guidelines for creating new DHCP options, and
report on the status of DHCPv4 option reclassification.

* Assess the requirements for a dual-stack host to use DHCP to obtain
configuration settings for both IPv4 and IPv6. Hosts that include
implementations of both IPv4 and IPv6 ("dual-stack hosts") may use
DHCP to obtain configuration settings (including assigned addresses)
for both IPv4 and IPv6. The DHCPv4 and DHCPv6 specifications (RFC
2131, RFC 2132, RFC 3315 and subsequent RFCs) do not explicitly
explain how a dual-stack host uses DHCP to obtain configuration
settings for both IP stacks. The DHC WG will evaluate solutions for
configuration of dual-stack hosts through DHCP and select a solution
that will be developed and published by the WG.

* Hold a discussion whether on-link prefix information and default
router information is needed in DHCP in addition to router
advertisements. Actual solutions are out of scope for the WG,
however.

Goals and Milestones