[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00 01

   DHC Working Group
   Internet Draft                                             J. Aiello
   draft-aiello-dhc-appliance-class-00.txt             Sylantro Systems
   Expires: July 2001                                      January 2001


                Appliance Class Identifier Option for DHCP


   Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.


   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or rendered obsolete by other
   documents at any time.  It is inappropriate to use Internet-Drafts
   as reference material or to cite them other than as "work in
   progress."

   The list of current Internet-Drafts can be accessed at
        http://www.ietf.org/ietf/1id-abstracts.txt
   The list of Internet-Draft Shadow Directories can be accessed at
        http://www.ietf.org/shadow.html.





Table of Contents

   1. Abstract........................................................2
   2. Conventions used in this document...............................2
   3. DHCP Terminology................................................2
   4. Overview........................................................2
   5. The Appliance Class Identifier Option...........................3
   7. Security Considerations.........................................3
   9. Acknowledgements................................................4
   10. Author's Addresses.............................................4








       Aiello       Informational - Expires July 2001             1
    

                  Appliance Class Identifier Option      January 2001

1. Abstract

   The Appliance Class Identifier option is used by a Dynamic Host
   Configuration Protocol (DHCP) client to identify the type of
   appliance it belongs to.  The information contained in this option is
   an opaque field that represents the appliance class of which
   identifies the type of client.  Based on this class, a DHCP server
   selects the appropriate address pool to assign an address to the
   client and the appropriate configuration parameters.  This option
   should be selected by the appliance manufacturer and included in the
   DHCP Discover/Request messages.

2. Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in
   this document are to be interpreted as described in RFC-2119 [1].

3. DHCP Terminology

   - "DHCP client"

   A DHCP client or "client" is an Internet host using DHCP to obtain
   configuration parameters such as a network address.

   - "DHCP server"

   A DHCP server is an Internet host that returns configuration
   parameters to DHCP clients.

   - "Appliance"

   An appliance is a DHCP client that not what is a special function
   device such as an IP phone.

   - "Appliance manufacturer"

   The entity who manufacturers the appliance or has it manufactured in
   their name.


4. Overview

   New and emerging IP based appliances (devices) may need to be
   identified by DHCP servers differently than other DHCP clients.
   These new appliances may require IP addresses and DHCP supplied
   options different than other DHCP clients.  Network devices such as
   routers and firewalls will require special handling of some
   appliances.  For example, an IP phone (appliance) may require an IP
   address that will not be translated by the router and may require
   unique options such as a Call Agent server IP address or a DNS

       Aiello       Informational - Expires July 2001             2
    

                  Appliance Class Identifier Option      January 2001

   server IP address used exclusively for Voice over IP networks.
   These appliances may need to have separate IP address pools
   allocated just for the various appliances.  The client identifies
   itself as a specific appliance class, by this new option, to the
   DHCP Server.  The DHCP shall issue an IP address allocated for that
   appliance type from the DHCP server.  This ensures no computer,
   printer, etc. receives an IP address allocated for a specific
   appliance type.  The DHCP server should support multiple Appliance
   Classes.


5. The Appliance Class Identifier Option

   The code for this option is TBD.

   The Appliance Class Identifier is used by the DHCP Client to
   optionally identify the appliance class it represents.  A DHCP
   server uses the Appliance Class Identifier to choose the IP address
   pool it allocates an IP address from and to select any other
   appliance specific configuration option(s).

   This option carries only one Appliance Class Identifier.

   The DHCP server MUST return the Appliance Class Identifier in the
   DHCP offer-s.

   The DHCP client must reject the DHCP offer if it does not contain
   the Appliance Class Identifier.

   The format of this option is as follows:

            Code   Len   Value
           +-----+-----+-------------------------------------+
           | TBD |  N  | Appliance Class Data                |
           +-----+-----+-------------------------------------+

   A server not equipped to interpret the appliance class should ignore
   it.  The server should report the unmatched class event.


6. IANA Considerations

   Option TBD has been assigned by IANA for this option.


7. Security Considerations

   DHCP currently provides no authentication or security mechanisms.
   Potential exposures to attack are discussed is section 7 of the
   protocol specification.

   This lack of authentication mechanism means that a DHCP server cannot
   check if a client or user is authorized to use a given appliance

       Aiello       Informational - Expires July 2001             3
    

                  Appliance Class Identifier Option      January 2001

   class. This introduces an obvious vulnerability when using the
   appliance class option.  For example, if the appliance class is used
   to give out a special parameter (e.g., a particular call agent
   server), there is no way to authenticate a client and it is therefore
   impossible to check if a client is authorized to use this parameter.

8. References


   [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
      Levels", BCP 14, RFC 2119, March 1997

   [2] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March
      1997.

   [3] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
      Extensions", RFC 2132, March 1997.

   [4] Bradner, S., "Key words for use in RFCs to Indicate Requirement
      Levels", BCP 14, RFC 2119, March 1997.

   [5] Stump, G., "User Class Option for DHCP", RFC 3004, November
      2000.


9. Acknowledgements
   The author would like to thank Eric Nielson for his input and
   contribution.


10. Author's Addresses

   Joe Aiello
   Sylantro Systems
   910 East Hamilton, Suite 300 Phone:  1-408-626-3032
   Campbell, CA USA             Email:  joe.aiello@Sylantro.com


















       Aiello       Informational - Expires July 2001             4


Html markup produced by rfcmarkup 1.123, available from https://tools.ietf.org/tools/rfcmarkup/