TCPM M. Scharf
Internet-Draft Hochschule Esslingen
Intended status: Standards Track V. Murgai
Expires: 9 January 2022 Samsung
M. Jethanandani
Kloud Services
8 July 2021
YANG Model for Transmission Control Protocol (TCP) Configuration
draft-ietf-tcpm-yang-tcp-02
Abstract
This document specifies a YANG model for TCP on devices that are
configured by network management protocols. The YANG model defines a
container for all TCP connections and groupings of some of the
parameters that can be imported and used in TCP implementations or by
other models that need to configure TCP parameters. The model
includes definitions from YANG Groupings for TCP Client and TCP
Servers (I-D.ietf-netconf-tcp-client-server). The model is NMDA (RFC
8342) compliant.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 9 January 2022.
Copyright Notice
Copyright (c) 2021 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.
Scharf, et al. Expires 9 January 2022 [Page 1]
Internet-Draft TCP Configuration July 2021
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
2.1. Note to RFC Editor . . . . . . . . . . . . . . . . . . . 3
3. Model Overview . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Modeling Scope . . . . . . . . . . . . . . . . . . . . . 4
3.2. Model Design . . . . . . . . . . . . . . . . . . . . . . 6
3.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 6
4. TCP YANG Model . . . . . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
5.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 13
5.2. The YANG Module Names Registry . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1. Normative References . . . . . . . . . . . . . . . . . . 14
7.2. Informative References . . . . . . . . . . . . . . . . . 16
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 17
Appendix B. Changes compared to previous versions . . . . . . . 17
Appendix C. Examples . . . . . . . . . . . . . . . . . . . . . . 18
C.1. Keepalive Configuration . . . . . . . . . . . . . . . . . 18
C.2. TCP-AO Configuration . . . . . . . . . . . . . . . . . . 19
Appendix D. Complete Tree Diagram . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
The Transmission Control Protocol (TCP) [RFC0793] is used by many
applications in the Internet, including control and management
protocols. Therefore, TCP is implemented on network elements that
can be configured via network management protocols such as NETCONF
[RFC6241] or RESTCONF [RFC8040]. This document specifies a YANG
[RFC7950] 1.1 model for configuring TCP on network elements that
support YANG data models, and is Network Management Datastore
Architecture (NMDA) [RFC8342] compliant. This module defines a
container for TCP connection, and includes definitions from YANG
Groupings for TCP Clients and TCP Servers
[I-D.ietf-netconf-tcp-client-server]. The model has a narrow scope
and focuses on fundamental TCP functions and basic statistics. The
model can be augmented or updated to address more advanced or
implementation-specific TCP features in the future.
Scharf, et al. Expires 9 January 2022 [Page 2]
Internet-Draft TCP Configuration July 2021
Many protocol stacks on Internet hosts use other methods to configure
TCP, such as operating system configuration or policies. Many TCP/IP
stacks cannot be configured by network management protocols such as
NETCONF [RFC6241] or RESTCONF [RFC8040]. Moreover, many existing
TCP/IP stacks do not use YANG data models. Such TCP implementations
often have other means to configure the parameters listed in this
document, which are outside the scope of this document.
This specification is orthogonal to the Management Information Base
(MIB) for the Transmission Control Protocol (TCP) [RFC4022]. The
basic statistics defined in this document follow the model of the TCP
MIB. An TCP Extended Statistics MIB [RFC4898] is also available, but
this document does not cover such extended statistics. It is
possible also to translate a MIB into a YANG model, for instance
using Translation of Structure of Management Information Version 2
(SMIv2) MIB Modules to YANG Modules [RFC6643]. However, this
approach is not used in this document, as such a translated model
would not be up-to-date.
There are other existing TCP-related YANG models, which are
orthogonal to this specification. Examples are:
* TCP header attributes are modeled in other models, such as YANG
Data Model for Network Access Control Lists (ACLs) [RFC8519] and
Distributed Denial-of-Service Open Thread Signaling (DOTS) Data
Channel Specification [RFC8783].
* TCP-related configuration of a NAT (e.g., NAT44, NAT64,
Destination NAT, ...) is defined in A YANG Module for Network
Address Translation (NAT) and Network Prefix Translation (NPT)
[RFC8512] and A YANG Data Model for Dual-Stack Lite (DS-Lite)
[RFC8513].
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2.1. Note to RFC Editor
This document uses several placeholder values throughout the
document. Please replace them as follows and remove this note before
publication.
Scharf, et al. Expires 9 January 2022 [Page 3]
Internet-Draft TCP Configuration July 2021
RFC XXXX, where XXXX is the number assigned to this document at the
time of publication.
2021-07-06 with the actual date of the publication of this document.
3. Model Overview
3.1. Modeling Scope
TCP is implemented on many different system architectures. As a
result, there are may different and often implementation-specific
ways to configure parameters of the TCP protocol engine. In
addition, in many TCP/IP stacks configuration exists for different
scopes:
* Global configuration: Many TCP implementations have configuration
parameters that affect all TCP connections. Typical examples
include enabling or disabling optional protocol features.
* Interface configuration: It can be useful to use different TCP
parameters on different interfaces, e.g., different device ports
or IP interfaces. In that case, TCP parameters can be part of the
interface configuration. Typical examples are the Maximum Segment
Size (MSS) or configuration related to hardware offloading.
* Connection parameters: Many implementations have means to
influence the behavior of each TCP connection, e.g., on the
programming interface used by applications. A typical example are
socket options in the socket API, such as disabling the Nagle
algorithm by TCP_NODELAY. If an application uses such an
interface, it is possible that the configuration of the
application or application protocol includes TCP-related
parameters. An example is the BGP YANG Model for Service Provider
Networks [I-D.ietf-idr-bgp-model].
* Policies: Setting of TCP parameters can also be part of system
policies, templates, or profiles. An example would be the
preferences defined in An Abstract Application Layer Interface to
Transport Services [I-D.ietf-taps-interface].
Scharf, et al. Expires 9 January 2022 [Page 4]
Internet-Draft TCP Configuration July 2021
As a result, there is no ground truth for setting certain TCP
parameters, and traditionally different TCP implementation have used
different modeling approaches. For instance, one implementation may
define a given configuration parameter globally, while another one
uses per-interface settings, and both approaches work well for the
corresponding use cases. Also, different systems may use different
default values. In addition, TCP can be implemented in different
ways and design choices by the protocol engine often affect
configuration options.
Nonetheless, a number of TCP stack parameters require configuration
by YANG models. This document therefore defines a minimal YANG model
with fundamental parameters directly following from TCP standards.
An important use case is the TCP configuration on network elements
such as routers, which often use YANG data models. The model
therefore specifies TCP parameters that are important on such TCP
stacks.
A typical example is the support of TCP-AO [RFC5925]. TCP-AO is
increasingly supported on routers to secure routing protocols such as
BGP. In that case, TCP-AO configuration is required on routers. The
model includes the required TCP parameters for TCP-AO configuration.
The key chain for TCP-AO can be modeled by the YANG Data Model for
Key Chains [RFC8177].
Given an installed base, the model also allows enabling of the legacy
TCP MD5 [RFC2385] signature option. As the TCP MD5 signature option
is obsoleted by TCP-AO, it is strongly RECOMMENDED to use TCP-AO.
Similar to the TCP MIB [RFC4022], this document also specifies basic
statistics and a TCP connection table.
* Statistics: Counters for the number of active/passive opens, sent
and received segments, errors, and possibly other detailed
debugging information
* TCP connection table: Access to status information for all TCP
connections
This allows implementations of TCP MIB [RFC4022] to migrate to the
YANG model defined in this memo. Note that the TCP MIB does not
include means to reset statistics, which are defined in this
document. This is not a major addition, as a reset can simply be
implemented by storing offset values for the counters.
Scharf, et al. Expires 9 January 2022 [Page 5]
Internet-Draft TCP Configuration July 2021
3.2. Model Design
The YANG model defined in this document includes definitions from the
YANG Groupings for TCP Clients and TCP Servers
[I-D.ietf-netconf-tcp-client-server]. Similar to that model, this
specification defines YANG groupings. This allows reuse of these
groupings in different YANG data models. It is intended that these
groupings will be used either standalone or for TCP-based protocols
as part of a stack of protocol-specific configuration models. An
example could be the BGP YANG Model for Service Provider Networks
[I-D.ietf-idr-bgp-model].
3.3. Tree Diagram
This section provides a abridged tree diagram for the YANG module
defined in this document. Annotations used in the diagram are
defined in YANG Tree Diagrams [RFC8340].
module: ietf-tcp
+--rw tcp!
+--rw connections
| ...
+--ro statistics {statistics}?
...
4. TCP YANG Model
<CODE BEGINS> file "ietf-tcp@2021-07-06.yang"
module ietf-tcp {
yang-version "1.1";
namespace "urn:ietf:params:xml:ns:yang:ietf-tcp";
prefix "tcp";
import ietf-yang-types {
prefix "yang";
reference
"RFC 6991: Common YANG Data Types.";
}
import ietf-tcp-common {
prefix "tcpcmn";
}
import ietf-inet-types {
prefix "inet";
}
organization
"IETF TCPM Working Group";
Scharf, et al. Expires 9 January 2022 [Page 6]
Internet-Draft TCP Configuration July 2021
contact
"WG Web: <http://tools.ietf.org/wg/tcpm>
WG List: <tcpm@ietf.org>
Authors: Michael Scharf (michael.scharf at hs-esslingen dot de)
Vishal Murgai (vmurgai at gmail dot com)
Mahesh Jethanandani (mjethanandani at gmail dot com)";
description
"This module focuses on fundamental and standard TCP functions
that widely implemented. The model can be augmented to address
more advanced or implementation specific TCP features.
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 XXXX
(https://www.rfc-editor.org/info/rfcXXXX); 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 "2021-07-06" {
description
"Initial Version";
reference
"RFC XXXX, TCP Configuration.";
}
// Features
feature statistics {
description
"This implementation supports statistics reporting.";
}
// TCP-AO Groupings
Scharf, et al. Expires 9 January 2022 [Page 7]
Internet-Draft TCP Configuration July 2021
grouping ao {
leaf enable-ao {
type boolean;
default "false";
description
"Enable support of TCP-Authentication Option (TCP-AO).";
}
leaf send-id {
type uint8 {
range "0..255";
}
must "../enable-ao = 'true'";
description
"The SendID is inserted as the KeyID of the TCP-AO option
of outgoing segments. The SendID must match the RecvID
at the other endpoint.";
reference
"RFC 5925: The TCP Authentication Option.";
}
leaf recv-id {
type uint8 {
range "0..255";
}
must "../enable-ao = 'true'";
description
"The RecvID is matched against the TCP-AO KeyID of incoming
segments. The RecvID must match the SendID at the other
endpoint.";
reference
"RFC 5925: The TCP Authentication Option.";
}
leaf include-tcp-options {
type boolean;
must "../enable-ao = 'true'";
default true;
description
"Include TCP options in MAC calculation.";
}
leaf accept-key-mismatch {
type boolean;
must "../enable-ao = 'true'";
description
"Accept TCP segments with a Master Key Tuple (MKT) that is not
configured.";
Scharf, et al. Expires 9 January 2022 [Page 8]
Internet-Draft TCP Configuration July 2021
}
description
"Authentication Option (AO) for TCP.";
reference
"RFC 5925: The TCP Authentication Option.";
}
// MD5 grouping
grouping md5 {
description
"Grouping for use in authenticating TCP sessions using MD5.";
reference
"RFC 2385: Protection of BGP Sessions via the TCP MD5
Signature.";
leaf enable-md5 {
type boolean;
default "false";
description
"Enable support of MD5 to authenticate a TCP session.";
}
}
// TCP configuration
container tcp {
presence "The container for TCP configuration.";
description
"TCP container.";
container connections {
list connection {
key "local-address remote-address local-port remote-port";
leaf local-address {
type inet:ip-address;
description
"Local address that forms the connection identifier.";
}
leaf remote-address {
type inet:ip-address;
description
"Remote address that forms the connection identifier.";
}
Scharf, et al. Expires 9 January 2022 [Page 9]
Internet-Draft TCP Configuration July 2021
leaf local-port {
type inet:port-number;
description
"Local TCP port that forms the connection identifier.";
}
leaf remote-port {
type inet:port-number;
description
"Remote TCP port that forms the connection identifier.";
}
container common {
uses tcpcmn:tcp-common-grouping;
choice authentication {
case ao {
uses ao;
description
"Use TCP-AO to secure the connection.";
}
case md5 {
uses md5;
description
"Use TCP-MD5 to secure the connection.";
}
description
"Choice of how to secure the TCP connection.";
}
description
"Common definitions of TCP configuration. This includes
parameters such as how to secure the connection,
that can be part of either the client or server.";
}
description
"List of TCP connections with their parameters. The list
is modelled as writeable, but implementations may not allow
creation of new TCP connections by adding entries to the
list. Furthermore, the behavior upon removal is
implementation-specific. Implementations may support
closing or reseting a TCP connection upon an operation that
removes the entry from the list.";
}
description
"A container of all TCP connections.";
}
Scharf, et al. Expires 9 January 2022 [Page 10]
Internet-Draft TCP Configuration July 2021
container statistics {
if-feature statistics;
config false;
leaf active-opens {
type yang:counter32;
description
"The number of times that TCP connections have made a direct
transition to the SYN-SENT state from the CLOSED state.";
}
leaf passive-opens {
type yang:counter32;
description
"The number of times TCP connections have made a direct
transition to the SYN-RCVD state from the LISTEN state.";
}
leaf attempt-fails {
type yang:counter32;
description
"The number of times that TCP connections have made a direct
transition to the CLOSED state from either the SYN-SENT
state or the SYN-RCVD state, plus the number of times that
TCP connections have made a direct transition to the
LISTEN state from the SYN-RCVD state.";
}
leaf establish-resets {
type yang:counter32;
description
"The number of times that TCP connections have made a direct
transition to the CLOSED state from either the ESTABLISHED
state or the CLOSE-WAIT state.";
}
leaf currently-established {
type yang:gauge32;
description
"The number of TCP connections for which the current state
is either ESTABLISHED or CLOSE-WAIT.";
}
leaf in-segments {
type yang:counter64;
description
"The total number of segments received, including those
received in error. This count includes segments received
Scharf, et al. Expires 9 January 2022 [Page 11]
Internet-Draft TCP Configuration July 2021
on currently established connections.";
}
leaf out-segments {
type yang:counter64;
description
"The total number of segments sent, including those on
current connections but excluding those containing only
retransmitted octets.";
}
leaf retransmitted-segments {
type yang:counter32;
description
"The total number of segments retransmitted; that is, the
number of TCP segments transmitted containing one or more
previously transmitted octets.";
}
leaf in-errors {
type yang:counter32;
description
"The total number of segments received in error (e.g., bad
TCP checksums).";
}
leaf out-resets {
type yang:counter32;
description
"The number of TCP segments sent containing the RST flag.";
}
action reset {
description
"Reset statistics action command.";
input {
leaf reset-at {
type yang:date-and-time;
description
"Time when the reset action needs to be
executed.";
}
}
output {
leaf reset-finished-at {
type yang:date-and-time;
description
"Time when the reset action command completed.";
Scharf, et al. Expires 9 January 2022 [Page 12]
Internet-Draft TCP Configuration July 2021
}
}
}
description
"Statistics across all connections.";
}
}
}
<CODE ENDS>
5. IANA Considerations
5.1. The IETF XML Registry
This document registers two URIs in the "ns" subregistry of the IETF
XML Registry [RFC3688]. Following the format in IETF XML Registry
[RFC3688], the following registrations are requested:
URI: urn:ietf:params:xml:ns:yang:ietf-tcp
Registrant Contact: The TCPM WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
5.2. The YANG Module Names Registry
This document registers a YANG modules in the YANG Module Names
registry YANG - A Data Modeling Language [RFC6020]. Following the
format in YANG - A Data Modeling Language [RFC6020], the following
registrations are requested:
name: ietf-tcp
namespace: urn:ietf:params:xml:ns:yang:ietf-tcp
prefix: tcp
reference: RFC XXXX
6. Security Considerations
The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) described in Using the NETCONF
protocol over SSH [RFC6242]. The lowest RESTCONF layer is HTTPS, and
the mandatory-to-implement secure transport is TLS [RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
Scharf, et al. Expires 9 January 2022 [Page 13]
Internet-Draft TCP Configuration July 2021
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., "config true", which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
TODO
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data
nodes and their sensitivity/vulnerability:
* Unrestricted access to connection information of the client or
server can be used by a malicious user to launch an attack, e.g.
MITM.
* Similarly, unrestricted access to statistics of the client or
server can be used by a malicious user to exploit any
vulnerabilities of the system.
Some of the RPC operations in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control access to these operations. These are the
operations and their sensitivity/vulnerability:
* The YANG module allows for the statistics to be cleared by
executing the reset action. This action should be restricted to
users with the right permission.
7. References
7.1. Normative References
[I-D.ietf-netconf-tcp-client-server]
Watsen, K. and M. Scharf, "YANG Groupings for TCP Clients
and TCP Servers", Work in Progress, Internet-Draft, draft-
ietf-netconf-tcp-client-server-09, 10 February 2021,
<https://www.ietf.org/archive/id/draft-ietf-netconf-tcp-
client-server-09.txt>.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981,
<https://www.rfc-editor.org/info/rfc793>.
Scharf, et al. Expires 9 January 2022 [Page 14]
Internet-Draft TCP Configuration July 2021
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2385] Heffernan, A., "Protection of BGP Sessions via the TCP MD5
Signature Option", RFC 2385, DOI 10.17487/RFC2385, August
1998, <https://www.rfc-editor.org/info/rfc2385>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
June 2010, <https://www.rfc-editor.org/info/rfc5925>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8177] Lindem, A., Ed., Qu, Y., Yeung, D., Chen, I., and J.
Zhang, "YANG Data Model for Key Chains", RFC 8177,
DOI 10.17487/RFC8177, June 2017,
<https://www.rfc-editor.org/info/rfc8177>.
Scharf, et al. Expires 9 January 2022 [Page 15]
Internet-Draft TCP Configuration July 2021
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
7.2. Informative References
[I-D.ietf-idr-bgp-model]
Jethanandani, M., Patel, K., Hares, S., and J. Haas, "BGP
YANG Model for Service Provider Networks", Work in
Progress, Internet-Draft, draft-ietf-idr-bgp-model-10, 15
November 2020, <https://www.ietf.org/archive/id/draft-
ietf-idr-bgp-model-10.txt>.
[I-D.ietf-taps-interface]
Trammell, B., Welzl, M., Enghardt, T., Fairhurst, G.,
Kuehlewind, M., Perkins, C., Tiesel, P. S., Wood, C. A.,
Pauly, T., and K. Rose, "An Abstract Application Layer
Interface to Transport Services", Work in Progress,
Internet-Draft, draft-ietf-taps-interface-12, 9 April
2021, <https://www.ietf.org/archive/id/draft-ietf-taps-
interface-12.txt>.
[I-D.touch-tcpm-ao-test-vectors]
Touch, J. and J. Kuusisaari, "TCP-AO Test Vectors", Work
in Progress, Internet-Draft, draft-touch-tcpm-ao-test-
vectors-02, 23 December 2020,
<https://www.ietf.org/archive/id/draft-touch-tcpm-ao-test-
vectors-02.txt>.
[RFC4022] Raghunarayan, R., Ed., "Management Information Base for
the Transmission Control Protocol (TCP)", RFC 4022,
DOI 10.17487/RFC4022, March 2005,
<https://www.rfc-editor.org/info/rfc4022>.
Scharf, et al. Expires 9 January 2022 [Page 16]
Internet-Draft TCP Configuration July 2021
[RFC4898] Mathis, M., Heffner, J., and R. Raghunarayan, "TCP
Extended Statistics MIB", RFC 4898, DOI 10.17487/RFC4898,
May 2007, <https://www.rfc-editor.org/info/rfc4898>.
[RFC6643] Schoenwaelder, J., "Translation of Structure of Management
Information Version 2 (SMIv2) MIB Modules to YANG
Modules", RFC 6643, DOI 10.17487/RFC6643, July 2012,
<https://www.rfc-editor.org/info/rfc6643>.
[RFC8512] Boucadair, M., Ed., Sivakumar, S., Jacquenet, C.,
Vinapamula, S., and Q. Wu, "A YANG Module for Network
Address Translation (NAT) and Network Prefix Translation
(NPT)", RFC 8512, DOI 10.17487/RFC8512, January 2019,
<https://www.rfc-editor.org/info/rfc8512>.
[RFC8513] Boucadair, M., Jacquenet, C., and S. Sivakumar, "A YANG
Data Model for Dual-Stack Lite (DS-Lite)", RFC 8513,
DOI 10.17487/RFC8513, January 2019,
<https://www.rfc-editor.org/info/rfc8513>.
[RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair,
"YANG Data Model for Network Access Control Lists (ACLs)",
RFC 8519, DOI 10.17487/RFC8519, March 2019,
<https://www.rfc-editor.org/info/rfc8519>.
[RFC8783] Boucadair, M., Ed. and T. Reddy.K, Ed., "Distributed
Denial-of-Service Open Threat Signaling (DOTS) Data
Channel Specification", RFC 8783, DOI 10.17487/RFC8783,
May 2020, <https://www.rfc-editor.org/info/rfc8783>.
Appendix A. Acknowledgements
Michael Scharf was supported by the StandICT.eu project, which is
funded by the European Commission under the Horizon 2020 Programme.
The following persons have contributed to this document by reviews:
Mohamed Boucadair
Appendix B. Changes compared to previous versions
Changes compared to draft-scharf-tcpm-yang-tcp-04
* Removed congestion control
* Removed global stack parameters
Changes compared to draft-scharf-tcpm-yang-tcp-03
Scharf, et al. Expires 9 January 2022 [Page 17]
Internet-Draft TCP Configuration July 2021
* Updated TCP-AO grouping
* Added congestion control
Changes compared to draft-scharf-tcpm-yang-tcp-02
* Initial proposal of a YANG model including base configuration
parameters, TCP-AO configuration, and a connection list
* Editorial bugfixes and outdated references reported by Mohamed
Boucadair
* Additional co-author Mahesh Jethanandani
Changes compared to draft-scharf-tcpm-yang-tcp-01
* Alignment with [I-D.ietf-netconf-tcp-client-server]
* Removing backward-compatibility to the TCP MIB
* Additional co-author Vishal Murgai
Changes compared to draft-scharf-tcpm-yang-tcp-00
* Editorial improvements
Appendix C. Examples
C.1. Keepalive Configuration
This particular example demonstrates how both a particular connection
can be configured for keepalives.
Scharf, et al. Expires 9 January 2022 [Page 18]
Internet-Draft TCP Configuration July 2021
[note: '\' line wrapping for formatting only]
<?xml version="1.0" encoding="UTF-8"?>
<!--
This example shows how TCP keepalive can be configured for
a given connection. An idle connection is dropped after
idle-time + (max-probes * probe-interval).
-->
<tcp
xmlns="urn:ietf:params:xml:ns:yang:ietf-tcp">
<connections>
<connection>
<local-address>192.168.1.1</local-address>
<remote-address>192.168.1.2</remote-address>
<local-port>1025</local-port>
<remote-port>80</remote-port>
<common>
<keepalives>
<idle-time>5</idle-time>
<max-probes>5</max-probes>
<probe-interval>10</probe-interval>
</keepalives>
</common>
</connection>
</connections>
</tcp>
C.2. TCP-AO Configuration
The following example demonstrates how to model a TCP-AO [RFC5925]
configuration for the example in TCP-AO Test Vectors
[I-D.touch-tcpm-ao-test-vectors], Section 5.1.1.
Scharf, et al. Expires 9 January 2022 [Page 19]
Internet-Draft TCP Configuration July 2021
[note: '\' line wrapping for formatting only]
<?xml version="1.0" encoding="UTF-8"?>
<!--
This example sets TCP-AO configuration parameters as
demonstrated by examples in draft-touch-tcpm-ao-test-vectors.
-->
<tcp
xmlns="urn:ietf:params:xml:ns:yang:ietf-tcp">
<connections>
<connection>
<local-address>192.168.1.1</local-address>
<remote-address>192.168.1.2</remote-address>
<local-port>1025</local-port>
<remote-port>80</remote-port>
<common>
<enable-ao>true</enable-ao>
</common>
</connection>
</connections>
</tcp>
<key-chains
xmlns="urn:ietf:params:xml:ns:yang:ietf-key-chain">
<key-chain>
<name>ao-config</name>
<description>"An example for TCP-AO configuration."</description>\
<key>
<key-id>61</key-id>
<crypto-algorithm>hmac-sha-1</crypto-algorithm>
<key-string>
<hexadecimal-string>01:23:a5:93:b9:db:70:62:9b:be:2c:a6:77:cd:fd:ea:\
6f:e0:ac:ad</hexadecimal-string>
</key-string>
</key>
</key-chain>
</key-chains>
Appendix D. Complete Tree Diagram
Here is the complete tree diagram for the TCP YANG model.
Scharf, et al. Expires 9 January 2022 [Page 20]
Internet-Draft TCP Configuration July 2021
module: ietf-tcp
+--rw tcp!
+--rw connections
| +--rw connection*
| [local-address remote-address local-port remote-port]
| +--rw local-address inet:ip-address
| +--rw remote-address inet:ip-address
| +--rw local-port inet:port-number
| +--rw remote-port inet:port-number
| +--rw common
| +--rw keepalives!
| | +--rw idle-time uint16
| | +--rw max-probes uint16
| | +--rw probe-interval uint16
| +--rw (authentication)?
| +--:(ao)
| | +--rw enable-ao? boolean
| | +--rw send-id? uint8
| | +--rw recv-id? uint8
| | +--rw include-tcp-options? boolean
| | +--rw accept-key-mismatch? boolean
| +--:(md5)
| +--rw enable-md5? boolean
+--ro statistics {statistics}?
+--ro active-opens? yang:counter32
+--ro passive-opens? yang:counter32
+--ro attempt-fails? yang:counter32
+--ro establish-resets? yang:counter32
+--ro currently-established? yang:gauge32
+--ro in-segments? yang:counter64
+--ro out-segments? yang:counter64
+--ro retransmitted-segments? yang:counter32
+--ro in-errors? yang:counter32
+--ro out-resets? yang:counter32
+---x reset
+---w input
| +---w reset-at? yang:date-and-time
+--ro output
+--ro reset-finished-at? yang:date-and-time
Authors' Addresses
Michael Scharf
Hochschule Esslingen - University of Applied Sciences
Flandernstr. 101
73732 Esslingen
Germany
Scharf, et al. Expires 9 January 2022 [Page 21]
Internet-Draft TCP Configuration July 2021
Email: michael.scharf@hs-esslingen.de
Vishal Murgai
Samsung
Email: vmurgai@gmail.com
Mahesh Jethanandani
Kloud Services
Email: mjethanandani@gmail.com
Scharf, et al. Expires 9 January 2022 [Page 22]
