| TOC |
|
The NETCONF protocol defines ways to read and edit configuration data from a NETCONF server. Part of this data may not be set by the NETCONF client, but rather a default value is used. In many situations the NETCONF client has a priori knowledge about default data, so the NETCONF server does not need to save it in a NETCONF datastore or send it to the client in a retrieval operation reply. In other situations the NETCONF client will need this data as part of the NETCONF <rpc-reply> messages. Not all server implementations treat this default data the same way. This document defines a capability-based extension to the NETCONF protocol that allows the NETCONF client to identify how defaults are handled by the server, and control whether default values are part of NETCONF <rpc-reply> messages or <copy-config> output to a file.
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 November 21, 2010.
Copyright (c) 2010 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 (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.
1.
Introduction
1.1.
Terminology
1.2.
Defaults Handling Behavior
1.3.
Client Controlled Retrieval of Default Data
2.
Defaults Handling Basic Modes
2.1.
'report-all' Basic Mode
2.1.1.
'report-all' Basic Mode Retrieval
2.1.2.
'report-all' <with-defaults> Retrieval
2.1.3.
'report-all' <edit-config> Behavior
2.1.4.
'report-all' Non-volatile Storage Behavior
2.2.
'trim' Basic Mode
2.2.1.
'trim' Basic Mode Retrieval
2.2.2.
'trim' <with-defaults> Retrieval
2.2.3.
'trim' <edit-config> Behavior
2.2.4.
'trim' Non-volatile Storage Behavior
2.3.
'explicit' Basic Mode
2.3.1.
'explicit' Basic Mode Retrieval
2.3.2.
'explicit' <with-defaults> Retrieval
2.3.3.
'explicit' <edit-config> Behavior
2.3.4.
'explicit' Non-volatile Storage Behavior
3.
Retrieval of Default Data
3.1.
'report-all-tagged' Retrieval Mode
4.
With-defaults Capability
4.1.
Overview
4.2.
Dependencies
4.3.
Conformance
4.4.
Capability Identifier
4.5.
New Operations
4.6.
Modifications to Existing Operations
4.6.1.
<get>, <get-config>, and <copy-config> Operations
4.6.2.
<edit-config> Operation
4.6.3.
Other Operations
4.7.
Interactions with Other Capabilities
5.
YANG Module for the <with-defaults> Parameter
6.
XSD for the 'wd:default' Attribute
7.
IANA Considerations
8.
Security Considerations
9.
Acknowledgements
10.
Normative References
Appendix A.
Usage Examples
A.1.
Example YANG Module
A.2.
Example Data Set
A.3.
Protocol Operation Examples
A.3.1.
<with-defaults> = 'report-all'
A.3.2.
<with-defaults> = 'report-all-tagged'
A.3.3.
<with-defaults> = 'trim'
A.3.4.
<with-defaults> = 'explicit'
Appendix B.
Change Log
B.1.
07-08
B.2.
06-07
B.3.
05-06
B.4.
04-05
B.5.
03-04
B.6.
02-03
B.7.
01-02
B.8.
00-01
B.9.
-00
§
Authors' Addresses
| TOC |
The NETCONF protocol [RFC4741] (Enns, R., “NETCONF Configuration Protocol,” December 2006.) defines ways to read configuration and state data from a NETCONF server. Part of the configuration data may not be set by the NETCONF client, but rather by a default value from the data model. In many situations the NETCONF client has a priori knowledge about default data, so the NETCONF server does not need to send it to the client. A priori knowledge can be e.g., a document formally describing the data models supported by the NETCONF server.
It can be important for a client to know exactly how a server implementation will handle default data. There are subtle differences in some protocol operations where the defaults handling behavior of the server will affect the outcome of the operation.
| TOC |
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.).
- Data model schema:
- A document or set of documents describing the data models supported by the NETCONF server.
- Management Application:
- A computer program running outside the NETCONF server that configures or supervises the NETCONF server. A management application can reach the device e.g. via NETCONF, CLI or SNMP.
- Schema default data:
- Data specified in the data model schema as default, that is set or used by the device whenever the NETCONF client or other management application/user does not provide a specific value for the relevant data item. Schema default data MAY or may not be stored as part of a configuration datastore, depending on the basic mode used by a particular server.
- Default data:
- Data considered by a particular server to contain a default value. Default data is not kept in a configuration datastore.
- Explicitly set data:
- Data that is set to any value by a NETCONF client or other management application by the way of an actual management operation, including any data model schema default value. Any value set by the NETCONF server which is not the schema defined default value is also considered explicitly set data.
The following terms are defined in [RFC4741] (Enns, R., “NETCONF Configuration Protocol,” December 2006.):
The following term is defined in [I‑D.ietf‑netmod‑yang] (Bjorklund, M., “YANG - A data modeling language for NETCONF,” April 2010.):
| TOC |
The defaults handling behavior used by a server will
impact NETCONF protocol operations in three ways:
| TOC |
A networking device may have a large number of default values. Often the default values are not interesting or specifically defined with a "reasonable" value, so that the management user does not have to handle them. For these reasons it is quite common for networking devices to suppress the output of parameters having the default value.
However, there are use-cases when a NETCONF client
will need the default data from the server:
In all these cases the NETCONF client will need default
data as part of the NETCONF <rpc-reply> messages.
This document defines a NETCONF protocol capability to identify
the server defaults handling behavior, and a YANG module extension to
the NETCONF protocol that allows the NETCONF client to control whether
default data is returned in certain NETCONF <rpc-reply> messages.
| TOC |
Not all server implementations treat default data in the same way. Instead of forcing a single implementation strategy, this document allows a server to advertise a particular style of defaults handling, and the client can adjust accordingly.
NETCONF servers report default data in different ways. This
document specifies three standard defaults handling
basic modes that a server implementor may choose from:
A server MUST select one of the three basic modes defined in this section for handling default data.
| TOC |
A server which uses the 'report-all' basic mode does not consider any data node to be default data.
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All data nodes MUST be reported.
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All data nodes MUST be reported, including any data nodes considered to be default data by the server.
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The server MUST consider every data node to exist,
even those represented by a schema default value.
| TOC |
All data nodes MUST be saved in non-volatile storage.
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A server which uses the 'trim' basic mode MUST consider any data node set to its schema default value to be default data.
| TOC |
Data nodes MUST NOT be reported if they match the schema default value. Non-configuration data nodes containing the schema default value MUST NOT be reported.
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Data nodes MUST NOT be reported if they match the schema default value. Non-configuration data nodes containing the schema default value MUST NOT be reported.
| TOC |
The server MUST consider any data node
that does not contain its schema default value to exist.
If the server supports the 'report-all-tagged' retrieval mode in its with-defaults capability, then the 'wd:default' attribute MUST be accepted in configuration input. If all NETCONF sub-operation parameters are valid, then the server will treat a tagged data node as a request to return that node to default data. If this request is valid within the context of the requested NETCONF operation, then the data node is removed and returned to its default value. If the data node within the NETCONF message contains a value in this case, it MUST be equal to the schema default value.
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All data nodes, except those set to their schema default value, MUST be saved in non-volatile storage.
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A server which uses the 'explicit' basic mode MUST consider any data node that is not explicitly set data to be default data.
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If a client set a data node to its schema default value, it MUST always be reported. If the server set a data node to its schema default value, it MUST NOT be reported. Non-configuration data nodes containing the schema default value MUST be reported.
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If a client set a data node to its schema default value, it MUST be reported. If the server set a data node to its schema default value, it MUST NOT be reported. Non-configuration data nodes containing the schema default value MUST be reported.
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The server considers any data node
that is explicitly set data to exist.
If the server supports the 'report-all-tagged' retrieval mode in its with-defaults capability, then the 'wd:default' attribute MUST be accepted in configuration input. If all NETCONF sub-operation parameters are valid, then the server will treat a tagged data node as a request to return that node to default data. If this request is valid within the context of the requested NETCONF operation, then the data node is removed and returned to its default value. If the data node within the NETCONF message contains a value in this case, it MUST be equal to the schema default value.
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All data nodes that are explicitly set data MUST be saved in non-volatile storage.
| TOC |
This document defines a new parameter, called <with-defaults>, which can be added to specific NETCONF operation request messages to control how retrieval of default data is treated by the server.
The server MUST accept the <with-defaults> parameter containing the enumeration for any of the defaults handling modes it supports, as defined in Section 5 (YANG Module for the <with-defaults> Parameter).
The <with-defaults> parameter contains one of the three basic mode enumerations defined above, to request that the retrieval operation be performed using the specified defaults handling basic mode.
| TOC |
In addition to the basic modes, a special variant of 'report-all' basic mode is available called 'report-all-tagged'. This mode MUST be supported on a server if the 'also-supported' parameter in the 'with-defaults' capability contains the 'report-all-tagged' option. Refer to Section 4 (With-defaults Capability) for encoding details for this capability.
In this mode the server returns all data nodes, just like the 'report-all' mode, except a data node that is considered by the server to contain default data will include an XML attribute to indicate this condition. This is useful for an application to determine which nodes are considered to contain default data by the server, within a single retrieval operation.
A server which supports 'report-all-tagged' MUST also accept the 'wd:default' XML attribute it is present within configuration input to the <edit-config> or <copy-config> operations. Refer to Section 6 (XSD for the 'wd:default' Attribute) for XML encoding details of the 'wd:default' XML attribute.
| TOC |
| TOC |
The :with-defaults capability indicates that the NETCONF server supports a specific defaults handling basic mode. It may also indicate support for additional defaults retrieval modes. These retrieval modes allow a NETCONF client to control whether default data is part of NETCONF <rpc-reply> messages. The capability affects both configuration and state data (while acknowledging that the usage of default values for state data is less prevalent). Sending of default data is controlled for each individual operation separately.
A NETCONF server implementing the :with-defaults capability:
| TOC |
None
| TOC |
Every NETCONF server SHOULD implement this capability.
| TOC |
urn:ietf:params:netconf:capability:with-defaults:1.0
The identifier MUST have a parameter: "basic-mode". This indicates how
the server will treat default data, as defined in
Section 2 (Defaults Handling Basic Modes).
The allowed values of this parameter are 'report-all', 'trim', and 'explicit', as defined in Section 2 (Defaults Handling Basic Modes).
The identifier MAY have another parameter: "also-supported". This parameter indicates which additional default handling modes the server supports. The value of the parameter is a comma separated list of one or more modes that are supported beside the mode indicated in the 'basic-mode' parameter. Possible modes are 'report-all', 'report-all-tagged', 'trim', and 'explicit', as defined in Section 5 (YANG Module for the <with-defaults> Parameter).
Note that this protocol capability URI is separate from the YANG module capability URI for the YANG module in Section 5 (YANG Module for the <with-defaults> Parameter). A server which implements this module MUST also advertise a YANG module capability URI according to the rules specified in [I‑D.ietf‑netmod‑yang] (Bjorklund, M., “YANG - A data modeling language for NETCONF,” April 2010.).
Examples:
urn:ietf:params:netconf:capability:with-defaults:1.0?basic-mode=explicit
urn:ietf:params:netconf:capability:with-defaults:1.0?basic-mode=explicit&also-supported=report-all,report-all-tagged
| TOC |
None
| TOC |
| TOC |
A new <with-defaults> XML element is added to the input for the <get>, <get-config> and <copy-config> operations. If the <with-defaults> element is present, it controls the reporting of default data. The server MUST return default data in the NETCONF <rpc-reply> messages according to the value of this element, if the server supports the specified retrieval mode.
This parameter only controls these specified retrieval operations, and does not impact any other operations or the non-volatile storage of configuration data.
The <with-defaults> element is defined in the XML namespace for the ietf-netconf-with-defaults.yang module in Section 5 (YANG Module for the <with-defaults> Parameter), not the XML namespace for the <get>, <get-config> and <copy-config> operations.
Allowed values of the with-defaults element are taken from the list in Section 2 (Defaults Handling Basic Modes). The allowed values are restricted to the values that the device indicates it supports within the with-defaults capability, in the 'basic-mode' and 'also-supported' parameters.
If an unsupported value is used, the NETCONF server MUST return an <rpc-reply> with an <rpc-error> element. The <error-tag> SHOULD be 'invalid-value', and the <error-app-tag> SHOULD be 'with-defaults-mode-not-supported'.
If the <with-defaults> element is not present, the server MUST follow its basic mode behavior as indicated by the with-defaults capability identifier's 'basic-mode' parameter, defined in Section 4.4 (Capability Identifier).
The <copy-config> operation is only affected if the target of the operation is specified with the <url> parameter. If the target is a NETCONF datastore (i.e., running, candidate or startup), the capability has no effect. The server MUST use its basic mode when copying data to a NETCONF datastore. If the with-defaults parameter is present in this case, it MUST be silently ignored by the server.
| TOC |
The <edit-config> operation has four sub-operations. The 'create' and 'delete' sub-operations are affected by the defaults handling basic mode.
The 'create' sub-operation MUST fail with a 'data-exists' error-tag value if the server considers the target data node to already have a current value.
If the client sets a data node to its schema default value, the server MUST accept the request if it is valid. The server MUST keep or discard the new value based on its defaults handling basic mode. For the 'trim' basic mode, all schema default values are discarded, otherwise a client-provided schema default value is saved in a NETCONF datastore.
If the server supports the 'report-all-tagged' mode, then the 'wd:default' attribute defined in Section 6 (XSD for the 'wd:default' Attribute) also impacts the edit-config operation. If the wd:default attribute is present and set to 'true', then the server MUST treat the new data node as a request to return that node to its default value (i.e., remove it from the database).
If this editing mode is used, then the effective sub-operation for the target data node MUST be 'create', 'merge' or 'replace'. If 'create' is the effective sub-operation, then the create request must be valid on its own (e.g., current data node MUST NOT exist). The procedure for determining the effective sub-operation is defined in [I‑D.ietf‑netconf‑4741bis] (Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, “Network Configuration Protocol (NETCONF),” February 2010.). It is derived from the 'default-operation' parameter and/or any 'nc:operation' attribute that are present in the data node or any of its ancestor nodes, within the <edit-config> request message.
| TOC |
Other operations that return configuration data SHOULD also handle default data according to the rules set in this document, and explicitly state this in their documentation. If this is not specified in the document defining the respective operation, the default handling rules described herein do not affect these operations.
| TOC |
None
| TOC |
The following YANG module defines the addition of the with-defaults element to the <get>, <get-config> and <copy-config> operations. The YANG language is defined in [I‑D.ietf‑netmod‑yang] (Bjorklund, M., “YANG - A data modeling language for NETCONF,” April 2010.). The above operations are defined in YANG in [I‑D.ietf‑netconf‑4741bis] (Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, “Network Configuration Protocol (NETCONF),” February 2010.). Every NETCONF server which supports the :with-defaults capability MUST implement this YANG module.
<CODE BEGINS> file="ietf-netconf-with-defaults@2010-05-19.yang"
module ietf-netconf-with-defaults {
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults";
prefix nwd;
import ietf-netconf { prefix nc; }
organization
"IETF NETCONF (Network Configuration Protocol) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
WG Chair: Bert Wijnen
<mailto:bertietf@bwijnen.net>
WG Chair: Mehmet Ersue
<mailto:mehmet.ersue@nsn.com>
Editor: Andy Bierman
<mailto:andyb@iwl.com>
Editor: Balazs Lengyel
<mailto:balazs.lengyel@ericsson.com>";
description
"This module defines a capability-based extension to the
NETCONF protocol that allows the NETCONF client to control
whether default values are part of NETCONF
<rpc-reply> messages or <copy-config> output to the target URL.
Copyright (c) 2010 IETF Trust and the persons identified as
the document authors. 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; see
the RFC itself for full legal notices.";
// RFC Ed.: replace XXXX with actual RFC number and remove this note
// RFC Ed.: remove this note
// Note: extracted from draft-ietf-netmod-with-defaults-08.txt
revision 2010-05-19 {
description
"Initial version.";
reference
"RFC XXXX: With-defaults capability for NETCONF";
}
// RFC Ed.: replace XXXX with actual RFC number and remove this note
typedef with-defaults-mode {
description
"Possible modes to report default data in
rpc-reply messages.";
type enumeration {
enum report-all {
description
"All default data is reported.";
}
enum report-all-tagged {
description
"All default data is reported.
Any nodes considered to be default data
will contain a 'wd:default' XML attribute,
set to 'true'.";
}
enum trim {
description
"Values are not reported if they match the default.";
}
enum explicit {
description
"Report values that match the definition of
explicitly set data.";
}
}
}
grouping with-defaults-parameters {
leaf with-defaults {
description
"The explicit defaults processing mode requested.";
type with-defaults-mode;
}
}
// extending the get-config operation
augment /nc:get-config/nc:input {
uses with-defaults-parameters;
}
// extending the get operation
augment /nc:get/nc:input {
uses with-defaults-parameters;
}
// extending the copy-config operation
augment /nc:copy-config/nc:input {
uses with-defaults-parameters;
}
}
<CODE ENDS>
| TOC |
The following XML Schema document defines the 'default' attribute, described within this document. This XSD is only relevant if the server supports the 'report-all-tagged' defaults retrieval mode.
<CODE BEGINS> file="defaults.xsd"
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns="urn:ietf:params:xml:ns:netconf:default:1.0"
targetNamespace="urn:ietf:params:xml:ns:netconf:default:1.0"
elementFormDefault="qualified"
attributeFormDefault="unqualified"
xml:lang="en">
<xs:annotation>
<xs:documentation>
This schema defines the syntax for the 'default' attribute
described within this document.
</xs:documentation>
</xs:annotation>
<!--
default attribute
-->
<xs:attribute name="default"
type="xs:boolean"
form="qualified"
default="false">
<xs:annotation>
<xs:documentation>
This attribute indicates whether the data node represented
by the XML element containing this attribute is considered
by the server to be default data. If set to 'true' then
the data node is default data. If 'false', then the
data node is not default data.
</xs:documentation>
</xs:annotation>
</xs:attribute>
</xs:schema>
<CODE ENDS>
| TOC |
This document registers the following capability identifier
URN in the 'Network Configuration Protocol
Capability URNs registry':
urn:ietf:params:netconf:capability:with-defaults:1.0
Note that the capability URN is compliant to
[RFC4741] (Enns, R., “NETCONF Configuration Protocol,” December 2006.) section 10.3.
This document registers two XML namespace URNs
in the 'IETF XML registry', following the format
defined in [RFC3688] (Mealling, M., “The IETF XML Registry,” January 2004.).
URI: urn:ietf:params:xml:ns:netconf:default:1.0
URI: urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URIs are XML namespaces.
This document registers one module name
in the 'YANG Module Names' registry,
defined in [I‑D.ietf‑netmod‑yang] (Bjorklund, M., “YANG - A data modeling language for NETCONF,” April 2010.) .
name: ietf-netconf-with-defaults
prefix: nwd
namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults
RFC: XXXX // RFC Ed.: replace XXXX and remove this comment
| TOC |
This document defines a minor extension to existing NETCONF protocol operations. It does not introduce any new or increased security risks into the management system.
The 'with-defaults' capability gives client control over the retrieval of particular types of XML data from a configuration datastore. They only suppress data that can already be retrieved with the standard protocol operations, and do not add any data to the configuration datastore.
| TOC |
Thanks to Martin Bjorklund, Sharon Chisholm, Phil Shafer, Juergen Schoenwaelder, Washam Fan and many other members of the NETCONF WG for providing important input to this document.
| TOC |
| [RFC2119] | Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML). |
| [RFC3688] | Mealling, M., “The IETF XML Registry,” BCP 81, RFC 3688, January 2004 (TXT). |
| [RFC4741] | Enns, R., “NETCONF Configuration Protocol,” RFC 4741, December 2006 (TXT). |
| [I-D.ietf-netconf-4741bis] | Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, “Network Configuration Protocol (NETCONF),” draft-ietf-netconf-4741bis-02 (work in progress), February 2010 (TXT). |
| [I-D.ietf-netmod-yang] | Bjorklund, M., “YANG - A data modeling language for NETCONF,” draft-ietf-netmod-yang-12 (work in progress), April 2010 (TXT). |
| [W3C.REC-xml-20081126] | Yergeau, F., Maler, E., Bray, T., Paoli, J., and C. Sperberg-McQueen, “Extensible Markup Language (XML) 1.0 (Fifth Edition),” World Wide Web Consortium Recommendation REC-xml-20081126, November 2008 (HTML). |
| TOC |
| TOC |
The following YANG module defines an example interfaces table to demonstrate how the <with-defaults> parameter behaves for a specific data model.
Note that this is not a real module, and implementation of this module is not required for conformance to the :with-defaults protocol capability, defined in Section 4 (With-defaults Capability). This module is not to be registered with IANA, and is not considered to be a code component. It is intentionally very terse, and includes few descriptive statements.
module example {
namespace "http://example.com/ns/interfaces";
prefix exam;
typedef itf-status-type {
description "Interface status";
type enumeration {
enum ok;
enum 'waking up';
enum 'not feeling so good';
enum 'better check it out';
enum 'better call for help';
}
default ok;
}
container interfaces {
description "Example interfaces group";
list interface {
description "Example interface entry";
key name;
leaf name {
description
"The administrative name of the interface.
This is an identifier which is only unique
within the scope of this list, and only
within a specific server.";
type string {
length "1 .. max";
}
}
leaf mtu {
description
"The maximum transmission unit (MTU) value assigned to
this interface.";
type uint32;
default 1500;
}
leaf itf-status {
description
"The current status of this interface.";
type itf-status-type;
config false;
}
}
}
}
| TOC |
The following data element shows the conceptual contents of the example server for the protocol operation examples in the next section. This includes all the configuration data nodes, non-configuration data nodes, and default leafs.
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<interfaces xmlns="http://example.com/ns/interfaces">
<interface>
<name>eth0</name>
<mtu>8192</mtu>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth1</name>
<mtu>1500</mtu>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth2</name>
<mtu>9000</mtu>
<itf-status>not feeling so good</itf-status>
</interface>
<interface>
<name>eth3</name>
<mtu>1500</mtu>
<itf-status>waking up</itf-status>
</interface>
</interfaces>
</data>
In this example, the 'mtu' field for each interface entry is set in the following manner:
| name | set by | mtu |
|---|---|---|
| eth0 | client | 8192 |
| eth1 | server | 1500 |
| eth2 | client | 9000 |
| eth3 | client | 1500 |
| TOC |
The following examples shows some <get> operations using the 'with-defaults' element. The data model used for these examples is defined in Appendix A.1 (Example YANG Module).
The client is retrieving all the data nodes within the 'interfaces' object, filtered with the <with-defaults> parameter.
| TOC |
The behavior of the <with-defaults> parameter handling for the value 'report-all' is demonstrated in this example.
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<interfaces xmlns="http://example.com/ns/interfaces"/>
</filter>
<with-defaults
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults">
report-all
</with-defaults>
</get>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<interfaces xmlns="http://example.com/ns/interfaces">
<interface>
<name>eth0</name>
<mtu>8192</mtu>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth1</name>
<mtu>1500</mtu>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth2</name>
<mtu>9000</mtu>
<itf-status>not feeling so good</itf-status>
</interface>
<interface>
<name>eth3</name>
<mtu>1500</mtu>
<itf-status>waking up</itf-status>
</interface>
</interfaces>
</data>
</rpc-reply>
| TOC |
The behavior of the <with-defaults> parameter handling for the value 'report-all-tagged' is demonstrated in this example. A 'tagged' data node is an element that contains the wd:default XML attribute, set to 'true'. Any subtrees within the element are also considered to be tagged as dafault data.
The actual data nodes tagged by the server depends on the defaults handling basic mode used by the server. Only the data nodes that are considered to be default data will be tagged.
In this example, the server's basic mode is equal to 'trim', so all data nodes that would contain the schema default value are tagged. If the server's basic mode is 'explicit', then only data nodes that are not explicitly set data are tagged. If the server's basic mode is 'report-all', then no data nodes are tagged.
<rpc message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<interfaces xmlns="http://example.com/ns/interfaces"/>
</filter>
<with-defaults
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults">
report-all-tagged
</with-defaults>
</get>
</rpc>
<rpc-reply message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
xmlns:wd="urn:ietf:params:xml:ns:netconf:default:1.0">
<data>
<interfaces xmlns="http://example.com/ns/interfaces">
<interface>
<name>eth0</name>
<mtu>8192</mtu>
<itf-status wd:default="true">up</itf-status>
</interface>
<interface>
<name>eth1</name>
<mtu wd:default="true">1500</mtu>
<itf-status wd:default="true">up</itf-status>
</interface>
<interface>
<name>eth2</name>
<mtu>9000</mtu>
<itf-status>not feeling so good</itf-status>
</interface>
<interface>
<name>eth3</name>
<mtu wd:default="true">1500</mtu>
<itf-status>waking up</itf-status>
</interface>
</interfaces>
</data>
</rpc-reply>
| TOC |
The behavior of the <with-defaults> parameter handling for the value 'trim' is demonstrated in this example.
<rpc message-id="103"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<interfaces xmlns="http://example.com/ns/interfaces"/>
</filter>
<with-defaults
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults">
trim
</with-defaults>
</get>
</rpc>
<rpc-reply message-id="103"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<interfaces xmlns="http://example.com/ns/interfaces">
<interface>
<name>eth0</name>
<mtu>8192</mtu>
</interface>
<interface>
<name>eth1</name>
</interface>
<interface>
<name>eth2</name>
<mtu>9000</mtu>
<itf-status>not feeling so good</itf-status>
</interface>
<interface>
<name>eth3</name>
<itf-status>waking up</itf-status>
</interface>
</interfaces>
</data>
</rpc-reply>
| TOC |
The behavior of the <with-defaults> parameter handling for the value 'explicit' is demonstrated in this example.
<rpc message-id="104"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<interfaces xmlns="http://example.com/ns/interfaces"/>
</filter>
<with-defaults
xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-with-defaults">
explicit
</with-defaults>
</get>
</rpc>
<rpc-reply message-id="104"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<interfaces xmlns="http://example.com/ns/interfaces">
<interface>
<name>eth0</name>
<mtu>8192</mtu>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth1</name>
<itf-status>up</itf-status>
</interface>
<interface>
<name>eth2</name>
<mtu>9000</mtu>
<itf-status>not feeling so good</itf-status>
</interface>
<interface>
<name>eth3</name>
<mtu>1500</mtu>
<itf-status>waking up</itf-status>
</interface>
</interfaces>
</data>
</rpc-reply>
| TOC |
-- RFC Ed.: remove this section before publication.
| TOC |
Added report-all-tagged mode.
Changed conformance so report-all or report-all-tagged mode SHOULD be supported.
Clarified capability requirements for each mode, for edit-config and NV storage requirements.
Changed rpc-error details for unsupported with-defaults value.
Added XSD for wd:default attribute
Expanded example to show report-all-tagged for a basic-mode=trim server.
| TOC |
Removed text in capability identifier section about adding YANG module capability URI parameters.
Changed YANG module namespace to match YANG format, and updated examples to use this new namespace.
Fixed some typos.
| TOC |
Removed ':1.0' from capability URI.
Removed open issues section because all known issues are closed.
Moved examples to a separate appendix, and expanded them.
Added example.yang as an appendix to properly explain the examples used within the document.
Replaced normative term 'SHALL' with 'MUST' to be consistent within this document.
Clarified <with-defaults> behavior for non-configuration data nodes.
Clarified various sections based on WGLC comments on mailing list.
Removed some unused terms.
Reversed the order of the change log sections so the most recent changes are shown first.
| TOC |
Updated I-D and YANG module boiler-plate.
Removed redundant 'with-defaults' YANG feature.
Changed definition of 'explicit' mode to match the YANG definition
Removed XSD because the YANG is normative and the XSD is unconstrained, and does not properly extend the 3 affected NETCONF operations.
Made the YANG module a normative section instead of non-normative appendix.
Changed YANG from an informative to a normative reference,
Changed 4741bis from an informative to a normative reference because the YANG module imports the ietf-netconf module in order to augment some operations.
Updated capability requirements to include YANG module capability parameters.
Added a description statement to the with-defaults leaf definition.
Update open issues section; ready to close all open issues.
| TOC |
Clarifications
Added non-netconf interfaces to the definition of explicitly set default data
| TOC |
Clarifications
YAM added
Use the same URN for the capability and the XML namespace to accommodate YANG, and avoid two separate URN/URIs being advertised in the HELLO message, for such a small function.
| TOC |
report-all made mandatory
Placeholder for YAM added, XSD will be removed when 4741 provides the NETCONF YAM
with-defaults is valid for state data as well (if state data has a defined default which might not be so frequent). The definition of explicit was modified for state data.
| TOC |
Changed value set of with-default capability and element
Added version to URI
| TOC |
Created from draft-bierman-netconf-with-defaults-01.txt
It was decided by the NETCONF mailing list, that with-defaults should be a
sub-element of each affected operation.
While this violates the XSD of RFC4741 this is acceptable and follows
the ideas behind NETCONF and YANG.
Hopefully it will be clarified in the 4741bis RFC whether such extensions are allowed.
| TOC |
| Andy Bierman | |
| InterWorking Labs | |
| Scotts Valley, CA | |
| USA | |
| Phone: | +1 831 460 7010 |
| Email: | andyb@iwl.com |
| Balazs Lengyel | |
| Ericsson | |
| Budapest, | |
| Hungary | |
| Email: | balazs.lengyel@ericsson.com |