2.3.3 Dynamic Host Configuration (dhc)

NOTE: This charter is a snapshot of the 50th IETF Meeting in Minneapolis, Minnesota. It may now be out-of-date. Last Modified: 14-Mar-01


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
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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



DHCP Option to Disable Stateless Auto-Configuration in IPv4 Clients



DHCP Options for Service Location Protocol



Procedure for Defining New DHCP Options and Message Types



The Name Service Search Option for DHCP



The User Class Option for DHCP



The Subnet Selection Option for DHCP



DHCP Relay Agent Information Option



DHC load balancing algorithm

Current Meeting Report

Summary of DHC WG meetings in Minneapolis.

Monday, 1530-1730 - DHCPv4 agenda items

DHC WG activities update Ralph Droms, 10 minutes

Droms announced that the relay information option, load balancing and authentication specs have been accepted as draft standards.

DHCP Option for SIP Servers Henning Schulzrinne, 20 minutes

The WG finds this option acceptable in principle; however, the specific format and encoding of data in the option is still an issue. Authors want simple ASCII text encoding of DNS name or dotted decimal IP address; WG recommends RFC1035 encoding for DNS name and binary encoding of IP address with flag to indicate which encoding is in use. WG has selected RFC1035 for other recent options.

Addition of Device Class to Agent Options Rich Woundy, 10 minutes

This spec is ready for WG last call.

The DHCP Client FQDN Option Mark Stapp, 10 minutes

Resolution of DNS Name Conflicts Among DHCP Clients

Author will rev spec, changing "MUST implement" to "SHOULD implement"; spec will then we ready for WG last call and fixing words for IPv6.

Encoding Long DHCP Options Ted Lemon, 10 minutes

This draft enables the CSR option and domain name search list (as well as other future options) that may require more than 255 data bytes. Kim Kinnear will forward spec fixes to author. Next rev of spec will be ready for WG last call.

The Classless Static Route Option for DHCP Ted Lemon, 10 minutes

This draft depends on the long DHCP options draft. Bernie Volz will forward spec fixes to author. Next rev of spec will be ready for WG last call.

DHCP Failover Protocol Kim Kinnear, 5 minutes

Kinnear will review last call comments and issue concerning addresses in protocol (does NAT affect server-server identification using IP addresses?). Next rev of spec will be ready for WG last call.

DHCP Lease Query Kim Kinnear, 10 minutes

Spec requires further work with input from WG:

1. Put multiple returns from client query into

2. Allow configuration of server for which IP address it returns
as the "most current" one (i.e., in the return packet instead
of in the DHCP requested address options).

3. Resolve the client-requested-host-name option along with
the FQDN option.

4. Go forward with the client-last-transaction time.

Subnet Selection sub-option for Relay Agent Information Option Kim Kinnear, 15 minutes

This spec is ready for WG last call.

DHCP VPN Information option

VPN Identifier sub-option for Relay Agent Information Option

These specs will be taken on as DHC WG work items.

Triggering AAA from DHCP Relay Agents George Tsirtsis, 20 minutes

Author will work with Droms and Schnizlein to revise draft.

Extensions to DHCP for Roaming Users Biswaroop Mukherjee, 15 minutes

This spec will be taken on as a DHC WG work item.


Wednesday, 0900-1130 - DHCPv6 review

Report from DDDT (Dynamic DNS Design Team) Rich Draves, 15 minutes

The DDDT has developed an "Analysis of DNS Server Discovery Mechanisms for IPv6" <draft-ietf-ipngwg-dns-discovery-00.txt>. One of the discovery mechanisms uses DHCP messages and semantics to pass DNS server information to clients. Aboba presented a summary of the report for the information of the DHC WG.

Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Jim Bound, Ralph Droms

- Review of changes in current draft
- Review of design team teleconference

Summary of changes:
* Added new messages: Confirm, Renew, Rebind, Decline
* Uniform format for all client-server messages
* Clarified relay agent forwarding
* Advertise messages include offered addresses for client selection
* Clients multicast all messages to accommodate relay agent options; will add new option to allow server control of use of unicast
* New Reconfigure-init semantics - "trigger" reconfigure state

Changes accepted by WG except for:
* Reconfigure-init - punt on multicast reconfigure-init
* Spec needs review of options - which are required in base spec?
* Spec needs review of error codes

Authors will revise spec according to WG input from meeting discussion and based on input from Francis Dupont.

- Discussion of outstanding issues
* Temporary addresses
* IA identification
* DHCP-DNS interaction

WG will continue to consider these issues through the WG mailing list.


Addition of Device Class to Relay Agent Options
AAA/DHCP Proposal
DHCP for supporting roaming users in access networks
DHCP option for SIP servers
DHCP Lease Query
DHCP Failover Protocol
Subnet-selection Sub-option
vpn-id Option | vpn-id Suboption