draft-ietf-ipv6-ra-flags-option-02.txt | rfc5075.txt | |||
---|---|---|---|---|
Network Working Group B. Haberman, Ed. | Network Working Group B. Haberman, Ed. | |||
Internet-Draft JHU APL | Request for Comments: 5075 JHU APL | |||
Intended status: Standards Track R. Hinden | Category: Standards Track R. Hinden | |||
Expires: March 16, 2008 Nokia | Nokia | |||
September 13, 2007 | November 2007 | |||
IPv6 Router Advertisement Flags Option | IPv6 Router Advertisement Flags Option | |||
draft-ietf-ipv6-ra-flags-option-02 | ||||
Status of this Memo | ||||
By submitting this Internet-Draft, each author represents that any | ||||
applicable patent or other IPR claims of which he or she is aware | ||||
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The list of Internet-Draft Shadow Directories can be accessed at | Status of This Memo | |||
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This Internet-Draft will expire on March 16, 2008. | ||||
Copyright Notice | ||||
Copyright (C) The IETF Trust (2007). | This document specifies an Internet standards track protocol for the | |||
Internet community, and requests discussion and suggestions for | ||||
improvements. Please refer to the current edition of the "Internet | ||||
Official Protocol Standards" (STD 1) for the standardization state | ||||
and status of this protocol. Distribution of this memo is unlimited. | ||||
Abstract | Abstract | |||
The IPv6 Neighbor Discovery's Router Advertisement message contains | The IPv6 Neighbor Discovery's Router Advertisement message contains | |||
an 8-bit field reserved for single-bit flags. Several protocols have | an 8-bit field reserved for single-bit flags. Several protocols have | |||
reserved flags in this field and others are preparing to reserve a | reserved flags in this field and others are preparing to reserve a | |||
sufficient number of flags to exhaust the field. This document | sufficient number of flags to exhaust the field. This document | |||
defines an option to the Router Advertisement message that expands | defines an option to the Router Advertisement message that expands | |||
the available number of flag bits available. | the available number of flag bits available. | |||
Table of Contents | Table of Contents | |||
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 | 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
3. Current Router Advertisement Flags . . . . . . . . . . . . . . 3 | 3. Current Router Advertisement Flags . . . . . . . . . . . . . . 2 | |||
4. Flags Expansion Option . . . . . . . . . . . . . . . . . . . . 4 | 4. Flags Expansion Option . . . . . . . . . . . . . . . . . . . . 3 | |||
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 | 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 | |||
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 | 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 | |||
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 | 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
7.1. Normative References . . . . . . . . . . . . . . . . . . . 6 | 7.1. Normative References . . . . . . . . . . . . . . . . . . . 5 | |||
7.2. Informative References . . . . . . . . . . . . . . . . . . 6 | 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 | |||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 | ||||
Intellectual Property and Copyright Statements . . . . . . . . . . 8 | ||||
1. Introduction | 1. Introduction | |||
The IPv6 Neighbor Discovery Protocol's [1] Router Advertisement | The IPv6 Neighbor Discovery Protocol's (NDP) [RFC4861] Router | |||
message contains an 8-bit field reserved for single-bit flags. | Advertisement message contains an 8-bit field reserved for single-bit | |||
Several protocols have reserved flags in this field and others are | flags. Several protocols have reserved flags in this field and | |||
preparing to reserve a sufficient number of flags to exhaust the | others are preparing to reserve a sufficient number of flags to | |||
field. | exhaust the field. | |||
This document defines an option for the Router Advertisement message | This document defines an option for the Router Advertisement message | |||
that expands the available number of flag bits by adding an | that expands the available number of flag bits by adding an | |||
additional 48 flag bits to NDP messages. | additional 48 flag bits to NDP messages. | |||
2. Terminology | 2. Terminology | |||
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 [2]. | document are to be interpreted as described in [RFC2119]. | |||
3. Current Router Advertisement Flags | 3. Current Router Advertisement Flags | |||
Currently, the NDP Router Advertisement message contains the | Currently, the NDP Router Advertisement message contains the | |||
following one-bit flags defined in published RFCs: | following one-bit flags defined in published RFCs: | |||
0 1 2 3 4 5 6 7 | 0 1 2 3 4 5 6 7 | |||
+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+ | |||
|M|O|H|Prf|P|R|R| | |M|O|H|Prf|P|R|R| | |||
+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+ | |||
Figure 1: Router Advertisement Flags | Figure 1: Router Advertisement Flags | |||
o M - Managed Address Configuration Flag [1] | o M - Managed Address Configuration Flag [RFC4861] | |||
o O - Other Configuration Flag [1] | o O - Other Configuration Flag [RFC4861] | |||
o H - Mobile IPv6 Home Agent Flag [4] | o H - Mobile IPv6 Home Agent Flag [RFC3775] | |||
o Prf - Router Selection Preferences [5] | o Prf - Router Selection Preferences [RFC4191] | |||
o P - Neighbor Discovery Proxy Flag [6] | o P - Neighbor Discovery Proxy Flag [RFC4389] | |||
o R - Reserved | o R - Reserved | |||
With other protocols in the works (e.g., Detecting Network | With other protocols in the works (e.g., Detecting Network | |||
Attachment) that are wanting to use flags in the NDP messages, it is | Attachment) that want to use flags in the NDP messages, it is | |||
necessary to define an expansion capability to support new features. | necessary to define an expansion capability to support new features. | |||
4. Flags Expansion Option | 4. Flags Expansion Option | |||
The Neighbor Discovery specification [1] contains the capability to | The Neighbor Discovery specification [RFC4861] contains the | |||
define NDP options. The following (Figure 2) is the definition of | capability to define NDP options. The following (Figure 2) is the | |||
the Expanded Flags Option (EFO) for NDP Router Advertisement | definition of the Expanded Flags Option (EFO) for NDP Router | |||
messages. | Advertisement messages. | |||
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 | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| Type | Length | Bit fields available .. | | Type | Length | Bit fields available .. | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
... for assignment | | ... for assignment | | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
Figure 2: Router Advertisement Expanded Flags Option | Figure 2: Router Advertisement Expanded Flags Option | |||
skipping to change at page 4, line 37 | skipping to change at page 3, line 37 | |||
MUST ignore any unrecognized data, and MUST be able to recognize | MUST ignore any unrecognized data, and MUST be able to recognize | |||
the specific length in order to skip over unrecognized bits. | the specific length in order to skip over unrecognized bits. | |||
o Bits - allocated by IANA | o Bits - allocated by IANA | |||
The definition and usage of these bits is to be found in the document | The definition and usage of these bits is to be found in the document | |||
requesting their allocation. | requesting their allocation. | |||
During the construction/transmission, this option: | During the construction/transmission, this option: | |||
o MUST only occur in Router Advertisement messages | o MUST only occur in Router Advertisement messages. | |||
o MUST occur prior to any additional options associated with any | o MUST occur prior to any additional options associated with any | |||
flags set in this option | flags set in this option. | |||
o MUST only occur once in the Router Advertisement message | o MUST only occur once in the Router Advertisement message. | |||
o MUST NOT be added to a Router Advertisement message if no flags in | o MUST NOT be added to a Router Advertisement message if no flags in | |||
the option are set | the option are set. | |||
o MUST set all unused flags to zero. | o MUST set all unused flags to zero. | |||
Upon reception, a receiver processing NDP messages containing this | Upon reception, a receiver processing NDP messages containing this | |||
option: | option: | |||
o MUST ignore the option if it occurs in a message other than a | o MUST ignore the option if it occurs in a message other than a | |||
Router Advertisement | Router Advertisement. | |||
o MUST ignore all instances of the option except the first one | o MUST ignore all instances of the option except the first one | |||
encountered in the Router Advertisement message | encountered in the Router Advertisement message. | |||
o MUST ignore the option if the Length is less than 1 | o MUST ignore the option if the Length is less than 1. | |||
o MUST ignore any unknown flag bits. | o MUST ignore any unknown flag bits. | |||
The bit fields within the option are numbered from left to right from | The bit fields within the option are numbered from left to right, | |||
8 to 55 (starting as bit offset 16 in the option) and follow the | from 8 to 55 (starting as bit offset 16 in the option) and follow the | |||
numbering of the flag bits in the RA option described in Figure 1. | numbering of the flag bits in the RA option described in Figure 1. | |||
Flag bits 0 to 7 are found in the Router Advertisement message header | Flag bits 0 to 7 are found in the Router Advertisement message header | |||
defined in [1] | defined in [RFC4861]. | |||
5. IANA Considerations | 5. IANA Considerations | |||
The IANA is requested to define a new IPv6 Neighbor Discovery option | IANA has defined a new IPv6 Neighbor Discovery option for the option | |||
for the option defined in this document of the form: | defined in this document of the form: | |||
+------+---------------------------+-----------+ | +------+---------------------------+-----------+ | |||
| Type | Description | Reference | | | Type | Description | Reference | | |||
+------+---------------------------+-----------+ | +------+---------------------------+-----------+ | |||
| TBA | RA Flags Extension Option | [RFCXXXX] | | | 26 | RA Flags Extension Option | [RFC5075] | | |||
+------+---------------------------+-----------+ | +------+---------------------------+-----------+ | |||
The registry for these options can be found at: | The registry for these options can be found at: | |||
http://www.iana.org/assignments/icmpv6-parameters | http://www.iana.org/assignments/icmpv6-parameters | |||
The IANA is requested to create a new registry for IPv6 ND Router | IANA has created a new registry for IPv6 ND Router Advertisement | |||
Advertisement flags. This should include the current flags in the RA | flags. This should include the current flags in the RA option and in | |||
option and in the extension option defined in this document. It is | the extension option defined in this document. The new registry has | |||
suggested the new registry be added to the icmpv6-parameters as shown | been added to the icmpv6-parameters as shown above. The format for | |||
above. The format for the registry is: | the registry is: | |||
+---------------+---------------------------------------+-----------+ | +---------------+---------------------------------------+-----------+ | |||
| RA Option Bit | Description | Reference | | | RA Option Bit | Description | Reference | | |||
+---------------+---------------------------------------+-----------+ | +---------------+---------------------------------------+-----------+ | |||
| 0 | M - Managed Address Configuration | [1] | | | 0 | M - Managed Address Configuration | [RFC4861] | | |||
| | Flag | | | | | Flag | | | |||
| 1 | O - Other Configuration Flag | [1] | | | 1 | O - Other Configuration Flag | [RFC4861] | | |||
| 2 | H - Mobile IPv6 Home Agent Flag | [4] | | | 2 | H - Mobile IPv6 Home Agent Flag | [RFC3775] | | |||
| 3 | Prf - Router Selection Preferences | [5] | | | 3 | Prf - Router Selection Preferences | [RFC4191] | | |||
| 4 | Prf - Router Selection Preferences | [5] | | | 4 | Prf - Router Selection Preferences | [RFC4191] | | |||
| 5 | P - Neighbor Discovery Proxy Flag | [6] | | | 5 | P - Neighbor Discovery Proxy Flag | [RFC4389] | | |||
| 6-53 | R - Reserved; Available for | | | | 6-53 | R - Reserved; Available for | | | |||
| | assignment | | | | | assignment | | | |||
| 54-55 | Private Experimentation | | | | 54-55 | Private Experimentation | | | |||
+---------------+---------------------------------------+-----------+ | +---------------+---------------------------------------+-----------+ | |||
The assignment of new RA flags in the RA option header and for the | The assignment of new RA flags in the RA option header and the bits | |||
bits defined in the RA extension option defined in this document | defined in the RA extension option defined in this document require | |||
require standards action or IESG approval[3]. | standards action or IESG approval [RFC2434]. | |||
6. Security Considerations | 6. Security Considerations | |||
This protocol shares the security issues of NDP that are documented | This protocol shares the security issues of NDP that are documented | |||
in the "Security Considerations" section of [1]. | in the "Security Considerations" section of [RFC4861]. | |||
The inclusion of additional optional bit fields provides a potential | The inclusion of additional optional bit fields provides a potential | |||
covert channel useful for passing information. | covert channel that is useful for passing information. | |||
7. References | 7. References | |||
7.1. Normative References | 7.1. Normative References | |||
[1] Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
for IP Version 6 (IPv6)", RFC 2461, December 1998. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement | [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an | |||
Levels", BCP 14, RFC 2119, March 1997. | IANA Considerations Section in RFCs", BCP 26, RFC 2434, | |||
October 1998. | ||||
[3] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA | [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, | |||
Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. | "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, | |||
September 2007. | ||||
7.2. Informative References | 7.2. Informative References | |||
[4] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in | [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support | |||
IPv6", RFC 3775, June 2004. | in IPv6", RFC 3775, June 2004. | |||
[5] Draves, R. and D. Thaler, "Default Router Preferences and More- | [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and | |||
Specific Routes", RFC 4191, November 2005. | More-Specific Routes", RFC 4191, November 2005. | |||
[6] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery | [RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery | |||
Proxies (ND Proxy)", RFC 4389, April 2006. | Proxies (ND Proxy)", RFC 4389, April 2006. | |||
Authors' Addresses | Authors' Addresses | |||
Brian Haberman (editor) | Brian Haberman (editor) | |||
Johns Hopkins University Applied Physics Lab | Johns Hopkins University Applied Physics Lab | |||
11100 Johns Hopkins Road | 11100 Johns Hopkins Road | |||
Laurel, MD 20723-6099 | Laurel, MD 20723-6099 | |||
USA | USA | |||
Phone: +1 443 778 1319 | Phone: +1 443 778 1319 | |||
Email: brian@innovationslab.net | EMail: brian@innovationslab.net | |||
Robert Hinden | Robert Hinden | |||
Nokia | Nokia | |||
313 Fairchild Drive | 313 Fairchild Drive | |||
Mountain View, CA 94043 | Mountain View, CA 94043 | |||
USA | USA | |||
Phone: +1 650 625 2004 | Phone: +1 650 625 2004 | |||
Email: bob.hinden@nokia.com | EMail: bob.hinden@nokia.com | |||
Full Copyright Statement | Full Copyright Statement | |||
Copyright (C) The IETF Trust (2007). | Copyright (C) The IETF Trust (2007). | |||
This document is subject to the rights, licenses and restrictions | This document is subject to the rights, licenses and restrictions | |||
contained in BCP 78, and except as set forth therein, the authors | contained in BCP 78, and except as set forth therein, the authors | |||
retain all their rights. | retain all their rights. | |||
This document and the information contained herein are provided on an | This document and the information contained herein are provided on an | |||
skipping to change at page 8, line 44 | skipping to change at line 280 | |||
attempt made to obtain a general license or permission for the use of | attempt made to obtain a general license or permission for the use of | |||
such proprietary rights by implementers or users of this | such proprietary rights by implementers or users of this | |||
specification can be obtained from the IETF on-line IPR repository at | specification can be obtained from the IETF on-line IPR repository at | |||
http://www.ietf.org/ipr. | http://www.ietf.org/ipr. | |||
The IETF invites any interested party to bring to its attention any | The IETF invites any interested party to bring to its attention any | |||
copyrights, patents or patent applications, or other proprietary | copyrights, patents or patent applications, or other proprietary | |||
rights that may cover technology that may be required to implement | rights that may cover technology that may be required to implement | |||
this standard. Please address the information to the IETF at | this standard. Please address the information to the IETF at | |||
ietf-ipr@ietf.org. | ietf-ipr@ietf.org. | |||
Acknowledgment | ||||
Funding for the RFC Editor function is provided by the IETF | ||||
Administrative Support Activity (IASA). | ||||
End of changes. 41 change blocks. | ||||
100 lines changed or deleted | 78 lines changed or added | |||
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