Base Notifications for NMDA
draft-wu-netconf-base-notification-nmda-01

Abstract

The Network Configuration Protocol (NETCONF) provides mechanisms to manipulate configuration datastores. NMDA introduces additional datastores for systems that support more advanced processing chains converting configuration to operational state. However, client applications are not able to be aware of common events pertaining to additional datstores, such as a data validation state change in NETCONF server, that may impact management applications. This document updates [RFC6470] to allow a NETCONF client to receive additional notifications for some common system events pertaining to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].

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 December 21, 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
• 1.1. Terminology
• 2. Summary of Updates to RFC 6470
• 3. NETCONF Base Notifications YANG Model extension for NMDA
• 3.1. Overview
• 3.2. Definitions
• 4. Security Considerations
• 5. IANA Considerations
• 6. Acknowledgements
• 7. Contributors
• 8. Normative References
• Authors' Addresses

1. Introduction

The Network Configuration Protocol (NETCONF) [RFC6470] provides mechanisms to manipulate configuration datastores. NMDA introduces additional datastores (e.g., <intended>, <operational>) for systems that support more advanced processing chains converting configuration to operational state. However, client applications are not able to be aware of common events pertaining to additional datastores, e.g., there are many background activities that happen during the time that configuration is committed to <running> to the time that the configuration is actually applied to <operational>. It is possible that some configuration could not be applied to <operational> due to either validation issues, or missing resource etc. There is a need for user to know the validation result of <intended> data-store and the reason why the configuration were not applied.

This document updates [RFC6470] to allows a NETCONF client to receive additional notifications for some common system events pertaining to the Network Management Datastore Architecture (NMDA) defined in [RFC8342]. These notification are not specific to any network management protocols such as NETCONF and RESTCONF.

The solution presented in this document is backwards compatible with [RFC6470].

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 [RFC8342] and are not redefined here:

• operational state datastore
• running configuration datastore
• intended configuration datastore

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:

• The existing notifications defined in [RFC6470] are remain unchanged, no additional information is added.
• A new event notification is defined in this document to overcome the shortcoming of [RFC6470] for supporting NMDA.

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:

• netconf-config-change
• netconf-capability-change
• netconf-session-start
• netconf-session-end
• netconf-confirmed-commit

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:

nmda-data-validate:

Generated when a server with network management protocol support detects that a data validation event has occurred from the time that configuration is committed to <running> to the time that the configuration is actually applied to <operational> during management session. Indicates the event and the current state of the data validation. A server MAY report events for non-NETCONF management sessions (such as RESTCONF,gPRC), using the 'session-id' value of zero.

These notification messages are accessible to clients via either the subscription mechanism described in [RFC5277] or dynamic subscription mechanism and configured subscription mechanism described in [I-D.ietf-netconf-netconf-event-notifications].

<notification xmlns="urn:ietf:params:xml:ns:netconf:notification:1.0">
 <eventTime>2017-06-16T16:30:59.137045+09:00</eventTime>
 <nmda-data-validate xmlns="urn:ietf:params:xml:ns:yang:ietf-nmda-notifications">
     <username>admin</username>
     <session-id>0</session-id>
     <source-host>10.251.93.83</source-host>
     <validate-event>start<validate-event>
     <validate-result>partial-fail</validate-result>
     <validate-fail-taget>
      <datastore>intended</datastore>
      <target> /ietf-interfaces:interfaces-state </target>
     </validate-fail-target>
     <validate-fail-taget>
      <datastore>intended</datastore>
      <target> /ietf-system:system </target>
     </validate-fail-target>
 </nmda-data-validate>
</notification>

The following are examples of a nmda-data-validation notification message:

3.2. Definitions

This section presents the YANG module defined in this document. This module imports data types from the 'ietf-netconf' module defined in [RFC6241] and 'ietf-inet-types' module defined in [RFC6021].

 <CODE BEGINS> file "ietf-nmda-notifications@2018-04-01.yang"
module ietf-nmda-notifications {
  namespace "urn:ietf:params:xml:ns:yang:ietf-nmda-notifications";
  prefix nmdan;

  import ietf-datastores {
    prefix ds;
  }
  import ietf-inet-types { prefix inet; }
  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:   Rohit R Ranade
               <mailto:rohitrranade@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 2018-04-01 {
    description
      "Initial version.";
    reference "RFC xxx: NETCONF Base Notifications for NMDA";
  }
  typedef session-id-or-zero-type { 
     type uint32; 
     description 
       "NETCONF Session Id or Zero to indicate none"; 
   } 

  grouping common-session-parms {
    description
      "Common session parameters to identify a
       management session.";

    leaf username {
      type string;
      mandatory true;
      description
        "Name of the user for the session.";
    }

    leaf session-id {
      type session-id-or-zero-type;
      mandatory true;
      description
        "Identifier of the session.
         A NETCONF session MUST be identified by a non-zero value.
         A non-NETCONF session MAY be identified by the value zero.";
    }

    leaf source-host {
      type inet:ip-address;
      description
        "Address of the remote host for the session.";
    }
  }
  notification nmda-data-validate {
    description
      "Generated when a NETCONF server detects that a
       Data validation event has occurred.  Indicates the event
       and the current state of the data validation procedure
       in progress.";
    reference "RFC 8342, Section 5";
    uses common-session-parms;
    leaf validate-event {
      type enumeration {
        enum "start" {
          description
            "The data validate procedure has started.";
        }
        enum "complete" {
          description
            "The data validation procedure has been completed.";
        }
      }
      mandatory true;
      description
        "Indicates the event that caused the notification.";
    }
    leaf validate-result {
      when "../validate-event = 'complete'";
      type enumeration {
        enum "fail" {
          description
            "The <intended> configuration fails to be validated
             before being applied to <operational>, e.g., resources
             are not available or otherwise not physically present
             leads to the whole set of <intended>are not applied.";
        }
        enum "partial-fail" {
          description
            "The <intended> configuration partially fails to be
             validated before being applied to <operational>,e.g.,
             resources are not available or otherwise not physically
             present leads to parts of <intended>are not applied";
        }
        enum "success" {
          description
            "The <intended> configuration is successfully validated
             before being applied to <operational>.";
        }
      }
      description
        "Result of validate";
    }
    list fail-validate-target {
      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.";
      }
      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.";
      }
      description
        "List for fail validate targets";
    }
  }
}
<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, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:

/nmda-data-validate/validate-event:

• Indicates the specific validate-event state change that occurred. A value of 'complete' probably indicates that data validation procedure has completed.

5. IANA Considerations

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

• URI: urn:ietf:params:xml:ns:yang:ietf-nmda-notifications
• Registrant Contact: The IESG.
• XML: N/A, the requested URI is an XML namespace.

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

• name: ietf-nmda-notifications
• prefix: ncdn
• namespace: urn:ietf:params:xml:ns:yang:ietf-nmda-notifications
• RFC: xxxx

6. Acknowledgements

Thanks to Juergen Schoenwaelder, Alex Clemm,Carey Timothy and Andy Berman to review this draft and provide important input to this document.

7. Contributors

   Xiaojian Ding
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: dingxiaojian1@huawei.com

8. Normative References

Authors' Addresses