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. 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 obsoleted 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. 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. Cadar Expires December 13, 2004 [Page 1] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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 Cadar Expires December 13, 2004 [Page 2] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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. Cadar Expires December 13, 2004 [Page 3] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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. Cadar Expires December 13, 2004 [Page 4] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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. Cadar Expires December 13, 2004 [Page 5] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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. Cadar Expires December 13, 2004 [Page 6] Internet-Draft Email Configuration Options for DHCPv6 June 2004 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 Cadar Expires December 13, 2004 [Page 7] Internet-Draft Email Configuration Options for DHCPv6 June 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. 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