A Revised Conceptual Model for YANG Datastores
draft-ietf-netmod-revised-datastores-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8342.
|
|
|---|---|---|---|
| Authors | Martin Björklund , Jürgen Schönwälder , Philip A. Shafer , Kent Watsen , Robert Wilton | ||
| Last updated | 2016-12-21 | ||
| Replaces | draft-nmdsdt-netmod-revised-datastores | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 8342 (Proposed Standard) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-netmod-revised-datastores-00
Network Working Group M. Bjorklund, Ed.
Internet-Draft Tail-f Systems
Intended status: Standards Track J. Schoenwaelder
Expires: June 22, 2017 Jacobs University
P. Shafer
K. Watsen
Juniper
R. Wilton
Cisco
December 19, 2016
A Revised Conceptual Model for YANG Datastores
draft-ietf-netmod-revised-datastores-00
Abstract
Datastores are a fundamental concept binding the YANG data modeling
language to protocols transporting data defined in YANG data models,
such as NETCONF or RESTCONF. This document defines a revised
conceptual model of datastores based on the experience gained with
the initial simpler model and addressing requirements that were not
well supported in the initial model.
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 http://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 June 22, 2017.
Copyright Notice
Copyright (c) 2016 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
Bjorklund, et al. Expires June 22, 2017 [Page 1]
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(http://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 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. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Original Model of Datastores . . . . . . . . . . . . . . . . 4
5. Revised Model of Datastores . . . . . . . . . . . . . . . . . 6
5.1. The <intended> datastore . . . . . . . . . . . . . . . . 8
5.2. The <applied> datastore . . . . . . . . . . . . . . . . . 8
5.2.1. Missing Resources . . . . . . . . . . . . . . . . . . 9
5.2.2. System-controlled Resources . . . . . . . . . . . . . 9
5.3. The <operational-state> datastore . . . . . . . . . . . . 9
6. Implications . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. Implications on NETCONF . . . . . . . . . . . . . . . . . 9
6.1.1. Migration Path . . . . . . . . . . . . . . . . . . . 10
6.2. Implications on RESTCONF . . . . . . . . . . . . . . . . 10
6.3. Implications on YANG . . . . . . . . . . . . . . . . . . 11
6.4. Implications on Data Models . . . . . . . . . . . . . . . 11
7. Data Model Design Guidelines . . . . . . . . . . . . . . . . 11
7.1. Auto-configured or Auto-negotiated Values . . . . . . . . 11
8. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 12
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
12.1. Normative References . . . . . . . . . . . . . . . . . . 15
12.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. Example Data . . . . . . . . . . . . . . . . . . . . 16
Appendix B. Open Issues . . . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
This document provides a revised architectural framework for
datastores as they are used by network management protocols such as
NETCONF [RFC6241], RESTCONF [I-D.ietf-netconf-restconf] and the YANG
[RFC7950] data modeling language. Datastores are a fundamental
concept binding management data models to network management
protocols and agreement on a common architectural model of datastores
ensures that data models can be written in a network management
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protocol agnostic way. This architectural framework identifies a set
of conceptual datastores but it does not mandate that all network
management protocols expose all these conceptual datastores.
Furthermore, the architecture does not detail how data is encoded by
network management protocols.
2. Background
NETCONF [RFC6241] provides the following definitions:
o datastore: A conceptual place to store and access information. A
datastore might be implemented, for example, using files, a
database, flash memory locations, or combinations thereof.
o configuration datastore: The datastore holding the complete set of
configuration data that is required to get a device from its
initial default state into a desired operational state.
YANG 1.1 [RFC7950] provides the following refinements when NETCONF is
used with YANG (which is the usual case but note that NETCONF was
defined before YANG did exist):
o datastore: When modeled with YANG, a datastore is realized as an
instantiated data tree.
o configuration datastore: When modeled with YANG, a configuration
datastore is realized as an instantiated data tree with
configuration data.
RFC 6244 defined operational state data as follows:
o Operational state data is a set of data that has been obtained by
the system at runtime and influences the system's behavior similar
to configuration data. In contrast to configuration data,
operational state is transient and modified by interactions with
internal components or other systems via specialized protocols.
Section 4.3.3 of RFC 6244 discusses operational state and among other
things mentions the option to consider operational state as being
stored in another datastore. Section 4.4 of this document then
concludes that at the time of the writing, modeling state as a
separate data tree is the recommended approach.
Implementation experience and requests from operators
[I-D.ietf-netmod-opstate-reqs], [I-D.openconfig-netmod-opstate]
indicate that the datastore model initially designed for NETCONF and
refined by YANG needs to be extended. In particular, the notion of
intended configuration and applied configuration has developed.
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Furthermore, separating operational state data from configuration
data in a separate branch in the data model has been found
operationally complicated. The relationship between the branches is
not machine readable and filter expressions operating on
configuration data and on related operational state data are
different.
3. Terminology
This document defines the following terms:
o configuration data: Data that determines how a device behaves.
Configuration data can originate from different sources. In YANG
1.1, configuration data is the "config true" nodes.
o static configuration data: Configuration data that is eventually
persistent and used to get a device from its initial default state
into its desired operational state.
o dynamic configuration data: Configuration data that is obtained
dynamically during the operation of a device through interaction
with other systems and not persistent.
o system configuration data: Configuration data that is supplied by
the device itself.
o data-model-defined configuration data: Configuration data that is
not explicitly provided but for which a value defined in the data
model is used. In YANG 1.1, such data can be defined with the
"default" statement or in "description" statements.
4. Original Model of Datastores
The following drawing shows the original model of datastores as it is
currently used by NETCONF [RFC6241]:
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+-------------+ +-----------+
| <candidate> | | <startup> |
| (ct, rw) |<---+ +--->| (ct, rw) |
+-------------+ | | +-----------+
| | | |
| +-----------+ |
+-------->| <running> |<--------+
| (ct, rw) |
+-----------+
|
v
operational state <--- control plane
(cf, ro)
ct = config true; cf = config false
rw = read-write; ro = read-only
boxes denote datastores
Note that read-only (ro) and read-write (rw) is to be understood at a
conceptual level. In NETCONF, for example, support for the
<candidate> and <startup> datastores is optional and the <running>
datastore does not have to be writable. Furthermore, the <startup>
datastore can only be modified by copying <running> to <startup> in
the standardized NETCONF datastore editing model. The RESTCONF
protocol does not expose these differences and instead provides only
a writable unified datastore, which hides whether edits are done
through a <candidate> datastore or by directly modifying the
<running> datastore or via some other implementation specific
mechanism. RESTCONF also hides how configuration is made persistent.
Note that implementations may also have additional datastores that
can propagate changes to the <running> datastore. NETCONF explicitly
mentions so called named datastores.
Some observations:
o Operational state has not been defined as a datastore although
there were proposals in the past to introduce an operational state
datastore.
o The NETCONF <get/> operation returns the content of the <running>
configuration datastore together with the operational state. It
is therefore necessary that config false data is in a different
branch than the config true data if the operational state data can
have a different lifetime compared to configuration data or if
configuration data is not immediately or successfully applied.
o Several implementations have proprietary mechanisms that allow
clients to store inactive data in the <running> datastore; this
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inactive data is only exposed to clients that indicate that they
support the concept of inactive data; clients not indicating
support for inactive data receive the content of the <running>
datastore with the inactive data removed. Inactive data is
conceptually removed during validation.
o Some implementations have proprietary mechanisms that allow
clients to define configuration templates in <running>. These
templates are expanded automatically by the system, and the
resulting configuration is applied internally.
o Some operators have reported that it is essential for them to be
able to retrieve the configuration that has actually been
successfully applied, which may be a subset or a superset of the
<running> configuration.
5. Revised Model of Datastores
Below is a new conceptual model of datastores extending the original
model in order reflect the experience gained with the original model.
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+-------------+ +-----------+
| <candidate> | | <startup> |
| (ct, rw) |<---+ +--->| (ct, rw) |
+-------------+ | | +-----------+
| | | |
| +-----------+ |
+-------->| <running> |<--------+
| (ct, rw) |
+-----------+
|
| // e.g., removal of 'inactive'
| // nodes, expansion of templates
v
+------------+
| <intended> | // subject to validation
| (ct, ro) |
+------------+
|
| // e.g., missing resources or
| // delays
v
+-----------+
| <applied> |<---+--- dynamic configuration
| (ct, ro) | | protocols
+-----------+ +--- control-plane datastores
|
| +--- auto-discovery
| +-----+--- control-plane protocols
| | +--- control-plane datastores
v v
+---------------------+
| <operational-state> |
| (ct + cf, ro) |
+---------------------+
ct = config true; cf = config false
rw = read-write; ro = read-only
boxes denote datastores
The model foresees control-plane datastores that are by definition
not part of the persistent configuration of a device. In some
contexts, these have been termed ephemeral datastores since the
information is ephemeral, i.e., lost upon reboot. The control-plane
datastores interact with the rest of the system through the <applied>
or <operational-state> datastores, depending on the type of data they
contain. Note that the ephemeral datastore discussed in I2RS
documents maps to a control-plane datastore in the revised datastore
model described here.
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5.1. The <intended> datastore
The <intended> datastore is a read-only datastore that consists of
config true nodes. It is tightly coupled to <running>. When data is
written to <running>, the data that is to be validated is also
conceptually written to <intended>. Validation is performed on the
contents of <intended>.
On a traditional NETCONF implementation, <running> and <intended> are
always the same.
Currently there are no standard mechanisms defined that affect
<intended> so that it would have different contents than <running>,
but this architecture allows for such mechanisms to be defined.
One example of such a mechanism is support for marking nodes as
inactive in <running>. Inactive nodes are not copied to <intended>,
and are thus not taken into account when validating the
configuration.
Another example is support for templates. Templates are expanded
when copied into <intended>, and the result is validated.
5.2. The <applied> datastore
The <applied> datastore is a read-only datastore that consists of
config true nodes. It contains the currently active configuration on
the device. This data can come from several sources; from
<intended>, from dynamic configuration protocols (e.g., DHCP), or
from control-plane datastores.
As data flows into the <applied> and <operational-state> datastores,
it is conceptually marked with a metadata annotation ([RFC7952]) that
indicates its origin. The "origin" metadata annotation is defined in
Section 8. The values are YANG identities. The following identities
are defined:
+-- origin
+-- static
+-- dynamic
+-- data-model
+-- system
These identities can be further refined, e.g., there might be an
identity "dhcp" derived from "dynamic".
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The <applied> datastore contains the subset of the instances in the
<operational-state> datastore where the "origin" values are derived
from or equal to "static" or "dynamic".
5.2.1. Missing Resources
Sometimes some parts of <intended> configuration refer to resources
that are not present and hence parts of the <intended> configuration
cannot be applied. A typical example is an interface configuration
that refers to an interface that is not currently present. In such a
situation, the interface configuration remains in <intended> but the
interface configuration will not appear in <applied>.
5.2.2. System-controlled Resources
Sometimes resources are controlled by the device and such system
controlled resources appear in (and disappear from) the
<operational-state> dynamically. If a system controlled resource has
matching configuration in <intended> when it appears, the system will
try to apply the configuration, which causes the configuration to
appear in <applied> eventually (if application of the configuration
was successful).
5.3. The <operational-state> datastore
The <operational-state> datastore is a read-only datastore that
consists of config true and config false nodes. In the original
NETCONF model the operational state only had config false nodes. The
reason for incorporating config true nodes here is to be able to
expose all operational settings without having to replicate
definitions in the data models.
The <operational-state> datastore contains all configura data
actually used by the system, i.e., all applied configuration, system
configuration and data-model-defined configuration. This data is
marked with the "origin" metadata annotation. In addition, the
<operational-state> datastore also contains state data.
In the <operational-state> datastore, semantic constraints defined in
the data model are not applied. See Appendix B.
6. Implications
6.1. Implications on NETCONF
o A mechanism is needed to announce support for <intended>,
<applied>, and <operational-state>.
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o Support for <intended>, <applied>, and <operational-state> should
be optional to implement.
o For systems supporting <intended> or <applied> configuration
datastores, the <get-config/> operation may be used to retrieve
data stored in these new datastores.
o A new operation should be added to retrieve the operational state
data store (e.g., <get-state/>). An alternative is to define a
new operation to retrieve data from any datastore (e.g.,
<get-data> with the name of the datastore as a parameter). In
principle <get-config/> could work but it would be a confusing
name.
o The <get/> operation will be deprecated since it returns data from
two datastores that may overlap in the revised datastore model.
6.1.1. Migration Path
A common approach in current data models is to have two separate
trees "/foo" and "/foo-state", where the former contains config true
nodes, and the latter config false nodes. A data model that is
designed for the revised architectural framework presented in this
document will have a single tree "/foo" with a combination of config
true and config false nodes.
A server that implements the <operational-state> datastore can
implement a module of the old design. In this case, some instances
are probably reported both in the "/foo" tree and in the "/foo-state"
tree.
A server that does not implement the <operational-state> datastore
can implement a module of the new design, but with limited
functionality. Specifically, it may not be possible to retrieve all
operationally used instances (e.g., dynamically configured or system-
controlled). The same limitation applies to a client that does not
implement the <operational-state> datastore, but talks to a server
that implements it.
6.2. Implications on RESTCONF
o The {+restconf}/data resource represents the combined
configuration and state data resources that can be accessed by a
client. This is effectively bundling <running> together with
<operational-state>, much like the <get/> operation of NETCONF.
This design should be deprecated.
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o A new query parameter is needed to indicate that data from
<operational-state> is requested.
6.3. Implications on YANG
o Some clarifications may be needed if this revised model is
adopted. YANG currently describes validation in terms of the
<running> configuration datastore while it really happens on the
<intended> configuration datastore.
6.4. Implications on Data Models
o Since the NETCONF <get/> operation returns the content of the
<running> configuration datastore and the operational state
together in one tree, data models were often forced to branch at
the top-level into a config true branch and a structurally similar
config false branch that replicated some of the config true nodes
and added state nodes. With the revised datastore model this is
not needed anymore since the different datastores handle the
different lifetimes of data objects. Introducing this model
together with the deprecation of the <get/> operation makes it
possible to write simpler models.
o There may be some differences in the value set of some nodes that
are used for both configuration and state. At this point of time,
these are considered to be rare cases that can be dealt with using
different nodes for the configured and state values.
o It is important to design data models with clear semantics that
work equally well for instantiation in a configuration datastore
and instantiation in the <operational-state> datastore.
7. Data Model Design Guidelines
7.1. Auto-configured or Auto-negotiated Values
Sometimes configuration leafs support special values that instruct
the system to automatically configure a value. An example is an MTU
that is configured to 'auto' to let the system determine a suitable
MTU value. Another example is Ethernet auto-negotiation of link
speed. In such a situation, it is recommended to model this as two
separate leafs, one config true leaf for the input to the auto-
negotiation process, and one config false leaf for the output from
the process.
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8. Data Model
<CODE BEGINS> file "ietf-yang-architecture@2016-10-13.yang"
module ietf-yang-architecture {
namespace "urn:ietf:params:xml:ns:yang:ietf-yang-architecture";
prefix arch;
import ietf-yang-metadata {
prefix md;
}
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
Editor: Martin Bjorklund
<mailto:mbj@tail-f.com>";
description
"This YANG module defines an 'origin' metadata annotation,
and a set of identities for the origin value. The 'origin'
metadata annotation is used to mark data in the applied
and operational state datastores with information on where
the data originated.
Copyright (c) 2016 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
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(http://www.rfc-editor.org/info/rfcxxxx); see the RFC itself
for full legal notices.";
revision 2016-10-13 {
description
"Initial revision.";
reference
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"RFC XXXX: A Revised Conceptual Model for YANG Datastores";
}
/*
* Identities
*/
identity origin {
description
"Abstract base identitiy for the origin annotation.";
}
identity static {
base origin;
description
"Denotes data from static configuration (e.g., <intended>).";
}
identity dynamic {
base origin;
description
"Denotes data from dynamic configuration protocols
or dynamic datastores (e.g., DHCP).";
}
identity system {
base origin;
description
"Denotes data created by the system independently of what
has been configured.";
}
identity data-model {
base origin;
description
"Denotes data that does not have an explicitly configured
value, but has a default value in use. Covers both simple
defaults and complex defaults.";
}
/*
* Metadata annotations
*/
md:annotation origin {
type identityref {
base origin;
}
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}
}
<CODE ENDS>
9. IANA Considerations
TBD
10. Security Considerations
This document discusses a conceptual model of datastores for network
management using NETCONF/RESTCONF and YANG. It has no security
impact on the Internet.
11. Acknowledgments
This document grew out of many discussions that took place since
2010. Several Internet-Drafts ([I-D.bjorklund-netmod-operational],
[I-D.wilton-netmod-opstate-yang], [I-D.ietf-netmod-opstate-reqs],
[I-D.kwatsen-netmod-opstate], [I-D.openconfig-netmod-opstate]) and
[RFC6244] touched on some of the problems of the original datastore
model. The following people were authors to these Internet-Drafts or
otherwise actively involved in the discussions that led to this
document:
o Lou Berger, LabN Consulting, L.L.C., <lberger@labn.net>
o Andy Bierman, YumaWorks, <andy@yumaworks.com>
o Marcus Hines, Google, <hines@google.com>
o Christian Hopps, Deutsche Telekom, <chopps@chopps.org>
o Acee Lindem, Cisco Systems, <acee@cisco.com>
o Ladislav Lhotka, CZ.NIC, <lhotka@nic.cz>
o Thomas Nadeau, Brocade Networks, <tnadeau@lucidvision.com>
o Anees Shaikh, Google, <aashaikh@google.com>
o Rob Shakir, Google, <robjs@google.com>
Juergen Schoenwaelder was partly funded by Flamingo, a Network of
Excellence project (ICT-318488) supported by the European Commission
under its Seventh Framework Programme.
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12. References
12.1. Normative References
[I-D.ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", draft-ietf-netconf-restconf-18 (work in
progress), October 2016.
[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,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<http://www.rfc-editor.org/info/rfc7950>.
[RFC7952] Lhotka, L., "Defining and Using Metadata with YANG",
RFC 7952, DOI 10.17487/RFC7952, August 2016,
<http://www.rfc-editor.org/info/rfc7952>.
12.2. Informative References
[I-D.bjorklund-netmod-operational]
Bjorklund, M. and L. Lhotka, "Operational Data in NETCONF
and YANG", draft-bjorklund-netmod-operational-00 (work in
progress), October 2012.
[I-D.ietf-netmod-opstate-reqs]
Watsen, K. and T. Nadeau, "Terminology and Requirements
for Enhanced Handling of Operational State", draft-ietf-
netmod-opstate-reqs-04 (work in progress), January 2016.
[I-D.kwatsen-netmod-opstate]
Watsen, K., Bierman, A., Bjorklund, M., and J.
Schoenwaelder, "Operational State Enhancements for YANG,
NETCONF, and RESTCONF", draft-kwatsen-netmod-opstate-02
(work in progress), February 2016.
[I-D.openconfig-netmod-opstate]
Shakir, R., Shaikh, A., and M. Hines, "Consistent Modeling
of Operational State Data in YANG", draft-openconfig-
netmod-opstate-01 (work in progress), July 2015.
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[I-D.wilton-netmod-opstate-yang]
Wilton, R., ""With-config-state" Capability for NETCONF/
RESTCONF", draft-wilton-netmod-opstate-yang-02 (work in
progress), December 2015.
[RFC6244] Shafer, P., "An Architecture for Network Management Using
NETCONF and YANG", RFC 6244, DOI 10.17487/RFC6244, June
2011, <http://www.rfc-editor.org/info/rfc6244>.
Appendix A. Example Data
In this example, the following fictional module is used:
module example-system {
yang-version 1.1;
namespace urn:example:system;
prefix sys;
import ietf-inet-types {
prefix inet;
}
container system {
leaf hostname {
type string;
}
list interface {
key name;
leaf name {
type string;
}
container auto-negotiation {
leaf enabled {
type boolean;
default true;
}
leaf speed {
type uint32;
units mbps;
description
"The advertised speed, in mbps.";
}
}
leaf speed {
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type uint32;
units mbps;
config false;
description
"The speed of the interface, in mbps.";
}
list address {
key ip;
leaf ip {
type inet:ip-address;
}
leaf prefix-length {
type uint8;
}
}
}
}
}
The operator has configured the host name and two interfaces, so the
contents of <intended> is:
<system xmlns="urn:example:system">
<hostname>foo</hostname>
<interface>
<name>eth0</name>
<auto-negotiation>
<speed>1000</speed>
</auto-negotiation>
<address>
<ip>2001:db8::10</ip>
<prefix-length>32</prefix-length>
</address>
</interface>
<interface>
<name>eth1</name>
<address>
<ip>2001:db8::20</ip>
<prefix-length>32</prefix-length>
</address>
</interface>
</system>
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The system has detected that the hardware for one of the configured
interfaces ("eth1") is not yet present, so the configuration for that
interface is not applied. Further, the system has received a host
name and an additional IP address for "eth0" over DHCP. This is
reflected in <applied>:
<system
xmlns="urn:example:system"
xmlns:arch="urn:ietf:params:xml:ns:yang:ietf-yang-architecture">
<hostname arch:origin="arch:dynamic">bar</hostname>
<interface arch:origin="arch:static">
<name>eth0</name>
<auto-negotiation>
<speed>1000</speed>
</auto-negotiation>
<address>
<ip>2001:db8::10</ip>
<prefix-length>32</prefix-length>
</address>
<address arch:origin="arch:dynamic">
<ip>2001:db8::1:100</ip>
<prefix-length>32</prefix-length>
</address>
</interface>
</system>
In <operational-state>, all data from <applied> is present, in
addition to a default value, a loopback interface automatically added
by the system, and the result of the "speed" auto-negotiation:
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<system
xmlns="urn:example:system"
xmlns:arch="urn:ietf:params:xml:ns:yang:ietf-yang-architecture">
<hostname arch:origin="arch:dynamic">bar</hostname>
<interface arch:origin="arch:static">
<name>eth0</name>
<auto-negotiation>
<enabled arch:origin="arch:data-model">true</enabled>
<speed>1000</speed>
</auto-negotiation>
<speed>100</speed>
<address>
<ip>2001:db8::10</ip>
<prefix-length>32</prefix-length>
</address>
<address arch:origin="arch:dynamic">
<ip>2001:db8::1:100</ip>
<prefix-length>32</prefix-length>
</address>
</interface>
<interface arch:origin="arch:system">
<name>lo0</name>
<address>
<ip>::1</ip>
<prefix-length>128</prefix-length>
</address>
</interface>
</system>
Appendix B. Open Issues
1. Do we need another DS <active> inbetween <running> and
<intended>? This DS would allow a client to see all active
nodes, including unexpanded templates.
2. How do we handle semantical constraints in <operational-state>?
Are they just ignored? Do we need a new YANG statement to define
if a "must" constraints applies to the <operational-state>?
3. Should it be possible to ask for <applied> in RESTCONF?
4. Better name for "static configuration"?
5. Better name for "intended"?
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Authors' Addresses
Martin Bjorklund (editor)
Tail-f Systems
Email: mbj@tail-f.com
Juergen Schoenwaelder
Jacobs University
Email: j.schoenwaelder@jacobs-university.de
Phil Shafer
Juniper
Email: phil@juniper.net
Kent Watsen
Juniper
Email: kwatsen@juniper.net
Rob Wilton
Cisco
Email: rwilton@cisco.com
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