draft-ietf-ntp-dhcpv6-ntp-opt-06.txt   rfc5908.txt 
Network Working Group R. Gayraud Internet Engineering Task Force (IETF) R. Gayraud
Internet-Draft Request for Comments: 5908 Unaffiliated
Intended status: Standards Track B. Lourdelet Category: Standards Track B. Lourdelet
Expires: July 11, 2010 Cisco Systems, Inc. ISSN: 2070-1721 Cisco Systems, Inc.
January 7, 2010 June 2010
Network Time Protocol (NTP) Server Option for DHCPv6 Network Time Protocol (NTP) Server Option for DHCPv6
draft-ietf-ntp-dhcpv6-ntp-opt-06.txt
Abstract Abstract
The NTP Server Option for Dynamic Host Configuration Protocol for The NTP Server Option for Dynamic Host Configuration Protocol for
IPv6 (DHCPv6) provides NTP (Network Time Protocol version 4) Server IPv6 (DHCPv6) provides NTPv4 (Network Time Protocol version 4) server
location information to DHCPv6 hosts. location information to DHCPv6 hosts.
Status of this Memo Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
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http://www.ietf.org/shadow.html. (IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on July 11, 2010. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5908.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction ....................................................2
2. Requirements notation . . . . . . . . . . . . . . . . . . . . 4 2. Requirements Notation ...........................................2
3. Related Work and Usage Model . . . . . . . . . . . . . . . . . 4 3. Related Work and Usage Model ....................................2
4. NTP Server Option for DHCPv6 . . . . . . . . . . . . . . . . . 4 4. NTP Server Option for DHCPv6 ....................................3
4.1. NTP Server Address Suboption . . . . . . . . . . . . . . . 6 4.1. NTP Server Address Suboption ...............................4
4.2. NTP Multicast Address Suboption . . . . . . . . . . . . . 6 4.2. NTP Multicast Address Suboption ............................5
4.3. NTP Server FQDN Suboption . . . . . . . . . . . . . . . . 7 4.3. NTP Server FQDN Suboption ..................................6
5. Appearance of this Option . . . . . . . . . . . . . . . . . . 8 5. Appearance of This Option .......................................6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations .........................................7
7. RFC 4075 Deprecation . . . . . . . . . . . . . . . . . . . . . 8 7. RFC 4075 Deprecation ............................................7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 8. IANA Considerations .............................................7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. References ......................................................8
9.1. Normative References . . . . . . . . . . . . . . . . . . . 9 9.1. Normative References .......................................8
9.2. Informative References . . . . . . . . . . . . . . . . . . 9 9.2. Informative References .....................................8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. 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 [RFC5905] or greater server
Server location information to DHCPv6 hosts. location information to DHCPv6 hosts.
2. Requirements notation 2. 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].
3. Related Work and Usage Model 3. Related Work and Usage Model
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 should not be abused, organizations. Those servers can be used but should not be abused,
so any method which is tasked to disseminate locations of NTP Servers so any method that is tasked to disseminate locations of NTP servers
must act responsibly in a manner that does not lead to public Server must 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 host with a hardcoded configuration, there is a need to distribute a host with a hardcoded configuration,
this configuration MUST NOT include Server location that is not part this configuration MUST NOT include server location that is not part
of the organization that distributes this device. Typical usage of of the organization that distributes this device. Typical usage of
this option is to specify an NTP Server that is part of the this option is to specify an NTP server that is part of the
organization that operates the DHCPv6 Server. organization that operates the DHCPv6 server.
The location of the NTP service, like any other Internet service, can The location of the NTP service, like any other Internet service, can
be specified by an IP address or a Fully Qualified Domain Name be specified by an IP address or a Fully Qualified Domain Name
(FQDN). By design, DHCP offers information to multiple devices and (FQDN). By design, DHCP offers information to multiple devices and
is prone to amplification of mistakes, so great care must be taken to is prone to amplification of mistakes, so great care must be taken to
define its configuration. Specification of the NTP service by FQDN define its configuration. Specification of the NTP service by FQDN
offers a level of indirection that works as a possible mitigation offers a level of indirection that works as a possible mitigation
tool in case of misconfiguration. DNS can be used to redirect tool in case of misconfiguration. DNS can be used to redirect
misconfigured clients to an IPv6 address that is not configured on misconfigured clients to an IPv6 address that is not configured on
any host instead of having to change the address of the NTP Server any host instead of having to change the address of the NTP server
itself. itself.
While the NTP specification defines a comprehensive set of While the NTP specification defines a comprehensive set of
configuration parameters, modification of those parameters is best configuration parameters, modification of those parameters is best
left to the decision of the client itself. The DHCPv6 option for NTP left to the decision of the client itself. The DHCPv6 option for NTP
is therefore restricted to Server location. is therefore restricted to server location.
4. NTP Server Option for DHCPv6 4. NTP Server Option for DHCPv6
This option serves as a container for Server location information This option serves as a container for server location information
related to one NTP Server or Simple Network Time Protocol (SNTP) related to one NTP server or Simple Network Time Protocol (SNTP)
[RFC4330] server. This option can appear multiple times in a DHCPv6
[RFC4330] Server. This option can appear multiple times in a DHCPv6
message. Each instance of this option is to be considered by the NTP message. Each instance of this option is to be considered by the NTP
client or SNTP client as a Server to include in its configuration. client or SNTP client as a server to include in its configuration.
The option itself does not contain any value. Instead, it contains The option itself does not contain any value. Instead, it contains
one or several suboptions that carry NTP Server or SNTP Server Server one or several suboptions that carry NTP server or SNTP server
location. This option MUST include one, and only one, time source location. This option MUST include one, and only one, time source
suboption. The currently defined time source suboptions are: suboption. The currently defined time source suboptions are
NTP_OPTION_SRV_ADDR, NTP_OPTION_SRV_MC_ADDR, NTP_OPTION_SRV_FQDN. It NTP_OPTION_SRV_ADDR, NTP_OPTION_SRV_MC_ADDR, and NTP_OPTION_SRV_FQDN.
carries the NTP Server or SNTP Server location, as a unicast or It carries the NTP server or SNTP server location as a unicast or
multicast IPv6 address or as an NTP Server or SNTP Server FQDN. More multicast IPv6 address or as an NTP server or SNTP server FQDN. More
time source suboptions may be defined in the future. While the FQDN time source suboptions may be defined in the future. While the FQDN
option offers the most deployment flexibility, resiliency as well as option offers the most deployment flexibility, resiliency as well as
security, the IP address options are defined to cover cases where a security, the IP address options are defined to cover cases where a
DNS dependancy is not desirable. DNS dependency is not desirable.
If the NTP Server or SNTP Server location is an IPv6 multicast If the NTP server or SNTP server location is an IPv6 multicast
address, the client SHOULD use this address as an NTP multicast group address, the client SHOULD use this address as an NTP multicast group
address and listen to messages sent to this group in order to address and listen to messages sent to this group in order to
synchronize its clock. synchronize its clock.
The format of the NTP Server Option is: The format of the NTP Server Option is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_NTP_SERVER | option-len | | OPTION_NTP_SERVER | option-len |
skipping to change at page 5, line 45 skipping to change at page 4, line 24
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboption-2 | | suboption-2 |
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboption-n | | suboption-n |
: : : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code: OPTION_NTP_SERVER (TBD_IANA), option-code: OPTION_NTP_SERVER (56),
option-len: Total length of the included suboptions. option-len: Total length of the included suboptions.
This document does not define any priority relationship between the This document does not define any priority relationship between the
client's embedded configuration (if any) and the NTP or SNTP Servers client's embedded configuration (if any) and the NTP or SNTP servers
discovered via this option. In particular, the client is allowed to discovered via this option. In particular, the client is allowed to
simultaneously use its own configured NTP Servers or SNTP Servers and simultaneously use its own configured NTP servers or SNTP servers and
the Servers discovered via DHCP. the servers discovered via DHCP.
4.1. NTP Server Address Suboption 4.1. 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 or option. It specifies the IPv6 unicast address of an NTP server or
SNTP Server available to the client. SNTP server available to the client.
The format of the NTP Server Address Suboption is: The format of the NTP Server Address Suboption is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NTP_SUBOPTION_SRV_ADDR | suboption-len = 16 | | NTP_SUBOPTION_SRV_ADDR | suboption-len = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| | | |
| IPv6 address of NTP Server | | IPv6 address of NTP server |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 address of the NTP Server: An IPv6 address, IPv6 address of the NTP server: An IPv6 address,
suboption-code: NTP_SUBOPTION_SRV_ADDR (1), suboption-code: NTP_SUBOPTION_SRV_ADDR (1),
suboption-len: 16. suboption-len: 16.
4.2. NTP Multicast Address Suboption 4.2. NTP Multicast 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 address of the IPv6 multicast group option. It specifies the IPv6 address of the IPv6 multicast group
address used by NTP on the local network. address used by NTP on the local network.
skipping to change at page 7, line 27 skipping to change at page 6, line 8
Multicast IPv6 address: An IPv6 address, Multicast IPv6 address: An IPv6 address,
suboption-code: NTP_SUBOPTION_MC_ADDR (2), suboption-code: NTP_SUBOPTION_MC_ADDR (2),
suboption-len: 16. suboption-len: 16.
4.3. NTP Server FQDN Suboption 4.3. NTP Server FQDN 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 FQDN of an NTP Server or SNTP Server option. It specifies the FQDN of an NTP server or SNTP server
available to the client. available to the client.
The format of the NTP Server FQDN Suboption is: The format of the NTP Server FQDN Suboption is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NTP_SUBOPTION_SRV_FQDN | suboption-len | | NTP_SUBOPTION_SRV_FQDN | suboption-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| 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 Qualified Domain Name of the NTP Server or SNTP Server. FQDN: Fully-Qualified Domain Name of the NTP server or SNTP server.
This field MUST be encoded as described in [RFC3315], This field MUST be encoded as described in [RFC3315],
section 8. Internationalized Domain Name are not allowed Section 8. Internationalized domain names are not allowed
in this field. in this field.
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 preferred 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 MUST 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
a malicious NTP Server or SNTP Server and adversely affect the clock a malicious NTP server or SNTP server and adversely affect the clock
of clients on the network. The consequences of such an attack can be of clients on the network. The consequences of such an attack can be
critical, because many security protocols depend on time critical, because many security protocols depend on time
synchronization to run their algorithms. As an example, an attacker synchronization to run their algorithms. As an example, an attacker
could break connectivity between SEND-enabled nodes [RFC3971], simply could break connectivity between SEND-enabled nodes [RFC3971], simply
by affecting the clock on these nodes. by affecting the clock on these nodes.
To prevent these attacks, it is strongly advisable to secure the use To prevent these attacks, it is strongly advisable to secure the use
of this option either by: of this option by either:
- using the NTPv4 Autokey public key authentication, as defined - using the NTPv4 Autokey public key authentication, as defined in
in [draft-autokey] or, [RFC5906] or,
- using authenticated DHCP as described in [RFC3315] section 21. - using authenticated DHCP as described in [RFC3315], Section 21.
7. RFC 4075 Deprecation 7. RFC 4075 Deprecation
[RFC4075] (SNTP Configuration Option for DHCPv6) provides some degree "Simple Network Time Protocol (SNTP) Configuration Option for DHCPv6"
of automatic time Server configuration for IPv6, as it specifies how [RFC4075] provides some degree of automatic time server configuration
to transmit SNTP [RFC4330] Servers addresses through DHCPv6. However for IPv6, as it specifies how to transmit SNTP [RFC4330] server
this approach is not suitable for all NTP deployments. It is not an addresses through DHCPv6. However, this approach is not suitable for
extensible mechanism and introduces some semantic confusion throught all NTP deployments. It is not an extensible mechanism and
the use of the "SNTP" acronym. Additionally the approach of only introduces some semantic confusion through the use of the "SNTP"
offering IPv6 addresses to specify Server location does not meet NTP acronym. Additionally, the approach of only offering IPv6 addresses
requirements that make use of a FQDN (Fully Qualified Domain Name) as to specify server location does not meet NTP requirements that make
well. For all the abovementioned reasons, this document makes use of an FQDN (Fully-Qualified Domain Name) as well. For all the
[RFC4075] deprecated. abovementioned reasons, this document makes [RFC4075] deprecated.
8. IANA Considerations 8. IANA Considerations
When this document is published, the IANA is requested to assign an IANA has assigned 56 as an option code from the "DHCPv6 Options
option code from the "DHCPv6 Options Codes" registry for Codes" registry for OPTION_NTP_SERVER.
OPTION_NTP_SERVER.
IANA is required to maintain a new number space of NTP time source IANA is required to maintain a new number space of NTP time source
suboptions, located in the BOOTP-DHCP Parameters Registry. The suboptions, located in the BOOTP-DHCP Parameters Registry. The
initial suboptions are described in section 4 of this document. IANA initial suboptions are described in Section 4 of this document. IANA
assigns future NTP time source suboptions with a "IETF Consensus" assigns future NTP time source suboptions with an "IETF Consensus"
policy as described in [RFC5226]. Future proposed suboptions are to policy as described in [RFC5226]. Future proposed suboptions are to
be referenced symbolically in the Internet-Drafts that describe them, be referenced symbolically in the documents that describe them, and
and shall be assigned numeric codes by IANA when approved for shall be assigned numeric codes by IANA when approved for publication
publication as an RFC. as an RFC.
9. References 9. References
9.1. Normative References 9.1. 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., [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.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
[draft-ntpv4] [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
Burbank, J., Kasch, W., Martin, J., and D. Mills, "Network "Network Time Protocol Version 4: Protocol and Algorithms
Time Protocol Version 4 Protocol And Algorithms Specification", RFC 5905, June 2010.
Specification", draft-ietf-ntp-ntpv4-proto-11 (work in
progress), September 2008.
[draft-autokey] [RFC5906] Haberman, B., Ed. and D. Mills, "Network Time Protocol
Haberman, B. and D. Mills, "Network Time Protocol Version Version 4: Autokey Specification", RFC 5906, June 2010.
4 Autokey Specification", draft-ietf-ntp-autokey-06 (work
in progress), July 2009.
9.2. Informative References 9.2. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
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
Unaffiliated
Email: richard.gayraud@free.fr EMail: richardgayraud@free.fr
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
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