draft-ietf-ntp-dhcpv6-ntp-opt-02.txt   draft-ietf-ntp-dhcpv6-ntp-opt-03.txt 
Network Working Group R. Gayraud Network Working Group R. Gayraud
Internet-Draft B. Lourdelet Internet-Draft None
Intended status: Standards Track Cisco Systems, Inc. Intended status: Standards Track B. Lourdelet
Expires: January 12, 2009 July 11, 2008 Expires: September 7, 2009 Cisco Systems, Inc.
March 6, 2009
Network Time Protocol (NTP) Server Option for DHCPv6 Network Time Protocol (NTP) Server Option for DHCPv6
draft-ietf-ntp-dhcpv6-ntp-opt-02.txt draft-ietf-ntp-dhcpv6-ntp-opt-03.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any This Internet-Draft is submitted to IETF in full conformance with the
applicable patent or other IPR claims of which he or she is aware provisions of BCP 78 and BCP 79. This document may contain material
have been or will be disclosed, and any of which he or she becomes from IETF Documents or IETF Contributions published or made publicly
aware will be disclosed, in accordance with Section 6 of BCP 79. available before November 10, 2008. The person(s) controlling the
copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be modified outside the IETF Standards Process, and
derivative works of it may not be created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on January 12, 2009. This Internet-Draft will expire on September 7, 2009.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Abstract Abstract
The NTP Server Option for DHCPv6 provides NTP (Network Time Protocol The NTP Server Option for DHCPv6 provides NTP (Network Time Protocol
version 4) configuration information to DHCPv6 hosts. version 4) configuration information to DHCPv6 hosts.
Table of Contents Table of Contents
1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Related Work and Usage Model . . . . . . . . . . . . . . . 3 2.1. Related Work and Usage Model . . . . . . . . . . . . . . . 3
3. NTP Server Option for DHCPv6 . . . . . . . . . . . . . . . . . 4 3. NTP Server Option for DHCPv6 . . . . . . . . . . . . . . . . . 4
3.1. NTP Server Address Suboption . . . . . . . . . . . . . . . 5 3.1. NTP Server Address Suboption . . . . . . . . . . . . . . . 5
3.2. NTP Multicast Address Suboption . . . . . . . . . . . . . 6 3.2. NTP Multicast Address Suboption . . . . . . . . . . . . . 5
3.3. NTP Server FQDN Suboption . . . . . . . . . . . . . . . . 6 3.3. NTP Server FQDN Suboption . . . . . . . . . . . . . . . . 6
4. Examples of use . . . . . . . . . . . . . . . . . . . . . . . 7 4. Examples of use . . . . . . . . . . . . . . . . . . . . . . . 6
5. Appearance of this Option . . . . . . . . . . . . . . . . . . 8 5. Appearance of this Option . . . . . . . . . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . . 10 8.2. Informative References . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10
Intellectual Property and Copyright Statements . . . . . . . . . . 11
1. Requirements notation 1. Requirements notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2. Introduction 2. Introduction
This document defines a DHCPv6 option and associated suboptions to This document defines a DHCPv6 option and associated suboptions to
provide Network Time Protocol version 4 [draft-ntpv4] or greater provide Network Time Protocol version 4 [draft-ntpv4] or greater
configuration information to DHCPv6 hosts. configuration information to DHCPv6 hosts.
2.1. Related Work and Usage Model 2.1. Related Work and Usage Model
[RFC4075] (SNTP Configuration Option for DHCPv6) provides some degree [RFC4075] (SNTP Configuration Option for DHCPv6) provides some degree
of automatic time server configuration for IPv6, as it specifies how of automatic time server configuration for IPv6, as it specifies how
to transmit SNTP [RFC4330] servers addresses through DHCPv6. to transmit SNTP [RFC4330] servers addresses through DHCPv6. However
However, this approach is not suitable for all NTP deployments. The this approach is not suitable for all NTP deployments. It is not an
use of the SNTP protocol is only authorized at the root and leafs of extensible mechanism and introduces some semantic confusion throught
an NTP tree (i.e. stratum 1 servers and highest stratum clients). the use of the "SNTP" acronym. Additionally the approach of only
But NTP servers that receive time from an upstream source, and offering IPv6 addresses to specify server location does not meet NTP
redistribute it to LAN workstations, are not allowed to run SNTP. requirements that make use of a FQDN (Fully Qualified Domain Name) as
This is why SNTP is not the protocol of choice for general purpose well.
NTP servers directly used by client workstations. Additionally the
approach of only offering IPv6 addresses to specify server location
does not meet NTP requirements that make uses of a FQDN (Fully
Qualified Domain Name) as well.
The NTP service is publicly offered on the Internet by a number of The NTP service is publicly offered on the Internet by a number of
organizations. Those servers can be used but not abused, so any organizations. Those servers can be used but not abused, so any
method which is tasked to disseminate locations of NTP servers must method which is tasked to disseminate locations of NTP servers must
act responsibly in a manner that does not lead to public server act responsibly in a manner that does not lead to public server
overloading. When using DHCPv6 to offer NTP server location, and if overloading. When using DHCPv6 to offer NTP server location, and if
there is a need to distribute a device with a hardcoded there is a need to distribute a device with a hardcoded
configuration, this configuration MUST NOT include server location configuration, this configuration MUST NOT include server location
that is not part of the organization that distribute this device. that is not part of the organization that distribute this device.
Typical usage of this option is to specify an NTP server that is part Typical usage of this option is to specify an NTP server that is part
skipping to change at page 5, line 25 skipping to change at page 5, line 4
| suboption-2 | | suboption-2 |
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboption-n | | suboption-n |
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code: OPTION_NTP_SERVER (TBD_IANA), option-code: OPTION_NTP_SERVER (TBD_IANA),
option-len: Total length of the included suboptions. option-len: Total length of the included suboptions.
A client that receives this option SHOULD use the specified NTP
server to synchronize its clock.
This document does not define any priority between the client's This document does not define any priority between the client's
embedded configuration and the NTP servers discovered via this embedded configuration and the NTP servers discovered via this
option. In particular, the client is allowed to simultaneously use option. In particular, the client is allowed to simultaneously use
its own configured NTP servers and the servers discovered via DHCP. its own configured NTP servers and the servers discovered via DHCP.
3.1. NTP Server Address Suboption 3.1. NTP Server Address Suboption
This suboption is intended to appear inside the OPTION_NTP_SERVER This suboption is intended to appear inside the OPTION_NTP_SERVER
option. It specifies the IPv6 unicast address of an NTP server option. It specifies the IPv6 unicast address of an NTP server
available to the client. An example of use is present in Section 4. available to the client. An example of use is present in Section 4.
skipping to change at page 7, line 21 skipping to change at page 6, line 44
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| FQDN of NTP server | | FQDN of NTP server |
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
suboption-code: NTP_SUBOPTION_SRV_FQDN (3), suboption-code: NTP_SUBOPTION_SRV_FQDN (3),
suboption-len: Length of the included FQDN field, suboption-len: Length of the included FQDN field,
FQDN: Fully Qualidied Domain Name of the NTP server. This FQDN: Fully Qualified Domain Name of the NTP server. This
field MUST be encoded as described in [RFC3315], field MUST be encoded as described in [RFC3315],
section 8. section 8.
4. Examples of use 4. Examples of use
To instruct a client to use an NTP server located at address 2001: To instruct a client to use an NTP server located at address 2001:
db8::1, a DHCP server shall use the following format: db8::1, a DHCP server shall use the following format:
0 1 2 3 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 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
skipping to change at page 9, line 4 skipping to change at page 8, line 28
5. Appearance of this Option 5. Appearance of this Option
The OPTION_NTP_SERVER option can appear multiple times in a DHCPv6 The OPTION_NTP_SERVER option can appear multiple times in a DHCPv6
message. The order in which these options appear is not significant. message. The order in which these options appear is not significant.
The client uses its usual algorithms to determine which server(s) or The client uses its usual algorithms to determine which server(s) or
multicast group(s) should be prefered to synchronize its clock. multicast group(s) should be prefered to synchronize its clock.
The OPTION_NTP_SERVER option MUST NOT appear in messages other than The OPTION_NTP_SERVER option MUST NOT appear in messages other than
the following: Solicit, Advertise, Request, Renew, Rebind, the following: Solicit, Advertise, Request, Renew, Rebind,
Information-Request, and Reply. If this option appears in messages Information-Request, and Reply. If this option appears in messages
other than those specified above, the receiver SHOULD ignore it. other than those specified above, the receiver MUST ignore it.
The option number for this option MAY appear in the "Option Request" The option number for this option MAY appear in the "Option Request"
option [RFC3315] in the following messages: Solicit, Request, Renew, option [RFC3315] in the following messages: Solicit, Request, Renew,
Rebind, Information-Request, and Reconfigure. If this option number Rebind, Information-Request, and Reconfigure. If this option number
appears in the "Option Request" option in messages other than those appears in the "Option Request" option in messages other than those
specified above, the receiver SHOULD ignore it. specified above, the receiver SHOULD ignore it.
6. Security Considerations 6. Security Considerations
This option could be used by an intruder to advertise the address of This option could be used by an intruder to advertise the address of
skipping to change at page 9, line 47 skipping to change at page 9, line 27
8.1. Normative References 8.1. Normative References
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003. IPv6 (DHCPv6)", RFC 3315, July 2003.
[draft-ntpv4] [draft-ntpv4]
Burbank, J., Kasch, W., Martin, J., and D. Mills, "Network Burbank, J., Kasch, W., Martin, J., and D. Mills, "Network
Time Protocol Version 4 Protocol And Algorithms Time Protocol Version 4 Protocol And Algorithms
Specification", draft-ietf-ntp-ntpv4-proto-08 (work in Specification", draft-ietf-ntp-ntpv4-proto-11 (work in
progress), November 2007. progress), September 2008.
[draft-autokey] [draft-autokey]
Haberman, B. and D. Mills, "Network Time Protocol Version Haberman, B. and D. Mills, "Network Time Protocol Version
4 Autokey Specification", draft-ietf-ntp-autokey-00 (work 4 Autokey Specification", draft-ietf-ntp-autokey-04 (work
in progress), September 2007. in progress), August 2008.
8.2. Informative References 8.2. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
Neighbor Discovery (SEND)", RFC 3971, March 2005. Neighbor Discovery (SEND)", RFC 3971, March 2005.
[RFC4075] Kalusivalingam, V., "Simple Network Time Protocol (SNTP) [RFC4075] Kalusivalingam, V., "Simple Network Time Protocol (SNTP)
Configuration Option for DHCPv6", RFC 4075, May 2005. Configuration Option for DHCPv6", RFC 4075, May 2005.
[RFC4330] Mills, D., "Simple Network Time Protocol (SNTP) Version 4 [RFC4330] Mills, D., "Simple Network Time Protocol (SNTP) Version 4
for IPv4, IPv6 and OSI", RFC 4330, January 2006. for IPv4, IPv6 and OSI", RFC 4330, January 2006.
Authors' Addresses Authors' Addresses
Richard Gayraud Richard Gayraud
Cisco Systems, Inc. None
Village ent. GreenSide, Bat T3,
400, Av de Roumanille,
06410 BIOT - Sophia-Antipolis Cedex
France
Phone: +33 4 97 23 26 49 Email: richard.gayraud@free.fr
Email: rgayraud@cisco.com
Benoit Lourdelet Benoit Lourdelet
Cisco Systems, Inc. Cisco Systems, Inc.
Village ent. GreenSide, Bat T3, Village ent. GreenSide, Bat T3,
400, Av de Roumanille, 400, Av de Roumanille,
06410 BIOT - Sophia-Antipolis Cedex 06410 BIOT - Sophia-Antipolis Cedex
France France
Phone: +33 4 97 23 26 23 Phone: +33 4 97 23 26 23
Email: blourdel@cisco.com Email: blourdel@cisco.com
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights 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; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
 End of changes. 19 change blocks. 
42 lines changed or deleted 48 lines changed or added

This html diff was produced by rfcdiff 1.35. The latest version is available from http://tools.ietf.org/tools/rfcdiff/