Network Working Group J. Manner Internet-Draft TKK Updates: RFC2113, RFC3175 A. McDonald (if approved) Siemens/Roke Intended status: Standards Track May 29, 2008 Expires: November 30, 2008 IANA Considerations for the IPv4 and IPv6 Router Alert Option draft-manner-router-alert-iana-03 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 November 30, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This document updates the IANA allocation rules and registry of IPv4 and IPv6 Router Alert Option Values. Manner & McDonald Expires November 30, 2008 [Page 1] Internet-Draft IANA Considerations for Router Alert May 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Use of the Router Alert Option Value Field . . . . . . . . . . 3 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 3.1. IANA Considerations for IPv4 Router Alert Option Values . . 5 3.2. IANA Considerations for IPv6 Router Alert Option Values . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.1. Normative References . . . . . . . . . . . . . . . . . . . 7 6.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . . 9 Manner & McDonald Expires November 30, 2008 [Page 2] Internet-Draft IANA Considerations for Router Alert May 2008 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. There can be up to 65536 values for the RAO. Yet, currently there is only a registry for IPv6 values. No registry or allocation policies are defined for IPv4. This document proposes updates to the IANA registry for managing IPv4 and IPv6 Router Alert Option Values, and proposes to remove one existing IPv6 Router Alert Option value. 2. Use of the Router Alert Option Value Field One difference between the specifications for the IPv4 and IPv6 Router Alert Options is the way 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. Neither a management mechanism (e.g., such as an IANA registry) nor an allocation policy are provided for the IPv4 RAO values. The IPv6 Router Alert Option has an IANA managed registry [IANA-IPv6RAO] containing allocations for the value field. In [RFC3175] the IPv4 Router Alert Option Value is described as a parameter that 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 IANA for indicating reservation levels. However, since other registrations had already been made in that registry these values are from 3-35 (that is actually a set of 33 values). Although it might have been desirable to have the same values being used in both the IPv4 and IPv6 registries, the initial allocations in Manner & McDonald Expires November 30, 2008 [Page 3] Internet-Draft IANA Considerations for Router Alert May 2008 [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] | | 36-65534 | Reserved | Reserved to IANA for future | | | | assignment | | 65535 | Reserved | Reserved [IANA-IPv6RAO] | +----------+-------------------------+------------------------------+ Note (*): The entry in the above table for the IPv6 RAO Value of 35 (Aggregated Reservation Nesting Level 32) has been marked due to an Manner & McDonald Expires November 30, 2008 [Page 4] Internet-Draft IANA Considerations for Router Alert May 2008 inconsistency in the text of [RFC3175], and that 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]). 3. IANA Considerations This section contains the proposed new procedures for managing IPv4 Router Alert Option values. This requires the creation of a registry for IPv4 Router Alert Option Values (described in Section 3.1) and updates the IPv6 Router Alert Option Values (described in Section 3.2). IP Router Alert Option values are currently managed separately for IPv4 and IPv6. This should not change, as there has been seen little value in forcing the two registry to be aligned. 3.1. 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 | [RFC2113] | | 1-32 | Aggregated Reservation Nesting Level | [RFC3175] | | 33-65502 | Available for assignment by the IANA | | | 65503-65534 | Available for experimental use | | | 65535 | Reserved | | +-------------+--------------------------------------+-----------+ New values are to be assigned via IETF Review as defined in [RFC5226]. 3.2. 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]. In addition, the following value should be removed from the IANA registry and reserved for possible future use (not to be allocated Manner & McDonald Expires November 30, 2008 [Page 5] Internet-Draft IANA Considerations for Router Alert May 2008 currently). The reason is that it is a duplicate value, aggregation level 0 means end-to-end signaling, and this already has an IPv6 RAO value "1" assigned. +-------+--------------------------+-----------+ | Value | Description | Reference | +-------+--------------------------+-----------+ | 3 | RSVP Aggregation level 0 | [RFC3175] | +-------+--------------------------+-----------+ The following IPv6 RAO values should be made available for experimental use: +-------------+------------------+-----------+ | Value | Description | Reference | +-------------+------------------+-----------+ | 65503-65534 | Experimental use | | +-------------+------------------+-----------+ 4. Security Considerations Since this document is only concerned with the IANA management of the IPv4 and IPv6 Router Alert Option values registry it raises no new security issues beyond those identified in [RFC2113] and [RFC2711]. Yet, as discussed in RFC 4727 [RFC4727] production networks do not necessarily support the use of experimental code points in IP option headers. The network scope of support for experimental values should carefully be evaluated before deploying any experimental RAO value across extended network domains, such as the public Internet. The potential to disrupt the stable operation of the network hosting the experiment through the use of unsupported experimental code points is a serious consideration when planning an experiment using such code points. When experimental RAO values are deployed within an administratively self-contained network domain, the network administrators should ensure that each value is used consistently to avoid interference between experiments. When experimental values are used in traffic that crosses multiple administrative domains, the experimenters should assume that there is a risk that the same values will be used simultaneously by other experiments and thus that there is a possibility that the experiments will interfere. Particular attention should be given to security threats that such interference might create. Manner & McDonald Expires November 30, 2008 [Page 6] Internet-Draft IANA Considerations for Router Alert May 2008 5. Acknowledgements Thanks to Robert Hancock, Martin Stiemerling, Alan Ford and Francois Le Faucheur for their helpful comments on this document. 6. References 6.1. Normative References [IANA-IPv6RAO] "IANA Registry for Internet Protocol version 6 (IPv6) Router Alert Option Values" . [RFC2113] Katz, D., "IP Router Alert Option", RFC 2113, February 1997. [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. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. 6.2. 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", RFC 4286, December 2005. [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, Manner & McDonald Expires November 30, 2008 [Page 7] Internet-Draft IANA Considerations for Router Alert May 2008 ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. [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. Authors' Addresses Jukka Manner Helsinki University of Technology (TKK) P.O. Box 3000 Espoo FIN-02015 TKK Finland Phone: +358 9 451 2481 Email: jukka.manner@tkk.fi Andrew McDonald Roke Manor Research Ltd (a Siemens company) Old Salisbury Lane Romsey, Hampshire SO51 0ZN United Kingdom Email: andrew.mcdonald@roke.co.uk Manner & McDonald Expires November 30, 2008 [Page 8] Internet-Draft IANA Considerations for Router Alert May 2008 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. 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