Network Working Group Z. Hu Internet-Draft Huawei Technologies Intended status: Standards Track K. Raza Expires: May 7, 2020 Cisco Systems, Inc. Y. Qu J. Dong Huawei Technologies November 4, 2019 YANG Data Model for OSPF SRv6 draft-hu-lsr-ospf-srv6-yang-01 Abstract This document defines a YANG data model that can be used to configure and manage OSPFv3 SRv6 [I-D.li-ospf-ospfv3-srv6-extensions]. 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 May 7, 2020. Copyright Notice Copyright (c) 2019 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 Hu, et al. Expires May 7, 2020 [Page 1] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 (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. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. OSPFv3 SRv6 . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. OSPFv3 SRv6 configuration . . . . . . . . . . . . . . . . . . 4 3.1. SRv6 activation . . . . . . . . . . . . . . . . . . . . . 4 3.2. Locator setting . . . . . . . . . . . . . . . . . . . . . 5 3.3. IP Fast reroute . . . . . . . . . . . . . . . . . . . . . 5 3.4. Microloop avoidance . . . . . . . . . . . . . . . . . . . 5 4. OSPFv3 SRv6 YANG Module . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 18 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 19 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 1. Overview YANG[RFC6020][RFC7950] is a data definition language used to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF[RFC6241]. YANG is proving relevant beyond its initial confines, as bindings to other interfaces (e.g., ReST) and encodings other than XML (e.g., JSON) are being defined. Furthermore, YANG data models can be used as the basis for implementation of other interfaces, such as CLI and programmatic APIs. This document defines a YANG data model that can be used to configure and manage OSPFv3 SRv6 and it is an augmentation to the OSPF YANG data model. 2. OSPFv3 SRv6 This document defines a model for OSPFv3 SRv6 feature. It is an augmentation of the OSPF base model. The OSPFv3 SRv6 YANG module requires support of OSPF base model [I-D.ietf-ospf-yang] which defines basic OSPF configuration and state. Hu, et al. Expires May 7, 2020 [Page 2] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 The figure below describes the overall structure of the ospfv3-srv6 YANG module: module: ietf-ospfv3-srv6 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/ospf:ospf: +--rw srv6-cfg | +--rw enable? boolean | +--rw default-locator? boolean | +--rw locator-name? -> /rt:routing/srv6:srv6 | | /locators/locator/name | +--rw persistent-end-x-sid? boolean +--rw micro-loop-avoidance +--rw srv6-enable? boolean +--rw srv6-rib-update-delay? uint16 augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/ospf:ospf /ospf:fast-reroute: +--rw srv6-ti-lfa {srv6-ti-lfa}? +--rw enable? boolean augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/ospf:ospf /ospf:database/ospf:as-scope-lsa-type /ospf:as-scope-lsas/ospf:as-scope-lsa /ospf:version/ospf:ospfv3 /ospf:ospfv3/ospf:body: +--ro srv6-locator +--ro srv6-locactor-tlv +--ro route-type? identityref +--ro algorithm? uint8 +--ro locator-length? uint8 +--ro flags? bits +--ro metric? uint32 +--ro locator* inet:ipv6-address-no-zone +--ro srv6-end-sid +--ro flags? uint8 +--ro endpoint-func | +--ro fuc-flags? uint8 | +--ro endpoint-func? identityref | +--ro undefined-endpoint-func? uint16 +--ro sid? srv6-sid-value +--ro srv6-sid-structure +--ro lb-length? uint8 +--ro ln-length? uint8 +--ro fun-length? uint8 +--ro arg-length? uint8 augment /rt:routing /rt:control-plane-protocols/rt:control-plane-protocol Hu, et al. Expires May 7, 2020 [Page 3] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 /ospf:ospf/ospf:database /ospf:as-scope-lsa-type/ospf:as-scope-lsas /ospf:as-scope-lsa/ospf:version/ospf:ospfv3 /ospf:ospfv3/ospf:body/ospf:router-information: +--ro srv6-capability | +--ro flags? bits +--ro v6-max-value-srh +--ro max-segments-left? uint8 +--ro max-end-pop? uint8 +--ro max-t-insert? uint8 +--ro max-t-encap? uint8 +--ro max-end-d? uint8 augment /rt:routing /rt:control-plane-protocols/rt:control-plane-protocol /ospf:ospf/ospf:database /ospf:as-scope-lsa-type/ospf:as-scope-lsas /ospf:as-scope-lsa/ospf:version/ospf:ospfv3 /ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router /ospfv3-e-lsa:e-router-tlvs /ospfv3-e-lsa:link-tlv: +--ro srv6-endx-sid +--ro endpoint-func | +--ro fuc-flags? uint8 | +--ro endpoint-func? identityref | +--ro undefined-endpoint-func? uint16 +--ro flags? bits +--ro algorithm? uint8 +--ro weight? uint8 +--ro sid* srv6-sid-value +--ro neighbor-router-id? yang:dotted-quad +--ro srv6-sid-structure +--ro lb-length? uint8 +--ro ln-length? uint8 +--ro fun-length? uint8 +--ro arg-length? uint8 3. OSPFv3 SRv6 configuration 3.1. SRv6 activation Activation of OSPFv3 SRv6 is done by setting the "enable" leaf to true. This triggers advertisement of SRv6 extensions based on the configuration parameters that have been setup using the base SRv6 module. Hu, et al. Expires May 7, 2020 [Page 4] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 3.2. Locator setting The basic SRv6 module defines the related locator leafs. When the OSPFv3 SRv6 module is enabled, set the locator by using the following strategy: firstly, it is reasonable to check whether the default locator is used, if not, to use the specified locator. The strategy is realized by adding the leaf "default-locator", "locator-name" . 3.3. IP Fast reroute OSPFv3 SRv6 model augments the fast-reroute container under interface. It brings the ability to activate ipv6 TI-LFA (topology independent LFA). 3.4. Microloop avoidance OSPFv3 SRv6 model augments the micro-loop-avoidance container, this container including the leaf "srv6-enable" brings the ability to activate SRv6 avoid-microloop. 4. OSPFv3 SRv6 YANG Module file "ietf-ospfv3-srv6@2019-11-04.yang" module ietf-ospfv3-srv6 { namespace "urn:ietf:params:xml:ns:" + "yang:ietf-ospfv3-srv6"; prefix ospfv3-srv6; import ietf-yang-types { prefix "yang"; } import ietf-routing { prefix "rt"; } import ietf-ospfv3-extended-lsa { prefix "ospfv3-e-lsa"; } import ietf-ospf { prefix "ospf"; } import ietf-srv6-base { prefix "srv6"; } Hu, et al. Expires May 7, 2020 [Page 5] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 import iana-routing-types { prefix "iana-rt-types"; } import ietf-inet-types { prefix "inet"; } organization "IETF LSR Working Group"; contact "WG List: <mailto:spring@ietf.org> Zhibo Hu <mailto:huzhibo@huawei.com> Jiajia Dong <mailto:dongjiajia@huawei.com> "; description "The YANG module defines a generic configuration model for Segment IPV6 routing OSPFv3 extensions common across all of the vendor implementations."; revision 2019-11-04 { description "Initial revision."; reference "RFC XXXX"; } /* Identities */ identity SRV6_END_FUNC_TYPE { description "Base identity type for srv6 endpoint function code points."; } identity SRV6_END_FUNC_NO_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "End (no PSP, no USP)."; } identity SRV6_END_FUNC_PSP { base "SRV6_END_FUNC_TYPE"; description "End with PSP."; } Hu, et al. Expires May 7, 2020 [Page 6] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 identity SRV6_END_FUNC_USP { base "SRV6_END_FUNC_TYPE"; description "END with USP."; } identity SRV6_END_FUNC_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "END with PSP & USP."; } identity SRV6_END_T_FUNC_NO_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "End.T (no PSP, no USP)."; } identity SRV6_END_T_FUNC_PSP { base "SRV6_END_FUNC_TYPE"; description "End.T with PSP."; } identity SRV6_END_T_FUNC_USP { base "SRV6_END_FUNC_TYPE"; description "End.T with USP."; } identity SRV6_END_T_FUNC_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "End.T with PSP & USP."; } identity SRV6_END_X_FUNC_NO_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "End.x (no PSP, no USP)."; } identity SRV6_END_X_FUNC_PSP { base "SRV6_END_FUNC_TYPE"; description "End.x with PSP."; } Hu, et al. Expires May 7, 2020 [Page 7] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 identity SRV6_END_X_FUNC_USP { base "SRV6_END_FUNC_TYPE"; description "End.x with USP."; } identity SRV6_END_X_FUNC_PSP_USP { base "SRV6_END_FUNC_TYPE"; description "End.x with PSP & USP."; } identity SRV6_END_FUNC_DX6 { base "SRV6_END_FUNC_TYPE"; description "End.DX6 function."; } identity SRV6_END_FUNC_DT6 { base "SRV6_END_FUNC_TYPE"; description "End.DT6 function."; } identity SRV6_END_FUNC_OTP { base "SRV6_END_FUNC_TYPE"; description "END.OTP."; } identity s1-bit { base ospf:ospfv3-lsa-option; description "the S1/S2 bits are dependent on the desired flooding scope for the LSA."; } identity s2-bit { base ospf:ospfv3-lsa-option; description "the S1/S2 bits are dependent on the desired flooding scope for the LSA."; } identity srv6-locator-lsa { base ospf:ospfv3-lsa-type; description "SRv6 Locator LSA - Type TBD"; Hu, et al. Expires May 7, 2020 [Page 8] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 } identity LOCATOR-ROUTE-TYPE { description "The type of the locator route."; } identity INTRA-AREA-LOCATOR { base "LOCATOR-ROUTE-TYPE"; description "Intra-Area"; } identity INTER-AREA-LOCATOR { base "LOCATOR-ROUTE-TYPE"; description "Inter-Area"; } identity AS-EXTERNAL-LOCATOR { base "LOCATOR-ROUTE-TYPE"; description "AS External"; } identity NSSA-EXTERNAL-LOCATOR { base "LOCATOR-ROUTE-TYPE"; description "NSSA External"; } /* typedef */ typedef srv6-sid-value { type inet:ipv6-address-no-zone; description "16 Octets encoded sid value."; } /* Features */ feature srv6-ti-lfa { description "Enhance SRv6 FRR with ti-lfa support"; } /* Groupings */ grouping srv6-msd { description Hu, et al. Expires May 7, 2020 [Page 9] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 "means to advertise to advertise node/link specific values for Maxium Sid Depths(MSD) of various types"; container v6-max-value-srh { description "Maximum SRv6 SID Depths."; leaf max-segments-left { type uint8; description "The maximum value of 'SL' field in the SRH of a recevied packet."; } leaf max-end-pop { type uint8; description "The maximum number of SIDS in the top SRH in an SRH stack to which the router can apply 'PSP' or 'USP'."; } leaf max-t-insert { type uint8; description "The maximum number of SIDs can be inserted as port of the 'T.insert' behavior."; } leaf max-t-encap { type uint8; description "The maximum number of SIDs can be included as part of the 'T.Encap' behavior."; } leaf max-end-d { type uint8; description "The maximum number of SIDs in an SRH when performing decapsulation associated with 'End.Dx' functions (e.g., 'End.DX6' and 'End.DT6')."; } } } grouping srv6-capabilities { description "SRV6 capability grouping."; container srv6-capability { description "SRv6 capability."; leaf flags { type bits { bit o-flag { position 1; description Hu, et al. Expires May 7, 2020 [Page 10] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 "If set, then router is capable of supporting SRH O-bit, as specified in [I-D.ali-spring-srv6-oam]"; } } description "Flags."; } } } grouping srv6-endpoint-func { description "This group defines srv6 endpoint function"; container endpoint-func { description "Srv6 Endpoint function Descriptor."; leaf fuc-flags { type uint8; description "No function flags are currently being defined."; } leaf endpoint-func { type identityref { base SRV6_END_FUNC_TYPE; } description "The endpoint function."; } leaf undefined-endpoint-func { type uint16; description "Unknown endpoint func value."; } } } grouping srv6-end-sids { description "This group defines srv6 end sid"; container srv6-end-sid { description "SRv6 Segment Identifier(SID) with Endpoint functions."; leaf flags { type uint8; description "NO flags are currently being defined."; } Hu, et al. Expires May 7, 2020 [Page 11] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 uses srv6-endpoint-func; leaf sid { type srv6-sid-value; description "SRV6 sid value."; } uses srv6-sid-structures; } } grouping srv6-sid-structures { description "This group defines SRv6 SID Structure sub-TLV."; container srv6-sid-structure { description "SRv6 SID Structure sub-TLV is used to advertise the length of each individual part of the SRv6 SID as defined in [I-D.ietf-spring-srv6-network-programming]"; leaf lb-length { type uint8; description "SRv6 SID Locator Block length in bits."; } leaf ln-length { type uint8; description "SRv6 SID Locator Node length in bits."; } leaf fun-length { type uint8; description "SRv6 SID Function length in bits."; } leaf arg-length { type uint8; description "SRv6 SID Argument length in bits."; } } } grouping srv6-endx-sids { description "This group defines SRv6 SIDs Associated with Adjacencies including Hu, et al. Expires May 7, 2020 [Page 12] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 SRv6 End.X SID Sub-TLV and SRv6 LAN End.X SID Sub-TLV."; container srv6-endx-sid { description "SRv6 sids associated with an adjacency."; uses srv6-endpoint-func; leaf flags { type bits { bit b-flag { position 0; description "Backup Flag. If set, the SID refers to a path that is eligible for protection"; } bit s-flag { position 1; description "Set Flag. When set, the S-Flag indicates that the End.X SID refers to a set of adjacencies (and therefore MAY be assigned to other adjacencies as well)."; } bit p-flag { position 2; description "Persistent Flag: If set, the SID is persistently allocated, i.e., the SID value remains consistent across router restart and session/interface flap."; } } description "Flags for end.x subtlv."; } leaf algorithm { type uint8; description "Associated algorithm."; } leaf weight { type uint8; description "8 bit field whose value represents the weight of the End.X SID for the purpose of load balancing"; } leaf-list sid { Hu, et al. Expires May 7, 2020 [Page 13] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 type srv6-sid-value; description "SRV6 sid value."; } leaf neighbor-router-id { type yang:dotted-quad; description "Neighbor router ID.This is only used on LAN adjacencies."; } uses srv6-sid-structures; } } grouping srv6-locactor-tlvs { description "This group defines srv6 locator tlv."; container srv6-locactor-tlv { description "This contains a srv6 locator tlv."; leaf route-type { type identityref { base LOCATOR-ROUTE-TYPE; } description "The type of the locator route"; } leaf algorithm { type uint8; description "Associated algorithm."; } leaf locator-length { type uint8; description "Carries the length of the Locator prefix as number of bits (1-128)"; } leaf flags { type bits { bit n-flag { position 0; description Hu, et al. Expires May 7, 2020 [Page 14] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 "When the locator uniquely identifies a node in the network (i.e. it is provisioned on one and only one node), the N bit MUST be set. Otherwise, this bit MUST be clear"; } bit a-flag { position 1; description "When the Locator is configured as anycast, the A bit SHOULD be set. Otherwise, this bit MUST be clear"; } } description "Flags for srv6 locator tlv."; } leaf metric { type uint32; description "Metric value."; } leaf-list locator { type inet:ipv6-address-no-zone; description "Advertised SRV6 locator."; } uses srv6-end-sids; } } /* Cfg */ augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol"+ "/ospf:ospf" { when "/rt:routing/rt:control-plane-protocols/"+ "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" { description "This augment OSPFv3 routing protocol when used"; } description "This augments OSPFv3 protocol configuration with SRv6."; container srv6-cfg{ leaf enable{ type boolean; default "false"; description "Enables SRv6 Hu, et al. Expires May 7, 2020 [Page 15] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 protocol extensions."; } leaf default-locator { type boolean; default "false"; description "Enable OSPFv3 segment-routing IPv6 with default Locator."; } leaf locator-name { when "not(../default-locator='true')"; type leafref { path "/rt:routing/srv6:srv6/srv6:locators/srv6:locator/srv6:name"; } description "Enable OSPFv3 segment-routing IPv6 with specified Locator."; } leaf persistent-end-x-sid{ type boolean; default "false"; description "Enable the persistent nature of End.X sid"; } description "Configuration about OSPFv3 segment-routing IPv6."; } container micro-loop-avoidance { leaf srv6-enable { type boolean; default "false"; description "Enable SRv6 avoid-microloop.Depend on SR IPv6 Enable."; } leaf srv6-rib-update-delay { type uint16 { range "1000..10000"; } units "ms"; default "5000"; description "Set the route delivery delay for SRv6 avoid-microloop.Depend on SR IPv6 Enable."; } description Hu, et al. Expires May 7, 2020 [Page 16] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 "Enable OSPFv3 avoid-microloop."; } } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol"+ "/ospf:ospf/ospf:fast-reroute"{ when "/rt:routing/rt:control-plane-protocols/"+ "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'"{ description "This augment OSPFv3 routing protocol when used"; } description "This augments OSPFv3 IP FRR with IPV6 TILFA."; container srv6-ti-lfa { if-feature srv6-ti-lfa; leaf enable { type boolean; description "Enables SRv6 TI-LFA computation."; } description "SRv6 TILFA configuration."; } } /* Database */ augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol/" + "ospf:ospf/ospf:database/" + "ospf:as-scope-lsa-type/ospf:as-scope-lsas/" + "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/" + "ospf:ospfv3/ospf:body" { when "/rt:routing/rt:control-plane-protocols/"+ "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" { description "This augment OSPFv3 routing protocol when used"; } description "This augments OSPFv3 protocol router capability."; container srv6-locator { description "SRv6 Locator LSA."; uses srv6-locactor-tlvs; } } Hu, et al. Expires May 7, 2020 [Page 17] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol/" + "ospf:ospf/ospf:database/" + "ospf:as-scope-lsa-type/ospf:as-scope-lsas/" + "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/" + "ospf:ospfv3/ospf:body/ospf:router-information" { when "/rt:routing/rt:control-plane-protocols/"+ "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" { description "This augment OSPFv3 routing protocol when used"; } description "This augments OSPFv3 protocol router capability."; uses srv6-capabilities; uses srv6-msd; } augment "/rt:routing/" + "rt:control-plane-protocols/rt:control-plane-protocol/" + "ospf:ospf/ospf:database/" + "ospf:as-scope-lsa-type/ospf:as-scope-lsas/" + "ospf:as-scope-lsa/ospf:version/ospf:ospfv3/" + "ospf:ospfv3/ospf:body/ospfv3-e-lsa:e-router/" + "ospfv3-e-lsa:e-router-tlvs/" + "ospfv3-e-lsa:link-tlv" { when "/rt:routing/rt:control-plane-protocols/"+ "rt:control-plane-protocol/rt:type = 'ospf:ospfv3'" { } description "This augments OSPFv3 protocol neighbor."; uses srv6-endx-sids; } /* Notifications */ } 5. Security Considerations Configuration and state data defined in this document are designed to be accessed via the NETCONF protocol [RFC6241]. As OSPF is an IGP protocol (critical piece of the network), ensuring stability and security of the protocol is mandatory for the network service. Hu, et al. Expires May 7, 2020 [Page 18] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 Authors recommends to implement NETCONF access control model ([RFC6536]) to restrict access to all or part of the configuration to specific users. 6. Contributors TBD. 7. Acknowledgements TBD. 8. IANA Considerations The IANA is requested to assign two new URIs from the IETF XML registry ([RFC3688]). Authors are suggesting the following URI: URI: urn:ietf:params:xml:ns:yang:ietf-ospfv3-srv6 Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace This document also requests one new YANG module name in the YANG Module Names registry ([RFC6020]) with the following suggestion : name: ietf-ospfv3-srv6 namespace: urn:ietf:params:xml:ns:yang:ietf-ospfv3-srv6 prefix: ospfv3-srv6 reference: RFC XXXX 9. References [I-D.ietf-ospf-yang] Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem, "YANG Data Model for OSPF Protocol", draft-ietf-ospf- yang-29 (work in progress), October 2019. [I-D.li-ospf-ospfv3-srv6-extensions] Li, Z., Hu, Z., Cheng, D., Talaulikar, K., and P. Psenak, "OSPFv3 Extensions for SRv6", draft-li-ospf- ospfv3-srv6-extensions-05 (work in progress), August 2019. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Hu, et al. Expires May 7, 2020 [Page 19] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . Authors' Addresses Zhibo Hu Huawei Technologies Huawei Bld., No.156 Beiqing Rd. Beijing 100095 China Email: huzhibo@huawei.com Kamran Raza Cisco Systems, Inc. 2000 Innovation Drive Kanata, ON K2K-3E8 CA Email: skraza@cisco.com Yingzhen Qu Huawei Technologies Huawei Bld., No.156 Beiqing Rd. Beijing 100095 China Email: yingzhen.qu@huawei.com Hu, et al. Expires May 7, 2020 [Page 20] Internet-Draft YANG Data Model for OSPF SRv6 November 2019 Jiajia Dong Huawei Technologies Huawei Bld., No.156 Beiqing Rd. Beijing 100095 China Email: dongjiajia@huawei.com Hu, et al. Expires May 7, 2020 [Page 21]