NTP Working Group N. Wu Internet-Draft Huawei Intended status: Standards Track A. Kumar S N Expires: December 24, 2018 RtBrick Inc. Y. Zhao Ericsson D. Dhody Huawei A. Sinha RtBrick Inc. June 22, 2018 A YANG Data Model for NTP draft-ietf-ntp-yang-data-model-03 Abstract This document defines a YANG data model for Network Time Protocol (NTP) implementations. The data model includes configuration data and state data. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 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 December 24, 2018. Wu, et al. Expires December 24, 2018 [Page 1] Internet-Draft YANG for NTP June 2018 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 1.1. Operational State . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.3. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3 1.4. Prefixes in Data Node Names . . . . . . . . . . . . . . . 3 2. NTP data model . . . . . . . . . . . . . . . . . . . . . . . 4 3. Relationship with NTPv4-MIB . . . . . . . . . . . . . . . . . 7 4. Relationship with RFC 7317 . . . . . . . . . . . . . . . . . 9 5. NTP YANG Module . . . . . . . . . . . . . . . . . . . . . . . 9 6. Usage Example . . . . . . . . . . . . . . . . . . . . . . . . 29 6.1. Unicast association . . . . . . . . . . . . . . . . . . . 29 6.2. Refclock master . . . . . . . . . . . . . . . . . . . . . 31 6.3. Authentication configuration . . . . . . . . . . . . . . 32 6.4. Access configuration . . . . . . . . . . . . . . . . . . 34 6.5. Multicast configuration . . . . . . . . . . . . . . . . . 34 6.6. Manycast configuration . . . . . . . . . . . . . . . . . 38 6.7. Clock state . . . . . . . . . . . . . . . . . . . . . . . 41 6.8. Get all association . . . . . . . . . . . . . . . . . . . 41 6.9. Global statistic . . . . . . . . . . . . . . . . . . . . 43 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 43 8. Security Considerations . . . . . . . . . . . . . . . . . . . 44 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 45 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 45 10.1. Normative References . . . . . . . . . . . . . . . . . . 45 10.2. Informative References . . . . . . . . . . . . . . . . . 47 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 47 Wu, et al. Expires December 24, 2018 [Page 2] Internet-Draft YANG for NTP June 2018 1. Introduction This document defines a YANG [RFC6020] data model for Network Time Protocol [RFC5905] implementations. The data model convers configuration of system parameters of NTP, such as access rules, authentication and VPN Routing and Forwarding (VRF) binding, and also associations of NTP in different modes and parameters of per-interface. It also provides information about running state of NTP implementations. 1.1. Operational State NTP Operational State is included in the same tree as NTP configuration, consistent with Network Management Datastore Architecture [RFC8342]. NTP current state and statistics are also maintained in the operational state. Additionally, the operational state also include the associations state. 1.2. Terminology The terminology used in this document is aligned to [RFC5905]. 1.3. Tree Diagrams A simplified graphical representation of the data model is used in this document. This document uses the graphical representation of data models defined in [RFC8340]. 1.4. Prefixes in Data Node Names In this document, names of data nodes and other data model objects are often used without a prefix, as long as it is clear from the context in which YANG module each name is defined. Otherwise, names are prefixed using the standard prefix associated with the corresponding YANG module, as shown in Table 1. Wu, et al. Expires December 24, 2018 [Page 3] Internet-Draft YANG for NTP June 2018 +----------+--------------------------+-----------------------------+ | Prefix | YANG module | Reference | +----------+--------------------------+-----------------------------+ | yang | ietf-yang-types | [RFC6991] | | inet | ietf-inet-types | [RFC6991] | | if | ietf-interfaces | [RFC8343] | | ianach | iana-crypt-hash | [RFC7317] | | key- | ietf-key-chain | [RFC8177] | | chain | | | | acl | ietf-access-control-list | [I-D.ietf-netmod-acl-model] | | rt-types | ietf-routing-types | [RFC8294] | +----------+--------------------------+-----------------------------+ Table 1: Prefixes and corresponding YANG modules 2. NTP data model This document defines the YANG module "ietf-ntp", which has the following structure: module: ietf-ntp +--rw ntp! +--rw port? uint16 {ntp-port}? +--rw refclock-master! | +--rw master-stratum? ntp-stratum +--rw authentication | +--rw auth-enabled? boolean | +--rw trusted-keys* [key-id] | | +--rw key-id | | -> /ntp/authentication/authentication-keys/key-id | +--rw authentication-keys* [key-id] | +--rw key-id uint32 | +--rw algorithm? identityref | +--rw password? ianach:crypt-hash +--rw access-rules | +--rw access-rule* [access-mode] | +--rw access-mode access-modes | +--rw acl? -> /acl:acls/acl/name +--ro clock-state | +--ro system-status | +--ro clock-state ntp-clock-status | +--ro clock-stratum ntp-stratum | +--ro clock-refid union | +--ro associations-address? | | -> /ntp/associations/address | +--ro associations-local-mode? | | -> /ntp/associations/local-mode | +--ro associations-isConfigured? Wu, et al. Expires December 24, 2018 [Page 4] Internet-Draft YANG for NTP June 2018 | | -> /ntp/associations/isConfigured | +--ro nominal-freq decimal64 | +--ro actual-freq decimal64 | +--ro clock-precision uint8 | +--ro clock-offset? decimal64 | +--ro root-delay? decimal64 | +--ro root-dispersion? decimal64 | +--ro reference-time? yang:date-and-time | +--ro sync-state ntp-sync-state +--rw unicast-configuration* [address type] | +--rw address inet:host | +--rw type unicast-configuration-type | +--rw authentication | | +--rw (authentication-type)? | | +--:(symmetric-key) | | +--rw key-id? leafref | +--rw prefer? boolean | +--rw burst? boolean | +--rw iburst? boolean | +--rw source? if:interface-ref | +--rw minpoll? ntp-minpoll | +--rw maxpoll? ntp-maxpoll | +--rw port? uint16 {ntp-port}? | +--rw version? ntp-version +--ro associations* [address local-mode isConfigured] | +--ro address inet:host | +--ro local-mode association-modes | +--ro isConfigured boolean | +--ro stratum? ntp-stratum | +--ro refid? union | +--ro authentication? | | -> /ntp/authentication/authentication-keys/key-id | +--ro prefer? boolean | +--ro peer-interface? if:interface-ref | +--ro minpoll? ntp-minpoll | +--ro maxpoll? ntp-maxpoll | +--ro port? uint16 {ntp-port}? | +--ro version? ntp-version | +--ro reach? uint8 | +--ro unreach? uint8 | +--ro poll? uint8 | +--ro now? uint32 | +--ro offset? decimal64 | +--ro delay? decimal64 | +--ro dispersion? decimal64 | +--ro originate-time? yang:date-and-time | +--ro receive-time? yang:date-and-time | +--ro transmit-time? yang:date-and-time Wu, et al. Expires December 24, 2018 [Page 5] Internet-Draft YANG for NTP June 2018 | +--ro input-time? yang:date-and-time | +--ro ntp-statistics | +--ro packet-sent? yang:counter32 | +--ro packet-sent-fail? yang:counter32 | +--ro packet-received? yang:counter32 | +--ro packet-dropped? yang:counter32 +--rw interfaces | +--rw interface* [name] | +--rw name if:interface-ref | +--rw broadcast-server! | | +--rw ttl? uint8 | | +--rw authentication | | | +--rw (authentication-type)? | | | +--:(symmetric-key) | | | +--rw key-id? leafref | | +--rw minpoll? ntp-minpoll | | +--rw maxpoll? ntp-maxpoll | | +--rw port? uint16 {ntp-port}? | | +--rw version? ntp-version | +--rw broadcast-client! | +--rw multicast-server* [address] | | +--rw address | | | rt-types:ip-multicast-group-address | | +--rw ttl? uint8 | | +--rw authentication | | | +--rw (authentication-type)? | | | +--:(symmetric-key) | | | +--rw key-id? leafref | | +--rw minpoll? ntp-minpoll | | +--rw maxpoll? ntp-maxpoll | | +--rw port? uint16 {ntp-port}? | | +--rw version? ntp-version | +--rw multicast-client* [address] | | +--rw address rt-types:ip-multicast-group-address | +--rw manycast-server* [address] | | +--rw address rt-types:ip-multicast-group-address | +--rw manycast-client* [address] | +--rw address | | rt-types:ip-multicast-group-address | +--rw authentication | | +--rw (authentication-type)? | | +--:(symmetric-key) | | +--rw key-id? leafref | +--rw ttl? uint8 | +--rw minclock? uint8 | +--rw maxclock? uint8 | +--rw beacon? uint8 | +--rw minpoll? ntp-minpoll Wu, et al. Expires December 24, 2018 [Page 6] Internet-Draft YANG for NTP June 2018 | +--rw maxpoll? ntp-maxpoll | +--rw port? uint16 {ntp-port}? | +--rw version? ntp-version +--ro ntp-statistics +--ro packet-sent? yang:counter32 +--ro packet-sent-fail? yang:counter32 +--ro packet-received? yang:counter32 +--ro packet-dropped? yang:counter32 grouping authentication-type-param +-- (authentication-type)? +--:(symmetric-key) +-- key-id? -> /ntp/authentication/authentication-keys/key-id grouping comman-attributes +-- minpoll? ntp-minpoll +-- maxpoll? ntp-maxpoll +-- port? uint16 {ntp-port}? +-- version? ntp-version grouping association-ref +-- associations-address? -> /ntp/associations/address +-- associations-local-mode? -> /ntp/associations/local-mode +-- associations-isConfigured? -> /ntp/associations/isConfigured grouping statistics +-- packet-sent? yang:counter32 +-- packet-sent-fail? yang:counter32 +-- packet-received? yang:counter32 +-- packet-dropped? yang:counter32 grouping authentication-key +-- key-id? uint32 +-- algorithm? identityref +-- password? ianach:crypt-hash This data model defines one top-level container which includes both the NTP configuration and the NTP running state including access rules, authentication, associations, unicast configurations, interfaces, system status and associations. 3. Relationship with NTPv4-MIB If the device implements the NTPv4-MIB [RFC5907], data nodes from YANG module can be mapped to table entries in NTPv4-MIB. The following tables list the YANG data nodes with corresponding objects in the NTPv4-MIB. Wu, et al. Expires December 24, 2018 [Page 7] Internet-Draft YANG for NTP June 2018 +--------------------------+--------------------------+ | YANG data nodes in /ntp/ | NTPv4-MIB objects | +--------------------------+--------------------------+ | ntp-enabled | ntpEntStatusCurrentMode | +--------------------------+--------------------------+ +--------------------------------------+---------------------+ | YANG data nodes in /ntp/associations | NTPv4-MIB objects | +--------------------------------------+---------------------+ | address | ntpAssocAddressType | | | ntpAssocAddress | +--------------------------------------+---------------------+ YANG NTP Configuration Data Nodes and Related NTPv4-MIB Objects +---------------------------------+---------------------------------+ | YANG data nodes in /ntp/clock- | NTPv4-MIB objects | | state/system-status | | +---------------------------------+---------------------------------+ | clock-state | ntpEntStatusCurrentMode | | clock-stratum | ntpEntStatusStratum | | clock-refid | ntpEntStatusActiveRefSourceId | | | ntpEntStatusActiveRefSourceName | | clock-precision | ntpEntTimePrecision | | clock-offset | ntpEntStatusActiveOffset | | root-dispersion | ntpEntStatusDispersion | +---------------------------------+---------------------------------+ +---------------------------------------+---------------------------+ | YANG data nodes in /ntp/associations/ | NTPv4-MIB objects | +---------------------------------------+---------------------------+ | address | ntpAssocAddressType | | | ntpAssocAddress | | stratum | ntpAssocStratum | | refid | ntpAssocRefId | | offset | ntpAssocOffset | | delay | ntpAssocStatusDelay | | dispersion | ntpAssocStatusDispersion | | ntp-statistics/packet-sent | ntpAssocStatOutPkts | | ntp-statistics/packet-received | ntpAssocStatInPkts | | ntp-statistics/packet-dropped | ntpAssocStatProtocolError | +---------------------------------------+---------------------------+ YANG NTP State Data Nodes and Related NTPv4-MIB Objects Wu, et al. Expires December 24, 2018 [Page 8] Internet-Draft YANG for NTP June 2018 4. Relationship with RFC 7317 This section describes the relationship with NTP definition in Section 3.2 System Time Management of [RFC7317] . YANG data nodes in /ntp/ also supports per-interface configurations which is not supported in /system/ntp +-------------------------------+--------------------------------+ | YANG data nodes in /ntp/ | YANG data nodes in /system/ntp | +-------------------------------+--------------------------------+ | ntp-enabled | enabled | | unicast-configuration | server | | | server/name | | unicast-configuration/address | server/transport/udp/address | | unicast-configuration/port | server/transport/udp/port | | unicast-configuration/type | server/association-type | | unicast-configuration/iburst | server/iburst | | unicast-configuration/prefer | server/prefer | +-------------------------------+--------------------------------+ YANG NTP Configuration Data Nodes and counterparts in RFC 7317 Objects 5. NTP YANG Module file "ietf-ntp@2018-06-22.yang" module ietf-ntp { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ntp"; prefix "ntp"; import ietf-yang-types { prefix "yang"; reference "RFC 6991"; } import ietf-inet-types { prefix "inet"; reference "RFC 6991"; } import ietf-interfaces { prefix "if"; reference "RFC 8343"; } Wu, et al. Expires December 24, 2018 [Page 9] Internet-Draft YANG for NTP June 2018 import iana-crypt-hash { prefix "ianach"; reference "RFC 7317"; } import ietf-key-chain { prefix "key-chain"; reference "RFC 8177"; } import ietf-access-control-list { prefix "acl"; reference "RFC XXXX"; } import ietf-routing-types { prefix "rt-types"; reference "RFC 8294"; } organization "IETF NTP (Network Time Protocol) Working Group"; contact "WG Web: WG List: Editor: Anil Kumar S N Editor: Yi Zhao Editor: Dhruv Dhody Editor: Ankit Kumar Sinha "; description "This YANG module defines essential components for the management of a routing subsystem. Copyright (c) 2018 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents Wu, et al. Expires December 24, 2018 [Page 10] Internet-Draft YANG for NTP June 2018 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2018-06-22 { description "Updated revision."; reference "RFC XXXX: A YANG Data Model for NTP Management"; } /* Typedef Definitions */ typedef ntp-stratum { type uint8 { range "1..16"; } description "The level of each server in the hierarchy is defined by a stratum number. Primary servers are assigned stratum one; secondary servers at each lower level are assigned stratum numbers one greater than the preceding level"; } typedef ntp-version { type uint8 { range "1..4"; } default "3"; description "The current NTP version supported by corresponding association."; } typedef ntp-minpoll { type uint8 { range "4..17"; } default "6"; description "The minimum poll exponent for this NTP association."; } typedef ntp-maxpoll { type uint8 { range "4..17"; } Wu, et al. Expires December 24, 2018 [Page 11] Internet-Draft YANG for NTP June 2018 default "10"; description "The maximul poll exponent for this NTP association."; } typedef access-modes { type enumeration { enum peer { value "0"; description "Sets the fully access authority. Both time request and control query can be performed on the local NTP service, and the local clock can be synchronized to the remote server."; } enum server { value "1"; description "Enables the server access and query. Both time requests and control query can be performed on the local NTP service, but the local clock cannot be synchronized to the remote server."; } enum synchronization { value "2"; description "Enables the server to access. Only time request can be performed on the local NTP service."; } enum query { value "3"; description "Sets the maximum access limitation. Control query can be performed only on the local NTP service."; } } description "This defines NTP acess modes."; } typedef unicast-configuration-type { type enumeration { enum server { value "0"; description Wu, et al. Expires December 24, 2018 [Page 12] Internet-Draft YANG for NTP June 2018 "Use client association mode. This device will not provide synchronization to the configured NTP server."; } enum peer { value "1"; description "Use symmetric active association mode. This device may provide synchronization to the configured NTP server."; } } description "This defines NTP unicast mode of operation."; } typedef association-modes { type enumeration { enum client { value "0"; description "Use client association mode(mode 3). This device will not provide synchronization to the configured NTP server."; } enum active { value "1"; description "Use symmetric active association mode(mode 1). This device may synchronize with its NTP peer, or provide synchronization to configured NTP peer."; } enum passive { value "2"; description "Use symmetric passive association mode(mode 2). This device has learnt this asso dynamically. This device may synchronize with its NTP peer."; } enum broadcast { value "3"; description "Use broadcast mode(mode 5). This mode defines that its eigther working as broadcast-server or multicast-server."; } enum broadcast-client { value "4"; description Wu, et al. Expires December 24, 2018 [Page 13] Internet-Draft YANG for NTP June 2018 "This mode defines that its eigther working as broadcast-client or multicast-client."; } } description "This defines NTP association modes."; } typedef ntp-clock-status { type enumeration { enum synchronized { value "0"; description "Indicates that the local clock has been synchronized with an NTP server or the reference clock."; } enum unsynchronized { value "1"; description "Indicates that the local clock has not been synchronized with any NTP server."; } } description "This defines NTP clock status."; } typedef ntp-sync-state { type enumeration { enum clock-not-set { value "0"; description "Indicates the clock is not updated."; } enum freq-set-by-cfg { value "1"; description "Indicates the clock frequency is set by NTP configuration."; } enum clock-set { value "2"; description "Indicates the clock is set."; } enum freq-not-determined { value "3"; Wu, et al. Expires December 24, 2018 [Page 14] Internet-Draft YANG for NTP June 2018 description "Indicates the clock is set but the frequency is not determined."; } enum clock-synchronized { value "4"; description "Indicates that the clock is synchronized"; } enum spike { value "5"; description "Indicates a time difference of more than 128 milliseconds is detected between NTP server and client clock. The clock change will take effect in XXX seconds."; } } description "This defines NTP clock sync states."; } /* feature */ feature ntp-port { description "Indicates that the device supports the configuration of the port for NTP. This is a 'feature', since many implementations do not support any port other than the default port."; } /* Groupings */ grouping authentication-key { description "To define an authentication key for a Network Time Protocol (NTP) time source."; leaf key-id { type uint32 { range "1..max"; } description "Authentication key identifier."; } leaf algorithm { type identityref { base key-chain:crypto-algorithm; } Wu, et al. Expires December 24, 2018 [Page 15] Internet-Draft YANG for NTP June 2018 description "Authentication algorithm."; } leaf password { type ianach:crypt-hash; description "Clear or encrypted mode for password text."; } } grouping authentication-type-param { description "Authentication type."; choice authentication-type { description "Type of authentication."; case symmetric-key { leaf key-id { type leafref { path "/ntp:ntp/ntp:authentication/" + "ntp:authentication-keys/ntp:key-id"; } description "Authentication key id referenced in this association."; } } } } grouping statistics { description "NTP packet statistic."; leaf packet-sent { type yang:counter32; description "Indicates the total number of packets sent."; } leaf packet-sent-fail { type yang:counter32; description "Indicates the number of times packet sending failed."; } leaf packet-received { type yang:counter32; description "Indicates the total number of packets received."; } Wu, et al. Expires December 24, 2018 [Page 16] Internet-Draft YANG for NTP June 2018 leaf packet-dropped { type yang:counter32; description "Indicates the number of packets dropped."; } } grouping comman-attributes { description "NTP common attributes for configuration."; leaf minpoll { type ntp-minpoll; description "The minimum poll interval used in this association."; } leaf maxpoll { type ntp-maxpoll; description "The maximul poll interval used in this association."; } leaf port { if-feature ntp-port; type uint16 { range "123 | 1025..max"; } default "123"; description "Specify the port used to send NTP packets."; } leaf version { type ntp-version; description "NTP version."; } } grouping association-ref { description "Reference to NTP association mode"; leaf associations-address { type leafref { path "/ntp:ntp/ntp:associations/ntp:address"; } description "Indicates the association address which result in clock synchronization."; } leaf associations-local-mode { Wu, et al. Expires December 24, 2018 [Page 17] Internet-Draft YANG for NTP June 2018 type leafref { path "/ntp:ntp/ntp:associations/ntp:local-mode"; } description "Indicates the association local-mode which result in clock synchronization."; } leaf associations-isConfigured { type leafref { path "/ntp:ntp/ntp:associations/" + "ntp:isConfigured"; } description "Indicates the association was configured or dynamic which result in clock synchronization."; } } /* Configuration data nodes */ container ntp { presence "NTP is enable"; description "Configuration parameters for NTP."; leaf port { if-feature ntp-port; type uint16 { range "123 | 1025..max"; } default "123"; description "Specify the port used to send NTP packets."; } container refclock-master { presence "NTP master clock is enable"; description "Configures the device as NTP server."; leaf master-stratum { type ntp-stratum; default "16"; description "Stratum level from which NTP clients get their time synchronized."; } } container authentication { description Wu, et al. Expires December 24, 2018 [Page 18] Internet-Draft YANG for NTP June 2018 "Configuration of authentication."; leaf auth-enabled { type boolean; default false; description "Controls whether NTP authentication is enabled or disabled on this device."; } list trusted-keys { key "key-id"; description "List of keys trusted by NTP."; leaf key-id { type leafref { path "/ntp:ntp/ntp:authentication/" + "ntp:authentication-keys/ntp:key-id"; } description "The key trusted by NTP."; } } list authentication-keys { key "key-id"; uses authentication-key; description "List of authentication key."; } } container access-rules { description "Configuration of access rules."; list access-rule { key "access-mode"; description "List of access rules."; leaf access-mode { type access-modes; description "NTP access mode."; } leaf acl { type leafref { path "/acl:acls/acl:acl/acl:name"; } description "NTP ACL."; } Wu, et al. Expires December 24, 2018 [Page 19] Internet-Draft YANG for NTP June 2018 } } container clock-state { config "false"; description "Operational state of the NTP."; container system-status { description "System status of NTP."; leaf clock-state { type ntp-clock-status; mandatory true; description "Indicates the state of system clock."; } leaf clock-stratum { type ntp-stratum; mandatory true; description "Indicates the stratum of the reference clock."; } leaf clock-refid { type union { type inet:ipv4-address; type binary { length "4"; } type string { length "4"; } } mandatory true; description "IPv4 address or first 32 bits of the MD5 hash of the IPv6 address or reference clock of the peer to which clock is synchronized."; } uses association-ref { description "Reference to Association mode"; } leaf nominal-freq { type decimal64 { fraction-digits 4; } mandatory true; Wu, et al. Expires December 24, 2018 [Page 20] Internet-Draft YANG for NTP June 2018 description "Indicates the nominal frequency of the local clock, in Hz."; } leaf actual-freq { type decimal64 { fraction-digits 4; } mandatory true; description "Indicates the actual frequency of the local clock, in Hz."; } leaf clock-precision { type uint8; mandatory true; description "Precision of the clock of this system in Hz.(prec=2^(-n))"; } leaf clock-offset { type decimal64 { fraction-digits 4; } description "Offset of clock to synchronized peer, in milliseconds."; } leaf root-delay { type decimal64 { fraction-digits 2; } description "Total delay along path to root clock, in milliseconds."; } leaf root-dispersion { type decimal64 { fraction-digits 2; } description "Indicates the dispersion between the local clock and the master reference clock, in milliseconds."; } leaf reference-time { type yang:date-and-time; description "Indicates reference timestamp."; Wu, et al. Expires December 24, 2018 [Page 21] Internet-Draft YANG for NTP June 2018 } leaf sync-state { type ntp-sync-state; mandatory true; description "Indicates the synchronization status of the local clock."; } } } list unicast-configuration { key "address type"; description "list of unicast-configuration."; leaf address { type inet:host; description "The address of this association."; } leaf type { type unicast-configuration-type; description "Type for this NTP configuration"; } container authentication{ description "Authentication type."; uses authentication-type-param; } leaf prefer { type boolean; default "false"; description "Whether this association is preferred."; } leaf burst { type boolean; default "false"; description "Sends a series of packets instead of a single packet within each synchronization interval to achieve faster synchronization."; } leaf iburst { type boolean; default "false"; description "Sends a series of packets instead of a single packet Wu, et al. Expires December 24, 2018 [Page 22] Internet-Draft YANG for NTP June 2018 within the initial synchronization interval to achieve faster initial synchronization."; } leaf source { type if:interface-ref; description "The interface whose ip address this association used as source address."; } uses comman-attributes { description "Common attribute like port, version, min and max poll."; } } list associations { key "address local-mode isConfigured"; config "false"; description "list of NTP association."; leaf address { type inet:host; description "The address of this association."; } leaf local-mode { type association-modes; description "Local mode for this NTP association."; } leaf isConfigured { type boolean; description "Whether this association is configured or dynamically learnt."; } leaf stratum { type ntp-stratum; description "Indicates the stratum of the reference clock."; } leaf refid { type union { type inet:ipv4-address; type binary { length "4"; } type string { Wu, et al. Expires December 24, 2018 [Page 23] Internet-Draft YANG for NTP June 2018 length "4"; } } description "Reference clock type or address for the peer."; } leaf authentication{ type leafref { path "/ntp:ntp/ntp:authentication/" + "ntp:authentication-keys/ntp:key-id"; } description "Authentication Key used for this association."; } leaf prefer { type boolean; default "false"; description "Whether this association is preferred."; } leaf peer-interface { type if:interface-ref; description "The interface which is used for communication."; } uses comman-attributes { description "Common attribute like port, version, min and max poll."; } leaf reach { type uint8; description "Indicates the reachability of the configured server or peer."; } leaf unreach { type uint8; description "Indicates the unreachability of the configured server or peer."; } leaf poll { type uint8; description "Indicates the polling interval for current, in seconds."; } Wu, et al. Expires December 24, 2018 [Page 24] Internet-Draft YANG for NTP June 2018 leaf now { type uint32; description "Indicates the time since the NTP packet was not received or last synchronized, in seconds."; } leaf offset { type decimal64 { fraction-digits 4; } description "Indicates the offset between the local clock and the superior reference clock."; } leaf delay { type decimal64 { fraction-digits 2; } description "Indicates the delay between the local clock and the superior reference clock."; } leaf dispersion { type decimal64 { fraction-digits 2; } description "Indicates the dispersion between the local clock and the superior reference clock."; } leaf originate-time { type yang:date-and-time; description "Indicates packet originate timestamp(T1)."; } leaf receive-time { type yang:date-and-time; description "Indicates packet receive timestamp(T2)."; } leaf transmit-time { type yang:date-and-time; description "Indicates packet transmit timestamp(T3)."; } leaf input-time { type yang:date-and-time; description Wu, et al. Expires December 24, 2018 [Page 25] Internet-Draft YANG for NTP June 2018 "Indicates packet input timestamp(T4)."; } container ntp-statistics { description "Per Peer packet send and receive statistic."; uses statistics { description "NTP send and receive packet statistic."; } } } container interfaces { description "Configuration parameters for NTP interfaces."; list interface { key "name"; description "List of interfaces."; leaf name { type if:interface-ref; description "The interface name."; } container broadcast-server { presence "NTP broadcast-server is configured"; description "Configuration of broadcast server."; leaf ttl { type uint8; description "Specifies the time to live (TTL) of a broadcast packet."; } container authentication{ description "Authentication type."; uses authentication-type-param; } uses comman-attributes { description "Common attribute like port, version, min and max poll."; } } Wu, et al. Expires December 24, 2018 [Page 26] Internet-Draft YANG for NTP June 2018 container broadcast-client { presence "NTP broadcast-client is configured"; description "Configuration of broadcast-client."; } list multicast-server { key "address"; description "Configuration of multicast server."; leaf address { type rt-types:ip-multicast-group-address; description "The IP address to send NTP multicast packets."; } leaf ttl { type uint8; description "Specifies the time to live (TTL) of a multicast packet."; } container authentication{ description "Authentication type."; uses authentication-type-param; } uses comman-attributes { description "Common attribute like port, version, min and max poll."; } } list multicast-client { key "address"; description "Configuration of multicast-client."; leaf address { type rt-types:ip-multicast-group-address; description "The IP address of the multicast group to join."; } } list manycast-server { key "address"; description "Configuration of manycast server."; Wu, et al. Expires December 24, 2018 [Page 27] Internet-Draft YANG for NTP June 2018 leaf address { type rt-types:ip-multicast-group-address; description "The multicast group IP address to receive manycast client messages ."; } reference "RFC 5905"; } list manycast-client { key "address"; description "Configuration of manycast-client."; leaf address { type rt-types:ip-multicast-group-address; description "The group IP address that the manycast client broadcasts the request message to."; } container authentication{ description "Authentication type."; uses authentication-type-param; } leaf ttl { type uint8; description "Specifies the maximum time to live (TTL) for the expanding ring search."; } leaf minclock { type uint8; description "The minimum manycast survivors in this association."; } leaf maxclock { type uint8; description "The maximum manycast candidates in this association."; } leaf beacon { type uint8; description "The maximum interval between beacons in this association."; } Wu, et al. Expires December 24, 2018 [Page 28] Internet-Draft YANG for NTP June 2018 uses comman-attributes { description "Common attribute like port, version, min and max poll."; } reference "RFC 5905"; } } } container ntp-statistics { config "false"; description "Total NTP packet statistic."; uses statistics { description "NTP send and receive packet statistic."; } } } } 6. Usage Example 6.1. Unicast association Below is the example on how to configure a preferred unicast server present at 192.0.2.1 running at port 1025 with authentication-key 10 and version 4 Wu, et al. Expires December 24, 2018 [Page 29] Internet-Draft YANG for NTP June 2018
192.0.2.1
server true 4 1025 10 An example with IPv6 would used the an IPv6 address (say 2001:DB8::1) in the "address" leaf with no change in any other data tree. Below is the example on how to get unicast configuration
192.0.2.1
server 10 true false Wu, et al. Expires December 24, 2018 [Page 30] Internet-Draft YANG for NTP June 2018 true 6 10 1025 4 9 20.1.1.1 255 0 128 10 0.025 0.5 0.6 10-10-2017 07:33:55.253 Z+05:30 10-10-2017 07:33:55.258 Z+05:30 10-10-2017 07:33:55.300 Z+05:30 10-10-2017 07:33:55.305 Z+05:30 20 0 20 0 6.2. Refclock master Below is the example on how to configure reference clock with stratum 8 Wu, et al. Expires December 24, 2018 [Page 31] Internet-Draft YANG for NTP June 2018 8 Below is the example on how to get reference clock configuration 8 6.3. Authentication configuration Below is the example on how to enable authentication and configure authentication key 10 with mode as md5 and password as abcd Wu, et al. Expires December 24, 2018 [Page 32] Internet-Draft YANG for NTP June 2018 true 10 md5 abcd Below is the example on how to get authentication related configuration false 10 md5 abcd Wu, et al. Expires December 24, 2018 [Page 33] Internet-Draft YANG for NTP June 2018 6.4. Access configuration Below is the example on how to configure acess type peer associated with acl 2000 peer 2000 Below is the example on how to get access related configuration peer 2000 6.5. Multicast configuration Below is the example on how to configure multicast-server with address as "224.1.1.1", port as 1025 and authentication keyid as 10 Wu, et al. Expires December 24, 2018 [Page 34] Internet-Draft YANG for NTP June 2018 Ethernet3/0/0
224.1.1.1
10 1025 Below is the example on how to get multicast-server related configuration Wu, et al. Expires December 24, 2018 [Page 35] Internet-Draft YANG for NTP June 2018 Ethernet3/0/0
224.1.1.1
224.1.1.1 10 6 10 1025 3 Below is the example on how to configure multicast-client with address as "224.1.1.1" Wu, et al. Expires December 24, 2018 [Page 36] Internet-Draft YANG for NTP June 2018 Ethernet3/0/0
224.1.1.1
 Below is the example on how to get multicast-client related configuration Ethernet3/0/0
224.1.1.1
 Wu, et al. Expires December 24, 2018 [Page 37] Internet-Draft YANG for NTP June 2018 6.6. Manycast configuration Below is the example on how to configure manycast-client with address as "224.1.1.1", port as 1025 and authentication keyid as 10 Ethernet3/0/0
224.1.1.1
10 1025 Below is the example on how to get manycast-client related configuration Wu, et al. Expires December 24, 2018 [Page 38] Internet-Draft YANG for NTP June 2018 Ethernet3/0/0
224.1.1.1
10 255 3 10 6 6 10 1025 Below is the example on how to configure manycast-server with address as "224.1.1.1" Wu, et al. Expires December 24, 2018 [Page 39] Internet-Draft YANG for NTP June 2018 Ethernet3/0/0
224.1.1.1
 Below is the example on how to get manycast-server related configuration Ethernet3/0/0
224.1.1.1
 Wu, et al. Expires December 24, 2018 [Page 40] Internet-Draft YANG for NTP June 2018 6.7. Clock state Below is the example on how to get clock current state synchronized 7 192.0.2.1 192.0.2.1 client yes 100.0 100.0 18 0.025 0.5 0.8 10-10-2017 07:33:55.258 Z+05:30 clock-synchronized 6.8. Get all association Below is the example on how to get all association present Wu, et al. Expires December 24, 2018 [Page 41] Internet-Draft YANG for NTP June 2018
192.0.2.1
9 20.1.1.1 client true 10 true Ethernet3/0/0 6 10 1025 4 255 0 128 10 0.025 0.5 0.6 10-10-2017 07:33:55.253 Z+05:30 10-10-2017 07:33:55.258 Z+05:30 10-10-2017 07:33:55.300 Z+05:30 10-10-2017 07:33:55.305 Z+05:30 20 0 20 0 Wu, et al. Expires December 24, 2018 [Page 42] Internet-Draft YANG for NTP June 2018 6.9. Global statistic Below is the example on how to get clock current state 30 5 20 2 7. IANA Considerations This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in RFC 3688, the following registration has been made. URI: urn:ietf:params:xml:ns:yang:ietf-ntp Registrant Contact: The NETMOD WG of the IETF. XML: N/A; the requested URI is an XML namespace. This document registers a YANG module in the "YANG Module Names" registry [RFC6020]. Name: ietf-ntp Namespace: urn:ietf:params:xml:ns:yang:ietf-ntp Prefix: ntp Reference: RFC XXXX Wu, et al. Expires December 24, 2018 [Page 43] Internet-Draft YANG for NTP June 2018 8. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246]. The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: /ntp/port - This data node specify the port number to be used to send NTP packets. Unexpected changes could lead to disruption and/or network misbehavior. /ntp/authentication and /ntp/access-rules - The entries in the list include the authentication and access control configurations. Car should be taken while setting these parameters. /ntp/unicast-configuration - The entries in the list include all unicast configurations (server or peer mode), and indirectly creates or modify the NTP associations. Unexpected changes could lead to disruption and/or network misbehavior. /ntp/interfaces/interface - The entries in the list inclide all per-interface configurations related to broadcast, multicast and manycast mode, and indirectly creates or modify the NTP associations. Unexpected changes could lead to disruption and/or network misbehavior. Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: Wu, et al. Expires December 24, 2018 [Page 44] Internet-Draft YANG for NTP June 2018 /ntp/associations - The entries in the list includes all active NTP associations of all modes. Unauthorized access to this needs to be curtailed. 9. Acknowledgments The authors would like to express their thanks to Sladjana Zoric, Danny Mayer, Harlan Stenn, Ulrich Windl, Miroslav Lichvar, and Maurice Angermann for their review and suggestions. 10. References 10.1. Normative References [I-D.ietf-netmod-acl-model] Jethanandani, M., Huang, L., Agarwal, S., and D. Blair, "Network Access Control List (ACL) YANG Data Model", draft-ietf-netmod-acl-model-19 (work in progress), April 2018. [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, . [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, . [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, . [RFC5907] Gerstung, H., Elliott, C., and B. Haberman, Ed., "Definitions of Managed Objects for Network Time Protocol Version 4 (NTPv4)", RFC 5907, DOI 10.17487/RFC5907, June 2010, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . Wu, et al. Expires December 24, 2018 [Page 45] Internet-Draft YANG for NTP June 2018 [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8177] Lindem, A., Ed., Qu, Y., Yeung, D., Chen, I., and J. Zhang, "YANG Data Model for Key Chains", RFC 8177, DOI 10.17487/RFC8177, June 2017, . [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, "Common YANG Data Types for the Routing Area", RFC 8294, DOI 10.17487/RFC8294, December 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . Wu, et al. Expires December 24, 2018 [Page 46] Internet-Draft YANG for NTP June 2018 10.2. Informative References [RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for System Management", RFC 7317, DOI 10.17487/RFC7317, August 2014, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . Authors' Addresses Nan Wu Huawei Huawei Bld., No.156 Beiqing Rd. Beijing 100095 China Email: eric.wu@huawei.com Anil Kumar S N RtBrick Inc. Bangalore, Kanataka India Email: anil.ietf@gmail.com Yi Zhao Ericsson China Digital Kingdom Bld., No.1 WangJing North Rd. Beijing 100102 China Email: yi.z.zhao@ericsson.com Dhruv Dhody Huawei Divyashree Techno Park, Whitefield Bangalore, Kanataka 560066 India Email: dhruv.ietf@gmail.com Wu, et al. Expires December 24, 2018 [Page 47] Internet-Draft YANG for NTP June 2018 Ankit kumar Sinha RtBrick Inc. Bangalore, Kanataka India Email: ankit.ietf@gmail.com Wu, et al. Expires December 24, 2018 [Page 48]