[Search] [txt|pdfized|bibtex] [Tracker] [Email] [Nits]
Versions: 00                                                            
Network Working Group                                              Z. Li
Internet-Draft                                                     Z. Hu
Intended status: Standards Track                                 J. Dong
Expires: September 22, 2022                          Huawei Technologies
                                                          March 21, 2022


              Topology Identifier in IPv6 Extension Header
                      draft-li-6man-topology-id-00

Abstract

   This document proposes a new Hop-by-Hop option of IPv6 extension
   header to carry the topology identifier, which is used to identify
   the forwarding table instance created by the Multi Topology Routing
   or Flexible Algorithm.

Requirements Language

   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].

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 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 September 22, 2022.

Copyright Notice

   Copyright (c) 2022 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



Li, et al.             Expires September 22, 2022               [Page 1]


Internet-Draft       Topology Identifier in IPv6 EH           March 2022


   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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminologies . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   2
   4.  New IPv6 Extension Header Option for Topologies . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   This document proposes a new Hop-by-Hop option of IPv6 extension
   header to carry the topology identifier, which is used to identify
   the forwarding table instance created by the Multi Topology Routing
   or Flexible Algorithm.

2.  Terminologies

   The following terminologies are used in this document.

   MT: Multi Topology

3.  Problem Statement

   [RFC4915] defines Multi-Topology Routing in OSPF and [RFC5120]
   defines Multi Topology Routing in ISIS.  Through Multi Topology
   Routing, there can be multiple forwarding tables in the data plane.
   [I-D.ietf-lsr-flex-algo] can also implement the similar purpose to
   install multiple forwarding tables for different Flexible Algorithm
   instances.

   In the MT IP Forwarding Considerations of [RFC5120],it is explained
   when multiple MTs share an Interface with overlapping addresses, some
   additional mechanism is needed to select the correct RIBs for the
   incoming IP packets to determine the correct RIB to make a forwarding
   decision.  But there is lack of the generic approach of packet to
   multiple MT RIB mapping over the same inbound interface.



Li, et al.             Expires September 22, 2022               [Page 2]


Internet-Draft       Topology Identifier in IPv6 EH           March 2022


4.  New IPv6 Extension Header Option for Topologies

   In order to solve the above issue, in the scenario of IPv6, the
   topology identifier information can be carried in the packet.  A new
   Hop-by-Hop option type "Topology" is defined to carry the topology
   related Identifier in an IPv6 packet.  Its format is shown as below:

    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
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |    Opt Type   |  Opt Data Len |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Topology ID           |       Reserved                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 1. Topology Option



   where:

   o Opt Type: Type value is TBD. 8-bit unsigned integer.  Identifier of
   the type of this Topology Option.

   o Opt Data Len: 8-bit unsigned integer.  It indicates the length of
   the option Data field of this option, in octets.  The value of Opt
   Data Len of Topology option SHOULD be set to 4.

   o Topology ID: 2-octet identifier which uniquely identifies the
   topology associated with the specific forwarding table created by the
   Multi Topology Routing or Flexible Algorithm.

   o Reserved: 2-octet reserved field.  It MUST be set as 0 and ignored
   when received.

5.  Security Considerations

   TBD

6.  IANA Considerations

   This document requests IANA to assign a new option type from "Hop-by-
   Hop Options" registry.

         Value      Description        Reference
         ------------------------------------------
         TBD       Topology Option    this document




Li, et al.             Expires September 22, 2022               [Page 3]


Internet-Draft       Topology Identifier in IPv6 EH           March 2022


7.  References

7.1.  Normative References

   [I-D.ietf-lsr-flex-algo]
              Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
              A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex-
              algo-18 (work in progress), October 2021.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC4915]  Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
              Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
              RFC 4915, DOI 10.17487/RFC4915, June 2007,
              <https://www.rfc-editor.org/info/rfc4915>.

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,
              <https://www.rfc-editor.org/info/rfc5120>.

7.2.  Informative References

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

Authors' Addresses

   Zhenbin Li
   Huawei Technologies
   Beijing  100095
   China

   Email: lizhenbin@huawei.com


   Zhibo Hu
   Huawei Technologies
   Beijing  100095
   China

   Email: huzhibo@huawei.com



Li, et al.             Expires September 22, 2022               [Page 4]


Internet-Draft       Topology Identifier in IPv6 EH           March 2022


   Jie Dong
   Huawei Technologies
   Beijing  100095
   China

   Email: jie.dong@huawei.com













































Li, et al.             Expires September 22, 2022               [Page 5]