Network Working Group                                           C. Cadar
Internet-Draft                                                       NEC
Expires: December 13, 2004                                 June 14, 2004


                 Email Configuration Options for DHCPv6
                draft-cadar-dhc-dhcpv6-opt-email-00.txt

Status of this Memo

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

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   This Internet-Draft will expire on December 13, 2004.

Copyright Notice

   Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

   This document describes three options for Email related configuration
   information in Dynamic Host Configuration Protocol for IPv6 (DHCPv6).
   The option for Internet Message Access Protocol (IMAP) and Post
   Office Protocol (POP3) Server addresses for message retrieval from
   mailboxes on these servers and the option for the Simple Mail
   Transfer Protocol (SMTP) Server addresses to route SMTP messages
   throughout the Internet to a mail server.








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Table of Contents

   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.   Requirements notation & Naming Conventions . . . . . . . . . . 3
   3.   Terminology  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   4.   The Internet Message Access Protocol (IMAP) Server Option  . . 3
   5.   The Post Office Protocol (POP3) Server Option  . . . . . . . . 4
   6.   The Simple Mail Transport Protocol (SMTP) Server Option  . . . 5
   7.   Appearance of these options  . . . . . . . . . . . . . . . . . 6
   8.   Security Considerations  . . . . . . . . . . . . . . . . . . . 6
   9.   IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 7
   10.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
   10.1   Normative References . . . . . . . . . . . . . . . . . . . . 7
   10.2   Informative References . . . . . . . . . . . . . . . . . . . 7
        Author's Address . . . . . . . . . . . . . . . . . . . . . . . 7
        Intellectual Property and Copyright Statements . . . . . . . . 8



































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1.  Introduction

   This document describes the options for email related configuration
   information in Dynamic Host Configuration Protocol for IPv6
   [RFC3315].

2.  Requirements notation & Naming Conventions

   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 [RFC2119].

3.  Terminology

   This document uses terminology specific to IPv6 and DHCPv6 as defined
   in "Terminology" section of the DHCPv6 specification [RFC3315].

4.  The Internet Message Access Protocol (IMAP) Server Option

   The Internet Message Access Protocol (IMAP) Server Option provides a
   list of one or more IPv6 addresses of IMAP [RFC2060] servers
   available to the clients for message retrieval from mailboxes on
   these servers.  The IMAP servers SHOULD be listed in the order of
   preference.  The format of the IMAP Protocol Servers option is shown
   in Figure 1.


























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    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      OPTION_IMAP_SERVERS      |          option-len           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     IMAP server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     IMAP server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       .....................                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 1: OPTION_IMAP_SERVERS

   option-code: OPTION_IMAP_SERVERS (tbd).

   option-len: Length of the 'IMAP server' fields in octets, it must be
      a multiple of 16.

   IMAP address: IPv6 address of IMAP server.


5.   The Post Office Protocol (POP3) Server Option

   The Post Office Protocol (POP3) Server Option provides a list of one
   or more IPv6 addresses of POP3 [RFC1939] servers available to the
   clients for message retrieval from mailboxes on these servers.  The
   POP3 servers SHOULD be listed in the order of preference.  The format
   of the POP3 Protocol Servers option is shown in Figure 2.
















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    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      OPTION_POP3_SERVERS      |          option-len           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     POP3 server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     POP3 server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       ....................                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 2: OPTION_POP3_SERVERS

   option-code: OPTION_POP3_SERVERS (tbd).

   option-len: Length of the 'POP3 server' fields in octets, it must be
      a multiple of 16.

   POP3 address: IPv6 address of POP3 server.


6.   The Simple Mail Transport Protocol (SMTP) Server Option

   The Simple Mail Transport Protocol (SMTP) Server Option provides a
   list of one or more IPv6 addresses of SMTP [RFC2821] servers
   available to the clients for routing SMTP messages throughout the
   Internet to a mail server.  The SMTP servers SHOULD be listed in the
   order of preference.  The format of the SMTP Protocol Servers option
   is shown in Figure 3.















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    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      OPTION_SMTP_SERVERS      |          option-len           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     SMTP server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     SMTP server (IPv6 address)                |
   |                                                               |
   |                                                               |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ........................                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 3: OPTION_SMTP_SERVERS

   option-code: OPTION_SMTP_SERVERS (tbd).

   option-len: Length of the 'SMTP server' fields in octets, it must be
      a multiple of 16.

   SMTP address: IPv6 address of SMTP server.


7.  Appearance of these options

   The IMAP, POP3 and SMTP server option MUST NOT appear in other than
   the following messages: Solicit, Advertise, Request, Renew, Rebind,
   Information-Request and Reply.  The option number for these options
   MAY appear in the Option Request Option [RFC3315] in the following
   messages: Solicit, Request, Renew, Rebind, Information-Request and
   Reconfigure.

8.  Security Considerations

   The IMAP, POP3 server option may be used by an intruder DHCPv6 server
   to cause DHCPv6 clients to contact a rogue IMAP or POP3 server,
   resulting in failure of email retrieval.  The SMTP server option may
   be used by an intruder DHCPv6 server to cause DHCPv6 clients to
   contact a rogue SMTP server, resulting in failure of email sending or
   in the worst case the intruder may gain access to the content of the
   email.  Also an intruder IMAP, POP3 or SMTP server may get the login
   name and password of the clients which attempt to contact the roque
   servers.



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   To avoid attacks through these options, the DHCPv6 client SHOULD use
   authenticated DHCPv6 (see "Authentication of DHCP messages" section
   in the DHCPv6 specification [RFC3315]).

9.  IANA Considerations

   IANA is requested to assign an option code to the following options
   from the option-code space defined in "DHCPv6 Options" section of the
   DHCPv6 specification Option Name Value Described in [RFC3315]

   OPTION_IMAP_SERVERS tbd Section 4.
   OPTION_POP3_SERVERS tbd Section 5.
   OPTION_SMTP_SERVERS tbd Section 6.

10.  References

10.1  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C. and
              M. Carney, "Dynamic Host Configuration Protocol for IPv6
              (DHCPv6)", RFC 3315, July 2003.

10.2  Informative References

   [RFC1939]  Myers, J. and M. Rose, "Post Office Protocol - Version 3",
              STD 53, RFC 1939, May 1996.

   [RFC2060]  Crispin, M., "Internet Message Access Protocol - Version
              4rev1", RFC 2060, December 1996.

   [RFC2821]  Klensin, J., "Simple Mail Transfer Protocol", RFC 2821,
              April 2001.


Author's Address

   Cristian Cadar
   NEC Europe Ltd.
   Kurfuersten-Anlage 36
   Heidelberg  69115
   Germany

   EMail: cristian.cadar@netlab.nec.de
   URI:   http://www.netlab.nec.de




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Intellectual Property Statement

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   Copyright (C) The Internet Society (2004).  All Rights Reserved.

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   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION



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   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.











































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