idnits 2.17.1 draft-krishnan-6man-header-reserved-bits-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords -- however, there's a paragraph with a matching beginning. Boilerplate error? (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). -- The document date (October 18, 2010) is 4939 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 6man Working Group S. Krishnan 3 Internet-Draft J. Halpern 4 Intended status: Standards Track Ericsson 5 Expires: April 21, 2011 October 18, 2010 7 Reserving bits in the IPv6 header for future use 8 draft-krishnan-6man-header-reserved-bits-00 10 Abstract 12 The IPv6 header does not contain any reserved bits for future 13 expansion. This document sets aside 4 bits from the flow label field 14 for future expansion. 16 Status of this Memo 18 This Internet-Draft is submitted in full conformance with the 19 provisions of BCP 78 and BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF). Note that other groups may also distribute 23 working documents as Internet-Drafts. The list of current Internet- 24 Drafts is at http://datatracker.ietf.org/drafts/current/. 26 Internet-Drafts are draft documents valid for a maximum of six months 27 and may be updated, replaced, or obsoleted by other documents at any 28 time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 This Internet-Draft will expire on April 21, 2011. 33 Copyright Notice 35 Copyright (c) 2010 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents 40 (http://trustee.ietf.org/license-info) in effect on the date of 41 publication of this document. Please review these documents 42 carefully, as they describe your rights and restrictions with respect 43 to this document. Code Components extracted from this document must 44 include Simplified BSD License text as described in Section 4.e of 45 the Trust Legal Provisions and are provided without warranty as 46 described in the Simplified BSD License. 48 Table of Contents 50 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 51 2. Conventions used in this document . . . . . . . . . . . . . . . 3 52 3. New IPv6 header format . . . . . . . . . . . . . . . . . . . . 3 53 4. Future use of the reserved bits . . . . . . . . . . . . . . . . 4 54 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 55 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 56 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 57 8. Normative References . . . . . . . . . . . . . . . . . . . . . 5 58 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 60 1. Introduction 62 The IPv6 header does not contain any reserved bits and all bits in 63 the header are currently accounted for. This means that it is not 64 possible to develop any future extension mechanisms that require bits 65 in the IPv6 header. Mechanisms such as ECN were possible in IPv4 66 because there were bits available in the IPv4 header. e.g. Re-ECN is 67 a proof of concept mechanism for ConEx that uses an unused bit (Bit 68 48) in the IPv4 header. It cannot be implemented analogously in the 69 IPv6 header. This document proposes reducing the size of the flow 70 label field from 20 bits to 16 bits and setting aside 4 bits for 71 future use. 73 2. Conventions used in this document 75 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT", 76 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 77 document are to be interpreted as described in [RFC2119]. 79 3. New IPv6 header format 81 This document updates Section 3 of [RFC2460] to reduce the length of 82 the flow label field from 20 bits to 16 bits, and in the process 83 creating a 4 bit reserved field. All other fields in the IPv6 header 84 remain unchanged from [RFC2460]. 86 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 87 |Version| Traffic Class | Resvd | Flow Label | 88 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 89 | Payload Length | Next Header | Hop Limit | 90 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 91 | | 92 + + 93 | | 94 + Source Address + 95 | | 96 + + 97 | | 98 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 99 | | 100 + + 101 | | 102 + Destination Address + 103 | | 104 + + 105 | | 106 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 108 Resvd 4-bit reserved field. 110 Flow Label 16-bit flow label. 112 All other fields are same as those defined by [RFC2460] 114 Figure 1: Modified IPv6 header format 116 Senders MUST set the bits in the reserved field to zero and receivers 117 MUST ignore them. 119 4. Future use of the reserved bits 121 New mechanisms that require allocation of one or more of the reserved 122 bits MUST require Standards Action as specified in [RFC5226]. 124 5. Acknowledgements 126 The authors would like to Pekka Savola, Christian Huitema, and 127 Ingemar Johansson for the discussions that led to this document. 129 6. Security Considerations 131 This document does not bring up any new security issues. 133 7. IANA Considerations 135 This document does not require any IANA action. 137 8. Normative References 139 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 140 Requirement Levels", BCP 14, RFC 2119, March 1997. 142 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 143 (IPv6) Specification", RFC 2460, December 1998. 145 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 146 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 147 May 2008. 149 Authors' Addresses 151 Suresh Krishnan 152 Ericsson 153 8400 Blvd Decarie 154 Town of Mount Royal, Quebec 155 Canada 157 Email: suresh.krishnan@ericsson.com 159 Joel Halpern 160 Ericsson 162 Email: joel.halpern@ericsson.com