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Versions: (draft-ietf-netconf-server-model) 00 01 02 03 04 05 06 07 08 09 10 11 12

NETCONF Working Group                                          K. Watsen
Internet-Draft                                          Juniper Networks
Intended status: Standards Track                                   G. Wu
Expires: January 9, 2017                                  Cisco Networks
                                                        J. Schoenwaelder
                                                Jacobs University Bremen
                                                            July 8, 2016


                    NETCONF Client and Server Models
              draft-ietf-netconf-netconf-client-server-00

Abstract

   This document defines two YANG modules, one module to configure a
   NETCONF client and the other module to configure a NETCONF server.
   Both modules support both the SSH and TLS transport protocols, and
   support both standard NETCONF and NETCONF Call Home connections.

Editorial Note (To be removed by RFC Editor)

   This draft contains many placeholder values that need to be replaced
   with finalized values at the time of publication.  This note
   summarizes all of the substitutions that are needed.  No other RFC
   Editor instructions are specified elsewhere in this document.

   This document contains references to other drafts in progress, both
   in the Normative References section, as well as in body text
   throughout.  Please update the following references to reflect their
   final RFC assignments:

   o  draft-ietf-netconf-system-keychain

   o  draft-ietf-netconf-ssh-client-server

   o  draft-ietf-netconf-tls-client-server

   Artwork in this document contains shorthand references to drafts in
   progress.  Please apply the following replacements:

   o  "XXXX" --> the assigned RFC value for this draft

   o  "YYYY" --> the assigned RFC value for draft-ietf-netconf-ssh-
      client-server

   o  "ZZZZ" --> the assigned RFC value for draft-ietf-netconf-tls-
      client-server




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   o  "AAAA" --> the assigned RFC value for draft-ietf-netconf-call-home

   Artwork in this document contains placeholder values for the date of
   publication of this draft.  Please apply the following replacement:

   o  "2016-07-08" --> the publication date of this draft

   The following two Appendix sections are to be removed prior to
   publication:

   o  Appendix A.  Change Log

   o  Appendix B.  Open Issues

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 January 9, 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
   (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.






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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
   2.  The NETCONF Client Model  . . . . . . . . . . . . . . . . . .   4
     2.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   5
     2.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .   6
     2.3.  YANG Model  . . . . . . . . . . . . . . . . . . . . . . .   8
   3.  The NETCONF Server Model  . . . . . . . . . . . . . . . . . .  14
     3.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .  15
     3.2.  Example Usage . . . . . . . . . . . . . . . . . . . . . .  17
     3.3.  YANG Model  . . . . . . . . . . . . . . . . . . . . . . .  21
   4.  Design Considerations . . . . . . . . . . . . . . . . . . . .  31
     4.1.  Support all NETCONF transports  . . . . . . . . . . . . .  31
     4.2.  Enable each transport to select which keys to use . . . .  32
     4.3.  Support authenticating NETCONF clients certificates . . .  32
     4.4.  Support mapping authenticated NETCONF client certificates
           to usernames  . . . . . . . . . . . . . . . . . . . . . .  32
     4.5.  Support both listening for connections and call home  . .  32
     4.6.  For Call Home connections . . . . . . . . . . . . . . . .  32
       4.6.1.  Support more than one NETCONF client  . . . . . . . .  32
       4.6.2.  Support NETCONF clients having more than one endpoint  33
       4.6.3.  Support a reconnection strategy . . . . . . . . . . .  33
       4.6.4.  Support both persistent and periodic connections  . .  33
       4.6.5.  Reconnection strategy for periodic connections  . . .  33
       4.6.6.  Keep-alives for persistent connections  . . . . . . .  33
       4.6.7.  Customizations for periodic connections . . . . . . .  34
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  34
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  34
     6.1.  The IETF XML Registry . . . . . . . . . . . . . . . . . .  34
     6.2.  The YANG Module Names Registry  . . . . . . . . . . . . .  34
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  35
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  35
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  35
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  36
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .  38
     A.1.  server-model-09 to 00 . . . . . . . . . . . . . . . . . .  38
   Appendix B.  Open Issues  . . . . . . . . . . . . . . . . . . . .  38
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  38

1.  Introduction

   This document defines two YANG [RFC6020] modules, one module to
   configure a NETCONF client and the other module to configure a
   NETCONF server.  Both modules support both the SSH and TLS transport
   protocols, and support both standard NETCONF and NETCONF Call Home
   connections.



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   NETCONF is defined by [RFC6241].  SSH is defined by [RFC4252],
   [RFC4253], and [RFC4254].  TLS is defined by [RFC5246].  NETCONF Call
   Home is defined by [draft-ietf-netconf-call-home]).

1.1.  Terminology

   The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1.2.  Tree Diagrams

   A simplified graphical representation of the data models is used in
   this document.  The meaning of the symbols in these diagrams is as
   follows:

   o  Brackets "[" and "]" enclose list keys.

   o  Braces "{" and "}" enclose feature names, and indicate that the
      named feature must be present for the subtree to be present.

   o  Abbreviations before data node names: "rw" means configuration
      (read-write) and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node, "!"
      means a presence container, and "*" denotes a list and leaf-list.

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

2.  The NETCONF Client Model

   The NETCONF client model presented in this section supports both
   clients initiating connections to servers, as well as clients
   listening for connections from servers calling home.

   This model supports both the SSH and TLS transport protocols, using
   the SSH client and TLS client groupings defined in
   [draft-ietf-netconf-ssh-client-server] and
   [draft-ietf-netconf-tls-client-server] respectively.

   All private keys and trusted certificates are held in the keychain
   model defined in [draft-ietf-netconf-system-keychain].





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   YANG feature statements are used to enable implementations to
   advertise which parts of the model the NETCONF client supports.

2.1.  Tree Diagram

   Note: all lines are folded at column 71 with no '\' character.

 module: ietf-netconf-client
    +--rw netconf-client
       +--rw initiate {initiate}?
       |  +--rw netconf-server* [name]
       |     +--rw name    string
       |     +--rw (transport)
       |        +--:(ssh) {ssh-initiate}?
       |           +--rw ssh
       |              +--rw address        inet:host
       |              +--rw port?          inet:port-number
       |              +--rw server-auth
       |              |  +--rw trusted-ssh-host-keys?   -> /kc:keychain/
 trusted-ssh-host-keys/name
       |              |  +--rw trusted-ca-certs?        -> /kc:keychain/
 trusted-certificates/name {ssh-x509-certs}?
       |              |  +--rw trusted-server-certs?    -> /kc:keychain/
 trusted-certificates/name
       |              +--rw client-auth
       |                 +--rw matches* [name]
       |                    +--rw name                     string
       |                    +--rw match* [name]
       |                    |  +--rw name                     string
       |                    |  +--rw trusted-ssh-host-keys?   -> /kc:key
 chain/trusted-ssh-host-keys/name
       |                    |  +--rw trusted-ca-certs?        -> /kc:key
 chain/trusted-certificates/name
       |                    |  +--rw trusted-server-certs?    -> /kc:key
 chain/trusted-certificates/name
       |                    +--rw user-auth-credentials?   -> /kc:keycha
 in/user-auth-credentials/user-auth-credential/username
       +--rw listen {listen}?
          +--rw max-sessions?   uint16
          +--rw idle-timeout?   uint16
          +--rw endpoint* [name]
             +--rw name    string
             +--rw (transport)
                +--:(ssh) {ssh-listen}?
                   +--rw ssh
                      +--rw address?       inet:ip-address
                      +--rw port?          inet:port-number
                      +--rw server-auth



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                      |  +--rw trusted-ssh-host-keys?   -> /kc:keychain/
 trusted-ssh-host-keys/name
                      |  +--rw trusted-ca-certs?        -> /kc:keychain/
 trusted-certificates/name {ssh-x509-certs}?
                      |  +--rw trusted-server-certs?    -> /kc:keychain/
 trusted-certificates/name
                      +--rw client-auth
                         +--rw matches* [name]
                            +--rw name                     string
                            +--rw match* [name]
                            |  +--rw name                     string
                            |  +--rw trusted-ssh-host-keys?   -> /kc:key
 chain/trusted-ssh-host-keys/name
                            |  +--rw trusted-ca-certs?        -> /kc:key
 chain/trusted-certificates/name
                            |  +--rw trusted-server-certs?    -> /kc:key
 chain/trusted-certificates/name
                            +--rw user-auth-credentials?   -> /kc:keycha
 in/user-auth-credentials/user-auth-credential/username

2.2.  Example Usage

   The following example illustrates configuring a NETCONF client to
   initiate connections, using both the SSH and TLS transport protocols,
   as well as listening for call-home connections, again using both the
   SSH and TLS transport protocols.

   This example is consistent with the examples presented in Section 2.2
   of [draft-ietf-netconf-system-keychain].

   <netconf-client
     xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-client">

     <!-- NETCONF servers to initiate NETCONF connections to -->
     <initiate>
       <netconf-server>
         <name>corp-fw1</name>
         <ssh>
           <address>corp-fw1.example.com</address>
           <server-auth>
             <trusted-server-certs>
               deployment-specific-ca-certs
             </trusted-server-certs>
           </server-auth>
           <client-auth>
             <matches>
               <match>
                 <trusted-ca-certs>



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                   deployment-specific-ca-certs
                 </trusted-ca-certs>
               </match>
               <user-auth-credentials>Bob</user-auth-credentials>
             </matches>
           </client-auth>
         </ssh>
       </netconf-server>
     </initiate>

     <!-- endpoints to listen for NETCONF Call Home connections on -->
     <listen>
       <endpoint>
         <name>Intranet-facing listener</name>
         <ssh>
           <address>11.22.33.44</address>
           <server-auth>
             <trusted-ca-certs>
               deployment-specific-ca-certs
             </trusted-ca-certs>
             <trusted-server-certs>
               explicitly-trusted-server-certs
             </trusted-server-certs>
             <trusted-ssh-host-keys>
               explicitly-trusted-ssh-host-keys
             </trusted-ssh-host-keys>
           </server-auth>
           <client-auth>
             <matches>
               <match>
                 <trusted-ca-certs>
                   deployment-specific-ca-certs
                 </trusted-ca-certs>
               </match>
               <user-auth-credentials>admin</user-auth-credentials>
             </matches>
             <matches>
               <match>
                 <trusted-ca-certs>
                   explicitly-trusted-server-certs
                 </trusted-ca-certs>
               </match>
               <user-auth-credentials>admin</user-auth-credentials>
             </matches>
             <matches>
               <match>
                 <trusted-ca-certs>
                   explicitly-trusted-ssh-host-keys



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                 </trusted-ca-certs>
               </match>
               <user-auth-credentials>admin</user-auth-credentials>
             </matches>
           </client-auth>
         </ssh>
       </endpoint>
     </listen>
   </netconf-client>

2.3.  YANG Model

   This YANG module imports YANG types from [RFC6991] and [RFC7407].


<CODE BEGINS> file "ietf-netconf-client@2016-07-08.yang"

module ietf-netconf-client {
  yang-version 1.1;

  namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-client";
  prefix "ncc";

  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 6991: Common YANG Data Types";
  }

  import ietf-x509-cert-to-name {
    prefix x509c2n;
    reference
      "RFC 7407: A YANG Data Model for SNMP Configuration";
  }

  import ietf-ssh-client {
    prefix ss;
    revision-date 2016-07-08; // stable grouping definitions
    reference
      "RFC YYYY: SSH Client and Server Models";
  }

  import ietf-tls-client {
    prefix ts;
    revision-date 2016-07-08; // stable grouping definitions
    reference
      "RFC ZZZZ: TLS Client and Server Models";
  }



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  organization
   "IETF NETCONF (Network Configuration) Working Group";

  contact
   "WG Web:   <http://tools.ietf.org/wg/netconf/>
    WG List:  <mailto:netconf@ietf.org>

    WG Chair: Mehmet Ersue
              <mailto:mehmet.ersue@nsn.com>

    WG Chair: Mahesh Jethanandani
              <mailto:mjethanandani@gmail.com>

    Author:   Kent Watsen
              <mailto:kwatsen@juniper.net>

    Author:   Gary Wu
              <mailto:garywu@cisco.com>";


  description
   "This module contains a collection of YANG definitions for
    configuring NETCONF servers.

    Copyright (c) 2014 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; see
    the RFC itself for full legal notices.";

  revision "2016-07-08" {
    description
     "Initial version";
    reference
     "RFC XXXX: NETCONF Client and Server Models";
  }

  // Features

  feature initiate {
    description



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     "The 'initiate' feature indicates that the NETCONF client
      supports initiating NETCONF connections to NETCONF servers
      using at least one transport (e.g., SSH, TLS, etc.).";
  }

  feature ssh-initiate {
    description
     "The 'ssh-initiate' feature indicates that the NETCONF client
      supports initiating SSH connections to NETCONF servers.";
    reference
     "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)";
  }

  feature tls-initiate {
    description
     "The 'tls-initiate' feature indicates that the NETCONF client
      supports initiating TLS connections to NETCONF servers.";
    reference
     "RFC 7589: Using the NETCONF Protocol over Transport
                Layer Security (TLS) with Mutual X.509
                Authentication";
  }

  feature listen {
    description
     "The 'listen' feature indicates that the NETCONF client
      supports opening a port to accept NETCONF server call home
      connections using at least one transport (e.g., SSH, TLS, etc.).";
  }

  feature ssh-listen {
    description
     "The 'ssh-listen' feature indicates that the NETCONF client
      supports opening a port to listen for incoming NETCONF
      server call-home SSH connections.";
    reference
     "RFC AAAA: NETCONF Call Home and RESTCONF Call Home";
  }

  feature tls-listen {
    description
     "The 'tls-listen' feature indicates that the NETCONF client
      supports opening a port to listen for incoming NETCONF
      server call-home TLS connections.";
    reference
     "RFC AAAA: NETCONF Call Home and RESTCONF Call Home";
  }




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  container netconf-client {
    description
      "Top-level container for NETCONF client configuration.";

    container initiate {
      if-feature initiate;
      description
        "Configures client intiating underlying TCP connections.";
      list netconf-server {
        key name;
        description
          "List of NETCONF servers the NETCONF client is to initiate
           connections to.";
        leaf name {
          type string;
          description
            "An arbitrary name for the NETCONF server.";
        }
        choice transport {
          mandatory true;
          description
            "Selects between available transports.";
          case ssh {
            if-feature ssh-initiate;
            container ssh {
              description
                "Specifies SSH-specific transport configuration.";
              leaf address {
                type inet:host;
                mandatory true;
                description
                 "The IP address or hostname of the endpoint.  If a
                  hostname is configured and the DNS resolution results
                  in more than one IP address, the NETCONF client
                  will process the IP addresses as if they had been
                  explicitly configured in place of the hostname.";
              }
              leaf port {
                type inet:port-number;
                default 830;
                description
                 "The IP port for this endpoint. The NETCONF client will
                  use the IANA-assigned well-known port if no value is
                  specified.";
              }
              uses ss:initiating-ssh-client-grouping;
            }
          }



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/*
          case tls {
            if-feature tls-initiate;
            container tls {
              description
                "Specifies TLS-specific transport configuration.";
              uses endpoints-container {
                refine endpoints/endpoint/port {
                  default 6513;
                }
              }
              uses ts:listening-tls-client-grouping {
                augment "client-auth" {
                  description
                    "Augments in the cert-to-name structure.";
                  uses cert-maps-grouping;
                }
              }
            }
          }
*/
        }
      }
    } // end initiate

    container listen {
      if-feature listen;
      description
        "Configures client accepting call-home TCP connections.";
      leaf max-sessions {
        type uint16;
        default 0;
        description
          "Specifies the maximum number of concurrent sessions
           that can be active at one time.  The value 0 indicates
           that no artificial session limit should be used.";
      }
      leaf idle-timeout {
        type uint16;
        units "seconds";
        default 3600; // one hour
        description
          "Specifies the maximum number of seconds that a NETCONF
           session may remain idle. A NETCONF session will be dropped
           if it is idle for an interval longer than this number of
           seconds.  If set to zero, then the server will never drop
           a session because it is idle.  Sessions that have a
           notification subscription active are never dropped.";



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      }
      list endpoint {
        key name;
        description
          "List of endpoints to listen for NETCONF connections on.";
        leaf name {
          type string;
          description
            "An arbitrary name for the NETCONF listen endpoint.";
        }
        choice transport {
          mandatory true;
          description
            "Selects between available transports.";
          case ssh {
            if-feature ssh-listen;
            container ssh {
              description
                "SSH-specific listening configuration for inbound
                 connections.";
              uses ss:listening-ssh-client-grouping {
                refine port {
                  default 4334;
                }
              }
            }
          }
/*
          case tls {
            if-feature tls-listen;
            container tls {
              description
                "TLS-specific listening configuration for inbound
                 connections.";
              uses ts:listening-tls-client-grouping {
                refine port {
                  default 4335;
                }
                augment "client-auth" {
                  description
                    "Augments in the cert-to-name structure.";
                  uses cert-maps-grouping;
                }
              }
            }
          }
*/
        }



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      }
    } // end listen
  }

  grouping cert-maps-grouping {
    description
      "A grouping that defines a container around the
       cert-to-name structure defined in RFC 7407.";
    container cert-maps {
      uses x509c2n:cert-to-name;
      description
       "The cert-maps container is used by a TLS-based NETCONF
        server to map the NETCONF client's presented X.509
        certificate to a NETCONF username.  If no matching and
        valid cert-to-name list entry can be found, then the
        NETCONF server MUST close the connection, and MUST NOT
        accept NETCONF messages over it.";
      reference
        "RFC WWWW: NETCONF over TLS, Section 7";
    }
  }

}


<CODE ENDS>

3.  The NETCONF Server Model

   The NETCONF server model presented in this section supports servers
   both listening for connections as well as initiating call-home
   connections.

   This model also supports both the SSH and TLS transport protocols,
   using the SSH server and TLS server groupings defined in
   [draft-ietf-netconf-ssh-client-server] and
   [draft-ietf-netconf-tls-client-server] respectively.

   All private keys and trusted certificates are held in the keychain
   model defined in [draft-ietf-netconf-system-keychain].

   YANG feature statements are used to enable implementations to
   advertise which parts of the model the NETCONF server supports.








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3.1.  Tree Diagram

   Note: all lines are folded at column 71 with no '\' character.

 module: ietf-netconf-server
    +--rw netconf-server
       +--rw session-options
       |  +--rw hello-timeout?   uint16
       +--rw listen {listen}?
       |  +--rw max-sessions?   uint16
       |  +--rw idle-timeout?   uint16
       |  +--rw endpoint* [name]
       |     +--rw name    string
       |     +--rw (transport)
       |        +--:(ssh) {ssh-listen}?
       |        |  +--rw ssh
       |        |     +--rw address?            inet:ip-address
       |        |     +--rw port?               inet:port-number
       |        |     +--rw host-keys
       |        |     |  +--rw host-key* [name]
       |        |     |     +--rw name           string
       |        |     |     +--rw (type)?
       |        |     |        +--:(public-key)
       |        |     |        |  +--rw public-key?    -> /kc:keychain/p
 rivate-keys/private-key/name
       |        |     |        +--:(certificate)
       |        |     |           +--rw certificate?   -> /kc:keychain/p
 rivate-keys/private-key/certificate-chains/certificate-chain/name {ssh-
 x509-certs}?
       |        |     +--rw client-cert-auth {ssh-x509-certs}?
       |        |        +--rw trusted-ca-certs?       -> /kc:keychain/t
 rusted-certificates/name
       |        |        +--rw trusted-client-certs?   -> /kc:keychain/t
 rusted-certificates/name
       |        +--:(tls) {tls-listen}?
       |           +--rw tls
       |              +--rw address?        inet:ip-address
       |              +--rw port?           inet:port-number
       |              +--rw certificates
       |              |  +--rw certificate* [name]
       |              |     +--rw name    -> /kc:keychain/private-keys/p
 rivate-key/certificate-chains/certificate-chain/name
       |              +--rw client-auth
       |                 +--rw trusted-ca-certs?       -> /kc:keychain/t
 rusted-certificates/name
       |                 +--rw trusted-client-certs?   -> /kc:keychain/t
 rusted-certificates/name
       |                 +--rw cert-maps



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       |                    +--rw cert-to-name* [id]
       |                       +--rw id             uint32
       |                       +--rw fingerprint    x509c2n:tls-fingerpr
 int
       |                       +--rw map-type       identityref
       |                       +--rw name           string
       +--rw call-home {call-home}?
          +--rw netconf-client* [name]
             +--rw name                  string
             +--rw (transport)
             |  +--:(ssh) {ssh-call-home}?
             |  |  +--rw ssh
             |  |     +--rw endpoints
             |  |     |  +--rw endpoint* [name]
             |  |     |     +--rw name       string
             |  |     |     +--rw address    inet:host
             |  |     |     +--rw port?      inet:port-number
             |  |     +--rw host-keys
             |  |     |  +--rw host-key* [name]
             |  |     |     +--rw name           string
             |  |     |     +--rw (type)?
             |  |     |        +--:(public-key)
             |  |     |        |  +--rw public-key?    -> /kc:keychain/p
 rivate-keys/private-key/name
             |  |     |        +--:(certificate)
             |  |     |           +--rw certificate?   -> /kc:keychain/p
 rivate-keys/private-key/certificate-chains/certificate-chain/name {ssh-
 x509-certs}?
             |  |     +--rw client-cert-auth {ssh-x509-certs}?
             |  |        +--rw trusted-ca-certs?       -> /kc:keychain/t
 rusted-certificates/name
             |  |        +--rw trusted-client-certs?   -> /kc:keychain/t
 rusted-certificates/name
             |  +--:(tls) {tls-call-home}?
             |     +--rw tls
             |        +--rw endpoints
             |        |  +--rw endpoint* [name]
             |        |     +--rw name       string
             |        |     +--rw address    inet:host
             |        |     +--rw port?      inet:port-number
             |        +--rw certificates
             |        |  +--rw certificate* [name]
             |        |     +--rw name    -> /kc:keychain/private-keys/p
 rivate-key/certificate-chains/certificate-chain/name
             |        +--rw client-auth
             |           +--rw trusted-ca-certs?       -> /kc:keychain/t
 rusted-certificates/name
             |           +--rw trusted-client-certs?   -> /kc:keychain/t



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 rusted-certificates/name
             |           +--rw cert-maps
             |              +--rw cert-to-name* [id]
             |                 +--rw id             uint32
             |                 +--rw fingerprint    x509c2n:tls-fingerpr
 int
             |                 +--rw map-type       identityref
             |                 +--rw name           string
             +--rw connection-type
             |  +--rw (connection-type)?
             |     +--:(persistent-connection)
             |     |  +--rw persistent!
             |     |     +--rw idle-timeout?   uint32
             |     |     +--rw keep-alives
             |     |        +--rw max-wait?       uint16
             |     |        +--rw max-attempts?   uint8
             |     +--:(periodic-connection)
             |        +--rw periodic!
             |           +--rw idle-timeout?        uint16
             |           +--rw reconnect_timeout?   uint16
             +--rw reconnect-strategy
                +--rw start-with?     enumeration
                +--rw max-attempts?   uint8

3.2.  Example Usage

   The following example illustrates configuring a NETCONF server to
   listen for NETCONF client connections using both the SSH and TLS
   transport protocols, as well as configuring call-home to two NETCONF
   clients, one using SSH and the other using TLS.

   This example is consistent with the examples presented in Section 2.2
   of [draft-ietf-netconf-system-keychain].

   <netconf-server
     xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
     <listen>

       <!-- listening for SSH connections -->
       <endpoint>
         <name>netconf/ssh</name>
         <ssh>
           <address>11.22.33.44</address>
           <host-keys>
             <host-key>
               <public-key>my-rsa-key</public-key>
             </host-key>
             <host-key>



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               <certificate>TPM key</certificate>
             </host-key>
           </host-keys>
           <client-cert-auth>
             <trusted-ca-certs>
               deployment-specific-ca-certs
             </trusted-ca-certs>
             <trusted-client-certs>
               explicitly-trusted-client-certs
             </trusted-client-certs>
           </client-cert-auth>
         </ssh>
       </endpoint>

       <!-- listening for TLS connections -->
       <endpoint>
         <name>netconf/tls</name>
         <tls>
           <address>11.22.33.44</address>
           <certificates>
             <certificate>ex-key-sect571r1-cert</certificate>
           </certificates>
           <client-auth>
             <trusted-ca-certs>
               deployment-specific-ca-certs
             </trusted-ca-certs>
             <trusted-client-certs>
               explicitly-trusted-client-certs
             </trusted-client-certs>
             <cert-maps>
               <cert-to-name>
                 <id>1</id>
                 <fingerprint>11:0A:05:11:00</fingerprint>
                 <map-type>x509c2n:san-any</map-type>
               </cert-to-name>
               <cert-to-name>
                 <id>2</id>
                 <fingerprint>B3:4F:A1:8C:54</fingerprint>
                 <map-type>x509c2n:specified</map-type>
                 <name>scooby-doo</name>
               </cert-to-name>
             </cert-maps>
           </client-auth>
         </tls>
       </endpoint>

     </listen>
     <call-home>



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       <!-- calling home to an SSH-based NETCONF client -->
       <netconf-client>
         <name>config-mgr</name>
         <ssh>
           <endpoints>
             <endpoint>
               <name>east-data-center</name>
               <address>11.22.33.44</address>
             </endpoint>
             <endpoint>
               <name>west-data-center</name>
               <address>55.66.77.88</address>
             </endpoint>
           </endpoints>
           <host-keys>
             <host-key>
               <certificate>TPM key</certificate>
             </host-key>
           </host-keys>
           <client-cert-auth>
             <trusted-ca-certs>
               deployment-specific-ca-certs
             </trusted-ca-certs>
             <trusted-client-certs>
               explicitly-trusted-client-certs
             </trusted-client-certs>
           </client-cert-auth>
         </ssh>
         <connection-type>
           <periodic>
             <idle-timeout>300</idle-timeout>
             <reconnect-timeout>60</reconnect-timeout>
           </periodic>
         </connection-type>
         <reconnect-strategy>
           <start-with>last-connected</start-with>
           <max-attempts>3</max-attempts>
         </reconnect-strategy>
       </netconf-client>

       <!-- calling home to a TLS-based NETCONF client -->
       <netconf-client>
         <name>event-correlator</name>
         <tls>
           <endpoints>
             <endpoint>
               <name>east-data-center</name>
               <address>22.33.44.55</address>



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             </endpoint>
             <endpoint>
               <name>west-data-center</name>
               <address>33.44.55.66</address>
             </endpoint>
           </endpoints>
           <certificates>
             <certificate>ex-key-sect571r1-cert</certificate>
           </certificates>
           <client-auth>
             <trusted-ca-certs>
               deployment-specific-ca-certs
             </trusted-ca-certs>
             <trusted-client-certs>
               explicitly-trusted-client-certs
             </trusted-client-certs>
             <cert-maps>
               <cert-to-name>
                 <id>1</id>
                 <fingerprint>11:0A:05:11:00</fingerprint>
                 <map-type>x509c2n:san-any</map-type>
               </cert-to-name>
               <cert-to-name>
                 <id>2</id>
                 <fingerprint>B3:4F:A1:8C:54</fingerprint>
                 <map-type>x509c2n:specified</map-type>
                 <name>scooby-doo</name>
               </cert-to-name>
             </cert-maps>
           </client-auth>
         </tls>
         <connection-type>
           <persistent>
             <idle-timeout>300</idle-timeout>
             <keep-alives>
               <max-wait>30</max-wait>
               <max-attempts>3</max-attempts>
             </keep-alives>
           </persistent>
         </connection-type>
         <reconnect-strategy>
           <start-with>first-listed</start-with>
           <max-attempts>3</max-attempts>
         </reconnect-strategy>
       </netconf-client>

     </call-home>
   </netconf-server>



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3.3.  YANG Model

   This YANG module imports YANG types from [RFC6991] and [RFC7407].


  <CODE BEGINS> file "ietf-netconf-server@2016-07-08.yang"

  module ietf-netconf-server {
    yang-version 1.1;

    namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server";
    prefix "ncs";

    import ietf-inet-types {
      prefix inet;
      reference
        "RFC 6991: Common YANG Data Types";
    }

    import ietf-x509-cert-to-name {
      prefix x509c2n;
      reference
        "RFC 7407: A YANG Data Model for SNMP Configuration";
    }

    import ietf-ssh-server {
      prefix ss;
      revision-date 2016-07-08; // stable grouping definitions
      reference
        "RFC YYYY: SSH Client and Server Models";
    }

    import ietf-tls-server {
      prefix ts;
      revision-date 2016-07-08; // stable grouping definitions
      reference
        "RFC ZZZZ: TLS Client and Server Models";
    }

    organization
     "IETF NETCONF (Network Configuration) Working Group";

    contact
     "WG Web:   <http://tools.ietf.org/wg/netconf/>
      WG List:  <mailto:netconf@ietf.org>

      WG Chair: Mehmet Ersue
                <mailto:mehmet.ersue@nsn.com>



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      WG Chair: Mahesh Jethanandani
                <mailto:mjethanandani@gmail.com>

      Editor:   Kent Watsen
                <mailto:kwatsen@juniper.net>";


    description
     "This module contains a collection of YANG definitions for
      configuring NETCONF servers.

      Copyright (c) 2014 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; see
      the RFC itself for full legal notices.";

    revision "2016-07-08" {
      description
       "Initial version";
      reference
       "RFC XXXX: NETCONF Client and Server Models";
    }


    // Features

    feature listen {
      description
       "The 'listen' feature indicates that the NETCONF server
        supports opening a port to accept NETCONF client connections
        using at least one transport (e.g., SSH, TLS, etc.).";
    }

    feature ssh-listen {
      description
       "The 'ssh-listen' feature indicates that the NETCONF server
        supports opening a port to accept NETCONF over SSH
        client connections.";
      reference
       "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)";



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    }

    feature tls-listen {
      description
       "The 'tls-listen' feature indicates that the NETCONF server
        supports opening a port to accept NETCONF over TLS
        client connections.";
      reference
       "RFC 7589: Using the NETCONF Protocol over Transport
                  Layer Security (TLS) with Mutual X.509
                  Authentication";
    }

    feature call-home {
      description
       "The 'call-home' feature indicates that the NETCONF server
        supports initiating NETCONF call home connections to NETCONF
        clients using at least one transport (e.g., SSH, TLS, etc.).";
      reference
       "RFC YYYY: NETCONF Call Home and RESTCONF Call Home";
    }

    feature ssh-call-home {
      description
       "The 'ssh-call-home' feature indicates that the NETCONF
        server supports initiating a NETCONF over SSH call
        home connection to NETCONF clients.";
      reference
       "RFC YYYY: NETCONF Call Home and RESTCONF Call Home";
    }

    feature tls-call-home {
      description
       "The 'tls-call-home' feature indicates that the NETCONF
        server supports initiating a NETCONF over TLS call
        home connection to NETCONF clients.";
      reference
       "RFC YYYY: NETCONF Call Home and RESTCONF Call Home";
    }


    // top-level container  (groupings below)
    container netconf-server {
      description
        "Top-level container for NETCONF server configuration.";

      container session-options {  // SHOULD WE REMOVE THIS ALTOGETHER?
        description



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          "NETCONF session options, independent of transport
           or connection strategy.";
        leaf hello-timeout {
          type uint16;
          units "seconds";
          default 600;
          description
            "Specifies the maximum number of seconds that a SSH/TLS
             connection may wait for a hello message to be received.
             A connection will be dropped if no hello message is
             received before this number of seconds elapses.  If set
             to zero, then the server will wait forever for a hello
             message.";
        }
      }

      container listen {
        if-feature listen;
        description
          "Configures listen behavior";
        leaf max-sessions {
          type uint16;
          default 0;
          description
            "Specifies the maximum number of concurrent sessions
             that can be active at one time.  The value 0 indicates
             that no artificial session limit should be used.";
        }
        leaf idle-timeout {
          type uint16;
          units "seconds";
          default 3600; // one hour
          description
            "Specifies the maximum number of seconds that a NETCONF
             session may remain idle. A NETCONF session will be dropped
             if it is idle for an interval longer than this number of
             seconds.  If set to zero, then the server will never drop
             a session because it is idle.  Sessions that have a
             notification subscription active are never dropped.";
        }
        list endpoint {
          key name;
          description
            "List of endpoints to listen for NETCONF connections on.";
          leaf name {
            type string;
            description
              "An arbitrary name for the NETCONF listen endpoint.";



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          }
          choice transport {
            mandatory true;
            description
              "Selects between available transports.";
            case ssh {
              if-feature ssh-listen;
              container ssh {
                description
                  "SSH-specific listening configuration for inbound
                   connections.";
                uses ss:listening-ssh-server-grouping {
                  refine port {
                    default 830;
                  }
                }
              }
            }
            case tls {
              if-feature tls-listen;
              container tls {
                description
                  "TLS-specific listening configuration for inbound
                   connections.";
                uses ts:listening-tls-server-grouping {
                  refine port {
                    default 6513;
                  }
                  augment "client-auth" {
                    description
                      "Augments in the cert-to-name structure.";
                    uses cert-maps-grouping;
                  }
                }
              }
            }
          }
        }
      }

      container call-home {
        if-feature call-home;
        description
          "Configures call-home behavior";
        list netconf-client {
          key name;
          description
            "List of NETCONF clients the NETCONF server is to initiate



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             call-home connections to.";
          leaf name {
            type string;
            description
              "An arbitrary name for the remote NETCONF client.";
          }
          choice transport {
            mandatory true;
            description
              "Selects between available transports.";
            case ssh {
              if-feature ssh-call-home;
              container ssh {
                description
                  "Specifies SSH-specific call-home transport
                   configuration.";
                uses endpoints-container {
                  refine endpoints/endpoint/port {
                    default 4334;
                  }
                }
                uses ss:non-listening-ssh-server-grouping;
              }
            }
            case tls {
              if-feature tls-call-home;
              container tls {
                description
                  "Specifies TLS-specific call-home transport
                   configuration.";
                uses endpoints-container {
                  refine endpoints/endpoint/port {
                    default 4335;
                  }
                }
                uses ts:non-listening-tls-server-grouping {
                  augment "client-auth" {
                    description
                      "Augments in the cert-to-name structure.";
                    uses cert-maps-grouping;
                  }
                }
              }
            }
          }
          container connection-type {
            description
             "Indicates the kind of connection to use.";



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            choice connection-type {
              description
                "Selects between available connection types.";
              case persistent-connection {
                container persistent {
                  presence true;
                  description
                   "Maintain a persistent connection to the NETCONF
                    client. If the connection goes down, immediately
                    start trying to reconnect to it, using the
                    reconnection strategy.

                    This connection type minimizes any NETCONF client
                    to NETCONF server data-transfer delay, albeit at
                    the expense of holding resources longer.";
                  leaf idle-timeout {
                    type uint32;
                    units "seconds";
                    default 86400;  // one day;
                    description
                      "Specifies the maximum number of seconds that a
                       a NETCONF session may remain idle. A NETCONF
                       session will be dropped if it is idle for an
                       interval longer than this number of seconds.
                       If set to zero, then the server will never drop
                       a session because it is idle.  Sessions that
                       have a notification subscription active are
                       never dropped.";
                  }
                  container keep-alives {
                    description
                      "Configures the keep-alive policy, to proactively
                       test the aliveness of the SSH/TLS client.  An
                       unresponsive SSH/TLS client will be dropped after
                       approximately max-attempts * max-wait seconds.";
                    reference
                      "RFC YYYY: NETCONF Call Home and RESTCONF Call
                       Home, Section 3.1, item S6";
                    leaf max-wait {
                      type uint16 {
                        range "1..max";
                      }
                      units seconds;
                      default 30;
                      description
                       "Sets the amount of time in seconds after which
                        if no data has been received from the SSH/TLS
                        client, a SSH/TLS-level message will be sent



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                        to test the aliveness of the SSH/TLS client.";
                    }
                    leaf max-attempts {
                      type uint8;
                      default 3;
                      description
                       "Sets the maximum number of sequential keep-alive
                        messages that can fail to obtain a response from
                        the SSH/TLS client before assuming the SSH/TLS
                        client is no longer alive.";
                    }
                  }
                }
              }
              case periodic-connection {
                container periodic {
                  presence true;
                  description
                   "Periodically connect to the NETCONF client, so that
                    the NETCONF client may deliver messages pending for
                    the NETCONF server.  The NETCONF client must close
                    the connection when it is ready to release it. Once
                    the connection has been closed, the NETCONF server
                    will restart its timer until the next connection.";
                  leaf idle-timeout {
                    type uint16;
                    units "seconds";
                    default 300; // five minutes
                    description
                      "Specifies the maximum number of seconds that a
                       a NETCONF session may remain idle. A NETCONF
                       session will be dropped if it is idle for an
                       interval longer than this number of seconds.
                       If set to zero, then the server will never drop
                       a session because it is idle.  Sessions that
                       have a notification subscription active are
                       never dropped.";
                  }
                  leaf reconnect_timeout {
                    type uint16 {
                      range "1..max";
                    }
                    units minutes;
                    default 60;
                    description
                     "Sets the maximum amount of unconnected time the
                      NETCONF server will wait before re-establishing
                      a connection to the NETCONF client.  The NETCONF



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                      server may initiate a connection before this
                      time if desired (e.g., to deliver an event
                      notification message).";
                  }
                }
              }
            }
          }
          container reconnect-strategy {
            description
             "The reconnection strategy directs how a NETCONF server
              reconnects to a NETCONF client, after discovering its
              connection to the client has dropped, even if due to a
              reboot.  The NETCONF server starts with the specified
              endpoint and tries to connect to it max-attempts times
              before trying the next endpoint in the list (round
              robin).";
            leaf start-with {
              type enumeration {
                enum first-listed {
                  description
                    "Indicates that reconnections should start with
                     the first endpoint listed.";
                }
                enum last-connected {
                  description
                    "Indicates that reconnections should start with
                     the endpoint last connected to.  If no previous
                     connection has ever been established, then the
                     first endpoint configured is used.   NETCONF
                     servers SHOULD be able to remember the last
                     endpoint connected to across reboots.";
                }
              }
              default first-listed;
              description
               "Specifies which of the NETCONF client's endpoints the
                NETCONF server should start with when trying to connect
                to the NETCONF client.";
            }
            leaf max-attempts {
              type uint8 {
                range "1..max";
              }
              default 3;
              description
               "Specifies the number times the NETCONF server tries to
                connect to a specific endpoint before moving on to the



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                next endpoint in the list (round robin).";
            }
          }
        }
      }
    }


    grouping cert-maps-grouping {
      description
        "A grouping that defines a container around the
         cert-to-name structure defined in RFC 7407.";
      container cert-maps {
        uses x509c2n:cert-to-name;
        description
         "The cert-maps container is used by a TLS-based NETCONF
          server to map the NETCONF client's presented X.509
          certificate to a NETCONF username.  If no matching and
          valid cert-to-name list entry can be found, then the
          NETCONF server MUST close the connection, and MUST NOT
          accept NETCONF messages over it.";
        reference
          "RFC WWWW: NETCONF over TLS, Section 7";
      }
    }


    grouping endpoints-container {
      description
        "This grouping is used by both the ssh and tls containers
         for call-home configurations.";
      container endpoints {
        description
          "Container for the list of endpoints.";
        list endpoint {
          key name;
          min-elements 1;
          ordered-by user;
          description
            "User-ordered list of endpoints for this NETCONF client.
             Defining more than one enables high-availability.";
          leaf name {
            type string;
            description
              "An arbitrary name for this endpoint.";
          }
          leaf address {
            type inet:host;



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            mandatory true;
            description
             "The IP address or hostname of the endpoint.  If a
              hostname is configured and the DNS resolution results
              in more than one IP address, the NETCONF server
              will process the IP addresses as if they had been
              explicitly configured in place of the hostname.";
          }
          leaf port {
            type inet:port-number;
            description
             "The IP port for this endpoint. The NETCONF server will
              use the IANA-assigned well-known port if no value is
              specified.";
          }
        }
      }
    }

  }


  <CODE ENDS>

4.  Design Considerations

   Editorial: this section is a hold over from before, previously called
   "Objectives".  It was only written two support the "server" (not the
   "client").  The question is if it's better to add the missing
   "client" parts, or remove this section altogether.

   The primary purpose of the YANG modules defined herein is to enable
   the configuration of the NETCONF client and servers.  This scope
   includes the following objectives:

4.1.  Support all NETCONF transports

   The YANG module should support all current NETCONF transports, namely
   NETCONF over SSH [RFC6242], NETCONF over TLS [RFC7589], and to be
   extensible to support future transports as necessary.

   Because implementations may not support all transports, the modules
   should use YANG "feature" statements so that implementations can
   accurately advertise which transports are supported.







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4.2.  Enable each transport to select which keys to use

   Servers may have a multiplicity of host-keys or server-certificates
   from which subsets may be selected for specific uses.  For instance,
   a NETCONF server may want to use one set of SSH host-keys when
   listening on port 830, and a different set of SSH host-keys when
   calling home.  The data models provided herein should enable
   configuration of which keys to use on a per-use basis.

4.3.  Support authenticating NETCONF clients certificates

   When a certificate is used to authenticate a NETCONF client, there is
   a need to configure the server to know how to authenticate the
   certificates.  The server should be able to authenticate the client's
   certificate either by using path-validation to a configured trust
   anchor or by matching the client-certificate to one previously
   configured.

4.4.  Support mapping authenticated NETCONF client certificates to
      usernames

   When a client certificate is used for TLS client authentication, the
   NETCONF server must be able to derive a username from the
   authenticated certificate.  Thus the modules defined herein should
   enable this mapping to be configured.

4.5.  Support both listening for connections and call home

   The NETCONF protocols were originally defined as having the server
   opening a port to listen for client connections.  More recently the
   NETCONF working group defined support for call-home
   ([draft-ietf-netconf-call-home]), enabling the server to initiate the
   connection to the client.  Thus the modules defined herein should
   enable configuration for both listening for connections and calling
   home.  Because implementations may not support both listening for
   connections and calling home, YANG "feature" statements should be
   used so that implementation can accurately advertise the connection
   types it supports.

4.6.  For Call Home connections

   The following objectives only pertain to call home connections.

4.6.1.  Support more than one NETCONF client

   A NETCONF server may be managed by more than one NETCONF client.  For
   instance, a deployment may have one client for provisioning and
   another for fault monitoring.  Therefore, when it is desired for a



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   server to initiate call home connections, it should be able to do so
   to more than one client.

4.6.2.  Support NETCONF clients having more than one endpoint

   A NETCONF client managing a NETCONF server may implement a high-
   availability strategy employing a multiplicity of active and/or
   passive endpoint.  Therefore, when it is desired for a server to
   initiate call home connections, it should be able to connect to any
   of the client's endpoints.

4.6.3.  Support a reconnection strategy

   Assuming a NETCONF client has more than one endpoint, then it becomes
   necessary to configure how a NETCONF server should reconnect to the
   client should it lose its connection to one the client's endpoints.
   For instance, the NETCONF server may start with first endpoint
   defined in a user-ordered list of endpoints or with the last
   endpoints it was connected to.

4.6.4.  Support both persistent and periodic connections

   NETCONF clients may vary greatly on how frequently they need to
   interact with a NETCONF server, how responsive interactions need to
   be, and how many simultaneous connections they can support.  Some
   clients may need a persistent connection to servers to optimize real-
   time interactions, while others prefer periodic interactions in order
   to minimize resource requirements.  Therefore, when it is necessary
   for server to initiate connections, it should be configurable if the
   connection is persistent or periodic.

4.6.5.  Reconnection strategy for periodic connections

   The reconnection strategy should apply to both persistent and
   periodic connections.  How it applies to periodic connections becomes
   clear when considering that a periodic "connection" is a logical
   connection to a single server.  That is, the periods of
   unconnectedness are intentional as opposed to due to external
   reasons.  A periodic "connection" should always reconnect to the same
   server until it is no longer able to, at which time the reconnection
   strategy guides how to connect to another server.

4.6.6.  Keep-alives for persistent connections

   If a persistent connection is desired, it is the responsibility of
   the connection initiator to actively test the "aliveness" of the
   connection.  The connection initiator must immediately work to
   reestablish a persistent connection as soon as the connection is



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   lost.  How often the connection should be tested is driven by NETCONF
   client requirements, and therefore keep-alive settings should be
   configurable on a per-client basis.

4.6.7.  Customizations for periodic connections

   If a periodic connection is desired, it is necessary for the NETCONF
   server to know how often it should connect.  This frequency
   determines the maximum amount of time a NETCONF client may have to
   wait to send data to a server.  A server may connect to a client
   before this interval expires if desired (e.g., to send data to a
   client).

5.  Security Considerations

   A denial of service (DoS) attack MAY occur if the NETCONF server
   limits the maximum number of NETCONF sessions it will accept (i.e.
   the 'max-sessions' field in the ietf-netconf-server module is not
   zero) and either the "hello-timeout" or "idle-timeout" fields in
   ietf-netconf-server module have been set to indicate the NETCONF
   server should wait forever (i.e. set to zero).

6.  IANA Considerations

6.1.  The IETF XML Registry

   This document registers two URIs in the IETF XML registry [RFC2119].
   Following the format in [RFC3688], the following registrations are
   requested:

      URI: urn:ietf:params:xml:ns:yang:ietf-netconf-client
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

      URI: urn:ietf:params:xml:ns:yang:ietf-netconf-server
      Registrant Contact: The NETCONF WG of the IETF.
      XML: N/A, the requested URI is an XML namespace.

6.2.  The YANG Module Names Registry

   This document registers two YANG modules in the YANG Module Names
   registry [RFC6020].  Following the format in [RFC6020], the the
   following registrations are requested:








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      name:         ietf-netconf-client
      namespace:    urn:ietf:params:xml:ns:yang:ietf-netconf-client
      prefix:       ncc
      reference:    RFC XXXX

      name:         ietf-netconf-server
      namespace:    urn:ietf:params:xml:ns:yang:ietf-netconf-server
      prefix:       ncs
      reference:    RFC XXXX

7.  Acknowledgements

   The authors would like to thank for following for lively discussions
   on list and in the halls (ordered by last name): Andy Bierman, Martin
   Bjorklund, Benoit Claise, Mehmet Ersue, David Lamparter, Alan Luchuk,
   Ladislav Lhotka, Radek Krejci, Tom Petch, Phil Shafer, Sean Turner,
   and Bert Wijnen.

   Juergen Schoenwaelder and was partly funded by Flamingo, a Network of
   Excellence project (ICT-318488) supported by the European Commission
   under its Seventh Framework Programme.

8.  References

8.1.  Normative References

   [draft-ietf-netconf-ssh-client-server]
              Watsen, K., "SSH Client and Server Models", draft-ieft-
              netconf-ssh-client-server-00 (work in progress), 2016,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-ssh-
              client-server>.

   [draft-ietf-netconf-system-keychain]
              Watsen, K., "System Keychain Model", draft-ieft-netconf-
              system-keychain-00 (work in progress), 2016,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-
              system-keychain>.

   [draft-ietf-netconf-tls-client-server]
              Watsen, K., "TLS Client and Server Models", draft-ieft-
              netconf-tls-client-server-00 (work in progress), 2016,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-tls-
              client-server>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.



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   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <http://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <http://www.rfc-editor.org/info/rfc6242>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <http://www.rfc-editor.org/info/rfc6991>.

   [RFC7407]  Bjorklund, M. and J. Schoenwaelder, "A YANG Data Model for
              SNMP Configuration", RFC 7407, DOI 10.17487/RFC7407,
              December 2014, <http://www.rfc-editor.org/info/rfc7407>.

   [RFC7589]  Badra, M., Luchuk, A., and J. Schoenwaelder, "Using the
              NETCONF Protocol over Transport Layer Security (TLS) with
              Mutual X.509 Authentication", RFC 7589,
              DOI 10.17487/RFC7589, June 2015,
              <http://www.rfc-editor.org/info/rfc7589>.

8.2.  Informative References

   [draft-ietf-netconf-call-home]
              Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
              draft-ieft-netconf-call-home-17 (work in progress), 2015,
              <https://datatracker.ietf.org/html/draft-ieft-netconf-
              call-home-17>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <http://www.rfc-editor.org/info/rfc3688>.

   [RFC4252]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
              January 2006, <http://www.rfc-editor.org/info/rfc4252>.

   [RFC4253]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Transport Layer Protocol", RFC 4253, DOI 10.17487/RFC4253,
              January 2006, <http://www.rfc-editor.org/info/rfc4253>.




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   [RFC4254]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Connection Protocol", RFC 4254, DOI 10.17487/RFC4254,
              January 2006, <http://www.rfc-editor.org/info/rfc4254>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <http://www.rfc-editor.org/info/rfc5246>.











































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Appendix A.  Change Log

A.1.  server-model-09 to 00

   o  This draft was split out from draft-ietf-netconf-server-model-09.

   o  Added in previously missing ietf-netconf-client module.

   o  Added in new features 'listen' and 'call-home' so future
      transports can be augmented in.

Appendix B.  Open Issues

   Please see: https://github.com/netconf-wg/netconf-client-server/
   issues.

Authors' Addresses

   Kent Watsen
   Juniper Networks

   EMail: kwatsen@juniper.net


   Gary Wu
   Cisco Networks

   EMail: garywu@cisco.com


   Juergen Schoenwaelder
   Jacobs University Bremen

   EMail: j.schoenwaelder@jacobs-university.de

















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