Network Working Group C. Cadar
Internet-Draft NEC
Expires: December 13, 2004 June 14, 2004
IMAP Configuration Option for DHCP
draft-cadar-dhc-opt-imap-00.txt
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Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
This document describes a new option for Email related configuration
information in Dynamic Host Configuration Protocol (DHCP), the option
for Internet Message Access Protocol (IMAP) Server addresses for
message retrieval from mailboxes on these servers.
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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 Server Option Format . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 3
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1 Normative References . . . . . . . . . . . . . . . . . . . . 4
7.2 Informative References . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 4
Intellectual Property and Copyright Statements . . . . . . . . 5
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1. Introduction
This document describes a new option for email related configuration
information in Dynamic Host Configuration Protocol [RFC2131].
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 DHCPv4 as defined in
"Terminology" section of the DHCPv4 specification [RFC2131].
4. The Internet Message Access Protocol Server Option Format
The Internet Message Access Protocol (IMAP) Server Option provides a
list of one or more IPv4 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.
Code Len Address 1 Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| TBD | n | a1 | a2 | a3 | a4 | a1 | a2 | ...
+-----+-----+-----+-----+-----+-----+-----+-----+--
Figure 1: IMAP_SERVERS
Code: is TBD as per [RFC2939].
Len: Length n gives the total number of octets of ipv4 IMAP server
addresses, it must be a multiple of 4.
5. Security Considerations
The IMAP server option may be used by an intruder DHCP server to
cause DHCP clients to contact a rogue IMAP server, resulting in
failure of email retrieval. Also a roque IMAP server may get the
login name and password of the clients which attempt to contact the
IMAP servers.
To avoid attacks through these option, the DHCP client SHOULD use
authenticated DHCP (see "Authentication for DHCP messages"
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specification [RFC3118]).
6. IANA Considerations
IANA is requested to assign a value for the IMAP option code in
accordance with [RFC2939].
7. References
7.1 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC
2131, March 1997.
7.2 Informative References
[RFC2060] Crispin, M., "Internet Message Access Protocol - Version
4rev1", RFC 2060, December 1996.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
[RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition
of New DHCP Options and Message Types", BCP 43, RFC 2939,
September 2000.
[RFC3118] Droms, R. and W. Arbaugh, "Authentication for DHCP
Messages", RFC 3118, June 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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Acknowledgment
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