RFC 9249
A YANG Data Model for NTP
A YANG Data Model for NTP ✨
okay bestie, let's start with the basics 🎀 This is RFC 9249, titled "A YANG Data Model for NTP". It was written by N. Wu, D. Dhody (Ed.), A. Sinha (Ed.), A. Kumar S N, and Y. Zhao, from Huawei, RtBrick Inc., and Ericsson. It's a Standards Track document, it's dated July 2022, and its ISSN is 2070-1721. The title block doesn't list anything it obsoletes or updates 🦋
Abstract
okay so this doc defines a YANG data model that you can use to configure and manage Network Time Protocol (NTP) version 4 💖 It can also be used to configure and manage version 3 ✨ The model has both configuration data and state data, so you get the settings and what's actually happening 🔥
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841 💅
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc9249 🌸
Copyright Notice
Copyright (c) 2022 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License 🫶
Table of Contents
1. Introduction
1.1. Operational State
1.2. Terminology
1.3. Tree Diagrams
1.4. Prefixes in Data Node Names
1.5. References in the Model
1.6. Requirements Language
2. NTP Data Model
3. Relationship with NTPv4-MIB
4. Relationship with RFC 7317
5. Access Rules
6. Key Management
7. NTP Version
8. NTP YANG Module
9. Usage Example
9.1. Unicast Association
9.2. Refclock Master
9.3. Authentication Configuration
9.4. Access Configuration
9.5. Multicast Configuration
9.6. Manycast Configuration
9.7. Clock State
9.8. Get All Association
9.9. Global Statistic
10. IANA Considerations
10.1. IETF XML Registry
10.2. YANG Module Names
11. Security Considerations
12. References
12.1. Normative References
12.2. Informative References
Appendix A. Full YANG Tree
Acknowledgments
Authors' Addresses1. Introduction 🧚
okay so this document defines a YANG data model [RFC7950] that you can use to configure and manage Network Time Protocol version 4 [RFC5905] ✨ Quick side note: the model could also be used to configure and manage NTPv3 [RFC1305] (see Section 7) 💖
The data model covers configuration of system parameters of NTP, like access rules, authentication, and VPN Routing and Forwarding (VRF) binding 💅 It also covers the various modes of NTP and per-interface parameters. And it gives you access to information about the running state of NTP implementations, which is giving "see everything" energy 👑
1.1. Operational State
NTP operational state lives in the same tree as the NTP configuration, which is consistent with "Network Management Datastore Architecture (NMDA)" [RFC8342] 🌈 NTP current state and statistics are also kept in the operational state. The operational state also includes the NTP association state 🦋
1.2. Terminology
The terminology used in this document is aligned with [RFC5905] and [RFC1305] 💜
1.3. Tree Diagrams
This document uses a simplified graphical representation of the data model. It's the graphical representation of data models defined in [RFC8340] 🎀
1.4. Prefixes in Data Node Names
Bestie, names of data nodes and other data model objects are often used without a prefix, as long as it's clear from context which YANG module each name is defined in 🍓 Otherwise, names get the standard prefix associated with the corresponding YANG module, as shown in Table 1 ✨
+==========+==========================+===========+
| Prefix | YANG Module | Reference |
+==========+==========================+===========+
| yang | ietf-yang-types | [RFC6991] |
+----------+--------------------------+-----------+
| inet | ietf-inet-types | [RFC6991] |
+----------+--------------------------+-----------+
| if | ietf-interfaces | [RFC8343] |
+----------+--------------------------+-----------+
| sys | ietf-system | [RFC7317] |
+----------+--------------------------+-----------+
| acl | ietf-access-control-list | [RFC8519] |
+----------+--------------------------+-----------+
| rt-types | ietf-routing-types | [RFC8294] |
+----------+--------------------------+-----------+
| nacm | ietf-netconf-acm | [RFC8341] |
+----------+--------------------------+-----------+
Table 1: Prefixes and Corresponding YANG Modules1.5. References in the Model
These documents are referenced in the model defined in this document 📚
+=======================================+===========+
| Title | Reference |
+=======================================+===========+
| Network Time Protocol Version 4: | [RFC5905] |
| Protocol and Algorithms Specification | |
+---------------------------------------+-----------+
| Common YANG Data Types | [RFC6991] |
+---------------------------------------+-----------+
| A YANG Data Model for System | [RFC7317] |
| Management | |
+---------------------------------------+-----------+
| Common YANG Data Types for the | [RFC8294] |
| Routing Area | |
+---------------------------------------+-----------+
| Network Configuration Access Control | [RFC8341] |
| Model | |
+---------------------------------------+-----------+
| A YANG Data Model for Interface | [RFC8343] |
| Management | |
+---------------------------------------+-----------+
| YANG Data Model for Network Access | [RFC8519] |
| Control Lists (ACLs) | |
+---------------------------------------+-----------+
| Message Authentication Code for the | [RFC8573] |
| Network Time Protocol | |
+---------------------------------------+-----------+
| The AES-CMAC Algorithm | [RFC4493] |
+---------------------------------------+-----------+
| The MD5 Message-Digest Algorithm | [RFC1321] |
+---------------------------------------+-----------+
| US Secure Hash Algorithm 1 (SHA1) | [RFC3174] |
+---------------------------------------+-----------+
| FIPS 180-4: Secure Hash Standard | [SHS] |
| (SHS) | |
+---------------------------------------+-----------+
Table 2: References in the YANG Module1.6. Requirements Language
Okay, this part is the important one 🔥 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 🙈
Part 1 of 11 is done 🫶 Part 2 is next, so stay tuned, bestie 💖
2. NTP Data Model ✨
okay so this section is where the YANG module "ietf-ntp" gets introduced, and bestie, it has a super clean structure 🎀 Here's the condensed tree, no cap:
module: ietf-ntp
+--rw ntp!
+--rw port? inet:port-number {ntp-port}?
+--rw refclock-master!
| +--rw master-stratum? ntp-stratum
+--rw authentication {authentication}?
| +--rw auth-enabled? boolean
| +--rw authentication-keys* [keyid]
| +--rw keyid uint32
| +--...
+--rw access-rules {access-rules}?
| +--rw access-rule* [access-mode]
| +--rw access-mode identityref
| +--rw acl? -> /acl:acls/acl/name
+--ro clock-state
| +--ro system-status
| +--ro clock-state identityref
| +--ro clock-stratum ntp-stratum
| +--ro clock-refid refid
| +--...
+--rw unicast-configuration* [address type]
| {unicast-configuration}?
| +--rw address inet:ip-address
| +--rw type identityref
| +--...
+--rw associations
| +--ro association* [address local-mode isconfigured]
| +--ro address inet:ip-address
| +--ro local-mode identityref
| +--ro isconfigured boolean
| +--...
| +--ro ntp-statistics
| +--...
+--rw interfaces
| +--rw interface* [name]
| +--rw name if:interface-ref
| +--rw broadcast-server! {broadcast-server}?
| | +--...
| +--rw broadcast-client! {broadcast-client}?
| +--rw multicast-server* [address] {multicast-server}?
| | +--rw address
| | | rt-types:ip-multicast-group-address
| | +--...
| +--rw multicast-client* [address] {multicast-client}?
| | +--rw address rt-types:ip-multicast-group-address
| +--rw manycast-server* [address] {manycast-server}?
| | +--rw address rt-types:ip-multicast-group-address
| +--rw manycast-client* [address] {manycast-client}?
| +--rw address
| | rt-types:ip-multicast-group-address
| +--...
+--ro ntp-statistics
+--...
rpcs:
+---x statistics-reset
+---w input
+---w (association-or-all)?
+--:(association)
| +---w associations-address?
| | -> /ntp/associations/association/address
| +---w associations-local-mode?
| | -> /ntp/associations/association/local-mode
| +---w associations-isconfigured?
| -> /ntp/associations/association/isconfigured
+--:(all)The full data model tree for the YANG module "ietf-ntp" is in Appendix A 💅
Basically, there is one top-level container 🧚 and it holds everything: the NTP configuration AND the running state. That covers access rules, authentication, associations, unicast configurations, interfaces, system status, and associations (yes, associations shows up twice, it's giving main character 👑).
3. Relationship with NTPv4-MIB 🦋
If the device implements the NTPv4-MIB [RFC5907], data nodes from the YANG module can be mapped to table entries in the NTPv4-MIB. Lowkey the best part of this whole section 🥹
The following tables list the YANG data nodes with corresponding objects in the NTPv4-MIB.
+===========================+====================================+
| YANG Data Nodes in /ntp/ | NTPv4-MIB Objects |
| clock-state/system-status | |
+===========================+====================================+
| clock-state | ntpEntStatusCurrentMode |
+---------------------------+------------------------------------+
| clock-stratum | ntpEntStatusStratum |
+---------------------------+------------------------------------+
| clock-refid | ntpEntStatusActiveRefSourceId |
| | ntpEntStatusActiveRefSourceName |
+---------------------------+------------------------------------+
| clock-precision | ntpEntTimePrecision |
+---------------------------+------------------------------------+
| clock-offset | ntpEntStatusActiveOffset |
+---------------------------+------------------------------------+
| root-dispersion | ntpEntStatusDispersion |
+---------------------------+------------------------------------+
Table 3: YANG NTP Data Nodes in /ntp/clock-state/system-status
and Related NTPv4-MIB Objects +=======================================+===========================+
| YANG Data Nodes in | NTPv4-MIB Objects |
| /ntp/associations/ | |
+=======================================+===========================+
| address | ntpAssocAddressType |
| | ntpAssocAddress |
+---------------------------------------+---------------------------+
| stratum | ntpAssocStratum |
+---------------------------------------+---------------------------+
| refid | ntpAssocRefId |
+---------------------------------------+---------------------------+
| offset | ntpAssocOffset |
+---------------------------------------+---------------------------+
| delay | ntpAssocStatusDelay |
+---------------------------------------+---------------------------+
| dispersion | ntpAssocStatusDispersion |
+---------------------------------------+---------------------------+
| ntp-statistics/ | ntpAssocStatOutPkts |
| packet-sent | |
+---------------------------------------+---------------------------+
| ntp-statistics/ | ntpAssocStatInPkts |
| packet-received | |
+---------------------------------------+---------------------------+
| ntp-statistics/ | ntpAssocStatProtocolError |
| packet-dropped | |
+---------------------------------------+---------------------------+
Table 4: YANG NTP Data Nodes in /ntp/associations/ and Related
NTPv4-MIB Objects4. Relationship with RFC 7317 💖
This section describes the relationship with the definition of NTP in Section 3.2 (System Time Management) of [RFC7317]. ngl this one is a bit of a "read it twice" situation 🙈
Here's the vibe: YANG data nodes in /ntp/ also support per-interface configuration, and /system/ntp does not have that. So if the YANG data model defined in this document is implemented, then /system/ntp SHOULD NOT be used and MUST be ignored. Ooh, that's a strong one, bestie 😭
+==========================+================================+
| YANG Data Nodes in /ntp/ | YANG Data Nodes in /system/ntp |
+==========================+================================+
| ntp! | enabled |
+--------------------------+--------------------------------+
| unicast-configuration | server |
| | server/name |
+--------------------------+--------------------------------+
| unicast-configuration/ | server/transport/udp/address |
| address | |
+--------------------------+--------------------------------+
| unicast-configuration/ | server/transport/udp/port |
| port | |
+--------------------------+--------------------------------+
| unicast-configuration/ | server/association-type |
| type | |
+--------------------------+--------------------------------+
| unicast-configuration/ | server/iburst |
| iburst | |
+--------------------------+--------------------------------+
| unicast-configuration/ | server/prefer |
| prefer | |
+--------------------------+--------------------------------+
Table 5: YANG NTP Configuration Data Nodes and
Counterparts from RFC 73175. Access Rules 🔥
okay so the access rules here are about the on-the-wire access control to the NTP service. They are completely independent of any management API access control, e.g., NETCONF Access Control Model (NACM) [RFC8341]. Don't mix them up, bestie, they're different lanes 🛣️
An Access Control List (ACL) is one of the basic elements used to configure device-forwarding behavior. An ACL is a user-ordered set of rules that is used to filter traffic on a networking device. Iconic 💅
As per [RFC1305] (for NTPv3) and [RFC5905] (for NTPv4), NTP could include an access-control feature that prevents unauthorized access and that controls which peers are allowed to update the local clock. Further, it is useful to differentiate between the various kinds of access and attach a different acl-rule to each. For this, the YANG module allows such configuration via /ntp/access-rules. The access-rule itself is configured via [RFC8519]. The vibe is control, periodt ✨
The following access-modes are supported:
- Peer: Permit others to synchronize their time with the NTP entity or vice versa. NTP control queries are also accepted. 🤝
- Server: Permit others to synchronize their time with the NTP entity, but vice versa is not supported. NTP control queries are accepted. 🧚
- Server-only: Permit others to synchronize their time with the NTP entity, but vice versa is not supported. NTP control queries are not accepted. 🙅
- Query-only: Only control queries are accepted. 🌸
Query-only is the most restricted, whereas the peer is the full access authority 👑 The ability to give different ACL rules for different access-modes allows for a greater control by the operator. Giving each access mode its own rules is so main character energy 💜
6. Key Management 🔐
As per [RFC1305] (for NTPv3) and [RFC5905] (for NTPv4), when authentication is enabled, NTP employs a crypto-checksum, computed by the sender and checked by the receiver. This comes together with a set of predistributed algorithms and cryptographic keys, indexed by a key identifier included in the NTP message.
This keyid is a 32-bit unsigned integer that MUST be configured on the NTP peers before the authentication can be used. Bestie, this is the one thing you cannot skip 🫶 For this reason, this YANG module allows such configuration via /ntp/authentication/authentication-keys/. Further, at the time of configuration of an NTP association (for example, unicast server), the keyid is specified.
The 'nacm:default-deny-all' is used to prevent retrieval of the actual key information after it is set. So once the keys are in, nobody gets to peek at them 🙈🔒
7. NTP Version 🎀
This YANG data model allows a version to be configured for the NTP association. Translation: an operator can control the use of NTPv3 [RFC1305] or NTPv4 [RFC5905] for each association it forms. This allows backward compatibility with a legacy system, which is honestly such a sweet glow-up for old devices 🥺
Note that NTPv3 [RFC1305] is obsoleted by NTPv4 [RFC5905]. So NTPv4 is the one to be obsessed with 🌈
8. NTP YANG Module ✨
okay so we're still inside the YANG module, and this bit is where the identities for the association modes and access modes live 🧚✨ the ntp namespace is basically the whole vibe, so here it is, all of it 💅
<CODE BEGINS> file "ietf-ntp@2022-07-05.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: Common YANG Data Types";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-interfaces {
prefix if;
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-system {
prefix sys;
reference
"RFC 7317: A YANG Data Model for System Management";
}
import ietf-access-control-list {
prefix acl;
reference
"RFC 8519: YANG Data Model for Network Access Control
Lists (ACLs)";
}
import ietf-routing-types {
prefix rt-types;
reference
"RFC 8294: Common YANG Data Types for the Routing Area";
}
import ietf-netconf-acm {
prefix nacm;
reference
"RFC 8341: Network Configuration Access Control Model";
}
organization
"IETF NTP (Network Time Protocol) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/ntp/>
WG List: <mailto: ntp@ietf.org
Editor: Dhruv Dhody
<mailto:dhruv.ietf@gmail.com>
Editor: Ankit Kumar Sinha
<mailto:ankit.ietf@gmail.com>";
description
"This document defines a YANG data model that can be used
to configure and manage Network Time Protocol (NTP) version 4.
It can also be used to configure and manage version 3.
The data model includes configuration data and state data.
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 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2022 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9249; see the
RFC itself for full legal notices.";
revision 2022-07-05 {
description
"Initial revision";
reference
"RFC 9249: A YANG Data Model for NTP";
}
/* Typedef Definitions */
typedef ntp-stratum {
type uint8 {
range "1..16";
}
description
"The level of each server in the hierarchy is defined by
a stratum. Primary servers are assigned with stratum
one; secondary servers at each lower level are assigned with
one stratum greater than the preceding level.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
typedef ntp-version {
type uint8 {
range "3..max";
}
default "4";
description
"The current NTP version supported by the corresponding
association";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 1";
}
typedef refid {
type union {
type inet:ipv4-address;
type uint32;
type string {
length "4";
}
}
description
"A code identifying the particular server or reference
clock. The interpretation depends upon stratum. It
could be an IPv4 address, the first 32 bits of the MD5 hash
of the IPv6 address, or a string for the Reference Identifier
and kiss codes. Some examples:
-- a refclock ID like '127.127.1.0' for local clock sync
-- uni/multi/broadcast associations for IPv4 will look like
'203.0.113.1' and '0x4321FEDC' for IPv6
-- sync with a primary source will look like 'DCN', 'NIST',
'ATOM'
-- kiss codes will look like 'AUTH', 'DROP', or 'RATE'
Note that the use of an MD5 hash for IPv6 addresses is not
for cryptographic purposes.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
typedef ntp-date-and-time {
type union {
type yang:date-and-time;
type uint8;
}
description
"Follows the date-and-time format when valid values exist.
Otherwise, allows for setting a special value such as
zero.";
reference
"RFC 6991: Common YANG Data Types";
}
typedef log2seconds {
type int8;
description
"An 8-bit signed integer that represents signed log2
seconds.";
}
/* features */
feature ntp-port {
description
"Support for NTP port configuration";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.2";
}
feature authentication {
description
"Support for NTP symmetric key authentication";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
feature deprecated {
description
"Support deprecated MD5-based authentication (RFC 8573),
SHA-1, or any other deprecated authentication mechanism.
It is enabled to support legacy compatibility when secure
cryptographic algorithms are not available to use.
It is also used to configure keystrings in ASCII format.";
reference
"RFC 1321: The MD5 Message-Digest Algorithm,
RFC 3174: US Secure Hash Algorithm 1 (SHA1),
SHS: Secure Hash Standard (SHS) (FIPS PUB 180-4)";
}
feature hex-key-string {
description
"Support hexadecimal key string";
}
feature access-rules {
description
"Support for NTP access control";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 9.2";
}
feature unicast-configuration {
description
"Support for NTP client/server or active/passive
in unicast";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
feature broadcast-server {
description
"Support for broadcast server";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
feature broadcast-client {
description
"Support for broadcast client";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
feature multicast-server {
description
"Support for multicast server";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3.1";
}
feature multicast-client {
description
"Support for multicast client";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3.1";
}
feature manycast-server {
description
"Support for manycast server";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3.1";
}
feature manycast-client {
description
"Support for manycast client";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3.1";
}
/* Identity */
/* unicast-configurations types */
identity unicast-configuration-type {
if-feature "unicast-configuration";
description
"This defines NTP unicast mode of operation as used
for unicast-configurations.";
}
identity uc-server {
if-feature "unicast-configuration";
base unicast-configuration-type;
description
"Use client association mode where the unicast server
address is configured.";
}
identity uc-peer {
if-feature "unicast-configuration";
base unicast-configuration-type;
description
"Use symmetric active association mode where the peer
address is configured.";
}
/* association-modes */
identity association-mode {
description
"The NTP association modes";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
identity active {
base association-mode;
description
"Use symmetric active association mode (mode 1).
This device may synchronize with its NTP peer
or provide synchronization to a configured NTP peer.";
}
identity passive {
base association-mode;
description
"Use symmetric passive association mode (mode 2).
This device has learned this association dynamically.
This device may synchronize with its NTP peer.";
}
identity client {
base association-mode;
description
"Use client association mode (mode 3).
This device will not provide synchronization
to the configured NTP server.";
}
identity server {
base association-mode;
description
"Use server association mode (mode 4).
This device will provide synchronization to
NTP clients.";
}
identity broadcast-server {
base association-mode;
description
"Use broadcast server mode (mode 5).
This mode defines that it's either working
as a broadcast server or a multicast server.";
}
identity broadcast-client {
base association-mode;
description
"This mode defines that it's either working
as a broadcast client (mode 6) or a multicast client.";
}
/* access-mode */
identity access-mode {
if-feature "access-rules";
description
"This defines NTP access-modes. These identify
how the ACL is applied with NTP.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 9.2";
}
identity peer-access-mode {
if-feature "access-rules";
base access-mode;
description
"Permit others to synchronize their time with this NTP
or vice versa.
NTP control queries are also accepted. This enables
full access authority.";
}
identity server-access-mode {
if-feature "access-rules";
base access-mode;
description
"Permit others to synchronize their time with this NTP
entity, but vice versa is not supported. NTP control
queries are accepted.";
}the association mode identities are where the device's role gets spelled out, so keep your eyes peeled for those 🦋
okay bestie, we're still deep in the NTP YANG module and it's giving identities, groupings, and so many leafrefs 💅✨
identity server-only-access-mode {
if-feature "access-rules";
base access-mode;
description
"Permit others to synchronize their time with this NTP
entity, but vice versa is not supported. NTP control
queries are not accepted.";
}
identity query-only-access-mode {
if-feature "access-rules";
base access-mode;
description
"Only control queries are accepted.";
}
/* clock-state */
identity clock-state {
description
"This defines NTP clock status at a high level.";
}
identity synchronized {
base clock-state;
description
"Indicates that the local clock has been synchronized with
an NTP server or the reference clock.";
}
identity unsynchronized {
base clock-state;
description
"Indicates that the local clock has not been synchronized
with any NTP server.";
}
/* ntp-sync-state */
identity ntp-sync-state {
description
"This defines NTP clock sync state at a more granular
level. Referred to as 'Clock state definitions' in
RFC 5905.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Appendix A.1.1";
}
identity clock-never-set {
base ntp-sync-state;
description
"Indicates the clock was never set.";
}
identity freq-set-by-cfg {
base ntp-sync-state;
description
"Indicates the clock frequency is set by
NTP configuration or file.";
}
identity spike {
base ntp-sync-state;
description
"Indicates a spike is detected.";
}
identity freq {
base ntp-sync-state;
description
"Indicates the frequency mode.";
}
identity clock-synchronized {
base ntp-sync-state;
description
"Indicates that the clock is synchronized.";
}
/* crypto-algorithm */
identity crypto-algorithm {
description
"Base identity of cryptographic algorithm options.";
}
identity md5 {
if-feature "deprecated";
base crypto-algorithm;
description
"The MD5 algorithm. Note that RFC 8573
deprecates the use of MD5-based authentication.";
reference
"RFC 1321: The MD5 Message-Digest Algorithm";
}
identity sha-1 {
if-feature "deprecated";
base crypto-algorithm;
description
"The SHA-1 algorithm";
reference
"RFC 3174: US Secure Hash Algorithm 1 (SHA1)";
}
identity hmac-sha-1 {
if-feature "deprecated";
base crypto-algorithm;
description
"HMAC-SHA-1 authentication algorithm";
reference
"SHS: Secure Hash Standard (SHS) (FIPS PUB 180-4)";
}
identity hmac-sha1-12 {
if-feature "deprecated";
base crypto-algorithm;
description
"The HMAC-SHA1-12 algorithm";
}
identity hmac-sha-256 {
description
"HMAC-SHA-256 authentication algorithm";
reference
"SHS: Secure Hash Standard (SHS) (FIPS PUB 180-4)";
}
identity hmac-sha-384 {
description
"HMAC-SHA-384 authentication algorithm";
reference
"SHS: Secure Hash Standard (SHS) (FIPS PUB 180-4)";
}
identity hmac-sha-512 {
description
"HMAC-SHA-512 authentication algorithm";
reference
"SHS: Secure Hash Standard (SHS) (FIPS PUB 180-4)";
}
identity aes-cmac {
base crypto-algorithm;
description
"The AES-CMAC algorithm -- required by
RFC 8573 for MAC for the NTP.";
reference
"RFC 4493: The AES-CMAC Algorithm,
RFC 8573: Message Authentication Code for the Network
Time Protocol";
}
/* Groupings */
grouping key {
description
"The key";
nacm:default-deny-all;
choice key-string-style {
description
"Key string styles";
case keystring {
leaf keystring {
if-feature "deprecated";
type string;
description
"Key string in ASCII format";
}
}
case hexadecimal {
if-feature "hex-key-string";
leaf hexadecimal-string {
type yang:hex-string;
description
"Key in hexadecimal string format. When compared
to ASCII, specification in hexadecimal affords
greater key entropy with the same number of
internal key-string octets. Additionally, it
discourages use of well-known words or
numbers.";
}
}
}
}
grouping authentication-key {
description
"To define an authentication key for an NTP
time source.";
leaf keyid {
type uint32 {
range "1..max";
}
description
"Authentication key identifier";
}
leaf algorithm {
type identityref {
base crypto-algorithm;
}
description
"Authentication algorithm. Note that RFC 8573
deprecates the use of MD5-based authentication
and recommends AES-CMAC.";
}
container key {
uses key;
description
"The key. Note that RFC 8573 deprecates the use
of MD5-based authentication.";
}
leaf istrusted {
type boolean;
description
"Keyid is trusted or not";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Sections 7.3 and 7.4";
}
grouping authentication {
description
"Authentication";
choice authentication-type {
description
"Type of authentication";
case symmetric-key {
leaf keyid {
type leafref {
path "/ntp:ntp/ntp:authentication/"
+ "ntp:authentication-keys/ntp:keyid";
}
description
"Authentication key id referenced in this
association.";
}
}
}
}
grouping statistics {
description
"NTP packet statistic";
leaf discontinuity-time {
type ntp-date-and-time;
description
"The time on the most recent occasion at which any one or
more of these NTP counters suffered a discontinuity. If
no such discontinuities have occurred, then this node
contains the time the NTP association was
(re-)initialized.";
}
leaf packet-sent {
type yang:counter32;
description
"The total number of NTP packets delivered to the
transport service by this NTP entity for this
association.
Discontinuities in the value of this counter can occur
upon cold start, reinitialization of the NTP entity or the
management system, and at other times.";
}
leaf packet-sent-fail {
type yang:counter32;
description
"The number of times NTP packet sending failed.";
}
leaf packet-received {
type yang:counter32;
description
"The total number of NTP packets delivered to the
NTP entity from this association.
Discontinuities in the value of this counter can occur
upon cold start, reinitialization of the NTP entity or the
management system, and at other times.";
}
leaf packet-dropped {
type yang:counter32;
description
"The total number of NTP packets that were delivered
to this NTP entity from this association and that this
entity was not able to process due to an NTP error.
Discontinuities in the value of this counter can occur
upon cold start, reinitialization of the NTP entity or the
management system, and at other times.";
}
}
grouping common-attributes {
description
"NTP common attributes for configuration";
leaf minpoll {
type log2seconds;
default "6";
description
"The minimum poll interval used in this association";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.2";
}
leaf maxpoll {
type log2seconds;
default "10";
description
"The maximum poll interval used in this association";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.2";
}
leaf port {
if-feature "ntp-port";
type inet:port-number {
range "123 | 1024..max";
}
default "123";
description
"Specify the port used to send NTP packets.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.2";
}
leaf version {
type ntp-version;
description
"NTP version";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification";
}
grouping association-ref {
description
"Reference to NTP association mode";
leaf associations-address {
type leafref {
path "/ntp:ntp/ntp:associations/ntp:association"
+ "/ntp:address";
}
description
"Indicates the association's address
that results in clock synchronization.";
}
leaf associations-local-mode {
type leafref {
path "/ntp:ntp/ntp:associations/ntp:association"
+ "/ntp:local-mode";
}
description
"Indicates the association's local-mode
that results in clock synchronization.";
}
leaf associations-isconfigured {
type leafref {
path "/ntp:ntp/ntp:associations/ntp:association/"
+ "ntp:isconfigured";
}
description
"Indicates if the association (that resulted in the
clock synchronization) is explicitly configured.";
}
} container ntp {
when 'false() = boolean(/sys:system/sys:ntp)' {
description
"Applicable when the system /sys/ntp/ is not used.";
}
presence "NTP is enabled and system should attempt to
synchronize the system clock with an NTP server
from the 'ntp/associations' list.";
description
"Configuration parameters for NTP";
leaf port {
if-feature "ntp-port";
type inet:port-number {
range "123 | 1024..max";
}
default "123";
description
"Specify the port used to send and receive NTP packets.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.2";
}
container refclock-master {
presence "NTP master clock is enabled.";
description
"Configures the local clock of this 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 {
if-feature "authentication";
description
"Configuration of authentication";
leaf auth-enabled {
type boolean;
default "false";
description
"Controls whether NTP authentication is enabled
or disabled on this device.";
}
list authentication-keys {
key "keyid";
uses authentication-key;
description
"List of authentication keys";
}
}
container access-rules {
if-feature "access-rules";
description
"Configuration to control access to NTP service
by using the NTP access-group feature.
The access-mode identifies how the ACL is
applied with NTP.";
list access-rule {
key "access-mode";
description
"List of access rules";
leaf access-mode {
type identityref {
base access-mode;
}
description
"The NTP access-mode. Some of the possible values
include peer, server, synchronization, query,
etc.";
}
leaf acl {
type leafref {
path "/acl:acls/acl:acl/acl:name";
}
description
"Control access configuration to be used.";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 9.2";
}
}
container clock-state {
config false;
description
"Clock operational state of the NTP";
container system-status {
description
"System status of NTP";
leaf clock-state {
type identityref {
base clock-state;
}
mandatory true;
description
"The state of the system clock. Some of the possible
values include synchronized and unsynchronized.";
}
leaf clock-stratum {
type ntp-stratum;
mandatory true;
description
"The NTP entity's own stratum value. Should be one
greater than the preceding level.
16 if unsynchronized.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
leaf clock-refid {
type refid;
mandatory true;
description
"A code identifying the particular server or reference
clock. The interpretation depends upon stratum. It
could be an IPv4 address, the first 32 bits of the MD5
hash of the IPv6 address, or a string for the Reference
Identifier and kiss codes. Some examples:
-- a refclock ID like '127.127.1.0' for local clock sync
-- uni/multi/broadcast associations for IPv4 will look
like '203.0.113.1' and '0x4321FEDC' for IPv6
-- sync with primary source will look like 'DCN',
'NIST', 'ATOM'
-- kiss codes will look like 'AUTH', 'DROP', 'RATE'
Note that the use of MD5 hash for IPv6 address is not
for cryptographic purposes.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
uses association-ref {
description
"Reference to association";
}
leaf nominal-freq {
type decimal64 {
fraction-digits 4;
}
units "Hz";
mandatory true;
description
"The nominal frequency of the local clock. An ideal
frequency with zero uncertainty.";
}
leaf actual-freq {
type decimal64 {
fraction-digits 4;
}
units "Hz";
mandatory true;
description
"The actual frequency of the local clock";
}
leaf clock-precision {
type log2seconds;
mandatory true;
description
"Clock precision of this system in signed integer format,
in log 2 seconds - (prec=2^(-n)). A value of 5 would
mean 2^-5 = 0.03125 seconds = 31.25 ms.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
leaf clock-offset {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"The signed time offset to the current selected reference
time source, e.g., '0.032ms' or '1.232ms'. The negative
value indicates that the local clock is behind the
current selected reference time source.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 9.1";
}
leaf root-delay {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"Total delay along the path to the root clock";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Sections 4 and 7.3";
}
leaf root-dispersion {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"The dispersion to the local clock
and the root clock, e.g., '6.927ms'.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Sections 4, 7.3, and 10";
}
leaf reference-time {
type ntp-date-and-time;
description
"The reference timestamp. Time when the system clock was
last set or corrected.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
leaf sync-state {
type identityref {
base ntp-sync-state;
}
mandatory true;
description
"The synchronization status of the local clock. Referred
to as 'Clock state definitions' in RFC 5905.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Appendix A.1.1";
}
}
}
list unicast-configuration {
if-feature "unicast-configuration";
key "address type";
description
"List of NTP unicast-configurations";
leaf address {
type inet:ip-address;
description
"Address of this association";
}
leaf type {
type identityref {
base unicast-configuration-type;
}
description
"The unicast configuration type, for example,
unicast-server";
}
container authentication {
if-feature "authentication";
description
"Authentication used for this association";
uses authentication;
}
leaf prefer {
type boolean;
default "false";
description
"Whether or not this association is preferred";
}
leaf burst {
type boolean;
default "false";
description
"If set, a series of packets are sent instead of a single
packet within each synchronization interval to achieve
faster synchronization.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 13.1";
}
leaf iburst {
type boolean;
default "false";
description
"If set, a series of packets are sent instead of a single
packet within the initial synchronization interval to
achieve faster initial synchronization.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 13.1";
}
leaf source {
type if:interface-ref;
description
"The interface whose IP address is used by this association
as the source address.";
}
uses common-attributes {
description
"Common attributes like port, version, and min and max
poll.";
}
}
container associations {
description
"Association parameters";
list association {
key "address local-mode isconfigured";
config false;
description
"List of NTP associations. Here address, local-mode,
and isconfigured are required to uniquely identify
a particular association. Let's take the following
examples:
1) If RT1 is acting as broadcast server
and RT2 is acting as broadcast client, then RT2
will form a dynamic association with the address as
RT1, local-mode as client, and isconfigured as false.
2) When RT2 is configured with unicast server RT1,
then RT2 will form an association with the address as
RT1, local-mode as client, and isconfigured as true.okay the YANG is getting really juicy now 🫶✨ the associations list is where the magic happens, so keep your eyes peeled for the examples about RT1 and RT2 💖 more of this module is coming, stay tuned 🦋
Thus, all three leaves are needed as key to uniquely
identify the association.";
leaf address {
type inet:ip-address;
description
"The remote address of this association. Represents the
IP address of a unicast/multicast/broadcast address.";
}
leaf local-mode {
type identityref {
base association-mode;
}
description
"Local-mode of this NTP association";
}
leaf isconfigured {
type boolean;
description
"Indicates if this association is configured (true) or
dynamically learned (false).";
}
leaf stratum {
type ntp-stratum;
description
"The association stratum value";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 3";
}
leaf refid {
type refid;
description
"A code identifying the particular server or reference
clock. The interpretation depends upon stratum. It
could be an IPv4 address or first 32 bits of the MD5
hash of the IPv6 address or a string for the Reference
Identifier and kiss codes. Some examples:
-- a refclock ID like '127.127.1.0' for local clock sync
-- uni/multi/broadcast associations for IPv4 will look
like '203.0.113.1' and '0x4321FEDC' for IPv6
-- sync with primary source will look like 'DCN',
'NIST', or 'ATOM'
-- kiss codes will look like 'AUTH', 'DROP', or 'RATE'okay so the key trio 🎀 the association is only uniquely identified when all three leaves are used together, so they're basically a team 🫶
leaf address 🌸 this is the remote address of the association. It can be a unicast, multicast, or broadcast IP address, so it's very versatile, bestie 🦋
leaf local-mode 💜 this one is an identityref based on association-mode, and it tells you the local-mode of the NTP association ✨
leaf isconfigured 🍓 a boolean that's true when the association was configured and false when it was dynamically learned. Simple, iconic 💅
leaf stratum 👑 the association's stratum value, with the type ntp-stratum. The reference points you to Section 3 of RFC 5905 🌈
leaf refid 🔥 okay this one is giving main character energy 💖 It's a code for the particular server or reference clock, and what it looks like depends on the stratum. It can be an IPv4 address, the first 32 bits of the MD5 hash of an IPv6 address, or a string for reference identifiers and kiss codes. The description has some examples too 🧚
Okay bestie, the YANG keeps going and it is SO good. 💅 Here's the rest of the module, with every line exactly as written.
Note that the use of an MD5 hash for IPv6 address is
not for cryptographic purposes.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
leaf authentication {
if-feature "authentication";
type leafref {
path "/ntp:ntp/ntp:authentication/"
+ "ntp:authentication-keys/ntp:keyid";
}
description
"Authentication key used for this association";
}
leaf prefer {
type boolean;
default "false";
description
"Indicates if this association is preferred";
}
leaf peer-interface {
type if:interface-ref;
description
"The interface that is used for communication";
}
uses common-attributes {
description
"Common attributes like port, version, and min and
max poll";
}
leaf reach {
type uint8;
description
"An 8-bit shift register that tracks packet
generation and receipt. It is used to determine
whether the server is reachable and the data are
fresh.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Sections 9.2 and 13";
}
leaf unreach {
type uint8;
units "seconds";
description
"A count of how long in second the server has been
unreachable, i.e., the reach value has been zero.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Sections 9.2 and 13";
}
leaf poll {
type log2seconds;
description
"The polling interval for current association in signed
log2 seconds.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 7.3";
}
leaf now {
type uint32;
units "seconds";
description
"The time since the last NTP packet was
received or last synchronized.";
}
leaf offset {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"The signed offset between the local clock
and the peer clock, e.g., '0.032ms' or '1.232ms'. The
negative value indicates that the local clock is behind
the peer.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 8";
}
leaf delay {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"The network delay between the local clock
and the peer clock";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 8";
}
leaf dispersion {
type decimal64 {
fraction-digits 3;
}
units "milliseconds";
description
"The root dispersion between the local clock
and the peer clock.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 10";
}
leaf originate-time {
type ntp-date-and-time;
description
"This is the local time, in timestamp format,
when the latest NTP packet was sent to the peer
(called T1).";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol and
Algorithms Specification, Section 8";
}
leaf receive-time {
type ntp-date-and-time;
description
"This is the local time, in timestamp format,
when the latest NTP packet arrived at the peer
(called T2). If the peer becomes unreachable,
the value is set to zero.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 8";
}
leaf transmit-time {
type ntp-date-and-time;
description
"This is the local time, in timestamp format,
at which the NTP packet departed the peer
(called T3). If the peer becomes unreachable,
the value is set to zero.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 8";
}
leaf input-time {
type ntp-date-and-time;
description
"This is the local time, in timestamp format,
when the latest NTP message from the peer arrived
(called T4). If the peer becomes unreachable,
value is set to zero.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 8";
}
container ntp-statistics {
description
"Per peer packet send and receive statistics";
uses statistics {
description
"NTP send and receive packet statistics";
}
}
}
}
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 {
if-feature "broadcast-server";
presence "NTP broadcast-server is configured on this
interface.";
description
"Configuration of broadcast server";
leaf ttl {
type uint8;
description
"Specifies the time to live (TTL) for a
broadcast packet";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
container authentication {
if-feature "authentication";
description
"Authentication used on this interface";
uses authentication;
}
uses common-attributes {
description
"Common attributes such as port, version, and min and
max poll";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
container broadcast-client {
if-feature "broadcast-client";
presence "NTP broadcast-client is configured on this
interface.";
description
"Configuration of broadcast client";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
list multicast-server {
if-feature "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 TTL for a multicast packet";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
container authentication {
if-feature "authentication";
description
"Authentication used on this interface";
uses authentication;
}
uses common-attributes {
description
"Common attributes such as port, version, and min and
max poll";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
list multicast-client {
if-feature "multicast-client";
key "address";
description
"Configuration of a multicast client";
leaf address {
type rt-types:ip-multicast-group-address;
description
"The IP address of the multicast group to
join";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
list manycast-server {
if-feature "manycast-server";
key "address";
description
"Configuration of a manycast server";
leaf address {
type rt-types:ip-multicast-group-address;
description
"The multicast group IP address to receive
manycast client messages.";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
list manycast-client {
if-feature "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 {
if-feature "authentication";
description
"Authentication used on this interface";
uses authentication;
}
leaf ttl {
type uint8;
description
"Specifies the maximum TTL for the expanding
ring search";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
leaf minclock {
type uint8;
description
"The minimum manycast survivors in this
association";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 13.2";
}
leaf maxclock {
type uint8;
description
"The maximum manycast candidates in this
association";
reference "RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 13.2";
}
leaf beacon {
type log2seconds;
description
"The beacon is the upper limit of the poll interval.
When the TTL reaches its limit without finding the
minimum number of manycast servers, the poll interval
increases until reaching the beacon value, when it
starts over from the beginning.";
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 13.2";
}
uses common-attributes {
description
"Common attributes like port, version, and min and
max poll";
}
reference
"RFC 5905: Network Time Protocol Version 4: Protocol
and Algorithms Specification, Section 3.1";
}
}
}
container ntp-statistics {
config false;
description
"Total NTP packet statistics";
uses statistics {
description
"NTP send and receive packet statistics";
}
}
}
rpc statistics-reset {
description
"Reset statistics collected.";
input {
choice association-or-all {
description
"Resets statistics for a particular association or
all.";
case association {
uses association-ref;
description
"This resets all the statistics collected for
the association.";
}
case all {
description
"This resets all the statistics collected.";
}
}
}
}
}
<CODE ENDS>9. Usage Example ✨
Okay, time for the fun part 🎀 This section is all about examples, so you can actually see what the YANG module looks like in action. They're here for illustration only, so think of them as little cheat sheets 💅
Note: '' indicates line wrapping per [RFC8792].
9.1. Unicast Association
Let's start with a preferred unicast server 💖 This one lives at 192.0.2.1, runs on port 1025, uses authentication-key 10, and sticks with version 4 (the default) 🌸
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<unicast-configuration>
<address>192.0.2.1</address>
<type>uc-server</type>
<prefer>true</prefer>
<port>1025</port>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
</unicast-configuration>
</ntp>
</config>
</edit-config>Okay but what if you want IPv6? Literally just swap the address! ✨ Use 2001:db8::1 in the "address" leaf and nothing else in the data tree changes 🦋
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<unicast-configuration>
<address>2001:db8::1</address>
<type>uc-server</type>
<prefer>true</prefer>
<port>1025</port>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
</unicast-configuration>
</ntp>
</config>
</edit-config>Now let's retrieve those unicast configurations 👀 This is the query:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<unicast-configuration>
</unicast-configuration>
</ntp>
</filter>
</get>And this is what comes back, and honestly it's giving everything 😭 ✨
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<unicast-configuration>
<address>192.0.2.1</address>
<type>uc-server</type>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
<prefer>true</prefer>
<burst>false</burst>
<iburst>true</iburst>
<source/>
<minpoll>6</minpoll>
<maxpoll>10</maxpoll>
<port>1025</port>
<stratum>9</stratum>
<refid>203.0.113.1</refid>
<reach>255</reach>
<unreach>0</unreach>
<poll>128</poll>
<now>10</now>
<offset>0.025</offset>
<delay>0.5</delay>
<dispersion>0.6</dispersion>
<originate-time>10-10-2017 07:33:55.253 Z+05:30\
</originate-time>
<receive-time>10-10-2017 07:33:55.258 Z+05:30\
</receive-time>
<transmit-time>10-10-2017 07:33:55.300 Z+05:30\
</transmit-time>
<input-time>10-10-2017 07:33:55.305 Z+05:30\
</input-time>
<ntp-statistics>
<packet-sent>20</packet-sent>
<packet-sent-fail>0</packet-sent-fail>
<packet-received>20</packet-received>
<packet-dropped>0</packet-dropped>
</ntp-statistics>
</unicast-configuration>
</ntp>
</data>9.2. Refclock Master
Next up: configuring a reference clock with stratum 8 🧚
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<refclock-master>
<master-stratum>8</master-stratum>
</refclock-master>
</ntp>
</config>
</edit-config>To check the reference clock configuration afterwards, you'd send this:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<refclock-master>
</refclock-master>
</ntp>
</filter>
</get>And the reply looks like this 🍓
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<refclock-master>
<master-stratum>8</master-stratum>
</refclock-master>
</ntp>
</data>9.3. Authentication Configuration
This one is all about security, bestie 🔐 It enables authentication and sets up trusted key 10, using AES-CMAC as the mode, with a hexadecimal string as the key 💜
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<authentication>
<auth-enabled>true</auth-enabled>
<authentication-keys>
<keyid>10</keyid>
<algorithm>aes-cmac</algorithm>
<key>
<hexadecimal-string>
bb1d6929e95937287fa37d129b756746
</hexadecimal-string>
</key>
<istrusted>true</istrusted>
</authentication-keys>
</authentication>
</ntp>
</config>
</edit-config>9.4. Access Configuration
Here we go with "peer-access-mode" tied to ACL 2000 🚪
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<access-rules>
<access-rule>
<access-mode>peer-access-mode</access-mode>
<acl>2000</acl>
</access-rule>
</access-rules>
</ntp>
</config>
</edit-config>And to pull the access-related configuration back out:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<access-rules>
</access-rules>
</ntp>
</filter>
</get>Reply:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<access-rules>
<access-rule>
<access-mode>peer-access-mode</access-mode>
<acl>2000</acl>
</access-rule>
</access-rules>
</ntp>
</data>9.5. Multicast Configuration
Multicast time, let's gooo 📡 This example sets up a multicast server at "224.0.1.1", on port 1025, using version 3 and authentication keyid 10 🌈
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<multicast-server>
<address>224.0.1.1</address>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
<port>1025</port>
<version>3</version>
</multicast-server>
</interface>
</interfaces>
</ntp>
</config>
</edit-config>To check the multicast-server settings:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<multicast-server>
</multicast-server>
</interface>
</interfaces>
</ntp>
</filter>
</get>Reply:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<multicast-server>
<address>224.0.1.1</address>
<ttl>8</ttl>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
<minpoll>6</minpoll>
<maxpoll>10</maxpoll>
<port>1025</port>
<version>3</version>
</multicast-server>
</interface>
</interfaces>
</ntp>
</data>Last one in this batch: a multicast client at "224.0.1.1" 🦋
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<multicast-client>
<address>224.0.1.1</address>
</multicast-client>
</interface>
</interfaces>
</ntp>
</config>
</edit-config>And the query for multicast-client settings:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<multicast-client>
</multicast-client>
</interface>
</interfaces>
</ntp>
</filter>
</get>Reply:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<multicast-client>
<address>224.0.1.1</address>
</multicast-client>
</interface>
</interfaces>
</ntp>
</data>That's the usage examples wrapped up for this part 🌈✨ More sections are coming, so stay tuned, bestie 💖
9.6. Manycast Configuration ✨
okay bestie, let's set up a manycast-client 🧚 with address "224.0.1.1", port 1025, and authentication keyid 10. Here's the edit-config:
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<manycast-client>
<address>224.0.1.1</address>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
<port>1025</port>
</manycast-client>
</interface>
</interfaces>
</ntp>
</config>
</edit-config>Next up, checking the manycast-client config with a get. It's giving filter-and-peek 👀:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<manycast-client>
</manycast-client>
</interface>
</interfaces>
</ntp>
</filter>
</get>And here's what comes back, bestie, and it's so pretty 🌸:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<manycast-client>
<address>224.0.1.1</address>
<authentication>
<symmetric-key>
<keyid>10</keyid>
</symmetric-key>
</authentication>
<ttl>8</ttl>
<minclock>3</minclock>
<maxclock>10</maxclock>
<beacon>6</beacon>
<minpoll>6</minpoll>
<maxpoll>10</maxpoll>
<port>1025</port>
</manycast-client>
</interface>
</interfaces>
</ntp>
</data>Now for the manycast-server, also at "224.0.1.1". Main character energy 👑:
<edit-config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<target>
<running/>
</target>
<config>
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<manycast-server>
<address>224.0.1.1</address>
</manycast-server>
</interface>
</interfaces>
</ntp>
</config>
</edit-config>To check the manycast-server config, get it like this 🔍:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<manycast-server>
</manycast-server>
</interface>
</interfaces>
</ntp>
</filter>
</get>And the reply:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<interfaces>
<interface>
<name>Ethernet3/0/0</name>
<manycast-server>
<address>224.0.1.1</address>
</manycast-server>
</interface>
</interfaces>
</ntp>
</data>9.7. Clock State 🕰️
okay so this one shows the current clock state, and it's giving precise 💅:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<clock-state>
</clock-state>
</ntp>
</filter>
</get>Here's the data that comes back, and the vibes are immaculate ✨:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<clock-state>
<system-status>
<clock-state>synchronized</clock-state>
<clock-stratum>7</clock-stratum>
<clock-refid>192.0.2.1</clock-refid>
<associations-address>192.0.2.1\
</associations-address>
<associations-local-mode>client\
</associations-local-mode>
<associations-isconfigured>yes\
</associations-isconfigured>
<nominal-freq>100.0</nominal-freq>
<actual-freq>100.0</actual-freq>
<clock-precision>18</clock-precision>
<clock-offset>0.025</clock-offset>
<root-delay>0.5</root-delay>
<root-dispersion>0.8</root-dispersion>
<reference-time>10-10-2017 07:33:55.258 Z+05:30\
</reference-time>
<sync-state>clock-synchronized</sync-state>
</system-status>
</clock-state>
</ntp>
</data>9.8. Get All Association 🦋
this one grabs every association in the system, so basically the full friend list 🫶:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<associations>
</associations>
</ntp>
</filter>
</get>and the reply is a whole vibe 🎀:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<associations>
<association>
<address>192.0.2.1</address>
<stratum>9</stratum>
<refid>203.0.113.1</refid>
<local-mode>client</local-mode>
<isconfigured>true</isconfigured>
<authentication-key>10</authentication-key>
<prefer>true</prefer>
<peer-interface>Ethernet3/0/0</peer-interface>
<minpoll>6</minpoll>
<maxpoll>10</maxpoll>
<port>1025</port>
<version>4</version>
<reach>255</reach>
<unreach>0</unreach>
<poll>128</poll>
<now>10</now>
<offset>0.025</offset>
<delay>0.5</delay>
<dispersion>0.6</dispersion>
<originate-time>10-10-2017 07:33:55.253 Z+05:30\
</originate-time>
<receive-time>10-10-2017 07:33:55.258 Z+05:30\
</receive-time>
<transmit-time>10-10-2017 07:33:55.300 Z+05:30\
</transmit-time>
<input-time>10-10-2017 07:33:55.305 Z+05:30\
</input-time>
<ntp-statistics>
<packet-sent>20</packet-sent>
<packet-sent-fail>0</packet-sent-fail>
<packet-received>20</packet-received>
<packet-dropped>0</packet-dropped>
</ntp-statistics>
</association>
</associations>
</ntp>
</data>9.9. Global Statistic 📊
last example in this part, bestie 🥹. This one gets the global statistics:
<get>
<filter type="subtree">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<ntp-statistics>
</ntp-statistics>
</ntp>
</filter>
</get>and the data that comes back:
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ntp xmlns="urn:ietf:params:xml:ns:yang:ietf-ntp">
<ntp-statistics>
<packet-sent>30</packet-sent>
<packet-sent-fail>5</packet-sent-fail>
<packet-received>20</packet-received>
<packet-dropped>2</packet-dropped>
</ntp-statistics>
</ntp>
</data>10. IANA Considerations 🌈
10.1. IETF XML Registry 🗂️
this document registers a URI in the "IETF XML Registry" [RFC3688]. It follows the format in RFC 3688, and the registration looks like this 💜:
URI: urn:ietf:params:xml:ns:yang:ietf-ntp
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.10.2. YANG Module Names 📝
this document also registers a YANG module in the "YANG Module Names" registry [RFC6020]. Here's the entry 🎀:
Name: ietf-ntp
Namespace: urn:ietf:params:xml:ns:yang:ietf-ntp
Prefix: ntp
Reference: RFC 924911. Security Considerations 🔐
bestie, this section is SERIOUS 😭 so please read it carefully. The YANG module in this document defines a schema for data that gets accessed through network management protocols like 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 [RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341] lets you restrict particular NETCONF or RESTCONF users to a preconfigured subset of all the available protocol operations and content. The 'nacm:default-deny-all' setting is used to stop anyone from retrieving the key information 🙈.
There are a bunch of data nodes in this YANG module that are writable, creatable, and deletable (that's config true, which is the default). These nodes may be sensitive or vulnerable in some network environments. Write operations (like edit-config) to them without proper protection can badly affect network operations 💀. Here are the subtrees and data nodes, plus their sensitivity and vulnerability:
/ntp/port: This data node sets the port number used to send NTP packets. Unexpected changes could lead to disruption and/or network misbehavior./ntp/authenticationand/ntp/access-rules: The entries in this list include the authentication and access control configurations. Take care when you set these parameters./ntp/unicast-configuration: The entries in this list include all unicast configurations (server or peer mode), and they indirectly create or modify the NTP associations. Unexpected changes could lead to disruption and/or network misbehavior./ntp/interfaces/interface: The entries in this list include all per-interface configurations related to broadcast, multicast, and manycast mode, and they indirectly create or modify the NTP associations. Unexpected changes could lead to disruption and/or network misbehavior. It could also lead to synchronizing to an untrusted source over trusted ones.
Some of the readable data nodes in this YANG module may also be sensitive or vulnerable in some network environments, so it's important to control read access to them (through get, get-config, or notification) 🛡️. Here are the subtrees and data nodes, plus their sensitivity and vulnerability:
/ntp/authentication/authentication-keys: The entries in this list include all the NTP authentication keys. Unauthorized access to the keys can easily be exploited to gain unauthorized access to the NTP service. This information is sensitive, so unauthorized access to it needs to be shut down./ntp/associations/association/: The entries in this list include all active NTP associations of all modes. Exposure of these nodes could reveal network topology or trust relationships. Unauthorized access to them also needs to be shut down./ntp/authenticationand/ntp/access-rules: The entries in this list include the authentication and access control configurations. Exposure of these nodes could reveal network topology or trust relationships.
Some of the RPC operations in this YANG module may also be sensitive or vulnerable in some network environments, so it's important to control access to them. Here's the operation and its sensitivity and vulnerability:
statistics-reset: This RPC is used to reset statistics. An unauthorized reset could impact monitoring.
The leaf /ntp/authentication/authentication-keys/algorithm can be set to cryptographic algorithms that are no longer considered secure. As per [RFC8573], AES-CMAC is the recommended algorithm 🔥.
12. References 📚
12.1. Normative References ✨
These are the must-reads, bestie 📚 Everything here is basically the foundation of the whole spec, so you can't skip any of it 💅
- [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997,
https://www.rfc-editor.org/info/rfc2119. - [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004,
https://www.rfc-editor.org/info/rfc3688. - [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,
https://www.rfc-editor.org/info/rfc5905. - [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010,
https://www.rfc-editor.org/info/rfc6020. - [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,
https://www.rfc-editor.org/info/rfc6241. - [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
https://www.rfc-editor.org/info/rfc6242. - [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013,
https://www.rfc-editor.org/info/rfc6991. - [RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for System Management", RFC 7317, DOI 10.17487/RFC7317, August 2014,
https://www.rfc-editor.org/info/rfc7317. - [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016,
https://www.rfc-editor.org/info/rfc7950. - [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
https://www.rfc-editor.org/info/rfc8040. - [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017,
https://www.rfc-editor.org/info/rfc8174. - [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,
https://www.rfc-editor.org/info/rfc8294. - [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
https://www.rfc-editor.org/info/rfc8340. - [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018,
https://www.rfc-editor.org/info/rfc8341. - [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
https://www.rfc-editor.org/info/rfc8343. - [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
https://www.rfc-editor.org/info/rfc8446. - [RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair, "YANG Data Model for Network Access Control Lists (ACLs)", RFC 8519, DOI 10.17487/RFC8519, March 2019,
https://www.rfc-editor.org/info/rfc8519. - [RFC8573] Malhotra, A. and S. Goldberg, "Message Authentication Code for the Network Time Protocol", RFC 8573, DOI 10.17487/RFC8573, June 2019,
https://www.rfc-editor.org/info/rfc8573.
12.2. Informative References 🌸
These ones are the extra context, the "ooh, go read this if you're curious" pile 🧚 Not required, but they're giving very helpful energy 🫶
- [RFC1305] Mills, D., "Network Time Protocol (Version 3) Specification, Implementation and Analysis", RFC 1305, DOI 10.17487/RFC1305, March 1992,
https://www.rfc-editor.org/info/rfc1305. - [RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, DOI 10.17487/RFC1321, April 1992,
https://www.rfc-editor.org/info/rfc1321. - [RFC3174] Eastlake 3rd, D. and P. Jones, "US Secure Hash Algorithm 1 (SHA1)", RFC 3174, DOI 10.17487/RFC3174, September 2001,
https://www.rfc-editor.org/info/rfc3174. - [RFC4493] Song, JH., Poovendran, R., Lee, J., and T. Iwata, "The AES-CMAC Algorithm", RFC 4493, DOI 10.17487/RFC4493, June 2006,
https://www.rfc-editor.org/info/rfc4493. - [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,
https://www.rfc-editor.org/info/rfc5907. - [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,
https://www.rfc-editor.org/info/rfc8342. - [RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
https://www.rfc-editor.org/info/rfc8792. - [SHS] National Institute of Standards and Technology (NIST), "Secure Hash Standard (SHS)", DOI 10.6028/NIST.FIPS.180-4, FIPS PUB 180-4, August 2015,
https://doi.org/10.6028/NIST.FIPS.180-4.
Appendix A. Full YANG Tree ✨
okay so this is the whole family tree for the ietf-ntp YANG data model 🌳💖 every branch, every leaf, all in one place. it's giving complete reference energy, so here it is in full:
module: ietf-ntp
+--rw ntp!
+--rw port? inet:port-number {ntp-port}?
+--rw refclock-master!
| +--rw master-stratum? ntp-stratum
+--rw authentication {authentication}?
| +--rw auth-enabled? boolean
| +--rw authentication-keys* [keyid]
| +--rw keyid uint32
| +--rw algorithm? identityref
| +--rw key
| | +--rw (key-string-style)?
| | +--:(keystring)
| | | +--rw keystring? string {deprecated}?
| | +--:(hexadecimal) {hex-key-string}?
| | +--rw hexadecimal-string? yang:hex-string
| +--rw istrusted? boolean
+--rw access-rules {access-rules}?
| +--rw access-rule* [access-mode]
| +--rw access-mode identityref
| +--rw acl? -> /acl:acls/acl/name
+--ro clock-state
| +--ro system-status
| +--ro clock-state identityref
| +--ro clock-stratum ntp-stratum
| +--ro clock-refid refid
| +--ro associations-address?
| | -> /ntp/associations/association/address
| +--ro associations-local-mode?
| | -> /ntp/associations/association/local-mode
| +--ro associations-isconfigured?
| | -> /ntp/associations/association/isconfigured
| +--ro nominal-freq decimal64
| +--ro actual-freq decimal64
| +--ro clock-precision log2seconds
| +--ro clock-offset? decimal64
| +--ro root-delay? decimal64
| +--ro root-dispersion? decimal64
| +--ro reference-time? ntp-date-and-time
| +--ro sync-state identityref
+--rw unicast-configuration* [address type]
| {unicast-configuration}?
| +--rw address inet:ip-address
| +--rw type identityref
| +--rw authentication {authentication}?
| | +--rw (authentication-type)?
| | +--:(symmetric-key)
| | +--rw keyid? leafref
| +--rw prefer? boolean
| +--rw burst? boolean
| +--rw iburst? boolean
| +--rw source? if:interface-ref
| +--rw minpoll? log2seconds
| +--rw maxpoll? log2seconds
| +--rw port? inet:port-number {ntp-port}?
| +--rw version? ntp-version
+--rw associations
| +--ro association* [address local-mode isconfigured]
| +--ro address inet:ip-address
| +--ro local-mode identityref
| +--ro isconfigured boolean
| +--ro stratum? ntp-stratum
| +--ro refid? refid
| +--ro authentication?
| | -> /ntp/authentication/authentication-keys/keyid
| | {authentication}?
| +--ro prefer? boolean
| +--ro peer-interface? if:interface-ref
| +--ro minpoll? log2seconds
| +--ro maxpoll? log2seconds
| +--ro port? inet:port-number {ntp-port}?
| +--ro version? ntp-version
| +--ro reach? uint8
| +--ro unreach? uint8
| +--ro poll? log2seconds
| +--ro now? uint32
| +--ro offset? decimal64
| +--ro delay? decimal64
| +--ro dispersion? decimal64
| +--ro originate-time? ntp-date-and-time
| +--ro receive-time? ntp-date-and-time
| +--ro transmit-time? ntp-date-and-time
| +--ro input-time? ntp-date-and-time
| +--ro ntp-statistics
| +--ro discontinuity-time? ntp-date-and-time
| +--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! {broadcast-server}?
| | +--rw ttl? uint8
| | +--rw authentication {authentication}?
| | | +--rw (authentication-type)?
| | | +--:(symmetric-key)
| | | +--rw keyid? leafref
| | +--rw minpoll? log2seconds
| | +--rw maxpoll? log2seconds
| | +--rw port? inet:port-number {ntp-port}?
| | +--rw version? ntp-version
| +--rw broadcast-client! {broadcast-client}?
| +--rw multicast-server* [address] {multicast-server}?
| | +--rw address
| | | rt-types:ip-multicast-group-address
| | +--rw ttl? uint8
| | +--rw authentication {authentication}?
| | | +--rw (authentication-type)?
| | | +--:(symmetric-key)
| | | +--rw keyid? leafref
| | +--rw minpoll? log2seconds
| | +--rw maxpoll? log2seconds
| | +--rw port? inet:port-number {ntp-port}?
| | +--rw version? ntp-version
| +--rw multicast-client* [address] {multicast-client}?
| | +--rw address rt-types:ip-multicast-group-address
| +--rw manycast-server* [address] {manycast-server}?
| | +--rw address rt-types:ip-multicast-group-address
| +--rw manycast-client* [address] {manycast-client}?
| +--rw address
| | rt-types:ip-multicast-group-address
| +--rw authentication {authentication}?
| | +--rw (authentication-type)?
| | +--:(symmetric-key)
| | +--rw keyid? leafref
| +--rw ttl? uint8
| +--rw minclock? uint8
| +--rw maxclock? uint8
| +--rw beacon? log2seconds
| +--rw minpoll? log2seconds
| +--rw maxpoll? log2seconds
| +--rw port? inet:port-number {ntp-port}?
| +--rw version? ntp-version
+--ro ntp-statistics
+--ro discontinuity-time? ntp-date-and-time
+--ro packet-sent? yang:counter32
+--ro packet-sent-fail? yang:counter32
+--ro packet-received? yang:counter32
+--ro packet-dropped? yang:counter32
rpcs:
+---x statistics-reset
+---w input
+---w (association-or-all)?
+--:(association)
| +---w associations-address?
| | -> /ntp/associations/association/address
| +---w associations-local-mode?
| | -> /ntp/associations/association/local-mode
| +---w associations-isconfigured?
| -> /ntp/associations/association/isconfigured
+--:(all)Acknowledgments 💖
big thank-yous to the squad 🫶 the authors gave a massive shoutout to Sladjana Zoric, Danny Mayer, Harlan Stenn, Ulrich Windl, Miroslav Lichvar, Maurice Angermann, Watson Ladd, and Rich Salz for reviewing the work and dropping suggestions. ✨
YANG doctor review 🩺 thanks to Andy Bierman for that one!
Shepherd and AD energy 🌸 thanks to Dieter Sibold for being the Document Shepherd, and to Erik Kline for being the Responsible AD. they kept the whole thing on track 👑
security and general reviews 🔐 thanks to Takeshi Takahashi for the SECDIR review, and to Tim Evens for the GENART review. 🦋
a special mention 💅 a very special thanks to Tom Petch for a super detailed YANG review and for giving great ideas on how to make things better. literally iconic behaviour 😭
the IESG crew 🌈 thanks for the IESG review from Benjamin Kaduk, Francesca Palombini, Eric Vyncke, Murray Kucherawy, Robert Wilton, Roman Danyliw, and Zaheduzzaman Sarker. the whole group was absolutely locked in 🧚
Authors' Addresses 🎀
here's who wrote it and where to find them, bestie 💌
- Nan Wu
- Huawei
- Huawei Bld., No.156 Beiqing Rd.
- Beijing
- 100095
- China
- Email: eric.wu@huawei.com
- Dhruv Dhody (editor)
- Huawei
- Divyashree Techno Park, Whitefield
- Bangalore 560066
- Kanataka
- India
- Email: dhruv.ietf@gmail.com
- Ankit Kumar Sinha (editor)
- RtBrick Inc.
- Bangalore
- Kanataka
- India
- Email: ankit.ietf@gmail.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
📦 where this page comes from
- ietf: rfc9249 2022-07
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms