idnits 2.17.1 draft-hilliard-v6ops-host-addr-update-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 : ---------------------------------------------------------------------------- ** The document seems to lack a Security Considerations section. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to use 'NOT RECOMMENDED' as an RFC 2119 keyword, but does not include the phrase in its RFC 2119 key words list. -- The document date (July 17, 2017) is 2447 days in the past. Is this intentional? Checking references for intended status: Best Current Practice ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 3736 (Obsoleted by RFC 8415) Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 v6ops N. Hilliard 3 Internet-Draft INEX 4 BCP: 204 J. Snijders 5 Updates: 7934 (if approved) NTT 6 Intended status: Best Current Practice July 17, 2017 7 Expires: January 18, 2018 9 Update for IPv6 Host Address Availability Recommendations 10 draft-hilliard-v6ops-host-addr-update-00 12 Abstract 14 The IPv6 Host Address Availability Recommendations Best Current 15 Practice (RFC 7934), describes why IPv6 hosts should use multiple 16 global addresses when attaching to a network. This document updates 17 RFC 7934 by removing a recommendation for networks to give the host 18 the ability to use new addresses without requiring explicit requests. 20 Requirements Language 22 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 23 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 24 document are to be interpreted as described in [RFC2119]. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on January 18, 2018. 43 Copyright Notice 45 Copyright (c) 2017 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 2. Updates to RFC7934 . . . . . . . . . . . . . . . . . . . . . 2 62 3. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 3 63 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 64 5. Normative References . . . . . . . . . . . . . . . . . . . . 3 65 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 67 1. Introduction 69 The IPv6 Host Address Availability Recommendations Best Current 70 Practice document [RFC7934] describes why IPv6 hosts should use 71 multiple global addresses when attaching to a network. The 72 recommendations in Section 8 of this document included the text: 74 Due to the drawbacks imposed by requiring explicit requests for 75 address space (see Section 4), it is RECOMMENDED that the network 76 give the host the ability to use new addresses without requiring 77 explicit requests. 79 This text could be interpreted as recommending that IPv6 networks 80 should not use not DHCPv6 [RFC3736], which provides new addresses in 81 response to explicit requests. This interpretation is based on the 82 fact that a host which uses DHCPv6 IA_NA or IA_TA cannot use new 83 addresses without requesting them from a DHCPv6 server on the 84 network. 86 2. Updates to RFC7934 88 This document updates [RFC7934] to remove the second and third 89 paragraphs of Section 8, so that the recommendations section of 90 [RFC7934] reads in its entirety as follows: 92 In order to avoid the problems described above and preserve the 93 Internet's ability to support new applications that use more than 94 one IPv6 address, it is RECOMMENDED that IPv6 network deployments 95 provide multiple IPv6 addresses from each prefix to general- 96 purpose hosts. To support future use cases, it is NOT RECOMMENDED 97 to impose a hard limit on the size of the address pool assigned to 98 a host. Particularly, it is NOT RECOMMENDED to limit a host to 99 only one IPv6 address per prefix. 101 3. Rationale 103 It has been argued in the v6ops Working Group that the first sentence 104 second paragraph technically relegates the status of DHCPv6 to "NOT 105 RECOMMENDED" on IPv6 networks, as it formally recommends that new 106 addresses should be assigned without explicit requests. This 107 implicitly excludes all address assignment mechanisms, including 108 DHCPv6, which are not handled by the host itself. A change of this 109 form to the status of DHCPv6 would be a serious and substantial 110 change to the status of DHCPv6 at the IETF, and not one that could or 111 should have been entertained without extensive debate as to whether 112 it was an appropriate move to make. This debate never happened and 113 the justification provided in section 4 of [RFC7934] is insufficient 114 per-se to warrant changing the recommendation status of such a 115 widely-deployed Standards Track protocol as DHCPv6. 117 The IPv6 self-selection addressing model does not necessarily suit 118 the deployment requirements for many types of ipv6 networks, 119 including enterprise, provider hosting, and various access network 120 protocols (e.g. docsis / gpon / ipoe); if the status of DHCPv6 were 121 changed to "NOT RECOMMENDED", then there would be no recommended IETF 122 model for stateful / operator-assigned IPv6 addressing, and this 123 would leave a glaring hole in the IPv6 host specification. 125 The subsequent sentences in the second paragraph provide alternatives 126 to DHCPv6, and are superfluous in the absence of the first paragraph. 128 The third paragraph notes that DHCPv6 stateful address assignment 129 (IA_NA or IA_TA) can be used to provide multiple addresses when the 130 host connects to the network, but does not mention that the host can 131 issue multiple dhcpv6 requests, thereby allowing arbitrary numbers of 132 assignments rather than the stated limit of approximately 30. As the 133 text in this paragraph is incorrect, it too has been removed. 135 4. IANA Considerations 137 There are no IANA considerations. 139 5. Normative References 141 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 142 Requirement Levels", BCP 14, RFC 2119, 143 DOI 10.17487/RFC2119, March 1997, 144 . 146 [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol 147 (DHCP) Service for IPv6", RFC 3736, DOI 10.17487/RFC3736, 148 April 2004, . 150 [RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi, 151 "Host Address Availability Recommendations", BCP 204, 152 RFC 7934, DOI 10.17487/RFC7934, July 2016, 153 . 155 Authors' Addresses 157 Nick Hilliard 158 INEX 159 4027 Kingswood Road 160 Dublin 24 161 IE 163 Email: nick@inex.ie 165 Job Snijders 166 NTT Communications 167 Theodorus Majofskistraat 100 168 Amsterdam 1065 SZ 169 The Netherlands 171 Email: job@ntt.net