YANG Groupings for
TCP Clients and TCP ServersWatsen Networkskent+ietf@watsen.net
Hochschule Esslingen - University of Applied Sciences
michael.scharf@hs-esslingen.de
Operations
NETCONF Working GroupThis document defines three YANG 1.1 modules
to support the configuration of TCP clients and TCP servers, either
as standalone or in conjunction with a stack protocol layer
specific configurations.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:
DDDD --> 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:
2020-08-20 --> the publication date of this draft
The following Appendix section is to be removed prior to publication:
. Change Log
IntroductionThis document defines three YANG 1.1 modules
to support the configuration of TCP clients and TCP servers, either
as standalone or in conjunction with a stack protocol layer
specific configurations.Relation to other RFCsThis document presents one or more YANG modules
that are part of a collection of RFCs that work together to
define configuration modules for clients and servers of both the
NETCONF and RESTCONF
protocols.The modules have been defined in a modular fashion to enable
their use by other efforts, some of which are known to be in
progress at the time of this writing, with many more expected
to be defined in time.The normative dependency relationship between the various RFCs in the collection
is presented in the below diagram. The labels in the diagram
represent the primary purpose provided by each RFC. Hyperlinks to
each RFC are provided below the diagram.
Label to RFC Mapping
Label in Diagram
Originating RFC
crypto-types
truststore
keystore
tcp-client-server
ssh-client-server
tls-client-server
http-client-server
netconf-client-server
restconf-client-server
Specification LanguageThe 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
when, and only when, they appear in all capitals, as shown here.Adherence to the NMDAThis document in compliant with the Network Management Datastore
Architecture (NMDA) . It does not define
any protocol accessible nodes that are "config false".The "ietf-tcp-common" ModuleThis section defines a YANG 1.1 module called
"ietf-tcp-common". A high-level overview of the module is provided in
. Examples illustatrating the module's use
are provided in Examples. The YANG
module itself is defined in .Data Model OverviewThis section provides an overview of the "ietf-tcp-common" module
in terms of its features and groupings.Model ScopeThis document defines a common "grouping" statement for basic TCP connection
parameters that matter to applications. In some TCP stacks, such parameters
can also directly be set by an application using system calls, such as the
socket API. The base YANG model in this document focuses on modeling TCP
keep-alives. This base model can be extended as needed.FeaturesThe following diagram lists all the "feature" statements
defined in the "ietf-tcp-common" module:GroupingsThe following diagram lists all the "grouping" statements
defined in the "ietf-keystore" module:Each of these groupings are presented in the following subsections.The "tcp-common-grouping" GroupingThe following tree diagram illustrates the
"tcp-common-grouping" grouping:Comments:
The "keepalives" node is a "presence" node so that the decendent nodes'
"mandatory true" doesn't imply that keepalives must be configured.
The "idle-time", "max-probes", and "probe-interval" nodes have the
common meanings. Please see the YANG module in
for details.
The "tcp-connection-grouping" GroupingThe following tree diagram illustrates the
"tcp-connection-grouping" grouping:Comments:
This grouping uses the "tcp-common-grouping" grouping discussed in
.
Protocol-accessible NodesThe "ietf-tcp-common" module does not contain any protocol-accessible nodes.Guidelines for Configuring TCP Keep-AlivesNetwork stacks may include "keep-alives" in their TCP implementations,
although this practice is not universally accepted. If keep-alives are
included, [RFC1122] [RFC793bis] mandates that the application MUST be
able to turn them on or off for each TCP connection, and that they MUST
default to off.Keep-alive mechanisms exist in many protocols. Depending on the protocol
stack, TCP keep-alives may only be one out of several alternatives. Which
mechanism(s) to use depends on the use case and application requirements. If
keep-alives are needed by an application, it is RECOMMENDED that the
aliveness check happens only at the protocol layers that are meaningful
to the application.A TCP keep-alive mechanism SHOULD only be invoked in server applications
that might otherwise hang indefinitely and consume resources unnecessarily
if a client crashes or aborts a connection during a network failure [RFC1122].
TCP keep-alives may consume significant resources both in the network and
in endpoints (e.g., battery power). In addition, frequent keep-alives
risk network congestion. The higher the frequency of keep-alives, the
higher the overhead.
Given the cost of keep-alives, parameters have to be configured carefully:
The default idle interval (leaf "idle-time") MUST default to no less
than two hours, i.e., 7200 seconds [RFC1122]. A lower value MAY be
configured, but keep-alive messages SHOULD NOT be transmitted more
frequently than once every 15 seconds. Longer intervals SHOULD be
used when possible.
The maximum number of sequential keep-alive probes that can fail
(leaf "max-probes") trades off responsiveness and robustness against
packet loss. ACK segments that contain no data are not reliably
transmitted by TCP. Consequently, if a keep-alive mechanism is
implemented it MUST NOT interpret failure to respond to any
specific probe as a dead connection [RFC1122]. Typically a
single-digit number should suffice.
TCP implementations may include a parameter for the number of
seconds between TCP keep-alive probes (leaf "probe-interval"). In
order to avoid congestion, the time interval between probes MUST NOT
be smaller than one second. Significantly longer intervals SHOULD be
used. It is important to note that keep-alive probes (or replies)
can get dropped due to network congestion. Sending further probe
messages into a congested path after a short interval, without
backing off timers, could cause harm and result in a congestion
collapse. Therefore it is essential to pick a large, conservative
value for this interval.
Example UsageThis section presents an example showing the "tcp-common-grouping"
populated with some data.15330
]]>YANG ModuleThe ietf-tcp-common YANG module references .<CODE BEGINS> file "ietf-tcp-common@2020-08-20.yang"
WG List:
Authors: Kent Watsen
Michael Scharf
";
description
"This module defines reusable groupings for TCP commons that
can be used as a basis for specific TCP common instances.
Copyright (c) 2020 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Simplified
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC DDDD
(https://www.rfc-editor.org/info/rfcDDDD); 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 2020-08-20 {
description
"Initial version";
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
// Features
feature keepalives-supported {
description
"Indicates that keepalives are supported.";
}
// Groupings
grouping tcp-common-grouping {
description
"A reusable grouping for configuring TCP parameters common
to TCP connections as well as the operating system as a
whole.";
container keepalives {
if-feature "keepalives-supported";
presence
"Indicates that keepalives are enabled. Present so that
the decendant nodes' 'mandatory true' doesn't imply that
this node must be configured.";
description
"Configures the keep-alive policy, to proactively test the
aliveness of the TCP peer. An unresponsive TCP peer is
dropped after approximately (idle-time + max-probes
* probe-interval) seconds.";
leaf idle-time {
type uint16 {
range "1..max";
}
units "seconds";
mandatory true;
description
"Sets the amount of time after which if no data has been
received from the TCP peer, a TCP-level probe message
will be sent to test the aliveness of the TCP peer.
Two hours (7200 seconds) is safe value, per RFC 1122.";
reference
"RFC 1122:
Requirements for Internet Hosts -- Communication Layers";
}
leaf max-probes {
type uint16 {
range "1..max";
}
mandatory true;
description
"Sets the maximum number of sequential keep-alive probes
that can fail to obtain a response from the TCP peer
before assuming the TCP peer is no longer alive.";
}
leaf probe-interval {
type uint16 {
range "1..max";
}
units "seconds";
mandatory true;
description
"Sets the time interval between failed probes. The interval
SHOULD be significantly longer than one second in order to
avoid harm on a congested link.";
}
} // container keepalives
} // grouping tcp-common-grouping
grouping tcp-connection-grouping {
description
"A reusable grouping for configuring TCP parameters common
to TCP connections.";
uses tcp-common-grouping;
}
}
]]><CODE ENDS>The "ietf-tcp-client" ModuleThis section defines a YANG 1.1 module called
"ietf-tcp-client". A high-level overview of the module is provided in
. Examples illustatrating the module's use
are provided in Examples. The YANG
module itself is defined in .Data Model OverviewThis section provides an overview of the "ietf-tcp-client" module
in terms of its features and groupings.FeaturesThe following diagram lists all the "feature" statements
defined in the "ietf-tcp-client" module:GroupingsThe following diagram lists all the "grouping" statements
defined in the "ietf-tcp-client" module:Each of these groupings are presented in the following subsections.The "tcp-client-grouping" GroupingThe following tree diagram illustrates the
"tcp-client-grouping" grouping:Comments:
The "remote-address" node, which is mandatory, may be configured as
an IPv4 address, an IPv6 address, a hostname.
The "remote-port" node is not mandatory, but its default value is
the invalid value '0', thus forcing the consuming data model to
refine it in order to provide it an appropriate default value.
The "local-address" node, which is enabled by the "local-binding-supported"
feature (), may be configured as
an IPv4 address, an IPv6 address, or a wildcard value.
The "local-port" node, which is enabled by the "local-binding-supported"
feature (), is not mandatory. Its default
value is '0', indicating that the operating system can pick an
arbitrary port number.
The "proxy-server" node is enabled by a "feature" statement and, for
servers that enable it, is a "presence" container so that the decendent
"mandatory true" choice node doesn't imply that the proxt-server node
must be configured.
This grouping uses the "tcp-connection-grouping" grouping discussed in
.
Protocol-accessible NodesThe "ietf-tcp-client" module does not contain any protocol-accessible nodes.Example UsageThis section presents two examples showing the "tcp-client-grouping"
populated with some data. This example shows a TCP-client configured to
not connect via a proxy:www.example.com4430.0.0.0015330
]]>This example shows a TCP-client configured to connect via a proxy:www.example.com4430.0.0.00proxy.my-domain.com1080foobarsecret15330
]]>YANG ModuleThe ietf-tcp-client YANG module references .<CODE BEGINS> file "ietf-tcp-client@2020-08-20.yang"
WG List:
Authors: Kent Watsen
Michael Scharf
";
description
"This module defines reusable groupings for TCP clients that
can be used as a basis for specific TCP client instances.
Copyright (c) 2020 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Simplified
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC DDDD
(https://www.rfc-editor.org/info/rfcDDDD); 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 2020-08-20 {
description
"Initial version";
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
// Features
feature local-binding-supported {
description
"Indicates that the server supports configuring local
bindings (i.e., the local address and local port) for
TCP clients.";
}
feature tcp-client-keepalives {
description
"Per socket TCP keepalive parameters are configurable for
TCP clients on the server implementing this feature.";
}
feature proxy-connect {
description
"Proxy connection configuration is configurable for
TCP clients on the server implementing this feature.";
}
feature socks5-gss-api {
description
"Indicates that the server supports authenticating
using GSSAPI when initiating TCP connections via
and SOCKS Version 5 proxy server.";
reference
"RFC 1928: SOCKS Protocol Version 5";
}
feature socks5-username-password {
description
"Indicates that the server supports authenticating
using username/password when initiating TCP
connections via and SOCKS Version 5 proxy
server.";
reference
"RFC 1928: SOCKS Protocol Version 5";
}
// Groupings
grouping tcp-client-grouping {
description
"A reusable grouping for configuring a TCP client.
Note that this grouping uses fairly typical descendent
node names such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue (e.g., by wrapping
the 'uses' statement in a container called
'tcp-client-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
leaf remote-address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the remote peer to
establish a connection with. If a domain name is
configured, then the DNS resolution should happen on
each connection attempt. If the DNS resolution
results in multiple IP addresses, the IP addresses
are tried according to local preference order until
a connection has been established or until all IP
addresses have failed.";
}
leaf remote-port {
type inet:port-number;
default "0";
description
"The IP port number for the remote peer to establish a
connection with. An invalid default value (0) is used
(instead of 'mandatory true') so that as application
level data model may 'refine' it with an application
specific default port number value.";
}
leaf local-address {
if-feature "local-binding-supported";
type inet:ip-address;
description
"The local IP address/interface (VRF?) to bind to for when
connecting to the remote peer. INADDR_ANY ('0.0.0.0') or
INADDR6_ANY ('0:0:0:0:0:0:0:0' a.k.a. '::') MAY be used to
explicitly indicate the implicit default, that the server
can bind to any IPv4 or IPv6 addresses, respectively.";
}
leaf local-port {
if-feature "local-binding-supported";
type inet:port-number;
default "0";
description
"The local IP port number to bind to for when connecting
to the remote peer. The port number '0', which is the
default value, indicates that any available local port
number may be used.";
}
container proxy-server {
if-feature "proxy-connect";
presence
"Indicates that a proxy connection is configured.
Present so that the 'proxy-type' node's 'mandatory
true' doesn't imply that the proxy connection
must be configured.";
choice proxy-type {
mandatory true;
description
"Selects a proxy connection protocol.";
case socks4 {
container socks4-parameters {
leaf remote-address {
type inet:ip-address;
mandatory true;
description
"The IP address of the proxy server.";
}
leaf remote-port {
type inet:port-number;
default "1080";
description
"The IP port number for the proxy server.";
}
description
"Parameters for connecting to a TCP-based proxy
server using the SOCKS4 protocol.";
reference
"SOCKS, Proceedings: 1992 Usenix Security Symposium.";
}
}
case socks4a {
container socks4a-parameters {
leaf remote-address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the proxy server.";
}
leaf remote-port {
type inet:port-number;
default "1080";
description
"The IP port number for the proxy server.";
}
description
"Parameters for connecting to a TCP-based proxy
server using the SOCKS4a protocol.";
reference
"SOCKS Proceedings:
1992 Usenix Security Symposium.
OpenSSH message:
SOCKS 4A: A Simple Extension to SOCKS 4 Protocol
https://www.openssh.com/txt/socks4a.protocol";
}
}
case socks5 {
container socks5-parameters {
leaf remote-address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the proxy server.";
}
leaf remote-port {
type inet:port-number;
default "1080";
description
"The IP port number for the proxy server.";
}
container authentication-parameters {
presence
"Indicates that an authentication mechanism
has been configured. Present so that the
'auth-type' node's 'mandatory true' doesn't
imply that an authentication mechanism
must be configured.";
description
"A container for SOCKS Version 5 authentication
mechanisms.
A complete list of methods is defined at:
https://www.iana.org/assignments/socks-methods
/socks-methods.xhtml.";
reference
"RFC 1928: SOCKS Protocol Version 5";
choice auth-type {
mandatory true;
description
"A choice amongst supported SOCKS Version 5
authentication mechanisms.";
case gss-api {
if-feature socks5-gss-api;
container gss-api {
description
"Contains GSS-API configuration. Defines
as an empty container to enable specific
GSS-API configuration to be augmented in
by future modules.";
reference
"RFC 1928: SOCKS Protocol Version 5
RFC 2743: Generic Security Service
Application Program Interface
Version 2, Update 1";
}
}
case username-password {
if-feature socks5-username-password;
container username-password {
leaf username {
type string;
mandatory true;
description
"The 'username' value to use for client
identification.";
}
uses ct:password-grouping {
description
"The password to be used for client
authentication.";
}
description
"Contains Username/Password configuration.";
reference
"RFC 1929: Username/Password Authentication
for SOCKS V5";
}
}
}
}
description
"Parameters for connecting to a TCP-based proxy server
using the SOCKS5 protocol.";
reference
"RFC 1928: SOCKS Protocol Version 5";
}
}
}
description
"Proxy server settings.";
}
uses tcpcmn:tcp-connection-grouping {
augment "keepalives" {
if-feature "tcp-client-keepalives";
description
"Add an if-feature statement so that implementations
can choose to support TCP client keepalives.";
}
}
}
}
]]><CODE ENDS>The "ietf-tcp-server" ModuleThis section defines a YANG 1.1 module called
"ietf-tcp-server". A high-level overview of the module is provided in
. Examples illustatrating the module's use
are provided in Examples. The YANG
module itself is defined in .Data Model OverviewThis section provides an overview of the "ietf-tcp-server" module
in terms of its features and groupings.FeaturesThe following diagram lists all the "feature" statements
defined in the "ietf-tcp-server" module:GroupingsThe following diagram lists all the "grouping" statements
defined in the "ietf-tcp-server" module:Each of these groupings are presented in the following subsections.The "tcp-server-grouping" GroupingThe following tree diagram illustrates the
"tcp-server-grouping" grouping:Comments:
The "local-address" node, which is mandatory, may be configured as
an IPv4 address, an IPv6 address, or a wildcard value.
The "local-port" node is not mandatory, but its default value is
the invalid value '0', thus forcing the consuming data model to
refine it in order to provide it an appropriate default value.
This grouping uses the "tcp-connection-grouping" grouping discussed in
.
Protocol-accessible NodesThe "ietf-tcp-server" module does not contain any protocol-accessible nodes.Example UsageThis section presents an example showing the "tcp-server-grouping"
populated with some data.10.20.30.40777715330
]]>YANG ModuleThe ietf-tcp-server YANG module references .<CODE BEGINS> file "ietf-tcp-server@2020-08-20.yang"
WG List:
Authors: Kent Watsen
Michael Scharf
";
description
"This module defines reusable groupings for TCP servers that
can be used as a basis for specific TCP server instances.
Copyright (c) 2020 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Simplified
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC DDDD
(https://www.rfc-editor.org/info/rfcDDDD); 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 2020-08-20 {
description
"Initial version";
reference
"RFC DDDD: YANG Groupings for TCP Clients and TCP Servers";
}
// Features
feature tcp-server-keepalives {
description
"Per socket TCP keepalive parameters are configurable for
TCP servers on the server implementing this feature.";
}
// Groupings
grouping tcp-server-grouping {
description
"A reusable grouping for configuring a TCP server.
Note that this grouping uses fairly typical descendent
node names such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue (e.g., by wrapping
the 'uses' statement in a container called
'tcp-server-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
leaf local-address {
type inet:ip-address;
mandatory true;
description
"The local IP address to listen on for incoming
TCP client connections. INADDR_ANY (0.0.0.0) or
INADDR6_ANY (0:0:0:0:0:0:0:0 a.k.a. ::) MUST be
used when the server is to listen on all IPv4 or
IPv6 addresses, respectively.";
}
leaf local-port {
type inet:port-number;
default "0";
description
"The local port number to listen on for incoming TCP
client connections. An invalid default value (0)
is used (instead of 'mandatory true') so that an
application level data model may 'refine' it with
an application specific default port number value.";
}
uses tcpcmn:tcp-connection-grouping {
augment "keepalives" {
if-feature "tcp-server-keepalives";
description
"Add an if-feature statement so that implementations
can choose to support TCP server keepalives.";
}
}
}
}
]]><CODE ENDS>Security ConsiderationsThe "ietf-tcp-common" YANG ModuleThe "ietf-tcp-common" YANG module defines "grouping" statements
that are designed to be accessed via YANG based management
protocols, such as NETCONF and RESTCONF
. Both of these protocols have
mandatory-to-implement secure transport layers (e.g., SSH, TLS)
with mutual authentication.The NETCONF access control model (NACM)
provides the means to restrict access for particular users to a
pre-configured subset of all available protocol operations and
content.Since the module in this document only define groupings,
these considerations are primarily for the designers of other
modules that use these groupings.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.The "ietf-tcp-client" YANG ModuleThe "ietf-tcp-client" YANG module defines "grouping" statements
that are designed to be accessed via YANG based management
protocols, such as NETCONF and RESTCONF
. Both of these protocols have
mandatory-to-implement secure transport layers (e.g., SSH, TLS)
with mutual authentication.The NETCONF access control model (NACM)
provides the means to restrict access for particular users to a
pre-configured subset of all available protocol operations and
content.Since the module in this document only define groupings,
these considerations are primarily for the designers of other
modules that use these groupings.One readable data node defined in this YANG module may be considered
sensitive or vulnerable in some network environments. This
node is as follows:
The "proxy-server/socks5-parameters/authentication-parameters/username-password/password" node:
The cleartext "password" node defined in the "tcp-client-grouping"
grouping is additionally sensitive to read operations such that,
in normal use cases, it should never be returned to a client.
For this reason, the NACM extension "default-deny-all" has been
applied to it.
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.The "ietf-tcp-server" YANG ModuleThe "ietf-tcp-server" YANG module defines "grouping" statements
that are designed to be accessed via YANG based management
protocols, such as NETCONF and RESTCONF
. Both of these protocols have
mandatory-to-implement secure transport layers (e.g., SSH, TLS)
with mutual authentication.The NETCONF access control model (NACM)
provides the means to restrict access for particular users to a
pre-configured subset of all available protocol operations and
content.Since the module in this document only define groupings,
these considerations are primarily for the designers of other
modules that use these groupings.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.IANA ConsiderationsThe "IETF XML" RegistryThis document registers two URIs in the "ns" subregistry of the
IETF XML Registry . Following the format in
, the following registrations are
requested:The "YANG Module Names" RegistryThis document registers two YANG modules in the YANG Module Names
registry . Following the format in , the following registrations are requested:ReferencesNormative ReferencesKey words for use in RFCs to Indicate Requirement LevelsIn many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]Common YANG Data TypesThis document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021.The YANG 1.1 Data Modeling LanguageYANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).Ambiguity of Uppercase vs Lowercase in RFC 2119 Key WordsRFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.Network Configuration Access Control ModelThe standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.This document obsoletes RFC 6536.Informative ReferencesThe IETF XML RegistryThis document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.Network Configuration Protocol (NETCONF)The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK]RESTCONF ProtocolThis document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).YANG Tree DiagramsThis document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language.Network Management Datastore Architecture (NMDA)Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.Change Log00 to 01
Added 'local-binding-supported' feature to TCP-client model.
Added 'keepalives-supported' feature to TCP-common model.
Added 'external-endpoint-values' container and 'external-endpoints' feature to TCP-server model.
01 to 02
Removed the 'external-endpoint-values' container and 'external-endpoints' feature from the TCP-server model.
02 to 03
Moved the common model section to be before the client and server specific sections.
Added sections "Model Scope" and "Usage Guidelines for Configuring TCP Keep-Alives" to
the common model section.
03 to 04
Fixed a few typos.
04 to 05
Removed commented out "grouping tcp-system-grouping" statement kept for reviewers.
Added a "Note to Reviewers" note to first page.
05 to 06
Added support for TCP proxies.
06 to 07
Expanded "Data Model Overview section(s) [remove "wall" of tree diagrams].
Updated the Security Considerations section.
08 to 09
Added missing IANA registration for "ietf-tcp-common"
Added "mandatory true" for the "username" and "password" leafs
Added an example of a TCP-client configured to connect via a proxy
Fixed issues found by the SecDir review of the "keystore" draft.
Updated the "ietf-tcp-client" module to use the new "password-grouping"
grouping from the "crypto-types" module.