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rfc:rfc7506

Internet Engineering Task Force (IETF) K. Raza Request for Comments: 7506 Cisco Systems, Inc. Updates: 4379 N. Akiya Category: Standards Track Big Switch Networks ISSN: 2070-1721 C. Pignataro

                                                   Cisco Systems, Inc.
                                                            April 2015
                      IPv6 Router Alert Option
     for MPLS Operations, Administration, and Maintenance (OAM)

Abstract

 RFC 4379 defines the MPLS Label Switched Path (LSP) Ping/Traceroute
 mechanism in which the Router Alert Option (RAO) MUST be set in the
 IP header of the MPLS Echo Request messages and may conditionally be
 set in the IP header of the MPLS Echo Reply messages depending on the
 Reply Mode used.  While a generic "Router shall examine packet"
 Option Value is used for the IPv4 RAO, there is no generic RAO value
 defined for IPv6 that can be used.  This document allocates a new,
 generic IPv6 RAO value that can be used by MPLS Operations,
 Administration, and Maintenance (OAM) tools, including the MPLS Echo
 Request and MPLS Echo Reply messages for MPLS in IPv6 environments.
 Consequently, it updates RFC 4379.
 The initial motivation to request an IPv6 RAO value for MPLS OAM
 comes from the MPLS LSP Ping/Traceroute.  However, this value is
 applicable to all MPLS OAM and not limited to MPLS LSP Ping/
 Traceroute.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc7506.

Raza, et al. Standards Track [Page 1] RFC 7506 MPLS OAM IPv6 Router Alert April 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.

Table of Contents

 1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
 2.  Specification of Requirements . . . . . . . . . . . . . . . .   3
 3.  IPv6 RAO Value for MPLS OAM . . . . . . . . . . . . . . . . .   3
 4.  Updates to RFC 4379 . . . . . . . . . . . . . . . . . . . . .   3
 5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
 6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
 7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   7.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
   7.2.  Informative References  . . . . . . . . . . . . . . . . .   5
 Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   5
 Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1. Introduction

 A commonly deployed MPLS OAM tool is specified in [RFC4379],
 "Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures",
 which is used to diagnose MPLS network data planes.  This
 specification, often referred to as "MPLS LSP Ping/Traceroute"
 [RFC4379], requires the use of the Router Alert Option (RAO) in the
 IP header.  For example, Section 4.3 of [RFC4379] states that the IP
 RAO MUST be set in the IP header of an MPLS Echo Request message.
 Similarly, Section 4.5 of [RFC4379] states that the IP RAO MUST be
 set in the IP header of an MPLS Echo Reply message if the Reply Mode
 in the Echo Request is set to "Reply via an IPv4/IPv6 UDP packet with
 Router Alert".
 [RFC2113] defines a generic Option Value 0x0 for IPv4 RAO that is
 used in LSP Ping and LSP Traceroute for MPLS in IPv4 environments.
 This IPv4 RAO value of 0x0 is assigned to "Router shall examine
 packet".  However, currently there is no generic IPV6 RAO value
 defined that can be used in LSP Ping and LSP Traceroute for MPLS in

Raza, et al. Standards Track [Page 2] RFC 7506 MPLS OAM IPv6 Router Alert April 2015

 IPv6 environments.  Specifically, [RFC2711] defined the Router Alert
 for a general IPv6 purpose but required the Value field in the RAO to
 indicate a specific reason for using the RAO.  Because there is no
 defined value for MPLS LSP Ping/Traceroute use or for general use, it
 is not possible for MPLS OAM tools to use the IPv6 Router Alert
 mechanism.
 As vendors are starting to implement MPLS on the IPv6 control plane
 (e.g., [LDP-IPV6]), there is a need to define and allocate such an
 Option Value for IPv6 in order to comply with [RFC4379].  This
 document defines a new IPv6 RAO value that can be used by MPLS OAM
 tools, including the MPLS Echo Request and MPLS Echo Reply messages
 for MPLS in IPv6 environments.
 This document closes the gap discussed in the third paragraph of
 Section 3.4.2 in [RFC7439].

2. Specification of Requirements

 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 [RFC2119].

3. IPv6 RAO Value for MPLS OAM

 This document defines a new Option Value (69) for the IPv6 RAO to
 alert transit routers to examine the packet more closely for MPLS OAM
 purposes.  This Option Value is used by any MPLS OAM application that
 requires their packets to be examined by a transit router.
 In the scope of this document, this Option Value will be used by the
 MPLS Echo Request and MPLS Echo Reply for its IPv6 messages, as is
 required by [RFC4379].

4. Updates to RFC 4379

 [RFC4379] specifies the use of the RAO in the IP header.  Sections
 4.3 and 4.5 of [RFC4379] are updated as follows:
 For every time in which the "Router Alert IP Option" is used, the
 following text is appended:
    In case of an IPv4 header, the generic IPv4 RAO value 0x0
    [RFC2113] SHOULD be used.  In case of an IPv6 header, the IPv6 RAO
    value (69) allocated through this document for MPLS OAM MUST be
    used.

Raza, et al. Standards Track [Page 3] RFC 7506 MPLS OAM IPv6 Router Alert April 2015

5. IANA Considerations

 This document defines a new value (69) for the IPv6 RAO to alert
 transit routers to examine the packet more closely for MPLS OAM
 purposes.  IANA has assigned a new code point under its "IPv6 Router
 Alert Option Values" registry defined by [RFC2711], updated by
 [RFC5350], and maintained in [IANA-IPv6-RAO].  The new code point is
 as follows:
    Value   Description                       Reference
    -----   -------------------------------   ---------------
       69   MPLS OAM                          RFC 7506

6. Security Considerations

 This document introduces no new security concerns in addition to what
 have already been captured in [RFC4379] and [RFC6398], the latter of
 which expands the security considerations of [RFC2113] and [RFC2711].
 IPv6 packets containing the MPLS OAM RAO are encapsulated with an
 MPLS header and are not expected to be inspected by every label
 switched hop within an MPLS LSP.  Consequently, this value of the RAO
 will be processed by the appropriate router and is not subject to the
 problem of being ignored, as described in Section 2.2 of [RFC7045].

7. References

7.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997,
            <http://www.rfc-editor.org/info/rfc2119>.
 [RFC2711]  Partridge, C. and A. Jackson, "IPv6 Router Alert Option",
            RFC 2711, October 1999,
            <http://www.rfc-editor.org/info/rfc2711>.
 [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
            Label Switched (MPLS) Data Plane Failures", RFC 4379,
            February 2006, <http://www.rfc-editor.org/info/rfc4379>.
 [RFC5350]  Manner, J. and A. McDonald, "IANA Considerations for the
            IPv4 and IPv6 Router Alert Options", RFC 5350, September
            2008, <http://www.rfc-editor.org/info/rfc5350>.
 [RFC6398]  Le Faucheur, F., Ed., "IP Router Alert Considerations and
            Usage", BCP 168, RFC 6398, October 2011,
            <http://www.rfc-editor.org/info/rfc6398>.

Raza, et al. Standards Track [Page 4] RFC 7506 MPLS OAM IPv6 Router Alert April 2015

7.2. Informative References

 [IANA-IPv6-RAO]
            IANA, "IPv6 Router Alert Option Values",
            <http://www.iana.org/assignments/ipv6-routeralert-values>.
 [LDP-IPV6] Asati, R., Pignataro, C., Raza, K., Manral, V., and R.
            Papneja, "Updates to LDP for IPv6", Work in Progress,
            draft-ietf-mpls-ldp-ipv6-17, February 2015.
 [RFC2113]  Katz, D., "IP Router Alert Option", RFC 2113, February
            1997, <http://www.rfc-editor.org/info/rfc2113>.
 [RFC7045]  Carpenter, B. and S. Jiang, "Transmission and Processing
            of IPv6 Extension Headers", RFC 7045, December 2013,
            <http://www.rfc-editor.org/info/rfc7045>.
 [RFC7439]  George, W., Ed. and C. Pignataro, Ed., "Gap Analysis for
            Operating IPv6-Only MPLS Networks", RFC 7439, January
            2015, <http://www.rfc-editor.org/info/rfc7439>.

Acknowledgements

 The authors would like to thank George Swallow, Ole Troan, Bob
 Hinden, Faisal Iqbal, Mathew Janelle, and Gregory Mirsky for their
 useful input.

Raza, et al. Standards Track [Page 5] RFC 7506 MPLS OAM IPv6 Router Alert April 2015

Authors' Addresses

 Kamran Raza
 Cisco Systems, Inc.
 2000 Innovation Drive
 Kanata, ON  K2K-3E8
 Canada
 EMail: skraza@cisco.com
 Nobo Akiya
 Big Switch Networks
 EMail: nobo.akiya.dev@gmail.com
 Carlos Pignataro
 Cisco Systems, Inc.
 7200-12 Kit Creek Road
 Research Triangle Park, NC  27709
 United States
 EMail: cpignata@cisco.com

Raza, et al. Standards Track [Page 6]

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