Network Working Group C. Cadar
Internet-Draft NEC
Expires: June 20, 2005 December 20, 2004
SMTP Option for DHCPv6
draft-cadar-dhc-dhcpv6-opt-smtp-00.txt
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Copyright Notice
Copyright (C) The Internet Society (2004).
Abstract
This document describes the SMTP option for Email related
configuration information in Dynamic Host Configuration Protocol for
IPv6 (DHCPv6). The purpose of the DHCPv6 option for Simple Mail
Transfer Protocol (SMTP) Server addresses is 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 Simple Mail Transport Protocol (SMTP) Server Option . . . 3
5. Appearance of these options . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1 Normative References . . . . . . . . . . . . . . . . . . . . 5
8.2 Informative References . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 5
Intellectual Property and Copyright Statements . . . . . . . . 6
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1. Introduction
This document describes the SMTP option for email related
configuration information in Dynamic Host Configuration Protocol for
IPv6 [RFC3315]. There is already a SMTP option available in Dynamic
Host Configuration Protocol for IPv4 [RFC2132] but since the
structure of protocol options for DHCPv6 differs from those used in
DHCPv4 there is a need for defining a new SMTP option in DHCPv6.
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 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 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_SMTP_SERVERS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SMTP server (IPv6 address) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SMTP server (IPv6 address) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ........................ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: 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.
5. Appearance of these options
The 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.
6. Security Considerations
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 SMTP server may
get the login name and password of the clients which attempt to
contact the roque servers.
To avoid attacks through these options, the DHCPv6 client SHOULD use
authenticated DHCPv6 (see "Authentication of DHCP messages" section
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in the DHCPv6 specification [RFC3315]).
7. 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_SMTP_SERVERS option code to be assigned by IANA.
8. References
8.1 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.
8.2 Informative References
[RFC1939] Myers, J. and M. Rose, "Post Office Protocol - Version 3",
STD 53, RFC 1939, May 1996.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
[RFC2821] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821,
April 2001.
[RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION
4rev1", RFC 3501, March 2003.
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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