Internet DRAFT - draft-ietf-netconf-netconf-client-server
draft-ietf-netconf-netconf-client-server
NETCONF Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Standards Track 1 March 2024
Expires: 2 September 2024
NETCONF Client and Server Models
draft-ietf-netconf-netconf-client-server-35
Abstract
This document presents two YANG modules, one module to configure a
NETCONF client and the other module to configure a NETCONF server.
Both modules support both the SSH and TLS transport protocols, and
support both standard NETCONF and NETCONF Call Home connections.
Editorial Note (To be removed by RFC Editor)
This draft contains placeholder values that need to be replaced with
finalized values at the time of publication. This note summarizes
all of the substitutions that are needed. No other RFC Editor
instructions are specified elsewhere in this document.
Artwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements (note: not all may
be present):
* AAAA --> the assigned RFC value for draft-ietf-netconf-crypto-
types
* BBBB --> the assigned RFC value for draft-ietf-netconf-trust-
anchors
* CCCC --> the assigned RFC value for draft-ietf-netconf-keystore
* DDDD --> the assigned RFC value for draft-ietf-netconf-tcp-client-
server
* EEEE --> the assigned RFC value for draft-ietf-netconf-ssh-client-
server
* FFFF --> the assigned RFC value for draft-ietf-netconf-tls-client-
server
* GGGG --> the assigned RFC value for draft-ietf-netconf-http-
client-server
* HHHH --> the assigned RFC value for this draft
Watsen Expires 2 September 2024 [Page 1]
Internet-Draft NETCONF Client and Server Models March 2024
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
* 2024-03-02 --> the publication date of this draft
The "Relation to other RFCs" section Section 1.1 contains the text
"one or more YANG modules" and, later, "modules". This text is
sourced from a file in a context where it is unknown how many modules
a draft defines. The text is not wrong as is, but it may be improved
by stating more directly how many modules are defined.
The "Relation to other RFCs" section Section 1.1 contains a self-
reference to this draft, along with a corresponding reference in the
Appendix. Please replace the self-reference in this section with
"This RFC" (or similar) and remove the self-reference in the
"Normative/Informative References" section, whichever it is in.
Tree-diagrams in this draft may use the '\' line-folding mode defined
in RFC 8792. However, nicer-to-the-eye is when the '\\' line-folding
mode is used. The AD suggested suggested putting a request here for
the RFC Editor to help convert "ugly" '\' folded examples to use the
'\\' folding mode. "Help convert" may be interpreted as, identify
what looks ugly and ask the authors to make the adjustment.
The following Appendix section is to be removed prior to publication:
* Appendix A. Change Log
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 2 September 2024.
Watsen Expires 2 September 2024 [Page 2]
Internet-Draft NETCONF Client and Server Models March 2024
Copyright Notice
Copyright (c) 2024 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 . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Relation to other RFCs . . . . . . . . . . . . . . . . . 4
1.2. Specification Language . . . . . . . . . . . . . . . . . 6
1.3. Adherence to the NMDA . . . . . . . . . . . . . . . . . . 6
1.4. Conventions . . . . . . . . . . . . . . . . . . . . . . . 6
2. The "ietf-netconf-client" Module . . . . . . . . . . . . . . 7
2.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 7
2.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 11
2.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 15
3. The "ietf-netconf-server" Module . . . . . . . . . . . . . . 27
3.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 27
3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 32
3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 38
4. Security Considerations . . . . . . . . . . . . . . . . . . . 53
4.1. Considerations for the "ietf-netconf-client" YANG
Module . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.2. Considerations for the "ietf-netconf-server" YANG
Module . . . . . . . . . . . . . . . . . . . . . . . . . 53
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54
5.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 54
5.2. The "YANG Module Names" Registry . . . . . . . . . . . . 55
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 55
6.1. Normative References . . . . . . . . . . . . . . . . . . 55
6.2. Informative References . . . . . . . . . . . . . . . . . 57
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 58
A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 58
A.2. 01 to 02 . . . . . . . . . . . . . . . . . . . . . . . . 58
A.3. 02 to 03 . . . . . . . . . . . . . . . . . . . . . . . . 59
A.4. 03 to 04 . . . . . . . . . . . . . . . . . . . . . . . . 59
A.5. 04 to 05 . . . . . . . . . . . . . . . . . . . . . . . . 59
A.6. 05 to 06 . . . . . . . . . . . . . . . . . . . . . . . . 59
A.7. 06 to 07 . . . . . . . . . . . . . . . . . . . . . . . . 59
Watsen Expires 2 September 2024 [Page 3]
Internet-Draft NETCONF Client and Server Models March 2024
A.8. 07 to 08 . . . . . . . . . . . . . . . . . . . . . . . . 60
A.9. 08 to 09 . . . . . . . . . . . . . . . . . . . . . . . . 60
A.10. 09 to 10 . . . . . . . . . . . . . . . . . . . . . . . . 60
A.11. 10 to 11 . . . . . . . . . . . . . . . . . . . . . . . . 60
A.12. 11 to 12 . . . . . . . . . . . . . . . . . . . . . . . . 60
A.13. 12 to 13 . . . . . . . . . . . . . . . . . . . . . . . . 61
A.14. 13 to 14 . . . . . . . . . . . . . . . . . . . . . . . . 61
A.15. 14 to 15 . . . . . . . . . . . . . . . . . . . . . . . . 61
A.16. 15 to 16 . . . . . . . . . . . . . . . . . . . . . . . . 61
A.17. 16 to 17 . . . . . . . . . . . . . . . . . . . . . . . . 61
A.18. 17 to 18 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.19. 18 to 19 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.20. 19 to 20 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.21. 20 to 21 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.22. 21 to 22 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.23. 22 to 23 . . . . . . . . . . . . . . . . . . . . . . . . 62
A.24. 23 to 24 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.25. 24 to 25 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.26. 25 to 26 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.27. 26 to 27 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.28. 27 to 28 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.29. 28 to 29 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.30. 29 to 30 . . . . . . . . . . . . . . . . . . . . . . . . 63
A.31. 30 to 31 . . . . . . . . . . . . . . . . . . . . . . . . 64
A.32. 31 to 32 . . . . . . . . . . . . . . . . . . . . . . . . 64
A.33. 32 to 34 . . . . . . . . . . . . . . . . . . . . . . . . 64
A.34. 34 to 35 . . . . . . . . . . . . . . . . . . . . . . . . 64
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 64
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 65
1. Introduction
This document presents two YANG [RFC7950] modules, one module to
configure a NETCONF [RFC6241] client and the other module to
configure a NETCONF server. Both modules support both NETCONF over
SSH [RFC6242] and NETCONF over TLS [RFC7589] and NETCONF Call Home
connections [RFC8071].
1.1. Relation to other RFCs
This document presents one or more YANG modules [RFC7950] that are
part of a collection of RFCs that work together to, ultimately,
support the configuration of both the clients and servers of both the
NETCONF [RFC6241] and RESTCONF [RFC8040] protocols.
The dependency relationship between the primary YANG groupings
defined in the various RFCs is presented in the below diagram. In
some cases, a draft may define secondary groupings that introduce
Watsen Expires 2 September 2024 [Page 4]
Internet-Draft NETCONF Client and Server Models March 2024
dependencies not illustrated in the diagram. The labels in the
diagram are a shorthand name for the defining RFC. The citation
reference for shorthand name is provided below the diagram.
Please note that the arrows in the diagram point from referencer to
referenced. For example, the "crypto-types" RFC does not have any
dependencies, whilst the "keystore" RFC depends on the "crypto-types"
RFC.
crypto-types
^ ^
/ \
/ \
truststore keystore
^ ^ ^ ^
| +---------+ | |
| | | |
| +------------+ |
tcp-client-server | / | |
^ ^ ssh-client-server | |
| | ^ tls-client-server
| | | ^ ^ http-client-server
| | | | | ^
| | | +-----+ +---------+ |
| | | | | |
| +-----------|--------|--------------+ | |
| | | | | |
+-----------+ | | | | |
| | | | | |
| | | | | |
netconf-client-server restconf-client-server
Watsen Expires 2 September 2024 [Page 5]
Internet-Draft NETCONF Client and Server Models March 2024
+======================+===========================================+
|Label in Diagram | Originating RFC |
+======================+===========================================+
|crypto-types | [I-D.ietf-netconf-crypto-types] |
+----------------------+-------------------------------------------+
|truststore | [I-D.ietf-netconf-trust-anchors] |
+----------------------+-------------------------------------------+
|keystore | [I-D.ietf-netconf-keystore] |
+----------------------+-------------------------------------------+
|tcp-client-server | [I-D.ietf-netconf-tcp-client-server] |
+----------------------+-------------------------------------------+
|ssh-client-server | [I-D.ietf-netconf-ssh-client-server] |
+----------------------+-------------------------------------------+
|tls-client-server | [I-D.ietf-netconf-tls-client-server] |
+----------------------+-------------------------------------------+
|http-client-server | [I-D.ietf-netconf-http-client-server] |
+----------------------+-------------------------------------------+
|netconf-client-server | [I-D.ietf-netconf-netconf-client-server] |
+----------------------+-------------------------------------------+
|restconf-client-server| [I-D.ietf-netconf-restconf-client-server] |
+----------------------+-------------------------------------------+
Table 1: Label in Diagram to RFC Mapping
1.2. Specification 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.
1.3. Adherence to the NMDA
This document is compliant with the Network Management Datastore
Architecture (NMDA) [RFC8342]. For instance, as described in
[I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore],
trust anchors and keys installed during manufacturing are expected to
appear in <operational> (Section 5.3 of [RFC8342]), and <system>
[I-D.ietf-netmod-system-config], if implemented.
1.4. Conventions
Various examples in this document use "BASE64VALUE=" as a placeholder
value for binary data that has been base64 encoded (per Section 9.8
of [RFC7950]). This placeholder value is used because real base64
encoded structures are often many lines long and hence distracting to
the example being presented.
Watsen Expires 2 September 2024 [Page 6]
Internet-Draft NETCONF Client and Server Models March 2024
2. The "ietf-netconf-client" Module
The NETCONF client model presented in this section supports both
clients initiating connections to servers, as well as clients
listening for connections from servers calling home, using either the
SSH and TLS transport protocols.
YANG feature statements are used to enable implementations to
advertise which potentially uncommon parts of the model the NETCONF
client supports.
2.1. Data Model Overview
This section provides an overview of the "ietf-netconf-client" module
in terms of its features and groupings.
2.1.1. Features
The following diagram lists all the "feature" statements defined in
the "ietf-netconf-client" module:
Features:
+-- ssh-initiate
+-- tls-initiate
+-- ssh-listen
+-- tls-listen
+-- central-netconf-client-supported
The diagram above uses syntax that is similar to but not defined in
[RFC8340].
2.1.2. Groupings
The "ietf-netconf-client" module defines the following "grouping"
statements:
* netconf-client-initiate-stack-grouping
* netconf-client-listen-stack-grouping
* netconf-client-app-grouping
Each of these groupings are presented in the following subsections.
2.1.2.1. The "netconf-client-initiate-stack-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-client-
initiate-stack-grouping" grouping:
Watsen Expires 2 September 2024 [Page 7]
Internet-Draft NETCONF Client and Server Models March 2024
grouping netconf-client-initiate-stack-grouping:
+-- (transport)
+--:(ssh) {ssh-initiate}?
| +-- ssh
| +-- tcp-client-parameters
| | +---u tcpc:tcp-client-grouping
| +-- ssh-client-parameters
| | +---u sshc:ssh-client-grouping
| +-- netconf-client-parameters
| +--u ncc:netconf-client-grouping
+--:(tls) {tls-initiate}?
+-- tls
+-- tcp-client-parameters
| +---u tcpc:tcp-client-grouping
+-- tls-client-parameters
| +---u tlsc:tls-client-grouping
+-- netconf-client-parameters
+---u ncc:netconf-client-grouping
Comments:
* The "netconf-client-initiate-stack-grouping" defines the
configuration for a full NETCONF protocol stack, for NETCONF
clients that initiate connections to NETCONF servers, as opposed
to receiving call-home [RFC8071] connections.
* The "transport" choice node enables either the SSH or TLS
transports to be configured, with each option enabled by a
"feature" statement.
* For the referenced grouping statement(s):
- The "tcp-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-tcp-client-server].
- The "ssh-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-ssh-client-server].
- The "tls-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-tls-client-server].
2.1.2.2. The "netconf-client-listen-stack-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-client-
listen-stack-grouping" grouping:
Watsen Expires 2 September 2024 [Page 8]
Internet-Draft NETCONF Client and Server Models March 2024
grouping netconf-client-listen-stack-grouping:
+-- (transport)
+--:(ssh) {ssh-listen}?
| +-- ssh
| +-- tcp-server-parameters
| | +---u tcps:tcp-server-grouping
| +-- ssh-client-parameters
| | +---u sshc:ssh-client-grouping
| +-- netconf-client-parameters
| +--u ncc:netconf-client-grouping
+--:(tls) {tls-listen}?
+-- tls
+-- tcp-server-parameters
| +---u tcps:tcp-server-grouping
+-- tls-client-parameters
| +---u tlsc:tls-client-grouping
+-- netconf-client-parameters
+---u ncc:netconf-client-grouping
Comments:
* The "netconf-client-listen-stack-grouping" defines the
configuration for a full NETCONF protocol stack, for NETCONF
clients that receive call-home [RFC8071] connections from NETCONF
servers.
* The "transport" choice node enables either the SSH or TLS
transports to be configured, with each option enabled by a
"feature" statement.
* For the referenced grouping statement(s):
- The "tcp-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-tcp-client-server].
- The "ssh-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-ssh-client-server].
- The "tls-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-tls-client-server].
2.1.2.3. The "netconf-client-app-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-client-
app-grouping" grouping:
Watsen Expires 2 September 2024 [Page 9]
Internet-Draft NETCONF Client and Server Models March 2024
grouping netconf-client-app-grouping:
+-- initiate! {ssh-initiate or tls-initiate}?
| +-- netconf-server* [name]
| +-- name? string
| +-- endpoints
| | +-- endpoint* [name]
| | +-- name? string
| | +---u netconf-client-initiate-stack-grouping
| +-- connection-type
| | +-- (connection-type)
| | +--:(persistent-connection)
| | | +-- persistent!
| | +--:(periodic-connection)
| | +-- periodic!
| | +-- period? uint16
| | +-- anchor-time? yang:date-and-time
| | +-- idle-timeout? uint16
| +-- reconnect-strategy
| +-- start-with? enumeration
| +-- max-wait? uint16
| +-- max-attempts? uint8
+-- listen! {ssh-listen or tls-listen}?
+-- idle-timeout? uint16
+-- endpoints
+-- endpoint* [name]
+-- name? string
+---u netconf-client-listen-stack-grouping
Comments:
* The "netconf-client-app-grouping" defines the configuration for a
NETCONF client that supports both initiating connections to
NETCONF servers as well as receiving call-home connections from
NETCONF servers.
* Both the "initiate" and "listen" subtrees are predicated by
"feature" statements.
* For the referenced grouping statement(s):
- The "netconf-client-initiate-stack-grouping" grouping is
discussed in Section 2.1.2.1 in this document.
- The "netconf-client-listen-stack-grouping" grouping is
discussed in Section 2.1.2.2 in this document.
Watsen Expires 2 September 2024 [Page 10]
Internet-Draft NETCONF Client and Server Models March 2024
2.1.3. Protocol-accessible Nodes
The following tree diagram [RFC8340] lists all the protocol-
accessible nodes defined in the "ietf-netconf-client" module:
module: ietf-netconf-client
+--rw netconf-client {central-netconf-client-supported}?
+---u netconf-client-app-grouping
Comments:
* Protocol-accessible nodes are those nodes that are accessible when
the module is "implemented", as described in Section 5.6.5 of
[RFC7950].
* The top-level node "netconf-client" is additionally constrained by
the feature "central-netconf-client-supported".
* The "netconf-client-app-grouping" grouping is discussed in
Section 2.1.2.3 in this document.
* The reason for why "netconf-client-app-grouping" exists separate
from the protocol-accessible nodes definition is so as to enable
instances of netconf-client-app-grouping to be instantiated in
other locations, as may be needed or desired by some modules.
2.2. Example Usage
The following example illustrates configuring a NETCONF client to
initiate connections, using both the SSH and TLS transport protocols,
as well as to listen for call-home connections, again using both the
SSH and TLS transport protocols.
This example is consistent with the examples presented in
Section 2.2.1 of [I-D.ietf-netconf-trust-anchors] and Section 2.2.1
of [I-D.ietf-netconf-keystore].
=============== NOTE: '\' line wrapping per RFC 8792 ================
<netconf-client xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-clie\
nt">
<!-- NETCONF servers to initiate connections to -->
<initiate>
<netconf-server>
<name>corp-fw1</name>
<endpoints>
<endpoint>
Watsen Expires 2 September 2024 [Page 11]
Internet-Draft NETCONF Client and Server Models March 2024
<name>corp-fw1.example.com</name>
<ssh>
<tcp-client-parameters>
<remote-address>corp-fw1.example.com</remote-address>
<keepalives>
<idle-time>7200</idle-time>
<max-probes>9</max-probes>
<probe-interval>75</probe-interval>
</keepalives>
</tcp-client-parameters>
<ssh-client-parameters>
<client-identity>
<username>foobar</username>
<public-key>
<central-keystore-reference>ssh-rsa-key</central-k\
eystore-reference>
</public-key>
</client-identity>
<server-authentication>
<ca-certs>
<central-truststore-reference>trusted-server-ca-ce\
rts</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-server-ee-ce\
rts</central-truststore-reference>
</ee-certs>
</server-authentication>
<keepalives>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</keepalives>
</ssh-client-parameters>
</ssh>
</endpoint>
<endpoint>
<name>corp-fw2.example.com</name>
<tls>
<tcp-client-parameters>
<remote-address>corp-fw2.example.com</remote-address>
<keepalives>
<idle-time>7200</idle-time>
<max-probes>9</max-probes>
<probe-interval>75</probe-interval>
</keepalives>
</tcp-client-parameters>
<tls-client-parameters>
<client-identity>
Watsen Expires 2 September 2024 [Page 12]
Internet-Draft NETCONF Client and Server Models March 2024
<certificate>
<central-keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-k\
ey>
<certificate>ex-rsa-cert</certificate>
</central-keystore-reference>
</certificate>
</client-identity>
<server-authentication>
<ca-certs>
<central-truststore-reference>trusted-server-ca-ce\
rts</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-server-ee-ce\
rts</central-truststore-reference>
</ee-certs>
</server-authentication>
<keepalives>
<test-peer-aliveness>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</test-peer-aliveness>
</keepalives>
</tls-client-parameters>
</tls>
</endpoint>
</endpoints>
<connection-type>
<persistent/>
</connection-type>
<reconnect-strategy>
<start-with>last-connected</start-with>
</reconnect-strategy>
</netconf-server>
</initiate>
<!-- endpoints to listen for NETCONF Call Home connections on -->
<listen>
<endpoints>
<endpoint>
<name>Intranet-facing SSH listener</name>
<ssh>
<tcp-server-parameters>
<local-address>192.0.2.7</local-address>
</tcp-server-parameters>
<ssh-client-parameters>
<client-identity>
Watsen Expires 2 September 2024 [Page 13]
Internet-Draft NETCONF Client and Server Models March 2024
<username>foobar</username>
<public-key>
<central-keystore-reference>ssh-rsa-key</central-key\
store-reference>
</public-key>
</client-identity>
<server-authentication>
<ca-certs>
<central-truststore-reference>trusted-server-ca-cert\
s</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-server-ee-cert\
s</central-truststore-reference>
</ee-certs>
<ssh-host-keys>
<central-truststore-reference>trusted-ssh-public-key\
s</central-truststore-reference>
</ssh-host-keys>
</server-authentication>
</ssh-client-parameters>
</ssh>
</endpoint>
<endpoint>
<name>Intranet-facing TLS listener</name>
<tls>
<tcp-server-parameters>
<local-address>192.0.2.7</local-address>
</tcp-server-parameters>
<tls-client-parameters>
<client-identity>
<certificate>
<central-keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-key>
<certificate>ex-rsa-cert</certificate>
</central-keystore-reference>
</certificate>
</client-identity>
<server-authentication>
<ca-certs>
<central-truststore-reference>trusted-server-ca-cert\
s</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-server-ee-cert\
s</central-truststore-reference>
</ee-certs>
</server-authentication>
Watsen Expires 2 September 2024 [Page 14]
Internet-Draft NETCONF Client and Server Models March 2024
<keepalives>
<peer-allowed-to-send/>
</keepalives>
</tls-client-parameters>
</tls>
</endpoint>
</endpoints>
</listen>
</netconf-client>
2.3. YANG Module
This YANG module has normative references to [RFC6242], [RFC6991],
[RFC7589], [RFC8071], [I-D.ietf-netconf-tcp-client-server],
[I-D.ietf-netconf-ssh-client-server], and
[I-D.ietf-netconf-tls-client-server].
<CODE BEGINS> file "ietf-netconf-client@2024-03-02.yang"
module ietf-netconf-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-client";
prefix ncc;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-tcp-client {
prefix tcpc;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tcp-server {
prefix tcps;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-ssh-client {
prefix sshc;
reference
"RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
}
Watsen Expires 2 September 2024 [Page 15]
Internet-Draft NETCONF Client and Server Models March 2024
import ietf-tls-client {
prefix tlsc;
reference
"RFC FFFF: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: https://datatracker.ietf.org/wg/netconf
WG List: NETCONF WG list <mailto:netconf@ietf.org>
Author: Kent Watsen <mailto:kent+ietf@watsen.net>";
description
"This module contains a collection of YANG definitions
for configuring NETCONF clients.
Copyright (c) 2024 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 HHHH
(https://www.rfc-editor.org/info/rfcHHHH); see the RFC
itself for full legal notices.
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.";
revision 2024-03-02 {
description
"Initial version";
reference
"RFC HHHH: NETCONF Client and Server Models";
}
// Features
Watsen Expires 2 September 2024 [Page 16]
Internet-Draft NETCONF Client and Server Models March 2024
feature ssh-initiate {
description
"The 'ssh-initiate' feature indicates that the NETCONF client
supports initiating SSH connections to NETCONF servers.";
reference
"RFC 6242:
Using the NETCONF Protocol over Secure Shell (SSH)";
}
feature tls-initiate {
description
"The 'tls-initiate' feature indicates that the NETCONF client
supports initiating TLS connections to NETCONF servers.";
reference
"RFC 7589: Using the NETCONF Protocol over Transport
Layer Security (TLS) with Mutual X.509 Authentication";
}
feature ssh-listen {
description
"The 'ssh-listen' feature indicates that the NETCONF client
supports opening a port to listen for incoming NETCONF
server call-home SSH connections.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-listen {
description
"The 'tls-listen' feature indicates that the NETCONF client
supports opening a port to listen for incoming NETCONF
server call-home TLS connections.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature central-netconf-client-supported {
description
"The 'central-netconf-client-supported' feature indicates
that the server that implements this module supports
the top-level 'netconf-client' node.
This feature is needed as some servers may want to use
features defined in this module, which requires this
module to be implemented, without having to support
the top-level 'netconf-client' node.";
}
Watsen Expires 2 September 2024 [Page 17]
Internet-Draft NETCONF Client and Server Models March 2024
// Groupings
grouping netconf-client-grouping {
description
"A reusable grouping for configuring a NETCONF client
without any consideration for how underlying transport
sessions are established.
This grouping currently does not define any nodes. It
exists only so the model can be consistent with other
'client-server' models.";
}
grouping netconf-client-initiate-stack-grouping {
description
"A reusable grouping for configuring a NETCONF client
'initiate' protocol stack for a single outbound connection.";
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-initiate";
container ssh {
description
"Specifies TCP, SSH, and NETCONF configuration
for the connection.";
container tcp-client-parameters {
description
"TCP-level client parameters to initiate
a NETCONF over SSH connection.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "830";
description
"The NETCONF client will attempt to connect
to the IANA-assigned well-known port value
for 'netconf-ssh' (830) if no value is
specified.";
}
}
}
container ssh-client-parameters {
description
"SSH-level client parameters to initiate
a NETCONF over SSH connection.";
uses sshc:ssh-client-grouping;
}
Watsen Expires 2 September 2024 [Page 18]
Internet-Draft NETCONF Client and Server Models March 2024
container netconf-client-parameters {
description
"NETCONF-level client parameters to initiate
a NETCONF over SSH connection.";
uses ncc:netconf-client-grouping;
}
}
}
case tls {
if-feature "tls-initiate";
container tls {
description
"Specifies TCP, TLS, and NETCONF configuration
for the connection.";
container tcp-client-parameters {
description
"TCP-level client parameters to initiate
a NETCONF over TLS connection.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "6513";
description
"The NETCONF client will attempt to connect
to the IANA-assigned well-known port value
for 'netconf-tls' (6513) if no value is
specified.";
}
}
}
container tls-client-parameters {
must client-identity {
description
"NETCONF/TLS clients MUST pass some
authentication credentials.";
}
description
"TLS-level client parameters to initiate
a NETCONF over TLS connection.";
uses tlsc:tls-client-grouping;
}
container netconf-client-parameters {
description
"NETCONF-level client parameters to initiate
a NETCONF over TLS connection.";
uses ncc:netconf-client-grouping;
}
}
}
Watsen Expires 2 September 2024 [Page 19]
Internet-Draft NETCONF Client and Server Models March 2024
}
} // netconf-client-initiate-stack-grouping
grouping netconf-client-listen-stack-grouping {
description
"A reusable grouping for configuring a NETCONF client
'listen' protocol stack for listening on a single port. The
'listen' stack supports call home connections, as
described in RFC 8071";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-listen";
container ssh {
description
"TCP, SSH, and NETCONF configuration to listen
for NETCONF over SSH Call Home connections.";
container tcp-server-parameters {
description
"TCP-level server parameters to listen for
NETCONF over SSH Call Home connections.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "4334";
description
"The NETCONF client will listen on the IANA-
assigned well-known port for 'netconf-ch-ssh'
(4334) if no value is specified.";
}
}
}
container ssh-client-parameters {
description
"SSH-level client parameters to listen for
NETCONF over SSH Call Home connections.";
uses sshc:ssh-client-grouping;
}
container netconf-client-parameters {
description
"NETCONF-level client parameters to listen for
NETCONF over SSH Call Home connections.";
uses ncc:netconf-client-grouping;
}
}
Watsen Expires 2 September 2024 [Page 20]
Internet-Draft NETCONF Client and Server Models March 2024
}
case tls {
if-feature "tls-listen";
container tls {
description
"TCP, TLS, and NETCONF configuration to listen
for NETCONF over TLS Call Home connections.";
container tcp-server-parameters {
description
"TCP-level server parameters to listen for
NETCONF over TLS Call Home connections.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "4335";
description
"The NETCONF client will listen on the IANA-
assigned well-known port for 'netconf-ch-tls'
(4335) if no value is specified.";
}
}
}
container tls-client-parameters {
must client-identity {
description
"NETCONF/TLS clients MUST pass some
authentication credentials.";
}
description
"TLS-level client parameters to listen for
NETCONF over TLS Call Home connections.";
uses tlsc:tls-client-grouping;
}
container netconf-client-parameters {
description
"NETCONF-level client parameters to listen for
NETCONF over TLS Call Home connections.";
uses ncc:netconf-client-grouping;
}
}
}
}
} // netconf-client-listen-stack-grouping
grouping netconf-client-app-grouping {
description
"A reusable grouping for configuring a NETCONF client
application that supports both 'initiate' and 'listen'
protocol stacks for a multiplicity of connections.";
Watsen Expires 2 September 2024 [Page 21]
Internet-Draft NETCONF Client and Server Models March 2024
container initiate {
if-feature "ssh-initiate or tls-initiate";
presence
"Indicates that client-initiated connections have been
configured. This statement is present so the mandatory
descendant nodes do not imply that this node must be
configured.";
description
"Configures client initiating underlying TCP connections.";
list netconf-server {
key "name";
min-elements 1;
description
"List of NETCONF servers the NETCONF client is to
maintain simultaneous connections with.";
leaf name {
type string;
description
"An arbitrary name for the NETCONF server.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key "name";
min-elements 1;
ordered-by user;
description
"A user-ordered list of endpoints that the NETCONF
client will attempt to connect to in the specified
sequence. Defining more than one enables
high-availability.";
leaf name {
type string;
description
"An arbitrary name for the endpoint.";
}
uses netconf-client-initiate-stack-grouping;
} // list endpoint
} // container endpoints
container connection-type {
description
"Indicates the NETCONF client's preference for how the
NETCONF connection is maintained.";
choice connection-type {
mandatory true;
description
Watsen Expires 2 September 2024 [Page 22]
Internet-Draft NETCONF Client and Server Models March 2024
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is to be
maintained.";
description
"Maintain a persistent connection to the NETCONF
server. If the connection goes down, immediately
start trying to reconnect to the NETCONF server,
using the reconnection strategy.
This connection type minimizes any NETCONF server
to NETCONF client data-transfer delay, albeit at
the expense of holding resources longer.";
}
}
case periodic-connection {
container periodic {
presence "Indicates that a periodic connection is
to be maintained.";
description
"Periodically connect to the NETCONF server.
This connection type decreases resource
utilization, albeit with increased delay in
NETCONF server to NETCONF client interactions.
The NETCONF client should close the underlying
TCP connection upon completing planned activities.
Connections are established at the same start
time regardless how long the previous connection
stayed open.
In the case that the previous connection is still
active, establishing a new connection is NOT
RECOMMENDED.";
leaf period {
type uint16;
units "minutes";
default "60";
description
"Duration of time between periodic connections.";
}
leaf anchor-time {
type yang:date-and-time {
// constrained to minute-level granularity
Watsen Expires 2 September 2024 [Page 23]
Internet-Draft NETCONF Client and Server Models March 2024
pattern '[0-9]{4}-(1[0-2]|0[1-9])-(0[1-9]|[1-2]'
+ '[0-9]|3[0-1])T(0[0-9]|1[0-9]|2[0-3]):['
+ '0-5][0-9]:00(Z|[\+\-]((1[0-3]|0[0-9]):'
+ '([0-5][0-9])|14:00))?';
}
description
"Designates a timestamp before or after which a
series of periodic connections are determined.
The periodic connections occur at a whole
multiple interval from the anchor time.
If an 'anchor-time' is not provided, then the
server may implicitly set it to the time when
this configuraton is applied (e.g., on boot).
For example, for an anchor time is 15 minutes
past midnight and a period interval of 24 hours,
then a periodic connection will occur 15 minutes
past midnight everyday.";
}
leaf idle-timeout {
type uint16;
units "seconds";
default 180; // three minutes
description
"Specifies the maximum number of seconds that
a NETCONF session may remain idle. A NETCONF
session will be dropped if it is idle for an
interval longer then this number of seconds.
If set to zero, then the NETCONF client will
never drop a session because it is idle.";
}
}
}
}
}
container reconnect-strategy {
description
"The reconnection strategy directs how a NETCONF client
reconnects to a NETCONF server, after discovering its
connection to the server has dropped, even if due to a
reboot. The NETCONF client starts with the specified
endpoint and tries to connect to it max-attempts times
before trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
Watsen Expires 2 September 2024 [Page 24]
Internet-Draft NETCONF Client and Server Models March 2024
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. NETCONF
clients SHOULD be able to remember the last
endpoint connected to across reboots.";
}
enum random-selection {
description
"Indicates that reconnections should start with
a random endpoint.";
}
}
default "first-listed";
description
"Specifies which of the NETCONF server's endpoints
the NETCONF client should start with when trying
to connect to the NETCONF server.";
}
leaf max-wait {
type uint16 {
range "1..max";
}
units "seconds";
default "5";
description
"Specifies the amount of time in seconds after which,
if the connection is not established, an endpoint
connection attempt is considered unsuccessful.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default "3";
description
"Specifies the number times the NETCONF client tries
to connect to a specific endpoint before moving on
to the next endpoint in the list (round robin).";
}
}
} // netconf-server
Watsen Expires 2 September 2024 [Page 25]
Internet-Draft NETCONF Client and Server Models March 2024
} // initiate
container listen {
if-feature "ssh-listen or tls-listen";
presence
"Indicates that client-listening ports have been configured.
This statement is present so the mandatory descendant nodes
do not imply that this node must be configured.";
description
"Configures the client to accept call-home TCP connections.";
leaf idle-timeout {
type uint16;
units "seconds";
default "180"; // three minutes
description
"Specifies the maximum number of seconds that a NETCONF
session may remain idle. A NETCONF session will be
dropped if it is idle for an interval longer than this
number of seconds. If set to zero, then the server
will never drop a session because it is idle.";
}
container endpoints {
description
"Container for a list of endpoints.";
list endpoint {
key "name";
min-elements 1;
description
"List of endpoints to listen for NETCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the NETCONF listen endpoint.";
}
uses netconf-client-listen-stack-grouping;
}
}
} // listen
} // netconf-client-app-grouping
// Protocol accessible node for clients that implement this module.
container netconf-client {
if-feature central-netconf-client-supported;
uses netconf-client-app-grouping;
description
"Top-level container for NETCONF client configuration.";
}
}
Watsen Expires 2 September 2024 [Page 26]
Internet-Draft NETCONF Client and Server Models March 2024
<CODE ENDS>
3. The "ietf-netconf-server" Module
The NETCONF server model presented in this section supports both
listening for connections as well as initiating call-home
connections, using either the SSH and TLS transport protocols.
YANG feature statements are used to enable implementations to
advertise which potentially uncommon parts of the model the NETCONF
server supports.
3.1. Data Model Overview
This section provides an overview of the "ietf-netconf-server" module
in terms of its features and groupings.
3.1.1. Features
The following diagram lists all the "feature" statements defined in
the "ietf-netconf-server" module:
Features:
+-- ssh-listen
+-- tls-listen
+-- ssh-call-home
+-- tls-call-home
+-- central-netconf-server-supported
The diagram above uses syntax that is similar to but not defined in
[RFC8340].
3.1.2. Groupings
The "ietf-netconf-server" module defines the following "grouping"
statements:
* netconf-server-grouping
* netconf-server-listen-stack-grouping
* netconf-server-callhome-stack-grouping
* netconf-server-app-grouping
Each of these groupings are presented in the following subsections.
3.1.2.1. The "netconf-server-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-server-
grouping" grouping:
Watsen Expires 2 September 2024 [Page 27]
Internet-Draft NETCONF Client and Server Models March 2024
grouping netconf-server-grouping:
+-- client-identity-mappings
+---u x509c2n:cert-to-name
Comments:
* The "netconf-server-grouping" defines the configuration for the
"NETCONF" part of a protocol stack. It does not, for instance,
define any configuration for the "TCP", "SSH" or "TLS" protocol
layers (for that, see Section 3.1.2.2 and Section 3.1.2.3).
* The "client-identity-mappings" node defines a mapping from
certificate fields to NETCONF user names.
* For the referenced grouping statement(s):
- The "cert-to-name" grouping is discussed in Section 4.1 of
[RFC7407].
3.1.2.2. The "netconf-server-listen-stack-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-server-
listen-stack-grouping" grouping:
grouping netconf-server-listen-stack-grouping:
+-- (transport)
+--:(ssh) {ssh-listen}?
| +-- ssh
| +-- tcp-server-parameters
| | +---u tcps:tcp-server-grouping
| +-- ssh-server-parameters
| | +---u sshs:ssh-server-grouping
| +-- netconf-server-parameters
| +---u ncs:netconf-server-grouping
+--:(tls) {tls-listen}?
+-- tls
+-- tcp-server-parameters
| +---u tcps:tcp-server-grouping
+-- tls-server-parameters
| +---u tlss:tls-server-grouping
+-- netconf-server-parameters
+---u ncs:netconf-server-grouping
Comments:
Watsen Expires 2 September 2024 [Page 28]
Internet-Draft NETCONF Client and Server Models March 2024
* The "netconf-server-listen-stack-grouping" defines the
configuration for a full NETCONF protocol stack for NETCONF
servers that listen for connections from NETCONF clients, as
opposed to initiating call-home [RFC8071] connections.
* The "transport" choice node enables either the SSH or TLS
transports to be configured, with each option enabled by a
"feature" statement.
* For the referenced grouping statement(s):
- The "tcp-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-tcp-client-server].
- The "ssh-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-ssh-client-server].
- The "tls-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-tls-client-server].
- The "netconf-server-grouping" is discussed in Section 3.1.2.1
of this document.
3.1.2.3. The "netconf-server-callhome-stack-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-server-
callhome-stack-grouping" grouping:
grouping netconf-server-callhome-stack-grouping:
+-- (transport)
+--:(ssh) {ssh-call-home}?
| +-- ssh
| +-- tcp-client-parameters
| | +---u tcpc:tcp-client-grouping
| +-- ssh-server-parameters
| | +---u sshs:ssh-server-grouping
| +-- netconf-server-parameters
| +---u ncs:netconf-server-grouping
+--:(tls) {tls-call-home}?
+-- tls
+-- tcp-client-parameters
| +---u tcpc:tcp-client-grouping
+-- tls-server-parameters
| +---u tlss:tls-server-grouping
+-- netconf-server-parameters
+---u ncs:netconf-server-grouping
Comments:
Watsen Expires 2 September 2024 [Page 29]
Internet-Draft NETCONF Client and Server Models March 2024
* The "netconf-server-callhome-stack-grouping" defines the
configuration for a full NETCONF protocol stack, for NETCONF
servers that initiate call-home [RFC8071] connections to NETCONF
clients.
* The "transport" choice node enables either the SSH or TLS
transports to be configured, with each option enabled by a
"feature" statement.
* For the referenced grouping statement(s):
- The "tcp-client-grouping" grouping is discussed in
Section 3.1.2.1 of [I-D.ietf-netconf-tcp-client-server].
- The "ssh-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-ssh-client-server].
- The "tls-server-grouping" grouping is discussed in
Section 4.1.2.1 of [I-D.ietf-netconf-tls-client-server].
- The "netconf-server-grouping" is discussed in Section 3.1.2.1
of this document.
3.1.2.4. The "netconf-server-app-grouping" Grouping
The following tree diagram [RFC8340] illustrates the "netconf-server-
app-grouping" grouping:
Watsen Expires 2 September 2024 [Page 30]
Internet-Draft NETCONF Client and Server Models March 2024
grouping netconf-server-app-grouping:
+-- listen! {ssh-listen or tls-listen}?
| +-- idle-timeout? uint16
| +-- endpoints
| +-- endpoint* [name]
| +-- name? string
| +---u netconf-server-listen-stack-grouping
+-- call-home! {ssh-call-home or tls-call-home}?
+-- netconf-client* [name]
+-- name? string
+-- endpoints
| +-- endpoint* [name]
| +-- name? string
| +---u netconf-server-callhome-stack-grouping
+-- connection-type
| +-- (connection-type)
| +--:(persistent-connection)
| | +-- persistent!
| +--:(periodic-connection)
| +-- periodic!
| +-- period? uint16
| +-- anchor-time? yang:date-and-time
| +-- idle-timeout? uint16
+-- reconnect-strategy
+-- start-with? enumeration
+-- max-wait? uint16
+-- max-attempts? uint8
Comments:
* The "netconf-server-app-grouping" defines the configuration for a
NETCONF server that supports both listening for connections from
NETCONF clients as well as initiating call-home connections to
NETCONF clients.
* Both the "listen" and "call-home" subtrees must be enabled by
"feature" statements.
* For the referenced grouping statement(s):
- The "netconf-server-listen-stack-grouping" grouping is
discussed in Section 3.1.2.2 in this document.
- The "netconf-server-callhome-stack-grouping" grouping is
discussed in Section 3.1.2.3 in this document.
Watsen Expires 2 September 2024 [Page 31]
Internet-Draft NETCONF Client and Server Models March 2024
3.1.3. Protocol-accessible Nodes
The following tree diagram [RFC8340] lists all the protocol-
accessible nodes defined in the "ietf-netconf-server" module:
module: ietf-netconf-server
+--rw netconf-server {central-netconf-server-supported}?
+---u netconf-server-app-grouping
Comments:
* Protocol-accessible nodes are those nodes that are accessible when
the module is "implemented", as described in Section 5.6.5 of
[RFC7950].
* The top-level node "netconf-server" is additionally constrained by
the feature "central-netconf-server-supported".
* The "netconf-server-app-grouping" grouping is discussed in
Section 3.1.2.4 in this document.
* The reason for why "netconf-server-app-grouping" exists separate
from the protocol-accessible nodes definition is so as to enable
instances of netconf-server-app-grouping to be instantiated in
other locations, as may be needed or desired by some modules.
3.2. Example Usage
The following example illustrates configuring a NETCONF server to
listen for NETCONF client connections using both the SSH and TLS
transport protocols, as well as configuring call-home to two NETCONF
clients, one using SSH and the other using TLS.
This example is consistent with the examples presented in
Section 2.2.1 of [I-D.ietf-netconf-trust-anchors] and Section 2.2.1
of [I-D.ietf-netconf-keystore].
=============== NOTE: '\' line wrapping per RFC 8792 ================
<netconf-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server"
xmlns:x509c2n="urn:ietf:params:xml:ns:yang:ietf-x509-cert-to-name">
<!-- endpoints to listen for NETCONF connections on -->
<listen>
<endpoints>
<endpoint> <!-- listening for SSH connections -->
<name>netconf/ssh</name>
Watsen Expires 2 September 2024 [Page 32]
Internet-Draft NETCONF Client and Server Models March 2024
<ssh>
<tcp-server-parameters>
<local-address>192.0.2.7</local-address>
</tcp-server-parameters>
<ssh-server-parameters>
<server-identity>
<host-key>
<name>deployment-specific-certificate</name>
<public-key>
<central-keystore-reference>ssh-rsa-key</central-k\
eystore-reference>
</public-key>
</host-key>
</server-identity>
<client-authentication>
</client-authentication>
</ssh-server-parameters>
<netconf-server-parameters>
<!-- nothing to configure -->
</netconf-server-parameters>
</ssh>
</endpoint>
<endpoint> <!-- listening for TLS sessions -->
<name>netconf/tls</name>
<tls>
<tcp-server-parameters>
<local-address>192.0.2.7</local-address>
</tcp-server-parameters>
<tls-server-parameters>
<server-identity>
<certificate>
<central-keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-key>
<certificate>ex-rsa-cert</certificate>
</central-keystore-reference>
</certificate>
</server-identity>
<client-authentication>
<ca-certs>
<central-truststore-reference>trusted-client-ca-cert\
s</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-client-ee-cert\
s</central-truststore-reference>
</ee-certs>
</client-authentication>
<keepalives>
Watsen Expires 2 September 2024 [Page 33]
Internet-Draft NETCONF Client and Server Models March 2024
<peer-allowed-to-send/>
</keepalives>
</tls-server-parameters>
<netconf-server-parameters>
<client-identity-mappings>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
<cert-to-name>
<id>2</id>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
</client-identity-mappings>
</netconf-server-parameters>
</tls>
</endpoint>
</endpoints>
</listen>
<!-- calling home to SSH and TLS based NETCONF clients -->
<call-home>
<netconf-client> <!-- SSH-based client -->
<name>config-mgr</name>
<endpoints>
<endpoint>
<name>east-data-center</name>
<ssh>
<tcp-client-parameters>
<remote-address>east.config-mgr.example.com</remote-ad\
dress>
<keepalives>
<idle-time>7200</idle-time>
<max-probes>9</max-probes>
<probe-interval>75</probe-interval>
</keepalives>
</tcp-client-parameters>
<ssh-server-parameters>
<server-identity>
<host-key>
<name>deployment-specific-certificate</name>
<public-key>
<central-keystore-reference>ssh-rsa-key</central\
-keystore-reference>
</public-key>
</host-key>
Watsen Expires 2 September 2024 [Page 34]
Internet-Draft NETCONF Client and Server Models March 2024
</server-identity>
</ssh-server-parameters>
<netconf-server-parameters>
<!-- nothing to configure -->
</netconf-server-parameters>
</ssh>
</endpoint>
<endpoint>
<name>west-data-center</name>
<ssh>
<tcp-client-parameters>
<remote-address>west.config-mgr.example.com</remote-ad\
dress>
</tcp-client-parameters>
<ssh-server-parameters>
<server-identity>
<host-key>
<name>deployment-specific-certificate</name>
<public-key>
<central-keystore-reference>ssh-rsa-key</central\
-keystore-reference>
</public-key>
</host-key>
</server-identity>
</ssh-server-parameters>
<netconf-server-parameters>
<!-- nothing to configure -->
</netconf-server-parameters>
</ssh>
</endpoint>
</endpoints>
<connection-type>
<periodic>
<idle-timeout>300</idle-timeout>
<period>60</period>
</periodic>
</connection-type>
<reconnect-strategy>
<start-with>last-connected</start-with>
<max-wait>3</max-wait>
<max-attempts>3</max-attempts>
</reconnect-strategy>
</netconf-client>
<netconf-client> <!-- TLS-based client -->
<name>data-collector</name>
<endpoints>
<endpoint>
<name>east-data-center</name>
Watsen Expires 2 September 2024 [Page 35]
Internet-Draft NETCONF Client and Server Models March 2024
<tls>
<tcp-client-parameters>
<remote-address>east.analytics.example.com</remote-add\
ress>
<keepalives>
<idle-time>7200</idle-time>
<max-probes>9</max-probes>
<probe-interval>75</probe-interval>
</keepalives>
</tcp-client-parameters>
<tls-server-parameters>
<server-identity>
<certificate>
<central-keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-k\
ey>
<certificate>ex-rsa-cert</certificate>
</central-keystore-reference>
</certificate>
</server-identity>
<client-authentication>
<ca-certs>
<central-truststore-reference>trusted-client-ca-ce\
rts</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-client-ee-ce\
rts</central-truststore-reference>
</ee-certs>
</client-authentication>
<keepalives>
<test-peer-aliveness>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</test-peer-aliveness>
</keepalives>
</tls-server-parameters>
<netconf-server-parameters>
<client-identity-mappings>
<cert-to-name>
<id>1</id>
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
<cert-to-name>
<id>2</id>
<map-type>x509c2n:san-any</map-type>
Watsen Expires 2 September 2024 [Page 36]
Internet-Draft NETCONF Client and Server Models March 2024
</cert-to-name>
</client-identity-mappings>
</netconf-server-parameters>
</tls>
</endpoint>
<endpoint>
<name>west-data-center</name>
<tls>
<tcp-client-parameters>
<remote-address>west.analytics.example.com</remote-add\
ress>
<keepalives>
<idle-time>7200</idle-time>
<max-probes>9</max-probes>
<probe-interval>75</probe-interval>
</keepalives>
</tcp-client-parameters>
<tls-server-parameters>
<server-identity>
<certificate>
<central-keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-k\
ey>
<certificate>ex-rsa-cert</certificate>
</central-keystore-reference>
</certificate>
</server-identity>
<client-authentication>
<ca-certs>
<central-truststore-reference>trusted-client-ca-ce\
rts</central-truststore-reference>
</ca-certs>
<ee-certs>
<central-truststore-reference>trusted-client-ee-ce\
rts</central-truststore-reference>
</ee-certs>
</client-authentication>
<keepalives>
<test-peer-aliveness>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</test-peer-aliveness>
</keepalives>
</tls-server-parameters>
<netconf-server-parameters>
<client-identity-mappings>
<cert-to-name>
<id>1</id>
Watsen Expires 2 September 2024 [Page 37]
Internet-Draft NETCONF Client and Server Models March 2024
<fingerprint>11:0A:05:11:00</fingerprint>
<map-type>x509c2n:specified</map-type>
<name>scooby-doo</name>
</cert-to-name>
<cert-to-name>
<id>2</id>
<map-type>x509c2n:san-any</map-type>
</cert-to-name>
</client-identity-mappings>
</netconf-server-parameters>
</tls>
</endpoint>
</endpoints>
<connection-type>
<persistent/>
</connection-type>
<reconnect-strategy>
<start-with>first-listed</start-with>
<max-wait>3</max-wait>
<max-attempts>3</max-attempts>
</reconnect-strategy>
</netconf-client>
</call-home>
</netconf-server>
3.3. YANG Module
This YANG module has normative references to [RFC6242], [RFC6991],
[RFC7407], [RFC7589], [RFC8071],
[I-D.ietf-netconf-tcp-client-server],
[I-D.ietf-netconf-ssh-client-server], and
[I-D.ietf-netconf-tls-client-server].
<CODE BEGINS> file "ietf-netconf-server@2024-03-02.yang"
module ietf-netconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server";
prefix ncs;
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-x509-cert-to-name {
prefix x509c2n;
Watsen Expires 2 September 2024 [Page 38]
Internet-Draft NETCONF Client and Server Models March 2024
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-tcp-client {
prefix tcpc;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tcp-server {
prefix tcps;
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-ssh-common {
prefix sshcmn;
reference
"RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
}
import ietf-ssh-server {
prefix sshs;
reference
"RFC EEEE: YANG Groupings for SSH Clients and SSH Servers";
}
import ietf-tls-server {
prefix tlss;
reference
"RFC FFFF: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: https://datatracker.ietf.org/wg/netconf
WG List: NETCONF WG list <mailto:netconf@ietf.org>
Author: Kent Watsen <mailto:kent+ietf@watsen.net>";
description
"This module contains a collection of YANG definitions
for configuring NETCONF servers.
Copyright (c) 2024 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Watsen Expires 2 September 2024 [Page 39]
Internet-Draft NETCONF Client and Server Models March 2024
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 HHHH
(https://www.rfc-editor.org/info/rfcHHHH); see the RFC
itself for full legal notices.
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.";
revision 2024-03-02 {
description
"Initial version";
reference
"RFC HHHH: NETCONF Client and Server Models";
}
// Features
feature ssh-listen {
description
"The 'ssh-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over SSH
client connections.";
reference
"RFC 6242:
Using the NETCONF Protocol over Secure Shell (SSH)";
}
feature tls-listen {
description
"The 'tls-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over TLS
client connections.";
reference
"RFC 7589: Using the NETCONF Protocol over Transport
Layer Security (TLS) with Mutual X.509
Authentication";
}
Watsen Expires 2 September 2024 [Page 40]
Internet-Draft NETCONF Client and Server Models March 2024
feature ssh-call-home {
description
"The 'ssh-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over SSH call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-call-home {
description
"The 'tls-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over TLS call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature central-netconf-server-supported {
description
"The 'central-netconf-server-supported' feature indicates
that the server supports the top-level 'netconf-server'
node.
This feature is needed as some servers may want to use
features defined in this module, which requires this
module to be implemented, without having to support
the top-level 'netconf-server' node.";
}
// Groupings
grouping netconf-server-grouping {
description
"A reusable grouping for configuring a NETCONF server
without any consideration for how underlying transport
sessions are established.
Note that this grouping uses a fairly typical descendant
node name such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue by wrapping the 'uses'
statement in a container called, e.g.,
'netconf-server-parameters'. This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container client-identity-mappings {
Watsen Expires 2 September 2024 [Page 41]
Internet-Draft NETCONF Client and Server Models March 2024
description
"Specifies mappings through which NETCONF client X.509
certificates are used to determine a NETCONF username,
per RFC 7407.
For TLS-based transports, if no matching and valid
cert-to-name list entry can be found, then the NETCONF
server MUST close the connection, and MUST NOT accept
NETCONF messages over it, per Section 7 in RFC 7589.
For SSH-based transports, a matching cert-to-name
entry overrides the username provided by the SSH
implementation, consistent with the second paragraph
of Section 3 in RFC 6242.";
reference
"RFC 6242:
Using the NETCONF Protocol over Secure Shell (SSH)
RFC 7589:
Using the NETCONF Protocol over Transport Layer
Security (TLS) with Mutual X.509 Authentication";
uses x509c2n:cert-to-name {
refine "cert-to-name/fingerprint" {
mandatory false;
description
"A 'fingerprint' value does not need to be specified
when the 'cert-to-name' mapping is independent of
fingerprint matching. A 'cert-to-name' having no
fingerprint value will match any client certificate
and therefore should only be present at the end of
the user-ordered 'cert-to-name' list.";
}
}
}
}
grouping netconf-server-listen-stack-grouping {
description
"A reusable grouping for configuring a NETCONF server
'listen' protocol stack for listening on a single port.";
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-listen";
container ssh {
description
"TCP, SSH, and NETCONF configuration to listen
Watsen Expires 2 September 2024 [Page 42]
Internet-Draft NETCONF Client and Server Models March 2024
for NETCONF over SSH connections.";
container tcp-server-parameters {
description
"TCP-level server parameters to listen
for NETCONF over SSH connections.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "830";
description
"The NETCONF server will listen on the
IANA-assigned well-known port value
for 'netconf-ssh' (830) if no value
is specified.";
}
}
}
container ssh-server-parameters {
description
"SSH-level server parameters to listen
for NETCONF over SSH connections.";
uses sshs:ssh-server-grouping;
}
container netconf-server-parameters {
description
"NETCONF-level server parameters to listen
for NETCONF over SSH connections.";
uses ncs:netconf-server-grouping {
refine "client-identity-mappings" {
if-feature "sshcmn:ssh-x509-certs";
description
"Adds in an 'if-feature' statement
ensuring the 'client-identity-mappings'
descendant is enabled only when SSH
supports X.509 certificates.";
}
augment "client-identity-mappings" {
description
"Adds a flag indicating if a cert-to-name
is required.";
leaf mapping-required {
type boolean;
description
"Indicates that the cert-to-name mapping
is required (i.e., the SSH-level username
is ignored).";
}
}
}
Watsen Expires 2 September 2024 [Page 43]
Internet-Draft NETCONF Client and Server Models March 2024
}
}
}
case tls {
if-feature "tls-listen";
container tls {
description
"TCP, TLS, and NETCONF configuration to listen
for NETCONF over TLS connections.";
container tcp-server-parameters {
description
"TCP-level server parameters to listen
for NETCONF over TLS connections.";
uses tcps:tcp-server-grouping {
refine "local-port" {
default "6513";
description
"The NETCONF server will listen on the
IANA-assigned well-known port value
for 'netconf-tls' (6513) if no value
is specified.";
}
}
}
container tls-server-parameters {
description
"TLS-level server parameters to listen
for NETCONF over TLS connections.";
uses tlss:tls-server-grouping {
refine "client-authentication" {
must 'ca-certs or ee-certs';
description
"NETCONF/TLS servers MUST validate client
certificates. This configures certificates
at the socket-level (i.e. bags). More
discriminating client-certificate checks
SHOULD be implemented by the application.";
reference
"RFC 7589:
Using the NETCONF Protocol over Transport Layer
Security (TLS) with Mutual X.509 Authentication";
}
}
}
container netconf-server-parameters {
description
"NETCONF-level server parameters to listen
for NETCONF over TLS connections.";
Watsen Expires 2 September 2024 [Page 44]
Internet-Draft NETCONF Client and Server Models March 2024
uses ncs:netconf-server-grouping {
refine "client-identity-mappings/cert-to-name" {
min-elements 1;
description
"The TLS transport requires a mapping.";
}
}
}
}
}
}
}
grouping netconf-server-callhome-stack-grouping {
description
"A reusable grouping for configuring a NETCONF server
'call-home' protocol stack, for a single outbound
connection.";
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature "ssh-call-home";
container ssh {
description
"TCP, SSH, and NETCONF configuration to initiate
a NETCONF over SSH Call Home connection.";
container tcp-client-parameters {
description
"TCP-level client parameters to initiate a
NETCONF over SSH Call Home connection.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "4334";
description
"The NETCONF server will attempt to connect
to the IANA-assigned well-known port for
'netconf-ch-ssh' (4334) if no value is
specified.";
}
}
}
container ssh-server-parameters {
description
"SSH-level server parameters to initiate a
NETCONF over SSH Call Home connection.";
uses sshs:ssh-server-grouping;
Watsen Expires 2 September 2024 [Page 45]
Internet-Draft NETCONF Client and Server Models March 2024
}
container netconf-server-parameters {
description
"NETCONF-level server parameters to initiate a
NETCONF over SSH Call Home connection.";
uses ncs:netconf-server-grouping {
refine "client-identity-mappings" {
if-feature "sshcmn:ssh-x509-certs";
description
"Adds in an 'if-feature' statement
ensuring the 'client-identity-mappings'
descendant is enabled only when SSH
supports X.509 certificates.";
}
augment "client-identity-mappings" {
description
"Adds a flag indicating if a cert-to-name
is required.";
leaf mapping-required {
type boolean;
description
"Indicates that the cert-to-name mapping
is required (i.e., the SSH-level username
is ignored).";
}
}
}
}
}
}
case tls {
if-feature "tls-call-home";
container tls {
description
"TCP, TLS, and NETCONF configuration to initiate
a NETCONF over TLS Call Home connection.";
container tcp-client-parameters {
description
"TCP-level client parameters to initiate a
NETCONF over TLS Call Home connection.";
uses tcpc:tcp-client-grouping {
refine "remote-port" {
default "4335";
description
"The NETCONF server will attempt to connect
to the IANA-assigned well-known port for
'netconf-ch-tls' (4335) if no value is
specified.";
Watsen Expires 2 September 2024 [Page 46]
Internet-Draft NETCONF Client and Server Models March 2024
}
}
}
container tls-server-parameters {
description
"TLS-level server parameters to initiate a
NETCONF over TLS Call Home connection.";
uses tlss:tls-server-grouping {
refine "client-authentication" {
must 'ca-certs or ee-certs';
description
"NETCONF/TLS servers MUST validate client
certificates. This configures certificates
at the socket-level (i.e. bags). More
discriminating client-certificate checks
SHOULD be implemented by the application.";
reference
"RFC 7589:
Using the NETCONF Protocol over Transport Layer
Security (TLS) with Mutual X.509 Authentication";
}
}
}
container netconf-server-parameters {
description
"NETCONF-level server parameters to initiate a
NETCONF over TLS Call Home connection.";
uses ncs:netconf-server-grouping {
refine "client-identity-mappings/cert-to-name" {
min-elements 1;
description
"The TLS transport requires a mapping.";
}
}
}
}
}
}
}
grouping netconf-server-app-grouping {
description
"A reusable grouping for configuring a NETCONF server
application that supports both 'listen' and 'call-home'
protocol stacks for a multiplicity of connections.";
container listen {
if-feature "ssh-listen or tls-listen";
presence
Watsen Expires 2 September 2024 [Page 47]
Internet-Draft NETCONF Client and Server Models March 2024
"Indicates that server-listening ports have been configured.
This statement is present so the mandatory descendant
nodes do not imply that this node must be configured.";
description
"Configures listen behavior";
leaf idle-timeout {
type uint16;
units "seconds";
default "180"; // three minutes
description
"Specifies the maximum number of seconds that a NETCONF
session may remain idle. A NETCONF session will be
dropped if it is idle for an interval longer than this
number of seconds. If set to zero, then the server
will never drop a session because it is idle.";
}
container endpoints {
description
"Container for a list of endpoints.";
list endpoint {
key "name";
min-elements 1;
description
"List of endpoints to listen for NETCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the NETCONF listen endpoint.";
}
uses netconf-server-listen-stack-grouping;
}
}
}
container call-home {
if-feature "ssh-call-home or tls-call-home";
presence
"Indicates that server-initiated call home connections have
been configured. This statement is present so the mandatory
descendant nodes do not imply that this node must be
configured.";
description
"Configures the NETCONF server to initiate the underlying
transport connection to NETCONF clients.";
list netconf-client {
key "name";
min-elements 1;
description
"List of NETCONF clients the NETCONF server is to
Watsen Expires 2 September 2024 [Page 48]
Internet-Draft NETCONF Client and Server Models March 2024
maintain simultaneous call-home connections with.";
leaf name {
type string;
description
"An arbitrary name for the remote NETCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key "name";
min-elements 1;
ordered-by user;
description
"A non-empty user-ordered list of endpoints for this
NETCONF server to try to connect to in sequence.
Defining more than one enables high-availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
uses netconf-server-callhome-stack-grouping;
}
}
container connection-type {
description
"Indicates the NETCONF server's preference for how the
NETCONF connection is maintained.";
choice connection-type {
mandatory true;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is to be
maintained.";
description
"Maintain a persistent connection to the NETCONF
client. If the connection goes down, immediately
start trying to reconnect to the NETCONF client,
using the reconnection strategy.
This connection type minimizes any NETCONF client
to NETCONF server data-transfer delay, albeit at
the expense of holding resources longer.";
}
Watsen Expires 2 September 2024 [Page 49]
Internet-Draft NETCONF Client and Server Models March 2024
}
case periodic-connection {
container periodic {
presence "Indicates that a periodic connection is
to be maintained.";
description
"Periodically connect to the NETCONF client.
This connection type decreases resource
utilization, albeit with increased delay in
NETCONF client to NETCONF server interactions.
The NETCONF client SHOULD gracefully close the
connection using <close-session> upon completing
planned activities. If the NETCONF session is
not closed gracefully, the NETCONF server MUST
immediately attempt to reestablish the connection.
Connections are established at the same start
time regardless how long the previous connection
stayed open.
In the case that the previous connection is still
active (i.e., the NETCONF client has not closed
it yet), establishing a new connection is NOT
RECOMMENDED.";
leaf period {
type uint16;
units "minutes";
default "60";
description
"Duration of time between periodic connections.";
}
leaf anchor-time {
type yang:date-and-time {
// constrained to minute-level granularity
pattern '[0-9]{4}-(1[0-2]|0[1-9])-(0[1-9]|[1-2]'
+ '[0-9]|3[0-1])T(0[0-9]|1[0-9]|2[0-3]):['
+ '0-5][0-9]:00(Z|[\+\-]((1[0-3]|0[0-9]):'
+ '([0-5][0-9])|14:00))?';
}
description
"Designates a timestamp before or after which a
series of periodic connections are determined.
The periodic connections occur at a whole
multiple interval from the anchor time.
If an 'anchor-time' is not provided, then the
Watsen Expires 2 September 2024 [Page 50]
Internet-Draft NETCONF Client and Server Models March 2024
server may implicitly set it to the time when
this configuraton is applied (e.g., on boot).
For example, for an anchor time is 15 minutes
past midnight and a period interval of 24 hours,
then a periodic connection will occur 15 minutes
past midnight everyday.";
}
leaf idle-timeout {
type uint16;
units "seconds";
default "180"; // three minutes
description
"Specifies the maximum number of seconds that
a NETCONF session may remain idle. A NETCONF
session will be dropped if it is idle for an
interval longer than this number of seconds.
If set to zero, then the server will never
drop a session because it is idle.";
}
}
} // case periodic-connection
} // choice connection-type
} // container connection-type
container reconnect-strategy {
description
"The reconnection strategy directs how a NETCONF server
reconnects to a NETCONF client, after discovering its
connection to the client has dropped, even if due to a
reboot. The NETCONF server starts with the specified
endpoint and tries to connect to it max-attempts times
before trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. NETCONF
servers SHOULD be able to remember the last
endpoint connected to across reboots.";
Watsen Expires 2 September 2024 [Page 51]
Internet-Draft NETCONF Client and Server Models March 2024
}
enum random-selection {
description
"Indicates that reconnections should start with
a random endpoint.";
}
}
default "first-listed";
description
"Specifies which of the NETCONF client's endpoints
the NETCONF server should start with when trying
to connect to the NETCONF client.";
}
leaf max-wait {
type uint16 {
range "1..max";
}
units "seconds";
default "5";
description
"Specifies the amount of time in seconds after which,
if the connection is not established, an endpoint
connection attempt is considered unsuccessful.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default "3";
description
"Specifies the number times the NETCONF server tries
to connect to a specific endpoint before moving on
to the next endpoint in the list (round robin).";
}
} // container reconnect-strategy
} // list netconf-client
} // container call-home
} // grouping netconf-server-app-grouping
// Protocol accessible node for servers that implement this module.
container netconf-server {
if-feature central-netconf-server-supported;
uses netconf-server-app-grouping;
description
"Top-level container for NETCONF server configuration.";
}
}
Watsen Expires 2 September 2024 [Page 52]
Internet-Draft NETCONF Client and Server Models March 2024
<CODE ENDS>
4. Security Considerations
4.1. Considerations for the "ietf-netconf-client" YANG Module
This section follows the template defined in Section 3.7.1 of
[RFC8407].
The "ietf-netconf-client" YANG module defines data nodes that are
designed to be accessed via YANG based management protocols, such as
NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols
have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
with mutual authentication.
The Network Access Control Model (NACM) [RFC8341] provides the means
to restrict access for particular users to a pre-configured subset of
all available protocol operations and content.
Please be aware that this YANG module uses groupings from other YANG
modules that define nodes that may be considered sensitive or
vulnerable in network environments. Please review the Security
Considerations for dependent YANG modules for information as to which
nodes may be considered sensitive or vulnerable in network
environments.
None of the readable data nodes defined in this YANG module are
considered sensitive or vulnerable in network environments. The NACM
"default-deny-all" extension has not been set for any data nodes
defined in this module.
None of the writable data nodes defined in this YANG module are
considered sensitive or vulnerable in network environments. The NACM
"default-deny-write" extension has not been set for any data nodes
defined in this module.
This module does not define any RPCs, actions, or notifications, and
thus the security consideration for such is not provided here.
Please be aware that this module uses groupings defined in other RFCs
that define data nodes that do set the NACM "default-deny-all" and
"default-deny-write" extensions.
4.2. Considerations for the "ietf-netconf-server" YANG Module
This section follows the template defined in Section 3.7.1 of
[RFC8407].
Watsen Expires 2 September 2024 [Page 53]
Internet-Draft NETCONF Client and Server Models March 2024
The "ietf-netconf-server" YANG module defines data nodes that are
designed to be accessed via YANG based management protocols, such as
NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols
have mandatory-to-implement secure transport layers (e.g., SSH, TLS)
with mutual authentication.
The Network Access Control Model (NACM) [RFC8341] provides the means
to restrict access for particular users to a pre-configured subset of
all available protocol operations and content.
Please be aware that this YANG module uses groupings from other YANG
modules that define nodes that may be considered sensitive or
vulnerable in network environments. Please review the Security
Considerations for dependent YANG modules for information as to which
nodes may be considered sensitive or vulnerable in network
environments.
None of the readable data nodes defined in this YANG module are
considered sensitive or vulnerable in network environments. The NACM
"default-deny-all" extension has not been set for any data nodes
defined in this module.
None of the writable data nodes defined in this YANG module are
considered sensitive or vulnerable in network environments. The NACM
"default-deny-write" extension has not been set for any data nodes
defined in this module.
This module does not define any RPCs, actions, or notifications, and
thus the security consideration for such is not provided here.
Please be aware that this module uses groupings defined in other RFCs
that define data nodes that do set the NACM "default-deny-all" and
"default-deny-write" extensions.
5. IANA Considerations
5.1. The "IETF XML" Registry
This document registers two URIs in the "ns" subregistry of the IETF
XML Registry [RFC3688]. Following the format in [RFC3688], the
following registrations are requested:
Watsen Expires 2 September 2024 [Page 54]
Internet-Draft NETCONF Client and Server Models March 2024
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-client
Registrant Contact: The IESG
XML: N/A, the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-server
Registrant Contact: The IESG
XML: N/A, the requested URI is an XML namespace.
5.2. The "YANG Module Names" Registry
This document registers two YANG modules in the YANG Module Names
registry [RFC6020]. Following the format in [RFC6020], the following
registrations are requested:
name: ietf-netconf-client
namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-client
prefix: ncc
reference: RFC HHHH
name: ietf-netconf-server
namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-server
prefix: ncs
reference: RFC HHHH
6. References
6.1. Normative References
[I-D.ietf-netconf-keystore]
Watsen, K., "A YANG Data Model for a Keystore and Keystore
Operations", Work in Progress, Internet-Draft, draft-ietf-
netconf-keystore-33, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
keystore-33>.
[I-D.ietf-netconf-ssh-client-server]
Watsen, K., "YANG Groupings for SSH Clients and SSH
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-ssh-client-server-38, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
ssh-client-server-38>.
[I-D.ietf-netconf-tcp-client-server]
Watsen, K. and M. Scharf, "YANG Groupings for TCP Clients
and TCP Servers", Work in Progress, Internet-Draft, draft-
ietf-netconf-tcp-client-server-22, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
tcp-client-server-22>.
Watsen Expires 2 September 2024 [Page 55]
Internet-Draft NETCONF Client and Server Models March 2024
[I-D.ietf-netconf-tls-client-server]
Watsen, K., "YANG Groupings for TLS Clients and TLS
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-tls-client-server-39, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
tls-client-server-39>.
[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>.
[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>.
[RFC7407] Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for
SNMP Configuration", RFC 7407, DOI 10.17487/RFC7407,
December 2014, <https://www.rfc-editor.org/info/rfc7407>.
[RFC7589] Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
NETCONF Protocol over Transport Layer Security (TLS) with
Mutual X.509 Authentication", RFC 7589,
DOI 10.17487/RFC7589, June 2015,
<https://www.rfc-editor.org/info/rfc7589>.
[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>.
[RFC8071] Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
RFC 8071, DOI 10.17487/RFC8071, February 2017,
<https://www.rfc-editor.org/info/rfc8071>.
Watsen Expires 2 September 2024 [Page 56]
Internet-Draft NETCONF Client and Server Models March 2024
[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>.
6.2. Informative References
[I-D.ietf-netconf-crypto-types]
Watsen, K., "YANG Data Types and Groupings for
Cryptography", Work in Progress, Internet-Draft, draft-
ietf-netconf-crypto-types-32, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
crypto-types-32>.
[I-D.ietf-netconf-http-client-server]
Watsen, K., "YANG Groupings for HTTP Clients and HTTP
Servers", Work in Progress, Internet-Draft, draft-ietf-
netconf-http-client-server-18, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
http-client-server-18>.
[I-D.ietf-netconf-netconf-client-server]
Watsen, K., "NETCONF Client and Server Models", Work in
Progress, Internet-Draft, draft-ietf-netconf-netconf-
client-server-34, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
netconf-client-server-34>.
[I-D.ietf-netconf-restconf-client-server]
Watsen, K., "RESTCONF Client and Server Models", Work in
Progress, Internet-Draft, draft-ietf-netconf-restconf-
client-server-34, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
restconf-client-server-34>.
[I-D.ietf-netconf-trust-anchors]
Watsen, K., "A YANG Data Model for a Truststore", Work in
Progress, Internet-Draft, draft-ietf-netconf-trust-
anchors-26, 22 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
trust-anchors-26>.
[I-D.ietf-netmod-system-config]
Ma, Q., Wu, Q., and C. Feng, "System-defined
Configuration", Work in Progress, Internet-Draft, draft-
ietf-netmod-system-config-05, 21 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netmod-
system-config-05>.
Watsen Expires 2 September 2024 [Page 57]
Internet-Draft NETCONF Client and Server Models March 2024
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>.
[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>.
[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>.
[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>.
[RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
Documents Containing YANG Data Models", BCP 216, RFC 8407,
DOI 10.17487/RFC8407, October 2018,
<https://www.rfc-editor.org/info/rfc8407>.
Appendix A. Change Log
A.1. 00 to 01
* Renamed "keychain" to "keystore".
A.2. 01 to 02
* Added to ietf-netconf-client ability to connected to a cluster of
endpoints, including a reconnection-strategy.
* Added to ietf-netconf-client the ability to configure connection-
type and also keep-alive strategy.
* Updated both modules to accommodate new groupings in the ssh/tls
drafts.
Watsen Expires 2 September 2024 [Page 58]
Internet-Draft NETCONF Client and Server Models March 2024
A.3. 02 to 03
* Refined use of tls-client-grouping to add a must statement
indicating that the TLS client must specify a client-certificate.
* Changed 'netconf-client' to be a grouping (not a container).
A.4. 03 to 04
* Added RFC 8174 to Requirements Language Section.
* Replaced refine statement in ietf-netconf-client to add a
mandatory true.
* Added refine statement in ietf-netconf-server to add a must
statement.
* Now there are containers and groupings, for both the client and
server models.
A.5. 04 to 05
* Now tree diagrams reference ietf-netmod-yang-tree-diagrams
* Updated examples to inline key and certificates (no longer a
leafref to keystore)
A.6. 05 to 06
* Fixed change log missing section issue.
* Updated examples to match latest updates to the crypto-types,
trust-anchors, and keystore drafts.
* Reduced line length of the YANG modules to fit within 69 columns.
A.7. 06 to 07
* Removed "idle-timeout" from "persistent" connection config.
* Added "random-selection" for reconnection-strategy's "starts-with"
enum.
* Replaced "connection-type" choice default (persistent) with
"mandatory true".
* Reduced the periodic-connection's "idle-timeout" from 5 to 2
minutes.
Watsen Expires 2 September 2024 [Page 59]
Internet-Draft NETCONF Client and Server Models March 2024
* Replaced reconnect-timeout with period/anchor-time combo.
A.8. 07 to 08
* Modified examples to be compatible with new crypto-types algs
A.9. 08 to 09
* Corrected use of "mandatory true" for "address" leafs.
* Updated examples to reflect update to groupings defined in the
keystore draft.
* Updated to use groupings defined in new TCP and HTTP drafts.
* Updated copyright date, boilerplate template, affiliation, and
folding algorithm.
A.10. 09 to 10
* Reformatted YANG modules.
A.11. 10 to 11
* Adjusted for the top-level "demux container" added to groupings
imported from other modules.
* Added "must" expressions to ensure that keepalives are not
configured for "periodic" connections.
* Updated the boilerplate text in module-level "description"
statement to match copyeditor convention.
* Moved "expanded" tree diagrams to the Appendix.
A.12. 11 to 12
* Removed the "Design Considerations" section.
* Removed the 'must' statement limiting keepalives in periodic
connections.
* Updated models and examples to reflect removal of the "demux"
containers in the imported models.
* Updated the "periodic-connnection" description statements to be
more like the RESTCONF draft, especially where it described
dropping the underlying TCP connection.
Watsen Expires 2 September 2024 [Page 60]
Internet-Draft NETCONF Client and Server Models March 2024
* Updated text to better reference where certain examples come from
(e.g., which Section in which draft).
* In the server model, commented out the "must 'pinned-ca-certs or
pinned-client-certs'" statement to reflect change made in the TLS
draft whereby the trust anchors MAY be defined externally.
* Replaced the 'listen', 'initiate', and 'call-home' features with
boolean expressions.
A.13. 12 to 13
* Updated to reflect changes in trust-anchors drafts (e.g., s/trust-
anchors/truststore/g + s/pinned.//)
A.14. 13 to 14
* Adjusting from change in TLS client model (removing the top-level
'certificate' container), by swapping refining-in a 'mandatory
true' statement with a 'must' statement outside the 'uses'
statement.
* Updated examples to reflect ietf-crypto-types change (e.g.,
identities --> enumerations)
A.15. 14 to 15
* Refactored both the client and server modules similar to how the
ietf-restconf-server module was refactored in -13 of that draft,
and the ietf-restconf-client grouping.
A.16. 15 to 16
* Added refinement to make "cert-to-name/fingerprint" be mandatory
false.
* Commented out refinement to "tls-server-grouping/client-
authentication" until a better "must" expression is defined.
A.17. 16 to 17
* Updated examples to include the "*-key-format" nodes.
* Updated examples to remove the "required" nodes.
* Updated examples to remove the "client-auth-defined-elsewhere"
nodes.
Watsen Expires 2 September 2024 [Page 61]
Internet-Draft NETCONF Client and Server Models March 2024
A.18. 17 to 18
* Updated examples to reflect new "bag" addition to truststore.
A.19. 18 to 19
* Updated examples to remove the 'algorithm' nodes.
* Updated examples to reflect the new TLS keepalives structure.
* Added keepalives to the tcp-client-parameters section in the
netconf-server SSH-based call-home example.
* Added a TLS-based call-home example to the netconf-client example.
* Added a "Note to Reviewers" note to first page.
A.20. 19 to 20
* Expanded "Data Model Overview section(s) [remove "wall" of tree
diagrams].
* Removed expanded tree diagrams that were listed in the Appendix.
* Updated the Security Considerations section.
A.21. 20 to 21
* Cleaned up titles in the IANA Considerations section
* Fixed issues found by the SecDir review of the "keystore" draft.
A.22. 21 to 22
* Addressed comments raised by YANG Doctor in the ct/ts/ks drafts.
A.23. 22 to 23
* Floated an 'if-feature' statement in a grouping down to where the
grouping is used.
* Clarified 'client-identity-mappings' for both the SSH and TLS
transports.
* For netconf-client, augmented-in a 'mapping-required' flag into
'client-identity-mappings' only for the SSH transport, and
refined-in a 'min-elements 1' only for the TLS transport.
Watsen Expires 2 September 2024 [Page 62]
Internet-Draft NETCONF Client and Server Models March 2024
* Aligned modules with `pyang -f` formatting.
A.24. 23 to 24
* Replaced "base64encodedvalue==" with "BASE64VALUE=" in examples.
* Minor editorial nits
A.25. 24 to 25
* Fixed up the 'WG Web' and 'WG List' lines in YANG module(s)
* Fixed up copyright (i.e., s/Simplified/Revised/) in YANG module(s)
A.26. 25 to 26
* Added feature "central-netconf-client-supported" to top-level node
"netconf-client".
* Added feature "central-netconf-server-supported" to top-level node
"netconf-server".
* Clarified container "netconf-client-parameters" description
statement.
* Removed unneccesary "xmlns:x509c2n" in a NETCONF server
configuration example.
A.27. 26 to 27
* Updated per Shepherd reviews impacting the suite of drafts.
* Added "max-wait" leaf to the "reconnect-strategy" nodes.
A.28. 27 to 28
* Updated per Shepherd reviews impacting the suite of drafts.
A.29. 28 to 29
* Updated (implicitly) via Tom Petch reviews.
* Fixed pattern statement for "leaf anchor-time".
A.30. 29 to 30
* Addresses AD review comments.
Watsen Expires 2 September 2024 [Page 63]
Internet-Draft NETCONF Client and Server Models March 2024
* Added note to Editor to fix line foldings.
* Removed netconf-client-grouping, since it was empty.
* Removed erronious statement "client-identity-mappings" must be
enabled by a "feature".
* Added Security Considerations text to also look a SC-section from
imported modules.
* Removed "A wrapper around the foobar parameters to avoid name
collisions" text.
* Added container "endpoints" to wrap list "endpoint".
A.31. 30 to 31
* Addresses AD review by Rob Wilton.
A.32. 31 to 32
* Addresses 1st-round of IESG reviews.
A.33. 32 to 34
* Addresses issues found in OpsDir review of the ssh-client-server
draft.
* s/defines/presents/ in a few places.
* Add refs to where the 'operational' and 'system' datastores are
defined.
* Renamed Security Considerations section s/Template for/
Considerations for/
A.34. 34 to 35
* Nothing added. Only bumped for automation...
Acknowledgements
The authors would like to thank the following for lively discussions
on list and in the halls (ordered by first name): Alan Luchuk, Andy
Bierman, Balázs Kovács, Benoit Claise, Bert Wijnen, David Lamparter,
Jürgen Schönwälder, Ladislav Lhotka, Martin Björklund, Mehmet Ersue,
Michal Vaško, Phil Shafer, Qiufang Ma, Radek Krejci, Ramkumar
Dhanapal, Rob Wilton, Sean Turner, and Tom Petch.
Watsen Expires 2 September 2024 [Page 64]
Internet-Draft NETCONF Client and Server Models March 2024
Author's Address
Kent Watsen
Watsen Networks
Email: kent+ietf@watsen.net
Watsen Expires 2 September 2024 [Page 65]
