Interdomain Routing Working Group M. Chen Internet-Draft S. Zhuang Intended status: Standards Track Huawei Expires: April 23, 2018 October 20, 2017 BGP Link-State Extensions for IPv6 Segment Routing draft-chen-idr-bgp-ls-srv6-00 Abstract This document defines extensions to BGP link-state (BGP-LS) to carry the information of IPv6 Segment Routing (SRv6). 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 April 23, 2018. Copyright Notice Copyright (c) 2017 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 Chen & Zhuang Expires April 23, 2018 [Page 1] Internet-Draft BGP-LS for SRv6 October 2017 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. BGP-LS Extensions for SRv6 . . . . . . . . . . . . . . . . . 3 2.1. TLV and Sub-TLV Format . . . . . . . . . . . . . . . . . 3 2.2. Common Attribute sub-TLVs . . . . . . . . . . . . . . . . 3 2.2.1. SRv6 Function sub-TLV . . . . . . . . . . . . . . . . 3 2.3. Node Attribute TLVs . . . . . . . . . . . . . . . . . . . 4 2.3.1. SRv6 Capability TLV . . . . . . . . . . . . . . . . . 4 2.3.2. SRv6 SID TLV . . . . . . . . . . . . . . . . . . . . 8 2.4. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 8 2.4.1. P2P SRv6 x-SID TLV . . . . . . . . . . . . . . . . . 9 2.4.2. LAN SRv6 X-SID TLV . . . . . . . . . . . . . . . . . 10 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 4. Security Considerations . . . . . . . . . . . . . . . . . . . 11 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.1. Normative References . . . . . . . . . . . . . . . . . . 11 6.2. Informative References . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction Segment Routing (SR) [I-D.ietf-spring-segment-routing] is a source routed forwarding method that allows to directly encode forwarding instructions in each packet, hence it enables to steer traffic through a network without the per-flow states maintained in the transit nodes. Segment Routing can be instantiated on MPLS data plane or IPv6 data plane. The former is called SR-MPLS [I-D.ietf-spring-segment-routing-mpls], the latter is called SRv6 [I- D.filsfils-spring-srv6-network-programming][I-D.ietf-6man-segment-rou ting-header]. SR-MPLS leverages the MPLS label stack to construct the SR path, SRv6 uses the Segment Routing Header [I-D.ietf-spring-segment-routing-mpls] to construct SR path. ISIS extensions in support of SRv6 are defined [I-D.bashandy-isis-srv6-extensions]. BGP-LS extensions for Segment Routing are defined [I-D.ietf-idr-bgp-ls-segment-routing-ext], it is mainly designed for SR-MPLS. This document defines extensions to BGP link-state (BGP-LS) [RFC7752] to carry the information of IPv6 Segment Routing (SRv6). Chen & Zhuang Expires April 23, 2018 [Page 2] Internet-Draft BGP-LS for SRv6 October 2017 2. BGP-LS Extensions for SRv6 BGP-LS[RFC7752] defines Node NLRI, Link NLRI and Prefix NLRI, each NLRI has its own corresponding attribute which are referred to as Node Attribute, Link Attribute and Prefix Attribute. These attributes are encoded as TLVs and/or sub-TLVs. This document defines new BGP-LS attribute TLVs and sub-TLVs that correspond to the IGP-SRv6 extensions. 2.1. TLV and Sub-TLV Format To align with those existing BGP-LS TLV and sub-TLV definition, all TLVs and sub-TLVs defined in this document have the following 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLV/sub-TLV Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Value (variable) ... ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o TLV/sub-TLV Type field is 2 octets in length. o The Length filed is 2 octets in length as well, its value indicates the length (in octets) of the Value field. o The Value filed is variable in length. 2.2. Common Attribute sub-TLVs This section defines common attribute sub-TLVs that are used to describe the common attributes of a SRv6 SID, these sub-TLVs can be shared by all kind of SRv6 SID TLVs. 2.2.1. SRv6 Function sub-TLV As defined [I-D.filsfils-spring-srv6-network-programming], an IPv6 Segment Identifier is a 128-bit value. A SRv6 SID is represented as LOC:FUNCT where LOC is the L most significant bits and FUNCT is the 128-L least significant bits. The LOC (location) part of the SID is routable and leads to the node which owns that SID, and the FUNCT (function) part of the SID is an opaque identification of a local function bound to the SID. Chen & Zhuang Expires April 23, 2018 [Page 3] Internet-Draft BGP-LS for SRv6 October 2017 The SRv6 Function sub-TLV is defined to describe the FUNCT part of a SRv6 SID. The SRv6 Function sub-TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Function | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD1. o Length: 2 octets in length, and the value is 4. o Flags: 1 octet in length. As defined [I-D.bashandy-isis-srv6-extensions]. o Function: 2 octets in length. As defined [I-D.bashandy-isis-srv6-extensions]. 2.3. Node Attribute TLVs This section defines the attribute TLVs that are only associated with the Node NLRI. 2.3.1. SRv6 Capability TLV The SRv6 Capability TLV is defined to advertise SRv6 capabilities that a SRv6 node can support. The SRv6 Capability TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: Chen & Zhuang Expires April 23, 2018 [Page 4] Internet-Draft BGP-LS for SRv6 October 2017 o Type: 2 octets in length, and the value is TBD2. o Length: 2 octets in length, and the value indicates the length (in octets) of the whole TLV (excluding the Type and Length fields). o Flags: 2 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. o Sub-TLVs: variable in length. This document defines 5 sub-TLVs in following sub-sections. 2.3.1.1. Maximum SL sub-TLV The Maximum SL sub-TLV is defined to advertise the maximum value of the "SL" field [I-D.ietf-6man-segment-routing-header] in the SRH of a received packet before applying the function associated with a SID. It is carried as a sub-TLV of the SRv6 Capability TLV. The Maximum SL sub-TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max SL | +-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD3. o Length: 2 octets in length, and the value is 1. o Max SL: 1 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. 2.3.1.2. Maximum End Pop SRH sub-TLV The Maximum End Pop SRH sub-TLV is defined to advertise the maximum number of SIDs in the top SRH in an SRH stack to which the router can apply "PSP" or USP" [I-D.filsfils-spring-srv6-network-programming] flavors. It is carried as a sub-TLV of the SRv6 Capability TLV. The Maximum End Pop SRH sub-TLV has the following format: Chen & Zhuang Expires April 23, 2018 [Page 5] Internet-Draft BGP-LS for SRv6 October 2017 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Max-End-Pop-SRH| +-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD4. o Length: 2 octets in length, and the value is 1. o Max-End-Pop-SRH: 1 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. 2.3.1.3. Maximum T.Insert SRH sub-TLV The Maximum T.Insert SRH sub-TLV is defined to advertise the maximum number of SIDs that can be inserted as part of the "T.insert" behavior [I-D.filsfils-spring-srv6-network-programming]. It is carried as a sub-TLV of the SRv6 Capability TLV. The Maximum T.Insert SRH sub-TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max-T.Insert | +-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD5. o Length: 2 octets in length, and the value is 1. o Max-T.Insert: 1 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. 2.3.1.4. Maximum T.Encap SRH sub-TLV The Maximum T.Encap SRH sub-TLV is defined to advertise the maximum number of SIDs that can be included as part of the "T.Encap" behavior Chen & Zhuang Expires April 23, 2018 [Page 6] Internet-Draft BGP-LS for SRv6 October 2017 [I-D.filsfils-spring-srv6-network-programming]. It is carried as a sub-TLV of the SRv6 Capability TLV. The Maximum T.Encap SRH sub-TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max-T.Encap | +-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD6. o Length: 2 octets in length, and the value is 1. o Max-T.Encap: 1 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. 2.3.1.5. Maximum End D SRH sub-TLV The Maximum End D SRH sub-TLV is defined to advertise the maximum number of SIDs in an SRH when applying "End.DX6" and "End.DT6" functions. It is carried as a sub-TLV of the SRv6 Capability TLV. The Maximum End D SRH sub-TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max End D | +-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD7. o Length: 2 octets in length, and the value is 1. o Max End D: 1 octets in length, as defined [I-D.bashandy-isis-srv6-extensions]. Chen & Zhuang Expires April 23, 2018 [Page 7] Internet-Draft BGP-LS for SRv6 October 2017 2.3.2. SRv6 SID TLV The SRv6 SID TLV is defined to describe a SRv6 SID that is associated with a node. The SRv6 SID TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | SID-size | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SID (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SRv6 Function Sub-TLVs (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD8. o Length: 2 octets in length, and the value indicates the length (in octets) of the whole TLV (excluding the Type and Length fields). o Flags: 1 octet in length. As defined [I-D.bashandy-isis-srv6-extensions]. o SID-size: 1 octet in length. Number of bits in the SID field. It can have the values 1-128 and indicates the number of bits in the SID. o SID: 1-16 octets. This field encodes the advertised SRv6 SID. o SRv6 Function Sub-TLVs: variable in length. This field can carry one or more sub-TLVs. Each sub-TLV specifies a function that associates with the SID. 2.4. Link Attribute TLVs This section defines the attribute TLVs that are only associated with the Link NLRI. Chen & Zhuang Expires April 23, 2018 [Page 8] Internet-Draft BGP-LS for SRv6 October 2017 2.4.1. P2P SRv6 x-SID TLV The P2P SRv6 x-SID TLV is defined to describe a SRv6 SID that is associated with End.X and End.DX6 [I-D.filsfils-spring-srv6-network-programming] functions over a point to point adjacency. The P2P SRv6 x-SID TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | SID-size | Weight | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SID (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SRv6 Function Sub-TLVs (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD9. o Length: 2 octets in length, and the value indicates the length (in octets) of the whole TLV (excluding the Type and Length fields). o Flags: 1 octet in length. As defined [I-D.bashandy-isis-srv6-extensions]. o SID-size: 1 octet in length. Number of bits in the SID field. It can have the values 1-128 and indicates the number of bits in the SID. o Weight: 1 octet in length. The value represents the weight of the Adj-SID for the purpose of load balancing. The use of the weight is defined in [I-D.ietf-spring-segment-routing]. o SID: 1-16 octets. This field encodes the advertised SRv6 SID. o SRv6 Function Sub-TLVs: variable in length. This field can carry one or more sub-TLVs. Each sub-TLV specifies a function that associates with the SID. Chen & Zhuang Expires April 23, 2018 [Page 9] Internet-Draft BGP-LS for SRv6 October 2017 2.4.2. LAN SRv6 X-SID TLV This LAN SRv6 X-SID TLV is defined to describe a SRv6 SIDs associated with End.X and End.DX6 [I-D.filsfils-spring-srv6-network-programming] functions over a LAN adjacency. The LAN SRv6 X-SID TLV has the following 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | SID-size | Weight | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OSPF Neighbor ID / IS-IS System-ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SID (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ SRv6 Function Sub-TLVs (variable) . . . ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o Type: 2 octets in length, and the value is TBD10. o Length: 2 octets in length, and the value indicates the length (in octets) of the whole TLV (excluding the Type and Length fields). o Flags: 1 octet in length. As defined [I-D.bashandy-isis-srv6-extensions]. o SID-size: 1 octet in length. Number of bits in the SID field. It can have the values 1-128 and indicates the number of bits in the SID. o Weight: 1 octet in length. The value represents the weight of the Adj-SID for the purpose of load balancing. The use of the weight is defined in [I-D.ietf-spring-segment-routing]. o SID: 1-16 octets. This field encodes the advertised SRv6 SID. o SRv6 Function Sub-TLVs: variable in length. This field can carry one or more sub-TLVs. Each sub-TLV specifies a function that associates with the SID. Chen & Zhuang Expires April 23, 2018 [Page 10] Internet-Draft BGP-LS for SRv6 October 2017 3. IANA Considerations IANA maintains a registry called "Border Gateway Protocol - Link State (BGP-LS) Parameters" with a sub-registry called "Node Anchor, Link Descriptor and Link Attribute TLVs". IANA is requested to assign the following TLV code points: +----------+--------------------------------------+---------------+ | TLV Code | Description | Value defined | | Point | | in | +----------+--------------------------------------+---------------+ | TBD1 | SRv6 Function TLV | this document | | TBD2 | SRv6 Capability TLV | this document | | TBD3 | Maximum SL sub-TLV | this document | | TBD4 | Maximum End Pop SRH sub-TLV | this document | | TBD5 | Maximum T.Insert SRH sub-TLV | this document | | TBD6 | Maximum T.Encap SRH sub-TLV | this document | | TBD7 | Maximum End D SRH sub-TLV | this document | | TBD8 | SRv6 SID TLV | this document | | TBD9 | P2P SRv6 x-SID TLV | this document | | TBD10 | LAN SRv6 X-SID TLV | this document | +----------+--------------------------------------+---------------+ 4. Security Considerations BGP security is discussed in [RFC4271], [RFC4272] and [RFC6952]. Procedures and protocol extensions defined in this document do not affect the BGP security model. 5. Acknowledgements 6. References 6.1. Normative References [I-D.bashandy-isis-srv6-extensions] Ginsberg, L., Bashandy, A., Filsfils, C., and B. Decraene, "IS-IS Extensions to Support Routing over IPv6 Dataplane", draft-bashandy-isis-srv6-extensions-01 (work in progress), September 2017. Chen & Zhuang Expires April 23, 2018 [Page 11] Internet-Draft BGP-LS for SRv6 October 2017 [I-D.filsfils-spring-srv6-network-programming] Filsfils, C., Leddy, J., daniel.voyer@bell.ca, d., daniel.bernier@bell.ca, d., Steinberg, D., Raszuk, R., Matsushima, S., Lebrun, D., Decraene, B., Peirens, B., Salsano, S., Naik, G., Elmalky, H., Jonnalagadda, P., Sharif, M., Ayyangar, A., Mynam, S., Henderickx, W., Bashandy, A., Raza, K., Dukes, D., Clad, F., and P. Camarillo, "SRv6 Network Programming", draft-filsfils- spring-srv6-network-programming-01 (work in progress), June 2017. [I-D.ietf-6man-segment-routing-header] Previdi, S., Filsfils, C., Raza, K., Leddy, J., Field, B., daniel.voyer@bell.ca, d., daniel.bernier@bell.ca, d., Matsushima, S., Leung, I., Linkova, J., Aries, E., Kosugi, T., Vyncke, E., Lebrun, D., Steinberg, D., and R. Raszuk, "IPv6 Segment Routing Header (SRH)", draft-ietf-6man- segment-routing-header-07 (work in progress), July 2017. [I-D.ietf-idr-bgp-ls-segment-routing-ext] Previdi, S., Psenak, P., Filsfils, C., Gredler, H., and M. Chen, "BGP Link-State extensions for Segment Routing", draft-ietf-idr-bgp-ls-segment-routing-ext-03 (work in progress), July 2017. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . 6.2. Informative References [I-D.ietf-spring-segment-routing] Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", draft-ietf- spring-segment-routing-12 (work in progress), June 2017. [I-D.ietf-spring-segment-routing-mpls] Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing with MPLS data plane", draft-ietf-spring-segment-routing-mpls-10 (work in progress), June 2017. [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, . Chen & Zhuang Expires April 23, 2018 [Page 12] Internet-Draft BGP-LS for SRv6 October 2017 [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", RFC 4272, DOI 10.17487/RFC4272, January 2006, . [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, . [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and S. Ray, "North-Bound Distribution of Link-State and Traffic Engineering (TE) Information Using BGP", RFC 7752, DOI 10.17487/RFC7752, March 2016, . Authors' Addresses Mach(Guoyi) Chen Huawei Email: mach.chen@huawei.com Shunwan Zhuang Huawei Email: zhuangshunwan@huawei.com Chen & Zhuang Expires April 23, 2018 [Page 13]