--- 1/draft-ietf-roll-turnon-rfc8138-15.txt 2020-09-24 05:13:15.959350001 -0700 +++ 2/draft-ietf-roll-turnon-rfc8138-16.txt 2020-09-24 05:13:15.983350607 -0700 @@ -1,19 +1,19 @@ ROLL P. Thubert, Ed. Internet-Draft L. Zhao -Updates: 6550, 8138 (if approved) Cisco Systems -Intended status: Standards Track 18 September 2020 -Expires: 22 March 2021 +Updates: 8138 (if approved) Cisco Systems +Intended status: Standards Track 24 September 2020 +Expires: 28 March 2021 A RPL DODAG Configuration Option for the 6LoWPAN Routing Header - draft-ietf-roll-turnon-rfc8138-15 + draft-ietf-roll-turnon-rfc8138-16 Abstract This document updates RFC 8138 by defining a bit in the RPL DODAG Configuration Option to indicate whether compression is used within the RPL Instance, and specify the behavior of RFC 8138-capable nodes when the bit is set and unset. Status of This Memo @@ -23,21 +23,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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." - This Internet-Draft will expire on 22 March 2021. + This Internet-Draft will expire on 28 March 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights @@ -46,21 +46,21 @@ as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. References . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3. Requirements Language . . . . . . . . . . . . . . . . . . 4 - 3. Updating RFC 6550 . . . . . . . . . . . . . . . . . . . . . . 4 + 3. Extending RFC 6550 . . . . . . . . . . . . . . . . . . . . . 4 4. Updating RFC 8138 . . . . . . . . . . . . . . . . . . . . . . 5 5. Transition Scenarios . . . . . . . . . . . . . . . . . . . . 5 5.1. Coexistence . . . . . . . . . . . . . . . . . . . . . . . 6 5.2. Inconsistent State While Migrating . . . . . . . . . . . 6 5.3. Rolling Back . . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 9. Normative References . . . . . . . . . . . . . . . . . . . . 8 10. Informative References . . . . . . . . . . . . . . . . . . . 9 @@ -145,21 +145,21 @@ SRH: Source Routing Header 2.3. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119][RFC8174] when, and only when, they appear in all capitals, as shown here. -3. Updating RFC 6550 +3. Extending RFC 6550 The DODAG Configuration Option is defined in Section 6.7.6 of [RFC6550]. Its purpose is extended to distribute configuration information affecting the construction and maintenance of the DODAG, as well as operational parameters for RPL on the DODAG, through the DODAG. As shown in Figure 1, the Option was originally designed with 4 bit positions reserved for future use as Flags. 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 @@ -169,36 +169,36 @@ Figure 1: DODAG Configuration Option (Partial View) This specification defines a new flag "Enable RFC8138 Compression" (T). The "T" flag is set to turn-on the use of [RFC8138] within the DODAG. The "T" flag is encoded in position 2 of the reserved Flags in the DODAG Configuration Option (counting from bit 0 as the most significant bit) and set to 0 in legacy implementations as specified respectively in Sections 20.14 and 6.7.6 of [RFC6550]. + Section 4.3 of [USEofRPLinfo] updates [RFC6550] to indicate that the + definition of the Flags applies to Mode of Operation (MOP) values + zero (0) to six (6) only, leaving the flags reserved for MOP value + seven (7). For a MOP value of 7, the bit in position 2 is considered + unallocated and [RFC8138] MUST be used on Links where 6LoWPAN Header + Compression [RFC6282] applies and MUST NOT be used otherwise. + The RPL DODAG Configuration Option is typically placed in a DODAG Information Object (DIO) message. The DIO message propagates down the DODAG to form and then maintain its structure. The DODAG Configuration Option is copied unmodified from parents to children. - - Section 6.3.1 of [RFC6550] defines a 3-bit Mode of Operation (MOP) in - the DIO Base Object. This specification applies to MOP values 0 to - 6. For a MOP value of 7, the bit in position 2 is considered - unallocated and [RFC8138] MUST be used by default. - [RFC6550] states that "Nodes other than the DODAG Root MUST NOT modify this information when propagating the DODAG Configuration option". Therefore, a legacy parent propagates the "T" flag as set - by the Root whether it supports this specification or not. So when - the "T" flag is set, it is transparently flooded to all the nodes in - the DODAG. + by the Root, and when the "T" flag is set, it is transparently + flooded to all the nodes in the DODAG. 4. Updating RFC 8138 A node SHOULD generate packets in the compressed form using [RFC8138] if and only if the "T" flag is set. This behavior can be overridden by configuration or network management. Overriding may be needed e.g., to turn on the compression in a network where all nodes support [RFC8138] but the Root does not support this specification and cannot set the "T" flag, or to disable it locally in case of a problem. @@ -382,20 +382,25 @@ . [UNAWARE-LEAVES] Thubert, P. and M. Richardson, "Routing for RPL Leaves", Work in Progress, Internet-Draft, draft-ietf-roll-unaware- leaves-18, 12 June 2020, . 10. Informative References + [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 + Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, + DOI 10.17487/RFC6282, September 2011, + . + [RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low- Power and Lossy Networks (RPL) Option for Carrying RPL Information in Data-Plane Datagrams", RFC 6553, DOI 10.17487/RFC6553, March 2012, . [RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for Constrained-Node Networks", RFC 7228, DOI 10.17487/RFC7228, May 2014, .