NETCONF Working Group Q. Wu
Internet-Draft X. Ding
Intended status: Standards Track Huawei
Expires: September 4, 2018 March 3, 2018

NETCONF Base Notifications for NMDA
draft-wu-netconf-base-notification-nmda-00

Abstract

NMDA introduces additional datastores for systems that support more advanced processing chains converting configuration to operational state. Support the monitoring of the base system events pertaining to these datatores hasn't been discussed in Network Configuration Protocol (NETCONF) Base Notifications [RFC6470]. This document updates [RFC6470] to support the Network Management Datastore Architecture (NMDA) defined in [I-D.ietf-netmod-revised-datastores].

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on September 4, 2018.

Copyright Notice

Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include 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

[RFC6470] provides standard mechanisms to support the monitoring of the base system events within the NETCONF server. Such mechanism allows a NETCONF client to receive notifications for some common system events (e.g., a change in NETCONF server capabilities, that may impact management applications.).

This document updates Network Configuration Protocol (NETCONF) Base Notifications [RFC6470] to support the Network Management Datastore Architecture (NMDA) defined in [I-D.ietf-netmod-revised-datastores]. Specifically, with NMDA, there are several additional datastores that are subject to system events. Extensions are needed to indicate the affected datastore and affected phase (because it is no longer simply about <running>; there are now also (for example) <intended> and <operational>).

The solution presented in this document is backwards compatible with [RFC6470]. This is achieved by only adding new top-level resources, and thereby leaving the semantics of all existing resources alone.

Note that "push-change-update" notification and "push-update" notification defined in [I-D.ietf-netconf-yang-push] are not general purpose notifications. and used to send to the receivers of a subscription entire or a portion of datastore contents. The solution presented in this document can work together with "push-change-update" notification and "push-update" notification defined in [I-D.ietf-netconf-yang-push] to indicate to yang push client fine granularity of data change metadata properties (e.g. who made configuration changes, identify specific location of configuration changes or phase of configuration changes) pertaining to multiple subscriptions of the same receivers.

1.1. Terminology

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.

The following terms are defined in [I-D.ietf-netmod-revised-datastores] and are not redefined here:

2. Summary of Updates to RFC 6470

This document is intended to provide an extension of notifications initially defined within [RFC6470], with the development of NMDA architcture and data model. Key relationships between these two documents include:

3. NETCONF Base Notifications YANG Model extension for NMDA

3.1. Overview

The YANG module in NETCONF Base Notifications [RFC6470] specifies the following 5 event notifications for the 'NETCONF' stream to notify a client application that the NETCONF server state has changed:

These event notifications used within the 'NETCONF' stream are accessible to clients via the subscription mechanism described in [RFC5277].

This document extends the YANG module defined in [RFC6470] to include NMDA specific extension which allows a NETCONF client to receive notifications for additional common system event as follows:

netconf-data-change:

<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
 <eventTime>2017-06-16T16:30:59.137045+09:00</eventTime>
 <netconf-data-change xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-notifications-nmda">
        <changed-by>
            <username>admin</username>
            <session-id>0</session-id>
            <source-host>10.251.93.83</source-host>
        </changed-by>
        <datastore>operational</datastore>
        <edit>
            <target>/ietf-interfaces:interfaces/ietf-interfaces:statistics</target>
            <operation>create</operation>
            <origin>default</orign>
            <current-phase>inactive</current-phase>
        </edit>
        <edit>
            <target>/ietf-interfaces:interfaces/ietf-interfaces:statistics/ietf-interfaces:in-octets</target>
            <operation>merge</operation>
            <origin>system</orign>
            <current-phase>in-use</current-phase>
        </edit>
 </netconf-config-change>
</notification>

The following is an example of a netconf-data-change notification message:

3.2. Definitions

This section presents the YANG module defined in this document.

 <CODE BEGINS> file "ietf-netconf-notifications-nmda@2018-02-01.yang"
module ietf-netconf-notifications-nmda {
  namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-notifications-nmda";
  prefix ncdn;

  import ietf-netconf {
    prefix nc;
  }
  import ietf-datastores {
    prefix ds;
  }
  import ietf-origin {
    prefix or;
  }
  import ietf-netconf-notifications {
    prefix ncn;
  }

  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: Kent Watsen
               <mailto:kwatsen@juniper.net>
     
     WG Chair: Mahesh Jethanandani
               <mailto:mjethanandani@gmail.com>
     
     Editor:   Qin Wu
               <mailto:bill.wu@huawei.com>
    
     Editor:   Xiaojian Ding
               <mailto:dingxiaojian1@huawei.com>";
  description
    "This module defines a YANG data model for use with the
     NETCONF protocol that allows the NETCONF client to
     receive additional common NETCONF base event notifications
      related to NMDA.
     
     Copyright (c) 2012 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.";

  revision 2018-02-01 {
    description
      "Initial version.";
    reference "RFC xxx: NETCONF Base Notifications for NMDA";
  }
  identity change-phase {
    description
      "Base identity for change phanse.";
  }

  identity inactive {
    base change-phase;
    description
      "Identity for inactive data.It is referred to as 
      configuration that is not currently used.";
  }

  identity in-use {
    base change-phase;
    description
      "Identity for the in use data. It is referred to as
       configuration that is actively used.";
  }

  identity Remnant  {
    base in-use;
    description
      "Identity for the remnant configuration. It indicates that
       both the previous and current configuration coexist.";
  }

  identity miss-resource {
    base in-use;
    description
      "Identity for the missing resource.It indicates that
       Configuration in <intended> can refer to resources that are not
      available or otherwise not physically present and parts of <intended>
      are not applied.";
  }

  identity sys-resource {
    base in-use;
    description
      "Identity for the system congtrolled resource.It indicates that
       a system controlled resource has matching configuration in 
      <intended>.";
  }
  notification netconf-data-change {
    description
      "Generated when the NETCONF server detects that the
       <operational> datastore or conventional configuration datastore
       has been changed by a management session.
       The notification summarizes the edits that
       have been detected.
       
       The server MAY choose to also generate this
       notification while loading a datastore during the
       boot process for the device.";
    uses ncn:changed-by-parms;
    leaf datastore {
      type identityref {
        base ds:datastore;
      }
      default "ds:operational";
      description
        "Indicates which datastore has changed or which datastore is 
         target of edit-data operation.";
    }

    list edit {
      description
        "An edit record SHOULD be present for each distinct
         edit operation that the server has detected on
         the target datastore.  This list MAY be omitted
         if the detailed edit operations are not known.
         The server MAY report entries in this list for
         changes not made by a NETCONF session (e.g., CLI).";
      leaf target {
        type instance-identifier;
        description
          "Topmost node associated with the configuration change.
           A server SHOULD set this object to the node within
           the datastore that is being altered.  A server MAY
           set this object to one of the ancestors of the actual
           node that was changed, or omit this object, if the
           exact node is not known.";
      }
      leaf origin {
        type identityref {
          base or:origin;
        }
        description
          "Indicate origin that most accurately reflects the source of the
           configuration that is in use by the system.";
      }
    leaf current-phase {
        type identityref {
          base change-phase;
        }
        description
          "Indicate the current phase of the <operational> datastore or 
           conventional configuration datastore change, e.g.,the intended
           datastore is validating, the intended datastore is validated,
           the configuration is applying, the configuration is applied.";
      }
      leaf operation {
        type nc:edit-operation-type;
        description
          "Type of edit operation performed.
           A server MUST set this object to the NETCONF edit
           operation performed on the target datastore.";
      }
    }
  }
}
<CODE ENDS>

4. Security Considerations

The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH, defined in [RFC6242].

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, get-data or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:

/netconf-data-change:

/netconf-data-change/changed-by:

/netconf-data-change/datastore:

/netconf-data-change/edit:

5. IANA Considerations

This document registers one XML namespace URN in the 'IETF XML registry', following the format defined in [RFC3688]:

This document registers one module name in the 'YANG Module Names' registry, defined in [RFC7950]:

6. Acknowledgements

Thanks to Juergen Schoenwaelder and Alex Clemm to review this draft and provide important input to this document.

7. Normative References

[I-D.ietf-netconf-yang-push] Clemm, A., Voit, E., Prieto, A., Tripathy, A., Nilsen-Nygaard, E., Bierman, A. and B. Lengyel, "YANG Datastore Subscription", Internet-Draft draft-ietf-netconf-yang-push-15, February 2018.
[I-D.ietf-netmod-revised-datastores] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture", Internet-Draft draft-ietf-netmod-revised-datastores-10, January 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004.
[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010.
[RFC6021] Schoenwaelder, J., "Common YANG Data Types", RFC 6021, DOI 10.17487/RFC6021, October 2010.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011.
[RFC6470] Bierman, A., "Network Configuration Protocol (NETCONF) Base Notifications", RFC 6470, DOI 10.17487/RFC6470, February 2012.

Appendix A. Appendix

A.1. Tree diagram

  module: ietf-netconf-notifications
  notifications:
    +---n netconf-data-change
       +--ro changed-by
       |  +--ro (server-or-user)
       |     +--:(server)
       |     |  +--ro server?        empty
       |     +--:(by-user)
       |        +--ro username       string
       |        +--ro session-id     nc:session-id-or-zero-type
       |        +--ro source-host?   inet:ip-address
       +--ro datastore?    identityref
       +--ro edit*
          +--ro target?      instance-identifier
          +--ro origin?      
          +--ro current-phase?
          +--ro operation?   nc:edit-operation-type

Authors' Addresses

Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: bill.wu@huawei.com
Xiaojian Ding Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China EMail: dingxiaojian1@huawei.com