| < draft-mirsky-spring-bfd-05.txt | draft-mirsky-spring-bfd-06.txt > | |||
|---|---|---|---|---|
| SPRING Working Group G. Mirsky | SPRING Working Group G. Mirsky | |||
| Internet-Draft ZTE Corp. | Internet-Draft ZTE Corp. | |||
| Intended status: Standards Track J. Tantsura | Intended status: Standards Track J. Tantsura | |||
| Expires: September 2, 2018 Nuage Networks | Expires: February 24, 2019 Nuage Networks | |||
| I. Varlashkin | I. Varlashkin | |||
| M. Chen | M. Chen | |||
| Huawei | Huawei | |||
| March 1, 2018 | August 23, 2018 | |||
| Bidirectional Forwarding Detection (BFD) in Segment Routing Networks | Bidirectional Forwarding Detection (BFD) in Segment Routing Networks | |||
| Using MPLS Dataplane | Using MPLS Dataplane | |||
| draft-mirsky-spring-bfd-05 | draft-mirsky-spring-bfd-06 | |||
| Abstract | Abstract | |||
| Segment Routing (SR) architecture leverages the paradigm of source | Segment Routing (SR) architecture leverages the paradigm of source | |||
| routing. It can be realized in the Multiprotocol Label Switching | routing. It can be realized in the Multiprotocol Label Switching | |||
| (MPLS) network without any change to the data plane. A segment is | (MPLS) network without any change to the data plane. A segment is | |||
| encoded as an MPLS label and an ordered list of segments is encoded | encoded as an MPLS label, and an ordered list of segments is encoded | |||
| as a stack of labels. Bidirectional Forwarding Detection (BFD) is | as a stack of labels. Bidirectional Forwarding Detection (BFD) is | |||
| expected to monitor any kind of paths between systems. This document | expected to monitor any existing path between systems. This document | |||
| defines how to use Label Switched Path Ping to bootstrap and control | defines how to use Label Switched Path Ping to bootstrap a BFD | |||
| path in reverse direction of a BFD session on the Segment Routing | session, control path in reverse direction of the SR-MPLS tunnel and | |||
| static MPLS tunnel and applicability of BFD Demand mode to SR-MPLS | applicability of BFD Demand mode in the SR-MPLS domain. | |||
| domain. | ||||
| Status of This Memo | Status of This Memo | |||
| This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on September 2, 2018. | This Internet-Draft will expire on February 24, 2019. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2018 IETF Trust and the persons identified as the | Copyright (c) 2018 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 1.1. Conventions used in this document . . . . . . . . . . . . 3 | 1.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 | 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 | 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 | |||
| 2. Bootstrapping BFD session over Segment Routed tunnel . . . . 3 | 2. Bootstrapping BFD Session over Segment Routed Tunnel with | |||
| 3. Use BFD Reverse Path TLV over Segment Routed MPLS Tunnel . . 4 | MPLS Data Plane . . . . . . . . . . . . . . . . . . . . . . . 3 | |||
| 4. Use Non-FEC Path TLV . . . . . . . . . . . . . . . . . . . . 4 | 3. Use BFD Reverse Path TLV over Segment Routed MPLS Tunnel . . 5 | |||
| 4. Use Non-FEC Path TLV . . . . . . . . . . . . . . . . . . . . 5 | ||||
| 5. BFD Reverse Path TLV over Segment Routed MPLS Tunnel with | 5. BFD Reverse Path TLV over Segment Routed MPLS Tunnel with | |||
| Dynamic Control Plane . . . . . . . . . . . . . . . . . . . . 6 | Dynamic Control Plane . . . . . . . . . . . . . . . . . . . . 7 | |||
| 6. Applicability of BFD Demand Mode in SR-MPLS Domain . . . . . 6 | 6. Applicability of BFD Demand Mode in SR-MPLS Domain . . . . . 7 | |||
| 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 | 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 | |||
| 7.1. Non-FEC Path TLV . . . . . . . . . . . . . . . . . . . . 7 | 7.1. Non-FEC Path TLV . . . . . . . . . . . . . . . . . . . . 7 | |||
| 7.2. Return Code . . . . . . . . . . . . . . . . . . . . . . . 8 | 7.2. Return Code . . . . . . . . . . . . . . . . . . . . . . . 8 | |||
| 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 | 8. Security Considerations . . . . . . . . . . . . . . . . . . . 9 | |||
| 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 | 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
| 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 | 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
| 10.1. Normative References . . . . . . . . . . . . . . . . . . 8 | 10.1. Normative References . . . . . . . . . . . . . . . . . . 9 | |||
| 10.2. Informative References . . . . . . . . . . . . . . . . . 10 | 10.2. Informative References . . . . . . . . . . . . . . . . . 11 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 | |||
| 1. Introduction | 1. Introduction | |||
| [RFC5880], [RFC5881], and [RFC5883] established the Bidirectional | [RFC5880], [RFC5881], and [RFC5883] defined the operation of | |||
| Forwarding Detection (BFD) protocol for IP networks. [RFC5884] and | Bidirectional Forwarding Detection (BFD) protocol between the two | |||
| [RFC7726] set rules of using BFD Asynchronous mode over Multiprotocol | systems over IP networks. [RFC5884] and [RFC7726] set rules for | |||
| using BFD Asynchronous mode over point-to-point (p2p) Multiprotocol | ||||
| Label Switching (MPLS) Label Switched Path (LSP). These latter | Label Switching (MPLS) Label Switched Path (LSP). These latter | |||
| standards implicitly assume that the egress BFD peer, which is the | standards implicitly assume that the egress BFD peer, which is the | |||
| egress Label Edge Router (LER), will use the shortest path route | egress Label Edge Router (LER), will use the shortest path route | |||
| regardless of the path the ingress LER uses to send BFD control | regardless of the path the ingress LER uses to send BFD Control | |||
| packets towards it. | packets towards it. | |||
| This document defines use of LSP Ping for Segment Routing networks | This document defines the use of LSP Ping for Segment Routing | |||
| over MPLS dataplane [RFC8287] to bootstrap and control path of a BFD | networks over MPLS data plane [RFC8287] to bootstrap and control path | |||
| session from the egress to ingress LER using static MPLS tunnel. | of a BFD session from the egress to ingress LER using Segment Routing | |||
| tunnel with MPLS data plane (SR-MPLS). | ||||
| 1.1. Conventions used in this document | 1.1. Conventions | |||
| 1.1.1. Terminology | 1.1.1. Terminology | |||
| BFD: Bidirectional Forwarding Detection | BFD: Bidirectional Forwarding Detection | |||
| FEC: Forwarding Equivalence Class | FEC: Forwarding Equivalence Class | |||
| MPLS: Multiprotocol Label Switching | MPLS: Multiprotocol Label Switching | |||
| SR-MPLS Segment Routing with MPLS data plane | SR-MPLS Segment Routing with MPLS data plane | |||
| LSP: Label Switching Path | LSP: Label Switched Path | |||
| LER: Label Edge Router | LSR Label Switching Router | |||
| LER Label Edge Router | ||||
| p2p Point-to-point | ||||
| SID Segment Identifier | ||||
| SR Segment Routing | SR Segment Routing | |||
| 1.1.2. Requirements Language | 1.1.2. Requirements Language | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | |||
| "OPTIONAL" in this document are to be interpreted as described in BCP | "OPTIONAL" in this document are to be interpreted as described in BCP | |||
| 14 [RFC2119] [RFC8174] when, and only when, they appear in all | 14 [RFC2119] [RFC8174] when, and only when, they appear in all | |||
| capitals, as shown here. | capitals, as shown here. | |||
| 2. Bootstrapping BFD session over Segment Routed tunnel | 2. Bootstrapping BFD Session over Segment Routed Tunnel with MPLS Data | |||
| Plane | ||||
| As demonstrated in [RFC8287] introduction of Segment Routing network | Use of an LSP Ping to bootstrap BFD over MPLS LSP is required, as | |||
| domains with an MPLS data plane requires three new sub-TLVs that MAY | documented in [RFC5884], to establish an association between a fault | |||
| be used with Target Forwarding Equivalence Class (FEC) TLV. | detection message, i.e., BFD Control message, and the Forwarding | |||
| Section 6.1 addresses use of the new sub-TLVs in Target FEC TLV in | Equivalency Class (FEC) of a single label stack LSP in case of | |||
| LSP ping and LSP traceroute. For the case of LSP ping the [RFC8287] | Penultimate Hop Popping or when the egress Label Switching Router | |||
| states that: | (LSR) distributes the Explicit NULL label to the penultimate hop | |||
| router. The Explicit NULL label is not advertised as a Segment | ||||
| Identifier (SID) by an SR node but, as demonstrated in section 3.1 | ||||
| [I-D.ietf-spring-segment-routing-mpls] if the operation at the | ||||
| penultimate hop is NEXT; then the egress SR node will receive an IP | ||||
| encapsulated packet. Thus the conclusion is that LSP Ping MUST be | ||||
| used to bootstrap a BFD session in SR-MPLS domain. | ||||
| Initiator MUST include FEC(s) corresponding to the destination | As demonstrated in [RFC8287], the introduction of Segment Routing | |||
| segment. | network domains with an MPLS data plane requires three new sub-TLVs | |||
| that MAY be used with Target FEC TLV. Section 6.1 addresses use of | ||||
| the new sub-TLVs in Target FEC TLV in LSP ping and LSP traceroute. | ||||
| For the case of LSP ping, the [RFC8287] states that: | ||||
| Initiator, i.e. ingress LSR, MAY include FECs corresponding to | The initiator, i.e., ingress LSR, MUST include FEC(s) | |||
| some or all of segments imposed in the label stack by the ingress | corresponding to the destination segment. | |||
| LSR to communicate the segments traversed. | ||||
| The initiator MAY include FECs corresponding to some or all of | ||||
| segments imposed in the label stack by the ingress LSR to | ||||
| communicate the segments traversed. | ||||
| It has been noted in [RFC5884] that a BFD session monitors for | It has been noted in [RFC5884] that a BFD session monitors for | |||
| defects particular <MPLS LSP, FEC> tuple. [RFC7726] clarified how to | defects particular <MPLS LSP, FEC> tuple. [RFC7726] clarified how to | |||
| establish and operate multiple BFD sessions for the same <MPLS LSP, | establish and operate multiple BFD sessions for the same <MPLS LSP, | |||
| FEC> tuple. Because only ingress edge router is aware of the SR- | FEC> tuple. Because only ingress edge router is aware of the SR- | |||
| based explicit route the egress edge router can associate the LSP | based explicit route, the egress edge router can associate the LSP | |||
| ping with BFD Discriminator TLV with only one of the FECs it | ping with BFD Discriminator TLV with only one of the FECs it | |||
| advertised for the particular segment. Thus this document clarifies | advertised for the particular segment. Thus this document clarifies | |||
| that: | that: | |||
| When LSP Ping is used to bootstrap a BFD session the FEC | When LSP Ping is used to bootstraping a BFD session for SR-MPLS | |||
| corresponding to the destination segment to be associated with the | tunnel the FEC corresponding to the segment to be associated with | |||
| BFD session MUST be as the very last sub-TLV in the Target FEC | the BFD session MUST be as the very last sub-TLV in the Target FEC | |||
| TLV. | TLV. | |||
| If the target segment is an anycast prefix segment | ||||
| ([I-D.ietf-spring-mpls-anycast-segments]) the corresponding Anycast | ||||
| SID MUST be included in the Target TLV as the very last sub-TLV. | ||||
| Also, for BFD control packet the ingress SR node MUST use precisely | ||||
| the same label stack encapsulation, especially Entropy Label | ||||
| ([RFC6790]), as for the LSP ping with the BFD Discriminator TLV that | ||||
| bootstrapped the BFD session. Other operational aspects of using BFD | ||||
| to monitor the continuity of the path to the particular Anycast SID, | ||||
| advertised by a group of SR-MPLS capable nodes, will be considered in | ||||
| the future versions of the document. | ||||
| Encapsulation of a BFD Control packet in Segment Routing network with | Encapsulation of a BFD Control packet in Segment Routing network with | |||
| MPLS dataplane MUST follow Section 7 [RFC5884] when IP/UDP header | MPLS data plane MUST follow Section 7 [RFC5884] when the IP/UDP | |||
| used and MUST follow Section 3.4 [RFC6428] without IP/UDP header | header used and MUST follow Section 3.4 [RFC6428] without IP/UDP | |||
| being used. | header being used. | |||
| 3. Use BFD Reverse Path TLV over Segment Routed MPLS Tunnel | 3. Use BFD Reverse Path TLV over Segment Routed MPLS Tunnel | |||
| For BFD over MPLS LSP case, per [RFC5884], egress LER MAY send BFD | For BFD over MPLS LSP case, per [RFC5884], egress LER MAY send BFD | |||
| control packet to the ingress LER either over IP network or an MPLS | control packet to the ingress LER either over IP network or an MPLS | |||
| LSP. Similarly, for the case of BFD over p2p segment tunnel with | LSP. Similarly, for the case of BFD over p2p SR-MPLS tunnel, the | |||
| MPLS data plane, the ingress LER MAY route BFD control packet over IP | egress LER MAY route BFD control packet over the IP network, as | |||
| network, as described in [RFC5883], or transmit over a segment | described in [RFC5883], or transmit over a segment tunnel, as | |||
| tunnel, as described in Section 7 [RFC5884]. In some cases there may | described in Section 7 [RFC5884]. In some cases, there may be a need | |||
| be a need to direct egress BFD peer to use specific path for the | to direct egress BFD peer to use specific path for the reverse | |||
| reverse direction of the BFD session by using the BFD Reverse Path | direction of the BFD session by using the BFD Reverse Path TLV and | |||
| TLV and following all procedures as defined in | following all procedures as defined in [I-D.ietf-mpls-bfd-directed]. | |||
| [I-D.ietf-mpls-bfd-directed]. | ||||
| 4. Use Non-FEC Path TLV | 4. Use Non-FEC Path TLV | |||
| For the case of MPLS dataplane, Segment Routing Architecture | For the case of MPLS data plane, Segment Routing Architecture | |||
| [I-D.ietf-spring-segment-routing] explains that "a segment is encoded | [RFC8402] explains that "a segment is encoded as an MPLS label. An | |||
| as an MPLS label. An ordered list of segments is encoded as a stack | ordered list of segments is encoded as a stack of labels." YANG Data | |||
| of labels." YANG Data Model for MPLS Static LSPs | Model for MPLS Static LSPs [I-D.ietf-mpls-static-yang] models | |||
| [I-D.ietf-mpls-static-yang] models outgoing MPLS labels to be imposed | outgoing MPLS labels to be imposed as leaf-list [RFC6020], i.e., as | |||
| as leaf-list [RFC6020], i.e., as array of rt-types:mpls-label | array of rt-types:mpls-label [RFC8294]. | |||
| [RFC8294]. | ||||
| This document defines new optional Non-FEC Path TLV. The format of | This document defines new optional Non-FEC Path TLV. The format of | |||
| the Non-FEC Path TLV is presented in Figure 1 | the Non-FEC Path TLV is presented in Figure 1 | |||
| 0 1 2 3 | 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 | 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 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Non-FEC Path TLV Type | Length | | | Non-FEC Path TLV Type | Length | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | | | | | | |||
| ~ Non-FEC Path ~ | ~ Non-FEC Path ~ | |||
| | | | | | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| Figure 1: Non-FEC Path TLV Format | Figure 1: Non-FEC Path TLV Format | |||
| Non-FEC Path TLV Type is 2 octets in length and has a value of TBD1 | Non-FEC Path TLV Type is two octets in length and has a value of TBD1 | |||
| (to be assigned by IANA as requested in Section 7.1). | (to be assigned by IANA as requested in Section 7.1). | |||
| Length field is 2 octets long and defines the length in octets of the | Length field is two octets long and defines the length in octets of | |||
| Non-FEC Path field. | the Non-FEC Path field. | |||
| Non-FEC Path field contains a sub-TLV. Any Non-FEC Path sub-TLV | Non-FEC Path field contains a sub-TLV. Any Non-FEC Path sub-TLV | |||
| (defined in this document or to be defined in the future) for Non-FEC | (defined in this document or to be defined in the future) for Non-FEC | |||
| Path TLV type MAY be used in this field. None or one sub-TLV MAY be | Path TLV type MAY be used in this field. None or one sub-TLV MAY be | |||
| included in the Non-FEC Path TLV. If no sub-TLV has been found in | included in the Non-FEC Path TLV. If no sub-TLV has been found in | |||
| the Non-FEC Path TLV, the egress BFD peer MUST revert to using the | the Non-FEC Path TLV, the egress BFD peer MUST revert to using the | |||
| reverse path selected based on its local policy. If there are more | reverse path selected based on its local policy. If there is more | |||
| than one sub-TLV, then the Return Code in echo reply MUST be set to | than one sub-TLV, then the Return Code in echo reply MUST be set to | |||
| value TBD3 "Too Many TLVs Detected" (to be assigned by IANA as | value TBD3 "Too Many TLVs Detected" (to be assigned by IANA as | |||
| requested in Table 4). | requested in Table 4). | |||
| Non-FEC Path TLV MAY be used to specify the reverse path of the BFD | Non-FEC Path TLV MAY be used to specify the reverse path of the BFD | |||
| session identified in the BFD Discriminator TLV. If the Non-FEC Path | session identified in the BFD Discriminator TLV. If the Non-FEC Path | |||
| TLV is present in the echo request message the BFD Discriminator TLV | TLV is present in the echo request message the BFD Discriminator TLV | |||
| MUST be present as well. If the BFD Discriminator TLV is absent when | MUST be present as well. If the BFD Discriminator TLV is absent when | |||
| the Non-FEC Path TLV is included, then it MUST be treated as | the Non-FEC Path TLV is included, then it MUST be treated as | |||
| malformed Echo Request, as described in [RFC8029]. | malformed Echo Request, as described in [RFC8029]. | |||
| This document defines Static Routing MPLS Tunnel sub-TLV that MAY be | This document defines Static Routing MPLS Tunnel sub-TLV that MAY be | |||
| used with the Non-FEC Path TLV. The format of the sub-TLV is | used with the Non-FEC Path TLV. The format of the sub-TLV is | |||
| presented in Figure 2. | presented in Figure 2. | |||
| 0 1 2 3 | 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 | 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 | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | SR MPLS Tunnel sub-TLV Type | Length | | | SR MPLS Tunnel sub-TLV Type | Length | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Label Entry 1 | | | Label Entry 1 (Top Label) | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Label Entry 2 | | | Label Entry 2 | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| ~ ~ | ~ ~ | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Label Entry N | | | Label Entry N (Bottom Label) | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| Figure 2: Segment Routing MPLS Tunnel sub-TLV | Figure 2: Segment Routing MPLS Tunnel sub-TLV | |||
| The Segment Routing MPLS Tunnel sub-TLV Type is two octets in length, | The Segment Routing MPLS Tunnel sub-TLV Type is two octets in length, | |||
| and has a value of TBD2 (to be assigned by IANA as requested in | and has a value of TBD2 (to be assigned by IANA as requested in | |||
| Section 7.1). | Section 7.1). | |||
| The egress LSR MUST use the Value field as label stack for BFD | The egress LSR MUST use the Value field as label stack for BFD | |||
| control packets for the BFD session identified by the source IP | control packets for the BFD session identified by the source IP | |||
| skipping to change at page 7, line 9 ¶ | skipping to change at page 7, line 30 ¶ | |||
| mode; | mode; | |||
| o once BFD session is Up, the ingress node switches the egress BFD | o once BFD session is Up, the ingress node switches the egress BFD | |||
| node into the Demand mode by setting D field in BFD Control packet | node into the Demand mode by setting D field in BFD Control packet | |||
| it transmits; | it transmits; | |||
| o if the egress BFD node detects the failure of the BFD session, it | o if the egress BFD node detects the failure of the BFD session, it | |||
| sends its BFD control packet to the ingress over the IP network | sends its BFD control packet to the ingress over the IP network | |||
| with Poll sequence; | with Poll sequence; | |||
| o if the ingress node receives BFD control packet from remote node | o if the ingress node receives a BFD control packet from the remote | |||
| in Demand mode with Poll sequence and Diag field indicating the | node in a Demand mode with Poll sequence and Diag field indicating | |||
| failure, the ingress transmits BFD control packet with Final over | the failure, the ingress transmits BFD control packet with Final | |||
| IP and switches the BFD over SR-MPLS back into Async mode, sending | over IP and switches the BFD over SR-MPLS back into Async mode, | |||
| BFD Control packets one per second. | sending BFD Control packets one per second. | |||
| 7. IANA Considerations | 7. IANA Considerations | |||
| 7.1. Non-FEC Path TLV | 7.1. Non-FEC Path TLV | |||
| IANA is requested to assign new TLV type from the from Standards | IANA is requested to assign new TLV type from the from Standards | |||
| Action range of the registry "Multiprotocol Label Switching | Action range of the registry "Multiprotocol Label Switching | |||
| Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters - | Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters - | |||
| TLVs" as defined in the Table 1. | TLVs" as defined in Table 1. | |||
| +-------+------------------+---------------+ | +-------+------------------+---------------+ | |||
| | Value | TLV Name | Reference | | | Value | TLV Name | Reference | | |||
| +-------+------------------+---------------+ | +-------+------------------+---------------+ | |||
| | TBD1 | Non-FEC Path TLV | This document | | | TBD1 | Non-FEC Path TLV | This document | | |||
| +-------+------------------+---------------+ | +-------+------------------+---------------+ | |||
| Table 1: New Non-FEC Path TLV | Table 1: New Non-FEC Path TLV | |||
| IANA is requested to create new Non-FEC Path sub-TLV registry for the | IANA is requested to create new Non-FEC Path sub-TLV registry for the | |||
| skipping to change at page 8, line 5 ¶ | skipping to change at page 8, line 27 ¶ | |||
| | 32768-49161 | Standards | This range is for optional TLVs | | | 32768-49161 | Standards | This range is for optional TLVs | | |||
| | | Action | that can be silently dropped if not | | | | Action | that can be silently dropped if not | | |||
| | | | recognized. | | | | | recognized. | | |||
| | 49162-64511 | Specification | Experimental RFC needed | | | 49162-64511 | Specification | Experimental RFC needed | | |||
| | | Required | | | | | Required | | | |||
| | 64512-65535 | Private Use | | | | 64512-65535 | Private Use | | | |||
| +-------------+---------------+-------------------------------------+ | +-------------+---------------+-------------------------------------+ | |||
| Table 2: Non-FEC Path sub-TLV registry | Table 2: Non-FEC Path sub-TLV registry | |||
| IANA is requested to allocate following values from the Non-FEC Path | IANA is requested to allocate the following values from the Non-FEC | |||
| sub-TLV registry as defined in Table 3. | Path sub-TLV registry as defined in Table 3. | |||
| +-------+-------------------------------------+---------------+ | +-------+-------------------------------------+---------------+ | |||
| | Value | Description | Reference | | | Value | Description | Reference | | |||
| +-------+-------------------------------------+---------------+ | +-------+-------------------------------------+---------------+ | |||
| | 0 | Reserved | This document | | | 0 | Reserved | This document | | |||
| | TBD2 | Segment Routing MPLS Tunnel sub-TLV | This document | | | TBD2 | Segment Routing MPLS Tunnel sub-TLV | This document | | |||
| | 65535 | Reserved | This document | | | 65535 | Reserved | This document | | |||
| +-------+-------------------------------------+---------------+ | +-------+-------------------------------------+---------------+ | |||
| Table 3: New Segment Routing Tunnel sub-TLV | Table 3: New Segment Routing Tunnel sub-TLV | |||
| 7.2. Return Code | 7.2. Return Code | |||
| IANA is requested to create Non-FEC Path sub-TLV subregistry for the | IANA is requested to create Non-FEC Path sub-TLV sub-registry for the | |||
| new Non-FEC Path TLV. assign a new Return Code value from the "Multi- | new Non-FEC Path TLV and assign a new Return Code value from the | |||
| Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping | "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) | |||
| Parameters" registry, "Return Codes" sub-registry, as follows using a | Ping Parameters" registry, "Return Codes" sub-registry, as follows | |||
| Standards Action value. | using a Standards Action value. | |||
| +--------+-------------------------+---------------+ | +--------+-------------------------+---------------+ | |||
| | Value | Description | Reference | | | Value | Description | Reference | | |||
| +--------+-------------------------+---------------+ | +--------+-------------------------+---------------+ | |||
| | X TBD3 | Too Many TLVs Detected. | This document | | | X TBD3 | Too Many TLVs Detected. | This document | | |||
| +--------+-------------------------+---------------+ | +--------+-------------------------+---------------+ | |||
| Table 4: New Return Code | Table 4: New Return Code | |||
| 8. Security Considerations | 8. Security Considerations | |||
| Security considerations discussed in [RFC5880], [RFC5884], [RFC7726], | Security considerations discussed in [RFC5880], [RFC5884], [RFC7726], | |||
| and [RFC8029] apply to this document. | and [RFC8029] apply to this document. | |||
| 9. Acknowledgements | 9. Acknowledgments | |||
| TBD | TBD | |||
| 10. References | 10. References | |||
| 10.1. Normative References | 10.1. Normative References | |||
| [I-D.ietf-mpls-bfd-directed] | [I-D.ietf-mpls-bfd-directed] | |||
| Mirsky, G., Tantsura, J., Varlashkin, I., and M. Chen, | Mirsky, G., Tantsura, J., Varlashkin, I., and M. Chen, | |||
| "Bidirectional Forwarding Detection (BFD) Directed Return | "Bidirectional Forwarding Detection (BFD) Directed Return | |||
| Path", draft-ietf-mpls-bfd-directed-08 (work in progress), | Path", draft-ietf-mpls-bfd-directed-09 (work in progress), | |||
| December 2017. | August 2018. | |||
| [I-D.ietf-spring-segment-routing] | [I-D.ietf-spring-segment-routing-mpls] | |||
| Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B., | Bashandy, A., Filsfils, C., Previdi, S., Decraene, B., | |||
| Litkowski, S., and R. Shakir, "Segment Routing | Litkowski, S., and R. Shakir, "Segment Routing with MPLS | |||
| Architecture", draft-ietf-spring-segment-routing-15 (work | data plane", draft-ietf-spring-segment-routing-mpls-14 | |||
| in progress), January 2018. | (work in progress), June 2018. | |||
| [I-D.mirsky-bfd-mpls-demand] | [I-D.mirsky-bfd-mpls-demand] | |||
| Mirsky, G., "BFD in Demand Mode over Point-to-Point MPLS | Mirsky, G., "BFD in Demand Mode over Point-to-Point MPLS | |||
| LSP", draft-mirsky-bfd-mpls-demand-02 (work in progress), | LSP", draft-mirsky-bfd-mpls-demand-03 (work in progress), | |||
| October 2017. | June 2018. | |||
| [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
| Requirement Levels", BCP 14, RFC 2119, | Requirement Levels", BCP 14, RFC 2119, | |||
| DOI 10.17487/RFC2119, March 1997, | DOI 10.17487/RFC2119, March 1997, | |||
| <https://www.rfc-editor.org/info/rfc2119>. | <https://www.rfc-editor.org/info/rfc2119>. | |||
| [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection | [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection | |||
| (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, | (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, | |||
| <https://www.rfc-editor.org/info/rfc5880>. | <https://www.rfc-editor.org/info/rfc5880>. | |||
| skipping to change at page 10, line 22 ¶ | skipping to change at page 10, line 48 ¶ | |||
| 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | |||
| May 2017, <https://www.rfc-editor.org/info/rfc8174>. | May 2017, <https://www.rfc-editor.org/info/rfc8174>. | |||
| [RFC8287] Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya, | [RFC8287] Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya, | |||
| N., Kini, S., and M. Chen, "Label Switched Path (LSP) | N., Kini, S., and M. Chen, "Label Switched Path (LSP) | |||
| Ping/Traceroute for Segment Routing (SR) IGP-Prefix and | Ping/Traceroute for Segment Routing (SR) IGP-Prefix and | |||
| IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data | IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data | |||
| Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017, | Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017, | |||
| <https://www.rfc-editor.org/info/rfc8287>. | <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 | 10.2. Informative References | |||
| [I-D.ietf-mpls-static-yang] | [I-D.ietf-mpls-static-yang] | |||
| Saad, T., Raza, K., Gandhi, R., Liu, X., and V. Beeram, "A | Saad, T., Raza, K., Gandhi, R., Liu, X., and V. Beeram, "A | |||
| YANG Data Model for MPLS Static LSPs", draft-ietf-mpls- | YANG Data Model for MPLS Static LSPs", draft-ietf-mpls- | |||
| static-yang-05 (work in progress), February 2018. | static-yang-05 (work in progress), February 2018. | |||
| [I-D.ietf-spring-mpls-anycast-segments] | ||||
| Sarkar, P., Gredler, H., Filsfils, C., Previdi, S., | ||||
| Decraene, B., and M. Horneffer, "Anycast Segments in MPLS | ||||
| based Segment Routing", draft-ietf-spring-mpls-anycast- | ||||
| segments-02 (work in progress), January 2018. | ||||
| [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for | [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for | |||
| the Network Configuration Protocol (NETCONF)", RFC 6020, | the Network Configuration Protocol (NETCONF)", RFC 6020, | |||
| DOI 10.17487/RFC6020, October 2010, | DOI 10.17487/RFC6020, October 2010, | |||
| <https://www.rfc-editor.org/info/rfc6020>. | <https://www.rfc-editor.org/info/rfc6020>. | |||
| [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and | ||||
| L. Yong, "The Use of Entropy Labels in MPLS Forwarding", | ||||
| RFC 6790, DOI 10.17487/RFC6790, November 2012, | ||||
| <https://www.rfc-editor.org/info/rfc6790>. | ||||
| [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, | [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, | |||
| "Common YANG Data Types for the Routing Area", RFC 8294, | "Common YANG Data Types for the Routing Area", RFC 8294, | |||
| DOI 10.17487/RFC8294, December 2017, | DOI 10.17487/RFC8294, December 2017, | |||
| <https://www.rfc-editor.org/info/rfc8294>. | <https://www.rfc-editor.org/info/rfc8294>. | |||
| Authors' Addresses | Authors' Addresses | |||
| Greg Mirsky | Greg Mirsky | |||
| ZTE Corp. | ZTE Corp. | |||
| End of changes. 43 change blocks. | ||||
| 95 lines changed or deleted | 142 lines changed or added | |||
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