2.3.2 Dynamic Host Configuration (dhc)

NOTE: This charter is a snapshot of the 46th IETF Meeting in Washington, DC. It may now be out-of-date. Last Modified: 29-Sep-99


Ralph Droms <droms@bucknell.edu>

Internet Area Director(s):

Thomas Narten <narten@raleigh.ibm.com>
Erik Nordmark <nordmark@eng.sun.com>

Internet Area Advisor:

Thomas Narten <narten@raleigh.ibm.com>

Mailing Lists:

General Discussion:dhcp-v4@bucknell.edu
To Subscribe: listserv@bucknell.edu
In Body: subscribe dhcp-v4 Your Name
Archive: Send email to listserv@bucknell.edu with HELP as the text.

Description of Working Group:

Other Lists:

A separate mailing list is used for discussing the IPv6 version of dhcp: dhcp-v6@bucknell.edu.

This working group has developed DHCP for automated allocation, configuration and management of IP addresses and TCP/IP protocol stack parameters. DHCP is currently a "Draft Standard" (RFC2131, RFC2132). The working group now has four main objectives:

* Revise and submit the DHCP specification for acceptance as a Full Standard

* Develop a roadmap for the review and acceptance of new options, define a new option syntax, develop an accurate list of assigned option codes and identify option codes that can be safely reassigned

* Develop a specification for DHCP for IPv6

* Develop an inter-server communication for coordination of multiple servers

* Review new options for DHCP, as deemed appropriate by the working group chair and/or the Internet area directors; specific options currently under review in the working group include:

o Mechanisms for the authentication of clients and servers

o Interaction between DHCP and DNS dynamic update protocol

o Definition of a DHCP MIB for management of DHCP servers through SNMP

o Definition of an LDAP schema to provide a standardized format for the storage and retrieval of DHCP information, primarily configuration and lease data; this schema will be developed in coordination with the Policy Frameworks Working Group as appropriate.

o Options through which DHCP relay agents can pass information to DHCP servers

o Other options: user class, server selection, domain search

Goals and Milestones:

Jun 99


Submit Internet-Draft on subnet selection option in time for Oslo IETF

Jun 99


Submit Internet-Draft on DAP schema for DHCP in time for Oslo IETF

Jun 99


Submit Internet-Draft on DHCP authentication in time for Oslo IETF

Jun 99


Submit Internet-Draft on failover protocol in time for Oslo IETF

Jun 99


Submit Internet-Draft on relay agent options in time for Oslo IETF

Jun 99


Submit Internet-Draft on DHCP-DNS interaction in time for Oslo IETF

Jul 99


Submit Internet-Draft on DHCP authentication for WG last call

Jul 99


Develop plan for review of DHCP specification and acceptance as Internet Standard.

Sep 99


Submit DHCP server MIB specification for WG last call

Sep 99


Submit subnet selection option specification for WG Last Call

Nov 99


Submit DHCP server MIB specification for IESG consideration as a Proposed Standard

Nov 99


Submit LDAP schema specification for WG last call

Mar 00


Submit LDAP schema specification to IESG for consideration as a Proposed Standard.


Request For Comments:







Interoperation Between DHCP and BOOTP



Clarifications and Extensions for the Bootstrap Protocol



DHCP Options and BOOTP Vendor Extensions



Dynamic Host Configuration Protocol



DHCP Options for Novell Directory Services



Netware/IP Domain Name and Information



DHCP Option for The Open Group's User Authentication Protocol



Procedure for Defining New DHCP Options



DHCP Options for Service Location Protocol

Current Meeting Report

Minutes from the DHC (Dynamic Host Configuration) working group meetings in Washington, DC. Reported by Ralph Droms with assistance from notes taken by Barr Hibbs, Kim Kinnear and Ann Demirtjis.

Tuesday, Nov 9 at 0900-1130 (DHCPv4)

Dynamic host configuration : DHCP reconfigure extension Yves T'Joens (Alcatel) draft-schrijvp-dhcpv4-reconfigure-00.txt

The author described a proposed option for a unicast message to trigger DHCP client reconfiguration. The WG provided feedback (add authentication, make draft more precise) and agreed to consider the option after a new draft is submitted.

The Name Service Search Option for DHCP
Carl Smith (Sun)

The WG suggested using a 16-bit value for the service numbers, and to define 0 as a reserved value to configure the client to look in local configuration table. The draft will be ready for WG last call after a final small revision.

DHCP Failover Protocol
Kim Kinnear (Cisco)

Kim reported on phone conferences held since last WG meeting. He will schedule one or two additional phone conferences and submit a new draft for (well before?) the next IETF.

The User Class Option for DHCP
Jerome Privat (BT)

The WG provided feedback on the most recent draft: simplify the draft, reduce "MUST" policy directives. The author will revise draft according to WG feedback.

Double Phase DHCP Configuration
Jerome Privat (BT)

WG suggested splitting this document into two drafts: an informational draft for the proxy mechanism and a standards track draft for redirect option. WG will continue to review this option after new drafts are published.

Dynamic Registration and Configuration Protocol (DRCP)
Anthony McAuley (Telcordia)

Protocol related to DHCP that reduces DHCP client-server communication latency through distributed DHCP servers (or proxies). The WG expressed the opinion that this may be a new protocol, not DHCP. The WG agreed to look at the next draft and decide whether or not to review the protocol.

Authentication for DHCP Messages
Bill Arbaugh (Penn)

Bill reported on suggestions from Volz. Ran Atkinson suggested splitting into two drafts; WG chose to leave "as is". Draft will go to WG last call after next revision.

DHCP Authentication Via Kerberos V
Bernard Aboba (Microsoft)

Bernard presented an extension to DHCP to provide Kerberos V authentication between clients and servers and to provide interdomain authentication. The basic mechanism is to transport Kerberos authentication data in DHCP messages (with, potentially, other communication between Kerberos participants). The WG suggested external, authoritative review of the application of Kerberos technology and took no specific action.

DHC load balancing algorithm
Bernie Volz (Process Software)

This draft results from load balancing technology developed with failover protocol, which seemed to have wider application to DHCP server configuration. Mike Patrick expressed concern about the necessity of configuring relay agents to match servers (if not, some requests may get dropped). Bernie will revise draft according to feedback from WG, and WG will continue to review the document.

The Server Selection Option for DHCP
Bill Sommerfield (Epilogue)

Rob Stevens suggested this option overlaps with load balancing; WG consensus was that overlap was small enough to warrant continued consideration of the server selection option. The WG suggested simplifying the draft (e.g., the descriptions of profiles), changing several "MUST"s to "SHOULD"s, and to allow lease time as tie breaker. Bill will revise and the WG will review the next draft.

Dynamic Host Configuration Protocol (DHCP) Server MIB
Barr Hibbs (Pacbell)

Barr will post specific questions to the WG mailing list and revise MIB according to feedback. Next revision should be ready for WG last call.

Interpreting Client Options for DHCP
Barr Hibbs (Pacbell)

Barr will withdraw this draft or let it expire. Ted Lemon volunteered to begin work on a revision of RFC 2131/2132 that will be submitted for full Standard status. This revision will include clarifications and revised text based on Barr's draft as well as other experience with DHCP.

Option for NAT/IPSec interaction
Jose Brustoloni (Bell Labs)
(no draft available)

This option addresses interoperation problems between NAT and IPSec. WG provided feedback and will review a revised draft.

Subnet selection option
Ted Lemon (for Glenn Waters)

Draft is ready for WG last call.

Static routes with subnet masks option
Ted Lemon
(no draft available)

Ted will write up draft for an option to pass a list of static routes with subnet masks.

Domain name search list option
Ted Lemon
Ted will track down previous draft and move it forward.

Tuesday, Nov 9 at 1300-1400 (DHCPv4)

DHCP Relay Agent Information Option
Mike Patrick (Motorola)

Mike described Motorola IPR statement. A few new issues were raised: subnet sub-option (WG consensus was to keep it); interaction between relay agent option and IPSec (relay agent should not add option); server should not assume relay agent is present and may choose to add a relay agent information option. The WG agreed to hold a last call on a revised document that addresses these points.

DHCP Schema for LDAP
Bernie Volz (Process Software)

Changes since last revision:

- New class, containment and inheritance hierarchy
- Uses common name attribute
- Added dhcpPolicy object class and text on mapping dhcpPolicy object to Policy WG schema
- Removed use of auxiliary classes

WG agreed to move forward as Proposed Standard document with (potentially?) last call after next revision.

Interaction between DHCP and DNS
Mark Stapp (Cisco)

A new RR for use with DHCP has been proposed. DHCP will use this instead of the previously proposed use of the KEY RR. Also, the security section must be updated to reflect TSIG. Mark will revise and resubmit the draft to reflect these changes.

A DNS RR for DHCP information
Andreas Gustafsson (Internet Engines)

The DHCP RR (name will likely change) is an opaque data item stored by a DNS server and holds a DHCP client identifier to indicate the client currently associated with a DNS entry. The new RR holds only a client identifier and no other information (e.g., lease). The WG consensus was that the DHCP RR will meet the requirements for DHCP-DNS interaction and should be moved forward.

New Option Review Guidelines and Mike Carney (Sun)
Additional Option Namespace

Mike solicited comments from the WG on section 5 (open issues) and would like to go to last call after minor revisions addressing those issues.

Tuesday, Nov 9 at 1415-1515 (DHCPv6)

Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
Mike Carney (Sun)
draft-ietf-dhc-dhcpv6-14.txt - Jim Bound (Compaq)
Extensions for the DHCP for IPv6 - Charlie Perkins (Nokia)

WG discussed several open issues:

- Releasable resources: IPv6 addresses are one example; are there others (none suggested). When and how should these resources be managed (what is leasing strategy) and released (to original server or any server)?
- Stateful autoconfiguration and multiple IP addresses: discussion centered on tradeoff between complexity and utility - client might make multiple requests for addresses in IPv4-IPv6 transition. Discussion will continue on DHCPv6 mailing list.
- Stateful autoconfiguration and use of multiple servers (e.g., failover): any useful input from experience with DHCPv4?
- Document organization: authors prefer to leave as two documents.

Authors will pose questions separately to DHCPv6 mailing list for WG discussion and publish revised draft by end of calendar year.


DHC Working Group DHCP Load Balancing
DHC Working Group DHCP LDAP Schema
Double-phase DHCP configuration
Dynamic Registration and Configuration Protocol (DRCP)
User Class Option: open issues