| Internet-Draft | NETCONF Client and Server Models | August 2024 |
| Watsen | Expires 15 February 2025 | [Page] |
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.¶
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¶
Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement:¶
2024-08-14 --> 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¶
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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.¶
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].¶
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.¶
Primary dependency relationships between the YANG groupings defined in the various RFCs is presented in the below diagram. In some cases, a draft may define secondary groupings that introduce 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
¶
| 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] |
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.¶
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.¶
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.¶
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.¶
This section provides an overview of the "ietf-netconf-client" module in terms of its features and groupings.¶
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].¶
The "ietf-netconf-client" module defines the following "grouping" statements:¶
Each of these groupings are presented in the following subsections.¶
The following tree diagram [RFC8340] illustrates the "netconf-client-initiate-stack-grouping" grouping:¶
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:¶
For the referenced grouping statement(s):¶
The following tree diagram [RFC8340] illustrates the "netconf-client-listen-stack-grouping" grouping:¶
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:¶
For the referenced grouping statement(s):¶
The following tree diagram [RFC8340] illustrates the "netconf-client-app-grouping" grouping:¶
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:¶
For the referenced grouping statement(s):¶
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:¶
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>
<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>
<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-bind>
<local-address>192.0.2.7</local-address>
</local-bind>
</tcp-server-parameters>
<ssh-client-parameters>
<client-identity>
<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-bind>
<local-address>192.0.2.7</local-address>
</local-bind>
</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>
<keepalives>
<peer-allowed-to-send/>
</keepalives>
</tls-client-parameters>
</tls>
</endpoint>
</endpoints>
</listen>
</netconf-client>
¶
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 "[email protected]"¶
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";
}
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:[email protected]>
Author: Kent Watsen <mailto:[email protected]>";
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 2024-08-14 {
description
"Initial version";
reference
"RFC HHHH: NETCONF Client and Server Models";
}
// Features
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.";
}
// 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;
}
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;
}
}
}
}
} // 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-bind/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;
}
}
}
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-bind/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.";
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
"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
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 {
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 known. If
no previous connection is known, then the
first endpoint configured is used.";
}
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
} // 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.";
}
}
¶
<CODE ENDS>¶
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.¶
This section provides an overview of the "ietf-netconf-server" module in terms of its features and groupings.¶
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].¶
The "ietf-netconf-server" module defines the following "grouping" statements:¶
Each of these groupings are presented in the following subsections.¶
The following tree diagram [RFC8340] illustrates the "netconf-server-grouping" grouping:¶
grouping netconf-server-grouping:
+-- client-identity-mappings
+---u x509c2n:cert-to-name
¶
Comments:¶
For the referenced grouping statement(s):¶
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:¶
For the referenced grouping statement(s):¶
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:¶
For the referenced grouping statement(s):¶
The following tree diagram [RFC8340] illustrates the "netconf-server-app-grouping" grouping:¶
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:¶
For the referenced grouping statement(s):¶
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:¶
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>
<ssh>
<tcp-server-parameters>
<local-bind>
<local-address>192.0.2.7</local-address>
</local-bind>
</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-bind>
<local-address>192.0.2.7</local-address>
</local-bind>
</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>
<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>
</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>
<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>
</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>
<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>
¶
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 "[email protected]"¶
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;
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:[email protected]>
Author: Kent Watsen <mailto:[email protected]>";
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.
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 2024-08-14 {
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";
}
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 {
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
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-bind/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).";
}
}
}
}
}
}
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-bind/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.";
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;
}
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.";
}
}
}
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
"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
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.";
}
}
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
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 known. If
no previous connection is known, then the
first endpoint configured is used.";
}
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.";
}
}
¶
<CODE ENDS>¶
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.¶
This section follows the template defined in Section 3.7.1 of [RFC8407].¶
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.¶
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:¶
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.¶
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¶
Renamed "keychain" to "keystore".¶
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.¶
Replaced reconnect-timeout with period/anchor-time combo.¶
Modified examples to be compatible with new crypto-types algs¶
Reformatted YANG modules.¶
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.¶
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.¶
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.¶
Updated to reflect changes in trust-anchors drafts (e.g., s/trust-anchors/truststore/g + s/pinned.//)¶
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.¶
Updated examples to reflect new "bag" addition to truststore.¶
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.¶
Addressed comments raised by YANG Doctor in the ct/ts/ks drafts.¶
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.¶
Aligned modules with `pyang -f` formatting.¶
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.¶
Updated per Shepherd reviews impacting the suite of drafts.¶
Addresses AD review comments.¶
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".¶
Addresses AD review by Rob Wilton.¶
Addresses 1st-round of IESG reviews.¶
Nothing changed. Only bumped for automation...¶
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.¶