ROLL Working Group M.I. Robles Internet-Draft Ericsson Intended status: Informational M. Richardson Expires: December 29, 2015 SSW June 27, 2015 When to use RFC 6553, 6554 and IPv6-in-IPv6 draft-robles-roll-useofrplinfo-00 Abstract This document states different cases where RFC 6553, RFC 6554 and IPv6-in-IPv6 encapsulation is required to set the bases to help defining the compression of RPL routing information in LLN environments. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 http://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 December 29, 2015. Copyright Notice Copyright (c) 2015 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 (http://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 and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Robles & Richardson Expires December 29, 2015 [Page 1] Internet-Draft Useof6553 June 2015 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology and Requirements Language . . . . . . . . . . . . 2 3. Sample/reference topology . . . . . . . . . . . . . . . . . . 3 4. Example flow from leaf to root . . . . . . . . . . . . . . . 4 4.1. Non-storing . . . . . . . . . . . . . . . . . . . . . . . 5 4.2. Storing . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Example flow from leaf to Internet . . . . . . . . . . . . . 6 5.1. Non-storing . . . . . . . . . . . . . . . . . . . . . . . 6 5.2. Storing . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. Example flow from leaf to leaf . . . . . . . . . . . . . . . 7 6.1. Traditional storing . . . . . . . . . . . . . . . . . . . 7 6.2. Traditional non-storing . . . . . . . . . . . . . . . . . 7 6.3. P2P non-storing . . . . . . . . . . . . . . . . . . . . . 7 7. Example flow from Internet to leaf . . . . . . . . . . . . . 7 7.1. Storing . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.2. Non-storing . . . . . . . . . . . . . . . . . . . . . . . 7 8. Example flow from root to leaf . . . . . . . . . . . . . . . 7 8.1. Storing . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.2. Non-storing . . . . . . . . . . . . . . . . . . . . . . . 7 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 10. Security Considerations . . . . . . . . . . . . . . . . . . . 8 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 12.1. Normative References . . . . . . . . . . . . . . . . . . 8 12.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction RPL [RFC6550] defines RPL Option to transmit routing information. RFC 6553 [RFC6553] defines how to transmit in a Hop-By-Hop Option RPL Information,such as information to avoid and detect loops. RFC 6554 [RFC6554] defines the use of Extension header for Source Routing. Several discussions in ROLL/6lo/6tisch Mailing Lists took place focusing in the definition how to compress RPL Information in constrained environment. ROLL Virtual Interim Meeting (02-2015) concluded that there is a need to define how to use RFC 6553, RFC6554 and tunneling (IP-in-IP) to be able to set the correct environment for compression. 2. Terminology and Requirements Language Robles & Richardson Expires December 29, 2015 [Page 2] Internet-Draft Useof6553 June 2015 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 RFC 2119 [RFC2119]. Terminology defined in [RFC7102] 3. Sample/reference topology In a typical topology we found 6LBR (6LoWPAN Border Router), 6lR (6LoWPAN Router) and 6LN (6LoWPAN Node) as leaf connected in a DODAG (Destination Oriented Directed Acyclic Graph). Between these entities messages such as DIS, DIO and DAO are transmitted. RPL defines the RPL Control message as an ICMPv6 information message with a Type of 155. RPL supports two modes of Downward traffic: Storing, it is fully stateful or Non-Storing it is fully source routed. Any given RPL Instance is either storing or non-storing. +--------------+ | Upper Layers | | | +--------------+ | RPL | | | +--------------+ | ICMPv6 | | | +--------------+ | IPv6 | | | +--------------+ | 6LoWPAN | | | +--------------+ | PHY-MAC | | | +--------------+ Figure 1: RPL Stack Robles & Richardson Expires December 29, 2015 [Page 3] Internet-Draft Useof6553 June 2015 +---------+ +---+Internet | | +---------+ | +----+--+ |DODAG | +---------+Root +----------+ | |6LBR | | | +----+--+ | | | | | | | | | | +-----+-+ +--+---+ +--+---+ |6LR | | | | | +-----+ | | | | | | | | | | | +------+ | +-----+-+ +-+----+ +-+----+ | | | | | | | | | | | | | | | | +-+---+ +-+---+ +--+--+ +- --+ +---+-+ |Leaf | | | | | | | | | |6LN | | | | | | | | | +-----+ +-----+ +-----+ +----+ +-----+ Figure 2: A reference RPL Topology In different scenarios the use of RFC 6553, RFC 6554 and tunneling can take place: -Flow from leaf to root -Flow from leaf to Internet -Flow from leaf to leaf -Flow from Internet to leaf -Flow from leaf to root 4. Example flow from leaf to root A leaf node generates DAO and DIS messages and in general does not accept them. Additionally, this kind of nodes accepts DIO messages, but in general do not generate them. (In inconsistency A leaf node generates DIO with infinite rank, to fix it). Robles & Richardson Expires December 29, 2015 [Page 4] Internet-Draft Useof6553 June 2015 4.1. Non-storing In non-storing in this case the leaf node uses Hop-By-Hop option (RFC 6553) to indicate the routing information to send messages to the DODAG root, this message is going to be analyzed in each node until arrive the DODAG root. RFC 6554 was created to strictly send information between RPL routers in the same RPL routing domain. How it would be in 6554? TBD: Tunneling is necessary in case that there is information to send outside RPL Domain and other cases? +------+ | | | 6LBR | | | +---+--+ | | LoWPAN_HC | Route= 6LN-6LR-6LBR ^ | | +---+-+ | | | | | 6LR | | | | | +--+--+ | | LoWPAN_HC | | Route= 6LN-6LR-6LBR | | + | +--+--+ | 6LN | | | | | +-----+ Figure 3: From leaf to Root - Non-Storing Mode 4.2. Storing IP6 6553{X,Y] ?ipip payload. In storing mode is suitable the use of RFC 6553 to send RPL Information through HBH field checking the routing table to find out where to send the message. It may include IP-in-IP encapsulation to transmit information not related with the RPL domain. Robles & Richardson Expires December 29, 2015 [Page 5] Internet-Draft Useof6553 June 2015 +------+ | | | 6LBR | | | +---+--+ | | LoWPAN_HC | 0x63|HBH Data ^ | | +---+-+ | | | | | 6LR | 6LR check in routing table | | | | +--+--+ | | LoWPAN_HC | | 0x63|HBH Data | | + | +--+--+ | 6LN | | | | | +-----+ Figure 4: From leaf to Root - Storing Mode 5. Example flow from leaf to Internet 5.1. Non-storing In this case the IP-in-IP encapsulation should take place to send information not related to the RPL domain inside of the RPL domain. RPL information from RFC 6553 should not go out to Internet. The router sould take this information out before send the packet to Internet. The HBH Option is going to be analyzed in each node to the root. Related to RFC 6554 the Source Header route is added and removed by DODAG root. However, RFC 6554 was created to strictly send information between RPL routers in the same RPL routing domain. How it would be in 6554? Robles & Richardson Expires December 29, 2015 [Page 6] Internet-Draft Useof6553 June 2015 5.2. Storing In storing the information of RFC 6553 should take away by DODAG root before go to Internet. 6. Example flow from leaf to leaf can leafs insert appropriate headers, without ipip? In [RFC6550] RPL allows a simple one-hop P2P optimization for both storing and non- storing networks. A node may send a P2P packet destined to a one-hop neighbor direclty to that node. Section 9 in [RFC6550]. 6.1. Traditional storing The route go through an ancestor that knows the route to the destination, using HBH [RFC6553] to carry RPL Information. 6.2. Traditional non-storing The route go through the DODAG root, using source routing [RFC6554]. 6.3. P2P non-storing (p2p storing? TBD) 7. Example flow from Internet to leaf A DODAG root do not add routing extension to incoming packets, it instead uses tunneling. 7.1. Storing DODAG root adds the HBH header [RFC6553] and send the packet downward to the destination. 7.2. Non-storing DODAG root is going to add the source route header [RFC6554] 8. Example flow from root to leaf 8.1. Storing DODAG root adds the HBH header [RFC6553] and send the packet downward to the destination. 8.2. Non-storing Robles & Richardson Expires December 29, 2015 [Page 7] Internet-Draft Useof6553 June 2015 DODAG root is going to add the source route header [RFC6554] 9. IANA Considerations There are no IANA considerations related to this document. 10. Security Considerations TBD. 11. Acknowledgements This work is partially funded by the FP7 Marie Curie Initial Training Network (ITN) METRICS project (grant agreement No. 607728) 12. References 12.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC6550] Winter, T., Thubert, P., Brandt, A., Hui, J., Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, JP., and R. Alexander, "RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks", RFC 6550, March 2012. [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, March 2012. [RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6 Routing Header for Source Routes with the Routing Protocol for Low-Power and Lossy Networks (RPL)", RFC 6554, March 2012. 12.2. Informative References [RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and Lossy Networks", RFC 7102, January 2014. Authors' Addresses Robles & Richardson Expires December 29, 2015 [Page 8] Internet-Draft Useof6553 June 2015 Maria Ines Robles Ericsson Hirsalantie 11 Jorvas 02420 Finland Email: maria.ines.robles@ericsson.com Michael C. Richardson Sandelman Software Works 470 Dawson Avenue Ottawa, ON K1Z 5V7 CA Email: mcr+ietf@sandelman.ca URI: http://www.sandelman.ca/ Robles & Richardson Expires December 29, 2015 [Page 9]