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Versions: 00

Network Work group                                         N. Kumar, Ed.
Internet-Draft                                         C. Pignataro, Ed.
Intended status: Standards Track                                F. Iqbal
Expires: April 26, 2019                                           Z. Ali
                                                                   Cisco
                                                        October 23, 2018


Label Switched Path (LSP) Ping/Traceroute for Segment Routing SIDs with
                            MPLS Data-plane
               draft-nainar-mpls-spring-lsp-ping-sids-00

Abstract

   RFC8402 introduces Segment Routing architecture that leverages source
   routing and tunneling paradigms and can be directly applied to the
   Multi Protocol Label Switching (MPLS) data plane.  A node steers a
   packet through a controlled set of instructions called segments, by
   prepending the packet with Segment Routing header.  SR architecture
   defines different types of segments with different forwarding
   semantics associated.

   RFC8287 defines the extensions to MPLS LSP Ping and Traceroute for
   Segment Routing IGP-Prefix and IGP-Adjacency Segment Identifier
   (SIDs) with an MPLS data plane.  RFC8287 defines the Target FEC Stack
   Sub-TLVs and the procedures to apply RFC8029 on SR architecture with
   MPLS data plane.

   This document defines the Target FEC Stack Sub-TLVs and the extension
   required for other SR Segments.

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 April 26, 2019.




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Copyright Notice

   Copyright (c) 2018 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 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Requirements notation . . . . . . . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Segment ID sub-TLV  . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  BGP Prefix Segment ID . . . . . . . . . . . . . . . . . .   4
     4.2.  BGP Peering Segment - Peer-Node-SID . . . . . . . . . . .   4
     4.3.  BGP Peering Segment - Peer-Adj-SID  . . . . . . . . . . .   5
     4.4.  BGP Peering Segment - Peer-Set-SID  . . . . . . . . . . .   7
       4.4.1.  Peer Set Sub-TLV  . . . . . . . . . . . . . . . . . .   8
     4.5.  Path Binding SID  . . . . . . . . . . . . . . . . . . . .   9
     4.6.  Multicast Replication . . . . . . . . . . . . . . . . . .  10
   5.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     5.1.  BGP Prefix SID  . . . . . . . . . . . . . . . . . . . . .  10
     5.2.  BGP Peering Segment Sub-TLVs  . . . . . . . . . . . . . .  10
       5.2.1.  Initiator Node Procedures . . . . . . . . . . . . . .  10
       5.2.2.  Responder Node Procedures . . . . . . . . . . . . . .  11
     5.3.  Path Binding SID  . . . . . . . . . . . . . . . . . . . .  11
       5.3.1.  Initiator Node Procedures . . . . . . . . . . . . . .  11
       5.3.2.  Responder Node Procedures . . . . . . . . . . . . . .  11
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   8.  Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  12
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  12
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     10.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14







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1.  Introduction

   [RFC8402] introduces and describes a Segment Routing architecture
   that leverages the source routing and tunneling paradigms.  A node
   steers a packet through a controlled set of instructions called
   segments, by prepending the packet with Segment Routing header.  A
   detailed definition of the Segment Routing architecture is available
   in [RFC8402]

   As described in [RFC8402] and [I-D.ietf-spring-segment-routing-mpls],
   the Segment Routing architecture can be directly applied to an MPLS
   data plane, the Segment identifier (Segment ID) will be of 20-bits
   size and the Segment Routing header is the label stack.

   [RFC8287] defines the mechanism to perform LSP Ping and Traceroute
   for Segment Routing with MPLS data plane.  [RFC8287] defines the
   Target FEC Stack Sub-TLVs for IGP-Prefix Segment ID and IGP-Adjacency
   Segment ID.

   There are various other Segment IDs proposed by different documents
   that are applicable for SR architecture.
   [I-D.ietf-idr-bgp-prefix-sid] defines BGP Prefix Segment ID,
   [I-D.ietf-idr-bgpls-segment-routing-epe] defines BGP Peering Segment
   ID such as Peer Node SID, Peer Adj SID and Peer Set SID.
   [I-D.sivabalan-pce-binding-label-sid] defines Path Binding Segment
   ID.

   As above Segment IDs get deployed in the field, operators require
   corresponding MPLS OAM procedures for the SIDs.  This document
   describes the target FEC Stack Sub-TLVs and the procedure to use LSP
   Ping and Traceroute for the above defined Segment IDs to support path
   validation and fault isolation.

2.  Requirements notation

   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.  Terminology

   This document uses the terminologies defined in [RFC8402], [RFC8029],
   readers are expected to be familiar with it.

   The term "BGP EPE node" is used to refer to node assigning and
   advertising BGP Peering Segment SIDs to steer traffic towards a BGP
   peer, as described in [I-D.ietf-spring-segment-routing-central-epe].




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4.  Segment ID sub-TLV

   As defined in Section 5 of [RFC8287], the format of the following
   Segment ID sub-TLVs defined in this document follows the philosophy
   of Target FEC Stack TLV carrying FECs corresponding to each label in
   the label stack.

4.1.  BGP Prefix Segment ID

   Section 3.2.13 and 3.2.14 of [RFC8029] defines the Sub-TLV for BGP
   labeled IPv4 and IPv6 prefix respectively.  This document proposes
   the use of the same Sub-TLV for IPv4 and IPv6 BGP Prefix SID without
   any change.

4.2.  BGP Peering Segment - Peer-Node-SID

   Peer-Node-SID identifies the peer node in the BGP Peering Segment.
   The sub-TLV format for Peer-Node-SID of BGP Peering Segment MUST be
   set as shown in the below TLV format:



        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Type = TBD1                    |          Length = x           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   AF.Type     |          Reserved                             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               Local BGP Router ID (4 octets)                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Local ASN (4 octets)                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Peer BGP Router ID (4 octets)                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Peer ASN (4 octets)                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          Local Interface address (4 or 16 octets)             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |           Remote Interface address (4 or 16 octets)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   AF.Type

      Set to 4 if the address in Local/Remote Interface address field is
      IPv4 and set to 6 if the address in Local/Remote Interface address
      field is IPv6.



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   Reserved

      MUST be set to 0 on send and MUST be ignored on receipt.

   Local BGP Router ID

      4-octet BGP Router ID of the node that assigns the Peer-Node-SID.

   Local ASN

      4-octet local ASN number of the node that assigns the Peer-Node-
      SID.

   Peer BGP Router ID

      4-octet BGP Router ID of the peer node.

   Peer ASN

      4-octet ASN number of the peer node.

   Local Interface Address

      Set to the address used by the local node for BGP session peering.
      When AF.Type is set to 4, this address is 4-octet IPv4 address and
      when AF.Type is set to 6, this address is 16-octet IPv6 address.

   Remote Interface Address

      Set to the address used by the peer node for BGP session peering.
      When AF.Type is set to 4, this address is 4-octet IPv4 address and
      when AF.Type is set to 6, this address is 16-octet IPv6 address.

4.3.  BGP Peering Segment - Peer-Adj-SID

   Peer-Adj-SID identifies the underlying link to the BGP peer node.
   The sub-TLV format for Peer-Adj-SID of BGP Peering Segment MUST be
   set as shown in the below TLV format:













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        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   Type = TBD2                 |          Length = 24          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               Local BGP Router ID (4 octets)                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Local ASN (4 octets)                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                Peer BGP Router ID (4 octets)                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Peer ASN (4 octets)                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |           Local Link Identifier  (4 octet)                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |           Remote Link Identifier  (4 octet)                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



   Local BGP Router ID

      4-octet BGP Router ID of the node that assigns the Peer-Node-SID.

   Local ASN

      4-octet local ASN number of the node that assigns the Peer-Node-
      SID.

   Peer BGP Router ID

      4-octet BGP Router ID of the peer node.

   Peer ASN

      4-octet ASN number of the peer node.

   Local Link Identifier

      Set to 4-octet link identifier of the local interface to which
      Peer-Adj-SID is assigned to.

   Remote Link Identifier

      Set to 4-octet link identifier of the peer interface to which
      Peer-Adj-SID is assigned to.  Set to all-zeros when this
      identifier is unknown.




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4.4.  BGP Peering Segment - Peer-Set-SID

   The sub-TLV format for Peer-Node-SID of BGP Peering Segment MUST be
   set as shown in the below TLV format:



        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Type = TBD3                    |          Length = x           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               Local BGP Router ID (4 octets)                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Local ASN (4 octets)                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Peer Set Count         |           Reserved            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           .                                                               .
       .                   List of Peer Set Sub-TLVs                   .
           .                                                               .
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Local BGP Router ID

      4-octet BGP Router ID of the node that assigns the Peer-Set-SID.

   Local ASN

      4-octet local ASN number of the node that assigns the Peer-Set-
      SID.

   Peer Set Count

      Set to the number of Peer Sub-TLVs included.

   Sub-TLV Length

      Total length in octets of the sub-TLVs associated with this TLV.

   Peer Set Sub-TLV

      Carries the Sub-TLVs defined in section 4.4.1.







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4.4.1.  Peer Set Sub-TLV

   As defined in section 5.3 of
   [I-D.ietf-idr-bgpls-segment-routing-epe], Peer-Set-SID can identify
   the set where the members can be Peer-Node or Peer-Adj from same or
   different ASN.  The format of the Peer Set Sub-TLV will identify each
   such member.

4.4.1.1.  Peer Node

   The format for this sub-TLV MUST be set 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Type = 1 (Peer)              |          Length = 8           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        Peer ASN  (4 octets)                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                   Peer BGP Router ID (4 octets)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Peer ASN

      4-octet ASN number of the peer node.

   Peer Router ID

      4-octet BGP Router ID of the peer node.

4.4.1.2.  Link Identifier

   The format for this sub-TLV is as below:















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        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Type = 2 (Link Id)           |          Length = 12          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        Peer ASN  (4 octets)                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               Local Link Identifier  (4 octet)                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              Remote Link Identifier  (4 octet)                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Peer ASN

      4-octet ASN number of the peer node.

   Local Link Identifier

      Set to 4-octet link identifier of the local interface to which
      Peer-Adj-SID is assigned to.

   Remote Link Identifier

      Set to 4-octet link identifier of the peer interface to which
      Peer-Adj-SID is assigned to.  Set to all-zeros when this
      identifier is unknown.

4.5.  Path Binding SID

   Path Binding SID identifies the Binding Segment Identifier associated
   with an RSVP-TE or SR-TE path.  The format for this sub-TLV is 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |Type = TBD4                    |          Length = x           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |       AF.Type |                  Reserved                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |               Head End Address (4 or 16 octets)               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



   AF.Type



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      Set to 4 if the address in Head End Address field is IPv4 and set
      to 6 if the address in Head End address field is IPv6.

   Reserved

      MUST be set to 0 on send and MUST be ignored on receipt.

   Head End Address

      Set to the address of the head end node to which the policy is
      assigned.  When AF.Type is 4, this address is IPv4 and when
      AF.Type is 6, it is IPv6.

4.6.  Multicast Replication

   [I-D.voyer-spring-sr-p2mp-policy] describes Segment Routing Multicast
   Replication Policy and introduces the notion of Tree SID to achieve
   this.  A future version of this document will describe LSP Ping and
   Traceroute Target FEC Stack sub-TLV and procedures for Tree SID
   validation.

5.  Procedures

   This section describes the aspects of LSP Ping and Traceroute
   operations that require further considerations beyond [RFC8029] and
   [RFC8287].

5.1.  BGP Prefix SID

   The procedures described in [RFC8029] are sufficient for MPLS Ping
   and Traceroute operations for BGP Prefix SID using the FEC
   definitions from Section 3.2.13 and 3.2.14 of [RFC8029].

5.2.  BGP Peering Segment Sub-TLVs

   BGP Peering Segment sub-TLVs (BGP-Node-SID, BGP-Adj-SID, Peer-Set-
   SID) are assigned by BGP EPE node for a particular BGP neighbor, and
   advertised to the peer nodes.  Any LSP Ping and Traceroute operation
   MUST be performed on the BGP EPE node, and not the remote neighbor
   node, as only the BGP EPE node can validate the contents of BGP
   Peering Segment sub-TLVs.  Additionally, leaking the echo packet to
   the peer node may not be desirable for network operators.

5.2.1.  Initiator Node Procedures

   If the bottom-most label in the label stack is BGP Peer Segment
   label, the initiating node MUST set the TTL of the bottom-most label
   to 1 to ensure that MPLS TTL expires at the BGP EPE node, and the



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   echo packet does not leak to the BGP peer node.  Echo packet MUST
   include one of BGP-Node-SID, BGP-Adj-SID, or Peer-Set-SID sub-TLV in
   the Target FEC Stack TLV corresponding to the BGP Peer Segment label.
   Operator MAY push one or more transport labels on top of the BGP Peer
   Segment label to forward the echo packet to the BGP EPE node.

5.2.2.  Responder Node Procedures

   In addition to procedures defined in [RFC8029], the responding node,
   upon TTL expiry of the echo packet, MUST process the incoming BGP
   Peer Segment sub-TLV of the Target FEC Stack.  It MUST validate that
   contents of the sub-TLV and ensure the incoming label is advertised
   for the processed BGP Peer Segment sub-TLV.

5.3.  Path Binding SID

5.3.1.  Initiator Node Procedures

   Similar to BGP Peering Segment sub-TLVs, Path Binding SID sub-TLV
   MUST be validated at the node assigning and advertising the Binding
   SID, instead of the endpoint of the path associated with the Binding
   SID.  The initiating node MUST set the TTL of the Binding SID label
   to 1 and include the associated Path Binding SID TLV in the Target
   FEC Stack TLV of the echo request.  Operator MAY push one or more
   transport labels on top of Binding SID label to forward echo packet
   from initiating node to the assigning node.

5.3.2.  Responder Node Procedures

   In addition to procedures defined in [RFC8029], the responding node,
   upon TTL expiry of the echo packet, MUST process the incoming Path
   Binding SID sub-TLV of the Target FEC Stack.  The responding node
   MUST ensure that it is the advertising node specified in the Path
   Bindng SID sub-TLV, and the incoming Binding SID label matches the
   advertised label value.

6.  IANA Considerations

   To be Updated.

7.  Security Considerations

   To be Updated








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8.  Acknowledgement

   TBD

9.  Contributors

   TBD

10.  References

10.1.  Normative References

   [I-D.ietf-idr-bgp-prefix-sid]
              Previdi, S., Filsfils, C., Lindem, A., Sreekantiah, A.,
              and H. Gredler, "Segment Routing Prefix SID extensions for
              BGP", draft-ietf-idr-bgp-prefix-sid-27 (work in progress),
              June 2018.

   [I-D.ietf-idr-bgpls-segment-routing-epe]
              Previdi, S., Filsfils, C., Patel, K., Ray, S., and J.
              Dong, "BGP-LS extensions for Segment Routing BGP Egress
              Peer Engineering", draft-ietf-idr-bgpls-segment-routing-
              epe-15 (work in progress), March 2018.

   [I-D.sivabalan-pce-binding-label-sid]
              Sivabalan, S., Tantsura, J., Filsfils, C., Previdi, S.,
              Hardwick, J., and D. Dhody, "Carrying Binding Label/
              Segment-ID in PCE-based Networks.", draft-sivabalan-pce-
              binding-label-sid-04 (work in progress), March 2018.

   [I-D.voyer-spring-sr-p2mp-policy]
              daniel.voyer@bell.ca, d., Hassen, C., Gillis, K.,
              Filsfils, C., Parekh, R., and H. Bidgoli, "SR Replication
              Policy for P2MP Service Delivery", draft-voyer-spring-sr-
              p2mp-policy-01 (work in progress), October 2018.

   [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>.

   [RFC3443]  Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing
              in Multi-Protocol Label Switching (MPLS) Networks",
              RFC 3443, DOI 10.17487/RFC3443, January 2003,
              <https://www.rfc-editor.org/info/rfc3443>.






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   [RFC4203]  Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
              Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
              <https://www.rfc-editor.org/info/rfc4203>.

   [RFC5307]  Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions
              in Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008,
              <https://www.rfc-editor.org/info/rfc5307>.

   [RFC8029]  Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
              Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
              Switched (MPLS) Data-Plane Failures", RFC 8029,
              DOI 10.17487/RFC8029, March 2017,
              <https://www.rfc-editor.org/info/rfc8029>.

   [RFC8287]  Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya,
              N., Kini, S., and M. Chen, "Label Switched Path (LSP)
              Ping/Traceroute for Segment Routing (SR) IGP-Prefix and
              IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data
              Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017,
              <https://www.rfc-editor.org/info/rfc8287>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

10.2.  Informative References

   [I-D.ietf-isis-segment-routing-extensions]
              Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A.,
              Gredler, H., Litkowski, S., Decraene, B., and J. Tantsura,
              "IS-IS Extensions for Segment Routing", draft-ietf-isis-
              segment-routing-extensions-19 (work in progress), July
              2018.

   [I-D.ietf-ospf-ospfv3-segment-routing-extensions]
              Psenak, P., Filsfils, C., Previdi, S., Gredler, H.,
              Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3
              Extensions for Segment Routing", draft-ietf-ospf-ospfv3-
              segment-routing-extensions-15 (work in progress), August
              2018.








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   [I-D.ietf-ospf-segment-routing-extensions]
              Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
              Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
              Extensions for Segment Routing", draft-ietf-ospf-segment-
              routing-extensions-25 (work in progress), April 2018.

   [I-D.ietf-spring-segment-routing-central-epe]
              Filsfils, C., Previdi, S., Dawra, G., Aries, E., and D.
              Afanasiev, "Segment Routing Centralized BGP Egress Peer
              Engineering", draft-ietf-spring-segment-routing-central-
              epe-10 (work in progress), December 2017.

   [I-D.ietf-spring-segment-routing-ldp-interop]
              Bashandy, A., Filsfils, C., Previdi, S., Decraene, B., and
              S. Litkowski, "Segment Routing interworking with LDP",
              draft-ietf-spring-segment-routing-ldp-interop-15 (work in
              progress), September 2018.

   [I-D.ietf-spring-segment-routing-mpls]
              Bashandy, A., Filsfils, C., Previdi, S., Decraene, B.,
              Litkowski, S., and R. Shakir, "Segment Routing with MPLS
              data plane", draft-ietf-spring-segment-routing-mpls-14
              (work in progress), June 2018.

   [IANA-MPLS-LSP-PING]
              IANA, "Multi-Protocol Label Switching (MPLS) Label
              Switched Paths (LSPs) Ping Parameters",
              <http://www.iana.org/assignments/mpls-lsp-ping-parameters/
              mpls-lsp-ping-parameters.xhtml>.

   [RFC0792]  Postel, J., "Internet Control Message Protocol", STD 5,
              RFC 792, DOI 10.17487/RFC0792, September 1981,
              <https://www.rfc-editor.org/info/rfc792>.

Authors' Addresses

   Nagendra Kumar (editor)
   Cisco Systems, Inc.
   7200-12 Kit Creek Road
   Research Triangle Park, NC  27709-4987
   US

   Email: naikumar@cisco.com








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Internet-Draft     LSP Ping/Trace for SR SIDs on MPLS       October 2018


   Carlos Pignataro (editor)
   Cisco Systems, Inc.
   7200-11 Kit Creek Road
   Research Triangle Park, NC  27709-4987
   US

   Email: cpignata@cisco.com


   Faisal Iqbal
   Cisco Systems, Inc.

   Email: faiqbal@cisco.com


   Zafar Ali
   Cisco Systems, Inc.

   Email: zali@cisco.com
































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