Network Working Group A. McDonald Internet-Draft Siemens/Roke Updates: RFC2113, RFC2711 (if October 16, 2006 approved) Intended status: Standards Track Expires: April 19, 2007 IANA Considerations for the IPv4 and IPv6 Router Alert Option draft-mcdonald-nsis-router-alert-iana-00 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 have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 April 19, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document provides new instructions to IANA on the allocation of IPv4 and IPv6 Router Alert Option Values. McDonald Expires April 19, 2007 [Page 1]
Internet-Draft IANA Considerations for Router Alert October 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements notation . . . . . . . . . . . . . . . . . . . . . 3 3. Use of the Router Alert Option Value Field . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 4.1. IANA Considerations for IPv4 Router Alert Option Values . . 5 4.2. IANA Considerations for IPv6 Router Alert Option Values . . 6 5. Alternative Proposals . . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . . 9 McDonald Expires April 19, 2007 [Page 2]
Internet-Draft IANA Considerations for Router Alert October 2006 1. Introduction The IP Router Alert Option is defined for IPv4 in [RFC2113]. A similar IPv6 option is defined in [RFC2711]. When one of these options is present in an IP datagram, it indicates that the contents of the datagram may be interesting to routers. The Router Alert Option (RAO) is used by protocols such as RSVP [RFC2205] and IGMP [RFC3376]. Both the IPv4 and IPv6 option contain a two octet value field to carry extra information. This information can be used, for example, by routers to determine whether or not the packet should be more closely examined by them. This document proposes the creation of a new IANA registry for managing IPv4 Router Alert Option Values. In conjunction with this, it also proposes an update to the way in which IPv6 Router Alert Option Values are assigned in the existing IANA registry. 2. Requirements notation 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. Use of the Router Alert Option Value Field One difference betwen the specifications for the IPv4 and IPv6 Router Alert Options is the way in which values for the value field are managed. In [RFC2113], the IPv4 Router Alert Option value field has the value 0 assigned to "Router shall examine packet". All other values (1-65535) are reserved. No mechanism is provided for the allocation of these values by IANA. The IPv6 Router Alert Option has an IANA managed registry [IANA-IPv6RAO] containing allocations for the value field. All values in this registry are assigned by IETF consensus. In [RFC3175] the IPv4 Router Alert Option Value is described as a parameter which provides "additional information" to the router in making its interception decision, rather than as a registry managed by IANA. As such, this aggregation mechanism makes use of the value field to carry the reservation aggregation level. For the IPv6 option, this document requests a set of 32 values to be assigned by McDonald Expires April 19, 2007 [Page 3]
Internet-Draft IANA Considerations for Router Alert October 2006 IANA for indicating reservation levels. However, since other registrations had already been made in that registry these values are from 3-35 (which is actually a set of 33 values). Although it would be strongly desirable to have the same values being used in both the IPv4 and IPv6 registries, the initial allocations in [RFC2711] and the aggregation level allocations in [RFC3175] have made this impossible. The following table shows the allocations in the IPv6 registry and values used in the IPv4 registry, where the latter have been deduced from [RFC2113] and [RFC3175] with the assumption that the number of aggregation levels can be limited to 32 as in the IPv6 case. Entries for values 6 to 31 have been elided for brevity. +----------+-------------------------+------------------------------+ | Value | IPv4 RAO Meaning | IPv6 RAO Meaning | +----------+-------------------------+------------------------------+ | 0 | Router shall examine | Datagram contains a | | | packet [RFC2113] | Multicast Listener Discovery | | | [RFC2205] [RFC3376] | message [RFC2711] [RFC2710] | | | [RFC4286] | [RFC4286] | | 1 | Aggregated Reservation | Datagram contains RSVP | | | Nesting Level 1 | message [RFC2711] [RFC2205] | | | [RFC3175] | | | 2 | Aggregated Reservation | Datagram contains an Active | | | Nesting Level 2 | Networks message [RFC2711] | | | [RFC3175] | [Schwartz2000] | | 3 | Aggregated Reservation | Aggregated Reservation | | | Nesting Level 3 | Nesting Level 0 [RFC3175] | | | [RFC3175] | | | 4 | Aggregated Reservation | Aggregated Reservation | | | Nesting Level 4 | Nesting Level 1 [RFC3175] | | | [RFC3175] | | | 5 | Aggregated Reservation | Aggregated Reservation | | | Nesting Level 5 | Nesting Level 2 [RFC3175] | | | [RFC3175] | | | ... | ... | ... | | 32 | Aggregated Reservation | Aggregated Reservation | | | Nesting Level 32 | Nesting Level 29 [RFC3175] | | | [RFC3175] | | | 33 | Reserved | Aggregated Reservation | | | | Nesting Level 30 [RFC3175] | | 34 | Reserved | Aggregated Reservation | | | | Nesting Level 31 [RFC3175] | | 35 | Reserved | Aggregated Reservation | | | | Nesting Level 32(?) | | | | [RFC3175] | McDonald Expires April 19, 2007 [Page 4]
Internet-Draft IANA Considerations for Router Alert October 2006 | 36-65534 | Reserved | Reserved to IANA for future | | | | use | | 65535 | Reserved | Reserved [IANA-IPv6RAO] | +----------+-------------------------+------------------------------+ The entry in the above table for the IPv6 RAO Value of 32 has been marked with a question mark due to an inconsistency in the text of [RFC3175], which is consequently reflected in the IANA registry. In that document the values 3-35 (i.e. 33 values) are defined for nesting levels 0-31 (i.e. 32 levels). It is unclear why nesting levels begin at 1 for IPv4 (described in section 1.4.9 of [RFC3175]) and 0 for IPv6 (allocated in section 6 of [RFC3175]). Although it is not possible to remedy the past inconsistency between the two sets of allocations, it is still preferable that future allocations should be made identically in both registries. 4. IANA Considerations This section contains the proposed new procedures for managing Router Alert Option Values. This requires the creation of a registry for IPv4 Router Alert Option Values (described in Section 4.1) and changes to the way in which IPv6 Router Alert Option Values are managed (described in Section 4.2). 4.1. IANA Considerations for IPv4 Router Alert Option Values The value field, as specified in [RFC2113] is two octets in length. The value field is registered and maintained by IANA. The initial contents of this registry are: +----------+--------------------------------------------+-----------+ | Value | Description | Reference | +----------+--------------------------------------------+-----------+ | 0 | Router shall examine packet | [RFC2119] | | 1-32 | Aggregated Reservation Nesting Level | [RFC3175] | | 33-35 | Reserved (not to be allocated) - Note: | | | | These values are allocated in the IPv6 | | | | Router Alert Option Values registry | | | 36-65534 | Reserved to IANA for future use | | | 65535 | Reserved | | +----------+--------------------------------------------+-----------+ New values are to be assigned via IETF Consensus as defined in [RFC2434]. When a new allocation is made in this registry an McDonald Expires April 19, 2007 [Page 5]
Internet-Draft IANA Considerations for Router Alert October 2006 identical registration MUST be made in the IPv6 Router Alert Option Values registry, or that value MUST be reserved. In the case that it is reserved rather than allocated, the registry entry should say "Reserved (not to be allocated) - Note: This value is allocated in the IPv6 Router Alert Options registry". 4.2. IANA Considerations for IPv6 Router Alert Option Values The registry for IPv6 Router Alert Option Values should continue to be maintained as specified in [RFC2711]. However, when a new allocation is made in this registry an identical registration MUST be made in the IPv4 Router Alert Option Values registry, or that value MUST be reserved. In the case that it is reserved rather than allocated, the registry entry should say "Reserved (not to be allocated) - Note: This value is allocated in the IPv4 Router Alert Options registry". 5. Alternative Proposals In Section 4 this document describes one way of modifying the Router Alert Option registry management, but this is not necessarily the only solution. One question that arises is what the intended status of this document should be. Currently this document is aimed as a standards track document, that modifies [RFC2113] and [RFC2711]. It is not clear whether this is the right option. A draft aimed at becoming a BCP might be an alternative. This document currently proposes the use of separate registries for IPv4 and IPv6 Router Alert Options, but with coordinated management of future allocations. This is mainly because of the differences in the existing allocation, e.g. for the 0 codepoint. An alternative proposal would be to use a single combined registry. It might also be desirable to align the Aggregated Reservation Nesting Levels, as defined in [RFC3175], for IPv4 and IPv6. Aggregated Nesting Level 1 for IPv4 would then need to move to using the codepoint 4, as in the IPv6 case. However, such a change may not be possible. 6. Security Considerations Since this document is only concerned with the IANA management of the IPv4 Router Alert Option values registry it raises no new security issues beyond those identified in [RFC2113] and [RFC2711]. McDonald Expires April 19, 2007 [Page 6]
Internet-Draft IANA Considerations for Router Alert October 2006 7. Acknowledgements Thanks to Robert Hancock, Martin Stiemerling and Alan Ford for their helpful comments on this document. 8. References 8.1. Normative References [IANA-IPv6RAO] "IANA Registry for Internet Protocol version 6 (IPv6) Router Alert Option Values" . <http://www.iana.org/assignments/ipv6-routeralert-values> [RFC2113] Katz, D., "IP Router Alert Option", RFC 2113, February 1997. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. [RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", RFC 2711, October 1999. [RFC3175] Baker, F., Iturralde, C., Le Faucheur, F., and B. Davie, "Aggregation of RSVP for IPv4 and IPv6 Reservations", RFC 3175, September 2001. 8.2. Informative References [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC2710] Deering, S., Fenner, W., and B. Haberman, "Multicast Listener Discovery (MLD) for IPv6", RFC 2710, October 1999. [RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A. Thyagarajan, "Internet Group Management Protocol, Version 3", RFC 3376, October 2002. [RFC4286] Haberman, B. and J. Martin, "Multicast Router Discovery", McDonald Expires April 19, 2007 [Page 7]
Internet-Draft IANA Considerations for Router Alert October 2006 RFC 4286, December 2005. [Schwartz2000] Schwartz, B., Jackson, A., Strayer, W., Zhou, W., Rockwell, D., and C. Partridge, "Smart Packets: Applying Active Networks to Network Management", ACM Transactions on Computer Systems (TOCS) Volume 18 , Issue 1, February 2000. Author's Address Andrew McDonald Roke Manor Research Ltd (a Siemens company) Old Salisbury Lane Romsey, Hampshire SO51 0ZN United Kingdom Email: andrew.mcdonald@roke.co.uk McDonald Expires April 19, 2007 [Page 8]
Internet-Draft IANA Considerations for Router Alert October 2006 Full Copyright Statement Copyright (C) The Internet Society (2006). 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 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). McDonald Expires April 19, 2007 [Page 9]