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Versions: (draft-bjorklund-netmod-interfaces-cfg) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 RFC 7223

Network Working Group                                       M. Bjorklund
Internet-Draft                                            Tail-f Systems
Intended status: Standards Track                            May 15, 2013
Expires: November 16, 2013


               A YANG Data Model for Interface Management
                  draft-ietf-netmod-interfaces-cfg-11

Abstract

   This document defines a YANG data model for the management of network
   interfaces.  It is expected that interface type specific data models
   augment the generic interfaces data model defined in this document.
   The data model includes configuration data, state data and counters
   for the collection of statistics.

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 November 16, 2013.

Copyright Notice

   Copyright (c) 2013 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  . . . . . . . . . . . . . . . . . . . . . . .  3
     1.2.  Tree Diagrams  . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Objectives . . . . . . . . . . . . . . . . . . . . . . . . . .  5
   3.  Interfaces Data Model  . . . . . . . . . . . . . . . . . . . .  6
     3.1.  The interface Lists  . . . . . . . . . . . . . . . . . . .  6
     3.2.  Interface References . . . . . . . . . . . . . . . . . . .  7
     3.3.  Interface Layering . . . . . . . . . . . . . . . . . . . .  7
   4.  Relationship to the IF-MIB . . . . . . . . . . . . . . . . . .  9
   5.  Interfaces YANG Module . . . . . . . . . . . . . . . . . . . . 11
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 26
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 27
   8.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 28
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 29
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 29
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 29
   Appendix A.  Example: Ethernet Interface Module  . . . . . . . . . 30
   Appendix B.  Example: Ethernet Bonding Interface Module  . . . . . 32
   Appendix C.  Example: VLAN Interface Module  . . . . . . . . . . . 33
   Appendix D.  Example: NETCONF <get> reply  . . . . . . . . . . . . 34
   Appendix E.  Examples: Interface Naming Schemes  . . . . . . . . . 37
     E.1.  Router with Restricted Interface Names . . . . . . . . . . 37
     E.2.  Router with Arbitrary Interface Names  . . . . . . . . . . 38
     E.3.  Ethernet Switch with Restricted Interface Names  . . . . . 39
     E.4.  Generic Host with Restricted Interface Names . . . . . . . 39
     E.5.  Generic Host with Arbitrary Interface Names  . . . . . . . 40
   Appendix F.  ChangeLog . . . . . . . . . . . . . . . . . . . . . . 42
     F.1.  Version -11  . . . . . . . . . . . . . . . . . . . . . . . 42
     F.2.  Version -08  . . . . . . . . . . . . . . . . . . . . . . . 42
     F.3.  Version -07  . . . . . . . . . . . . . . . . . . . . . . . 42
     F.4.  Version -06  . . . . . . . . . . . . . . . . . . . . . . . 42
     F.5.  Version -05  . . . . . . . . . . . . . . . . . . . . . . . 42
     F.6.  Version -04  . . . . . . . . . . . . . . . . . . . . . . . 43
     F.7.  Version -03  . . . . . . . . . . . . . . . . . . . . . . . 43
     F.8.  Version -02  . . . . . . . . . . . . . . . . . . . . . . . 43
     F.9.  Version -01  . . . . . . . . . . . . . . . . . . . . . . . 43
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 44












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1.  Introduction

   This document defines a YANG [RFC6020] data model for the management
   of network interfaces.  It is expected that interface type specific
   data models augment the generic interfaces data model defined in this
   document.

   Network interfaces are central to the management of many Internet
   protocols.  Thus, it is important to establish a common data model
   for how interfaces are identified, configured, and monitored.

   The data model includes configuration data, state data and counters
   for the collection of statistics.

1.1.  Terminology

   The keywords "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].

   The following terms are defined in [RFC6241] and are not redefined
   here:

   o  client

   o  configuration data

   o  server

   o  state data

   The following terms are defined in [RFC6020] and are not redefined
   here:

   o  augment

   o  data model

   o  data node

1.2.  Tree Diagrams

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





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

   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 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.






































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2.  Objectives

   This section describes some of the design objectives for the model
   presented in Section 5.

   o  It is recognized that existing implementations will have to map
      the interface data model defined in this memo to their proprietary
      native data model.  The data model should be simple to facilitate
      such mappings.

   o  The data model should be suitable for new implementations to use
      as-is, without requiring a mapping to a different native model.

   o  References to interfaces should be as simple as possible,
      preferably by using a single leafref.

   o  The mapping to ifIndex [RFC2863] used by SNMP to identify
      interfaces must be clear.

   o  The model must support interface layering, both simple layering
      where one interface is layered on top of exactly one other
      interface, and more complex scenarios where one interface results
      from the aggregation of N other interfaces, or when N interfaces
      are multiplexed over one other interface.

   o  The data model should support the pre-provisioning of interface
      configuration, i.e., it should be possible to configure an
      interface whose physical interface hardware is not present on the
      device.  It is recommended that devices that support dynamic
      addition and removal of physical interfaces also support pre-
      provisioning.

   o  The data model should support both physical interfaces as well as
      logical interfaces.

   o  The data model should include read-only counters in order to
      gather statistics for octets, packets and errors, sent and
      received.













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3.  Interfaces Data Model

   This document defines the YANG module "ietf-interfaces", which has
   the following structure:

      +--rw interfaces
      |  +--rw interface* [name]
      |     +--rw name                        string
      |     +--rw description?                string
      |     +--rw type                        ianaift:iana-if-type
      |     +--rw enabled?                    boolean
      |     +--rw link-up-down-trap-enable?   enumeration
      +--ro interfaces-state
         +--ro interface* [name]
            +--ro name               string
            +--ro type               ianaift:iana-if-type
            +--ro admin-status       enumeration
            +--ro oper-status        enumeration
            +--ro last-change?       yang:date-and-time
            +--ro if-index           int32
            +--ro phys-address?      yang:phys-address
            +--ro higher-layer-if*   interface-state-ref
            +--ro lower-layer-if*    interface-state-ref
            +--ro speed?             yang:gauge64
            +--ro statistics
               +--ro discontinuity-time    yang:date-and-time
               +--ro in-octets?            yang:counter64
               +--ro in-unicast-pkts?      yang:counter64
               +--ro in-broadcast-pkts?    yang:counter64
               +--ro in-multicast-pkts?    yang:counter64
               +--ro in-discards?          yang:counter32
               +--ro in-errors?            yang:counter32
               +--ro in-unknown-protos?    yang:counter32
               +--ro out-octets?           yang:counter64
               +--ro out-unicast-pkts?     yang:counter64
               +--ro out-broadcast-pkts?   yang:counter64
               +--ro out-multicast-pkts?   yang:counter64
               +--ro out-discards?         yang:counter32
               +--ro out-errors?           yang:counter32

3.1.  The interface Lists

   The data model for interfaces presented in this document uses a flat
   list of interfaces.  Each interface in the list is identified by its
   name.  Furthermore, each interface has a mandatory "type" leaf.

   There is one list of configured interfaces ("/interfaces/interface"),
   and a separate list for the operational state of all interfaces



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   ("/interfaces-state/interface").

   It is expected that interface type specific data models augment the
   interface lists, and use the "type" leaf to make the augmentation
   conditional.

   As an example of such an interface type specific augmentation,
   consider this YANG snippet.  For a more complete example, see
   Appendix A.

     import interfaces {
         prefix "if";
     }

     augment "/if:interfaces/if:interface" {
         when "if:type = 'ethernetCsmacd'";

         container ethernet {
             leaf duplex {
                 ...
             }
         }
     }

   For physical interfaces, the "name" is the device-specific name of
   the interface.  It is used to identify the physical hardware
   interface.  The 'config false' list "/interfaces-state/interface"
   contains all currently existing interfaces on the device.

   If the device supports arbitrarily named logical interfaces, the
   NETCONF server advertises the feature "arbitrary-names".  If the
   device does not advertise this feature, the names of logical
   interfaces MUST match the device's naming scheme.  How a client can
   learn the naming scheme of such devices is outside the scope of this
   document.

3.2.  Interface References

   An interface is identified by its name, which is unique within the
   server.  This property is captured in the "interface-ref" and
   "interface-state-ref" typedefs, which other YANG modules SHOULD use
   when they need to reference a configured interface or operationally
   used interface, respectively.

3.3.  Interface Layering

   There is no generic mechanism for how an interface is configured to
   be layered on top of some other interface.  It is expected that



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   interface type specific models define their own data nodes for
   interface layering, by using "interface-ref" types to reference lower
   layers.

   Below is an example of a model with such nodes.  For a more complete
   example, see Appendix B.

     import interfaces {
         prefix "if";
     }

     augment "/if:interfaces/if:interface" {
         when "if:type = 'ieee8023adLag'";

         leaf-list slave-if {
             type if:interface-ref;
             must "/if:interfaces/if:interface[if:name = current()]"
                + "/if:type = 'ethernetCsmacd'" {
                 description
                     "The type of a slave interface must be ethernet";
             }
         }
         // other bonding config params, failover times etc.
     }

   Two state data leaf-lists, "higher-layer-if" and "lower-layer-if",
   represent a read-only view of the interface layering hierarchy.
























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4.  Relationship to the IF-MIB

   If the device implements IF-MIB [RFC2863], each entry in the
   "/interfaces-state/interface" list is typically mapped to one
   ifEntry.  The "if-index" leaf MUST contain the value of the
   corresponding ifEntry's ifIndex.

   In most cases, the "name" of an "interface" entry is mapped to
   ifName. ifName is defined as an DisplayString [RFC2579] which uses a
   7-bit ASCII character set.  An implementation MUST restrict the
   allowed values for "name" to match the restrictions of ifName.

   The IF-MIB allows two different ifEntries to have the same ifName.
   Devices that support this feature, and also support the data model
   defined in this document, cannot have a 1-1 mapping between the
   "name" leaf and ifName.

   The configured "description" of an "interface" has traditionally been
   mapped to ifAlias in some implementations.  This document allows this
   mapping, but implementers should be aware of the differences in the
   value space and persistence for these objects.  See the YANG module
   definition of the leaf "description" in Section 5 for details.

   The IF-MIB also defines the writable object ifPromiscuousMode.  Since
   this object typically is not a configuration object, it is not mapped
   to the "ietf-interfaces" module.

   There are a number of counters in the IF-MIB that exist in two
   versions; one with 32 bits and one with 64 bits.  The YANG module
   contains the 64 bits counters only.  Note that NETCONF and SNMP may
   differ in the time granularity in which they provide access to the
   counters.  For example, it is common that SNMP implementations cache
   counter values for some time.

   The following table lists the YANG data nodes with corresponding
   objects in the IF-MIB.















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       +----------------------------------+------------------------+
       | YANG data node                   | IF-MIB object          |
       +----------------------------------+------------------------+
       | interface                        | ifEntry                |
       | name                             | ifName                 |
       | description                      | ifAlias                |
       | type                             | ifType                 |
       | enabled / admin-status           | ifAdminStatus          |
       | oper-status                      | ifOperStatus           |
       | last-change                      | ifLastChange           |
       | if-index                         | ifIndex                |
       | link-up-down-trap-enable         | ifLinkUpDownTrapEnable |
       | phys-address                     | ifPhysAddress          |
       | higher-layer-if / lower-layer-if | ifStackTable           |
       | speed                            | ifSpeed                |
       | in-octets                        | ifHCInOctets           |
       | in-unicast-pkts                  | ifHCInUcastPkts        |
       | in-broadcast-pkts                | ifHCInBroadcastPkts    |
       | in-multicast-pkts                | ifHCInMulticastPkts    |
       | in-discards                      | ifInDiscards           |
       | in-errors                        | ifInErrors             |
       | in-unknown-protos                | ifInUnknownProtos      |
       | out-octets                       | ifHCOutOctets          |
       | out-unicast-pkts                 | ifHCOutUcastPkts       |
       | out-broadcast-pkts               | ifHCOutBroadcastPkts   |
       | out-multicast-pkts               | ifHCOutMulticastPkts   |
       | out-discards                     | ifOutDiscards          |
       | out-errors                       | ifOutErrors            |
       +----------------------------------+------------------------+

                YANG data nodes and related IF-MIB objects




















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5.  Interfaces YANG Module

   This YANG module imports typedefs from [I-D.ietf-netmod-rfc6021-bis]
   and [I-D.ietf-netmod-iana-if-type].

   RFC Ed.: update the date below with the date of RFC publication and
   remove this note.

   <CODE BEGINS> file "ietf-interfaces@2013-05-15.yang"

   module ietf-interfaces {

     namespace "urn:ietf:params:xml:ns:yang:ietf-interfaces";
     prefix if;

     import ietf-yang-types {
       prefix yang;
     }
     import iana-if-type {
       prefix ianaift;
     }

     organization
       "IETF NETMOD (NETCONF Data Modeling Language) Working Group";

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

        WG Chair: David Kessens
                  <mailto:david.kessens@nsn.com>

        WG Chair: Juergen Schoenwaelder
                  <mailto:j.schoenwaelder@jacobs-university.de>

        Editor:   Martin Bjorklund
                  <mailto:mbj@tail-f.com>";

     description
       "This module contains a collection of YANG definitions for
        managing network interfaces.

        Copyright (c) 2013 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



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        set forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX; see
        the RFC itself for full legal notices.";

     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.
     revision 2013-05-15 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for Interface Management";
     }

     /* Typedefs */

     typedef interface-ref {
       type leafref {
         path "/if:interfaces/if:interface/if:name";
       }
       description
         "This type is used by data models that need to reference
          configured interfaces.";
     }

     typedef interface-state-ref {
       type leafref {
         path "/if:interfaces-state/if:interface/if:name";
       }
       description
         "This type is used by data models that need to reference
          the operationally present interfaces.";
     }

     /* Features */

     feature arbitrary-names {
       description
         "This feature indicates that the device allows logical
          interfaces to be named arbitrarily.";
     }

     feature pre-provisioning {



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       description
         "This feature indicates that the device supports
          pre-provisioning of interface configuration, i.e., it is
          possible to configure an interface whose physical interface
          hardware is not present on the device.";
     }

     feature if-mib {
       description
         "This feature indicates that the device implements IF-MIB.";
       reference
         "RFC 2863: The Interfaces Group MIB";
     }

     /* Data nodes */

     container interfaces {
       description
         "Interface configuration parameters.";

       list interface {
         key "name";

         description
           "The list of configured interfaces on the device.

            The operational state of an interface is available in the
            /interfaces-state/interface list.  If the configuration of a
            physical interface cannot be used by the system (e.g., the
            physical interface present is not matching the interface
            type), then the configuration is not applied to the physical
            interface shown in the /interfaces-state/interface list. If
            the the configuration of a logical interface cannot be used
            by the system, the configured interface is not instantiated
            in the /interfaces-state/interface list.";

        leaf name {
           type string;
           description
             "The name of the interface.

              A device MAY restrict the allowed values for this leaf,
              possibly depending on the type of the interface.

              For physical interfaces, this leaf is the device-specific
              name of the interface.  The 'config false' list
              /interfaces-state/interface contains the currently
              existing interfaces on the device.



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              If a client tries to create configuration for a physical
              interface that is not present, the server MAY reject the
              request, if the implementation does not support
              pre-provisioning of interfaces, or if the name refers to
              an interface that can never exist in the system.
              A NETCONF server MUST reply with an rpc-error with the
              error-tag 'invalid-value' in this case.

              If the device supports pre-provisioning of interface
              configuration, the feature 'pre-provisioning' is
              advertised.

              If the device allows arbitrarily named logical interfaces,
              the feature 'arbitrary-names' is advertised.

              When a configured logical interface is created by the
              system, it is instantiated in the
              /interface-state/interface list.  Since the name in that
              list MAY be mapped to ifName by an implementation, such an
              implementation MUST restrict the allowed values for this
              leaf so that it matches the restrictions of ifName.

              If a NETCONF server that implements this restriction is
              sent a value that doesn't match the restriction, it MUST
              reply with an rpc-error with the error-tag
              'invalid-value'.";
         }

         leaf description {
           type string;
           description
             "A textual description of the interface.

              This leaf MAY be mapped to ifAlias by an implementation.
              Such an implementation MUST restrict the allowed values
              for this leaf so that it matches the restrictions of
              ifAlias.

              If a NETCONF server that implements this restriction is
              sent a value that doesn't match the restriction, it MUST
              reply with an rpc-error with the error-tag
              'invalid-value'.

              Since ifAlias is defined to be stored in non-volatile
              storage, the SNMP implementation MUST map ifAlias to the
              value of 'description' in the persistently stored
              datastore.




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              Specifically, if the device supports ':startup', when
              ifAlias is read the device MUST return the value of
              'description' in the 'startup' datastore, and when it is
              written, it MUST be written to the 'running' and 'startup'
              datastores.  Note that it is up to the implementation if
              it modifies this single leaf in 'startup', or if it
              performs an implicit copy-config from 'running' to
              'startup'.

              If the device does not support ':startup', ifAlias MUST
              be mapped to the 'description' leaf in the 'running'
              datastore.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifAlias";
         }

         leaf type {
           type ianaift:iana-if-type;
           mandatory true;
           description
             "The type of the interface.

              When an interface entry is created, a server MAY
              initialize the type leaf with a valid value, e.g., if it
              is possible to derive the type from the name of the
              interface.

              If a client tries to set the type of an interface to a
              value that can never be used by the system, e.g., if the
              type is not supported or if the type does not match the
              name of the interface, the server MUST reject the request.
              A NETCONF server MUST reply with an rpc-error with the
              error-tag 'invalid-value' in this case.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifType";
         }

         leaf enabled {
           type boolean;
           default "true";
           description
             "This leaf contains the configured, desired state of the
              interface.

              Systems that implement the IF-MIB use the value of this
              leaf in the 'running' datastore to set
              IF-MIB.ifAdminStatus to 'up' or 'down' after an ifEntry
              has been initialized, as described in RFC 2863.



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              Changes in this leaf in the 'running' datastore are
              reflected in ifAdminStatus, but if ifAdminStatus is
              changed over SNMP, this leaf is not affected.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifAdminStatus";
         }

         leaf link-up-down-trap-enable {
           if-feature if-mib;
           type enumeration {
             enum enabled {
               value 1;
             }
             enum disabled {
               value 2;
             }
           }
           description
             "Controls whether linkUp/linkDown SNMP notifications
              should be generated for this interface.

              If this node is not configured, the value 'enabled' is
              operationally used by the server for interfaces which do
              not operate on top of any other interface (i.e., there are
              no 'lower-layer-if' entries), and 'disabled' otherwise.";
           reference
             "RFC 2863: The Interfaces Group MIB -
                        ifLinkUpDownTrapEnable";
         }
       }
     }

     container interfaces-state {
       config false;
       description
         "Data nodes for the operational state of interfaces.";

       list interface {
         key "name";

         description
           "The list of interfaces on the device.

            Physical interfaces detected by the system are always
            present in this list, if they are configured or not.";

         leaf name {
           type string;



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           description
             "The name of the interface.

              This leaf MAY be mapped to ifName by an implementation.
              Such an implementation MUST restrict the values
              for this leaf so that it matches the restrictions of
              ifName.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifName";
         }

         leaf type {
           type ianaift:iana-if-type;
           mandatory true;
           description
             "The type of the interface.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifType";
         }

         leaf admin-status {
           if-feature if-mib;
           type enumeration {
             enum up {
               value 1;
               description
                 "Ready to pass packets.";
             }
             enum down {
               value 2;
               description
                 "Not ready to pass packets and not in some test mode.";
             }
             enum testing {
               value 3;
               description
                 "In some test mode.";
             }
           }
           mandatory true;
           description
             "The desired state of the interface.

              This leaf has the same semantics as ifAdminStatus.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifAdminStatus";
         }




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         leaf oper-status {
           type enumeration {
             enum up {
               value 1;
               description
                 "Ready to pass packets.";
             }
             enum down {
               value 2;
               description
                 "The interface does not pass any packets.";
             }
             enum testing {
               value 3;
               description
                 "In some test mode.  No operational packets can
                  be passed.";
             }
             enum unknown {
               value 4;
               description
                 "Status cannot be determined for some reason.";
             }
             enum dormant {
               value 5;
               description
                 "Waiting for some external event.";
             }
             enum not-present {
               value 6;
               description
                 "Some component (typically hardware) is missing.";
             }
             enum lower-layer-down {
               value 7;
               description
                 "Down due to state of lower-layer interface(s).";
             }
           }
           mandatory true;
           description
             "The current operational state of the interface.

              This leaf has the same semantics as ifOperStatus.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifOperStatus";
         }




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         leaf last-change {
           type yang:date-and-time;
           description
             "The time the interface entered its current operational
              state.  If the current state was entered prior to the
              last re-initialization of the local network management
              subsystem, then this node is not present.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifLastChange";
         }

         leaf if-index {
           if-feature if-mib;
           type int32 {
             range "1..2147483647";
           }
           mandatory true;
           description
             "The ifIndex value for the ifEntry represented by this
              interface.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifIndex";
         }

         leaf phys-address {
           type yang:phys-address;
           description
             "The interface's address at its protocol sub-layer.  For
             example, for an 802.x interface, this object normally
             contains a MAC address.  The interface's media-specific
             modules must define the bit and byte ordering and the
             format of the value of this object.  For interfaces that do
             not have such an address (e.g., a serial line), this node
             is not present.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifPhysAddress";
         }

         leaf-list higher-layer-if {
           type interface-state-ref;
           description
             "A list of references to interfaces layered on top of this
              interface.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifStackTable";
         }

         leaf-list lower-layer-if {



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           type interface-state-ref;
           description
             "A list of references to interfaces layered underneath this
              interface.";
           reference
             "RFC 2863: The Interfaces Group MIB - ifStackTable";
         }

         leaf speed {
           type yang:gauge64;
           units "bits / second";
           description
               "An estimate of the interface's current bandwidth in bits
                per second.  For interfaces that do not vary in
                bandwidth or for those where no accurate estimation can
                be made, this node should contain the nominal bandwidth.
                For interfaces that have no concept of bandwidth, this
                node is not present.";
           reference
             "RFC 2863: The Interfaces Group MIB -
                        ifSpeed, ifHighSpeed";
         }

         container statistics {
           description
             "A collection of interface-related statistics objects.";

           leaf discontinuity-time {
             type yang:date-and-time;
             mandatory true;
             description
               "The time on the most recent occasion at which any one or
                more of this interface's counters suffered a
                discontinuity.  If no such discontinuities have occurred
                since the last re-initialization of the local management
                subsystem, then this node contains the time the local
                management subsystem re-initialized itself.";
           }

           leaf in-octets {
             type yang:counter64;
             description
               "The total number of octets received on the interface,
                including framing characters.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of



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                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifHCInOctets";
           }
           leaf in-unicast-pkts {
             type yang:counter64;
             description
               "The number of packets, delivered by this sub-layer to a
                higher (sub-)layer, which were not addressed to a
                multicast or broadcast address at this sub-layer.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifHCInUcastPkts";
           }
           leaf in-broadcast-pkts {
             type yang:counter64;
             description
               "The number of packets, delivered by this sub-layer to a
                higher (sub-)layer, which were addressed to a broadcast
                address at this sub-layer.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB -
                          ifHCInBroadcastPkts";
           }
           leaf in-multicast-pkts {
             type yang:counter64;
             description
               "The number of packets, delivered by this sub-layer to a
                higher (sub-)layer, which were addressed to a multicast
                address at this sub-layer.  For a MAC layer protocol,
                this includes both Group and Functional addresses.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB -
                          ifHCInMulticastPkts";



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           }
           leaf in-discards {
             type yang:counter32;
             description
               "The number of inbound packets which were chosen to be
                discarded even though no errors had been detected to
                prevent their being deliverable to a higher-layer
                protocol.  One possible reason for discarding such a
                packet could be to free up buffer space.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifInDiscards";
           }
           leaf in-errors {
             type yang:counter32;
             description
               "For packet-oriented interfaces, the number of inbound
                packets that contained errors preventing them from being
                deliverable to a higher-layer protocol.  For character-
                oriented or fixed-length interfaces, the number of
                inbound transmission units that contained errors
                preventing them from being deliverable to a higher-layer
                protocol.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifInErrors";
           }
           leaf in-unknown-protos {
             type yang:counter32;
             description
               "For packet-oriented interfaces, the number of packets
                received via the interface which were discarded because
                of an unknown or unsupported protocol.  For
                character-oriented or fixed-length interfaces that
                support protocol multiplexing the number of transmission
                units received via the interface which were discarded
                because of an unknown or unsupported protocol.  For any
                interface that does not support protocol multiplexing,
                this counter is not present.




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                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifInUnknownProtos";
           }

           leaf out-octets {
             type yang:counter64;
             description
               "The total number of octets transmitted out of the
                interface, including framing characters.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifHCOutOctets";
           }
           leaf out-unicast-pkts {
             type yang:counter64;
             description
               "The total number of packets that higher-level protocols
                requested be transmitted, and which were not addressed
                to a multicast or broadcast address at this sub-layer,
                including those that were discarded or not sent.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifHCOutUcastPkts";
           }
           leaf out-broadcast-pkts {
             type yang:counter64;
             description
               "The total number of packets that higher-level protocols
                requested be transmitted, and which were addressed to a
                broadcast address at this sub-layer, including those
                that were discarded or not sent.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";



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             reference
               "RFC 2863: The Interfaces Group MIB -
                          ifHCOutBroadcastPkts";
           }
           leaf out-multicast-pkts {
             type yang:counter64;
             description
               "The total number of packets that higher-level protocols
                requested be transmitted, and which were addressed to a
                multicast address at this sub-layer, including those
                that were discarded or not sent.  For a MAC layer
                protocol, this includes both Group and Functional
                addresses.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB -
                          ifHCOutMulticastPkts";
           }
           leaf out-discards {
             type yang:counter32;
             description
               "The number of outbound packets which were chosen to be
                discarded even though no errors had been detected to
                prevent their being transmitted.  One possible reason
                for discarding such a packet could be to free up buffer
                space.

                Discontinuities in the value of this counter can occur
                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifOutDiscards";
           }
           leaf out-errors {
             type yang:counter32;
             description
               "For packet-oriented interfaces, the number of outbound
                packets that could not be transmitted because of errors.
                For character-oriented or fixed-length interfaces, the
                number of outbound transmission units that could not be
                transmitted because of errors.

                Discontinuities in the value of this counter can occur



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                at re-initialization of the management system, and at
                other times as indicated by the value of
                'discontinuity-time'.";
             reference
               "RFC 2863: The Interfaces Group MIB - ifOutErrors";
           }
         }
       }
     }
   }

   <CODE ENDS>







































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6.  IANA Considerations

   This document registers a URI in the IETF XML registry [RFC3688].
   Following the format in RFC 3688, the following registration is
   requested to be made.

        URI: urn:ietf:params:xml:ns:yang:ietf-interfaces

        Registrant Contact: The IESG.

        XML: N/A, the requested URI is an XML namespace.

   This document registers a YANG module in the YANG Module Names
   registry [RFC6020].

     name:         ietf-interfaces
     namespace:    urn:ietf:params:xml:ns:yang:ietf-interfaces
     prefix:       if
     reference:    RFC XXXX
































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7.  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 [RFC6242].  The NETCONF access control model
   [RFC6536] provides the means to restrict access for particular
   NETCONF users to a pre-configured subset of all available NETCONF
   protocol operations and content.

   There are a number of data nodes defined in the YANG module which are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., <edit-config>)
   to these data nodes without proper protection can have a negative
   effect on network operations.  These are the subtrees and data nodes
   and their sensitivity/vulnerability:

   /interfaces/interface:  This list specifies the configured interfaces
      on a device.  Unauthorized access to this list could cause the
      device to ignore packets it should receive and process.

   /interfaces/interface/enabled:  This leaf controls if an interface is
      enabled or not.  Unauthorized access to this leaf could cause the
      device to ignore packets it should receive and process.


























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8.  Acknowledgments

   The author wishes to thank Alexander Clemm, Per Hedeland, Ladislav
   Lhotka, and Juergen Schoenwaelder for their helpful comments.















































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9.  References

9.1.  Normative References

   [I-D.ietf-netmod-iana-if-type]
              Bjorklund, M., "IANA Interface Type and Address Family
              YANG Modules", draft-ietf-netmod-iana-if-type-06 (work in
              progress), April 2013.

   [I-D.ietf-netmod-rfc6021-bis]
              Schoenwaelder, J., "Common YANG Data Types",
              draft-ietf-netmod-rfc6021-bis-02 (work in progress),
              May 2013.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB", RFC 2863, June 2000.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

9.2.  Informative References

   [RFC2579]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Textual Conventions for SMIv2",
              STD 58, RFC 2579, April 1999.

   [RFC6241]  Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
              Bierman, "Network Configuration Protocol (NETCONF)",
              RFC 6241, June 2011.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, June 2011.

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              March 2012.








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Appendix A.  Example: Ethernet Interface Module

   This section gives a simple example of how an Ethernet interface
   module could be defined.  It demonstrates how media-specific
   configuration parameters can be conditionally augmented to the
   generic interface list.  It also shows how operational state
   parameters can be conditionally augmented to the operational
   interface list.  The example is not intended as a complete module for
   ethernet configuration.

   module ex-ethernet {
     namespace "http://example.com/ethernet";
     prefix "eth";

     import ietf-interfaces {
       prefix if;
     }

     // configuration parameters for ethernet interfaces
     augment "/if:interfaces/if:interface" {
       when "if:type = 'ethernetCsmacd'";

       container ethernet {
         choice transmission-params {
           case auto {
             leaf auto-negotiate {
               type empty;
             }
           }
           case manual {
             leaf duplex {
               type enumeration {
                 enum "half";
                 enum "full";
               }
             }
             leaf speed {
               type enumeration {
                 enum "10Mb";
                 enum "100Mb";
                 enum "1Gb";
                 enum "10Gb";
               }
             }
           }
         }
         // other ethernet specific params...
       }



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     }

     // operational state parameters for ethernet interfaces
     augment "/if:interfaces-state/if:interface" {
       when "if:type = 'ethernetCsmacd'";

       container ethernet {
         leaf duplex {
           type enumeration {
             enum "half";
             enum "full";
           }
         }
         // other ethernet specific params...
       }
     }
   }


































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Appendix B.  Example: Ethernet Bonding Interface Module

   This section gives an example of how interface layering can be
   defined.  An ethernet bonding interface is defined, which bonds
   several ethernet interfaces into one logical interface.

   module ex-ethernet-bonding {
     namespace "http://example.com/ethernet-bonding";
     prefix "bond";

     import ietf-interfaces {
       prefix if;
     }

     augment "/if:interfaces/if:interface" {
       when "if:type = 'ieee8023adLag'";

       leaf-list slave-if {
         type if:interface-ref;
         must "/if:interfaces/if:interface[if:name = current()]"
            + "/if:type = 'ethernetCsmacd'" {
           description
             "The type of a slave interface must be ethernet.";
         }
       }
       leaf bonding-mode {
         type enumeration {
           enum round-robin;
           enum active-backup;
           enum broadcast;
         }
       }
       // other bonding config params, failover times etc.
     }
   }
















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Appendix C.  Example: VLAN Interface Module

   This section gives an example of how a vlan interface module can be
   defined.

   module ex-vlan {
     namespace "http://example.com/vlan";
     prefix "vlan";

     import ietf-interfaces {
       prefix if;
     }

     augment "/if:interfaces/if:interface" {
       when "if:type = 'ethernetCsmacd' or
             if:type = 'ieee8023adLag'";
       leaf vlan-tagging {
         type boolean;
         default false;
       }
     }

     augment "/if:interfaces/if:interface" {
       when "if:type = 'l2vlan'";

       leaf base-interface {
         type if:interface-ref;
         must "/if:interfaces/if:interface[if:name = current()]"
            + "/vlan:vlan-tagging = 'true'" {
           description
             "The base interface must have vlan tagging enabled.";
         }
       }
       leaf vlan-id {
         type uint16 {
           range "1..4094";
         }
         must "../base-interface" {
           description
             "If a vlan-id is defined, a base-interface must
              be specified.";
         }
       }
     }
   }






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Appendix D.  Example: NETCONF <get> reply

   This section gives an example of a reply to the NETCONF <get> request
   for a device that implements the example data models above.

 <rpc-reply
     xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
     message-id="101">
   <data>

     <interfaces
         xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"
         xmlns:vlan="http://example.com/vlan">

       <interface>
         <name>eth0</name>
         <type>ethernetCsmacd</type>
         <enabled>false</enabled>
       </interface>

       <interface>
         <name>eth1</name>
         <type>ethernetCsmacd</type>
         <enabled>true</enabled>
         <vlan:vlan-tagging>true</vlan:vlan-tagging>
       </interface>

       <interface>
         <name>eth1.10</name>
         <type>l2vlan</type>
         <enabled>true</enabled>
         <vlan:base-interface>eth1</vlan:base-interface>
         <vlan:vlan-id>10</vlan:vlan-id>
       </interface>

       <interface>
         <name>lo1</name>
         <type>softwareLoopback</type>
         <enabled>true</enabled>
       </interface>

     </interfaces>

     <interfaces-state
         xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">

       <interface>
         <name>eth0</name>



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         <type>ethernetCsmacd</type>
         <admin-status>down</admin-status>
         <oper-status>down</oper-status>
         <if-index>2</if-index>
         <phys-address>00:01:02:03:04:05</phys-address>
         <statistics>
           <discontinuity-time>2013-04-01T03:00:00Z</discontinuity-time>
           <!-- counters now shown here -->
         </statistics>
       </interface>

       <interface>
         <name>eth1</name>
         <type>ethernetCsmacd</type>
         <admin-status>up</admin-status>
         <oper-status>up</oper-status>
         <if-index>7</if-index>
         <phys-address>00:01:02:03:04:06</phys-address>
         <higher-layer-if>eth1.10</higher-layer-if>
         <statistics>
           <discontinuity-time>2013-04-01T03:00:00Z</discontinuity-time>
           <!-- counters now shown here -->
         </statistics>
       </interface>

       <interface>
         <name>eth1.10</name>
         <type>l2vlan</type>
         <admin-status>up</admin-status>
         <oper-status>up</oper-status>
         <if-index>9</if-index>
         <lower-layer-if>eth1</lower-layer-if>
         <statistics>
           <discontinuity-time>2013-04-01T03:00:00Z</discontinuity-time>
           <!-- counters now shown here -->
         </statistics>
       </interface>

       <!-- This interface is not configured -->
       <interface>
         <name>eth2</name>
         <type>ethernetCsmacd</type>
         <admin-status>down</admin-status>
         <oper-status>down</oper-status>
         <if-index>8</if-index>
         <phys-address>00:01:02:03:04:07</phys-address>
         <statistics>
           <discontinuity-time>2013-04-01T03:00:00Z</discontinuity-time>



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           <!-- counters now shown here -->
         </statistics>
       </interface>

       <interface>
         <name>lo1</name>
         <type>softwareLoopback</type>
         <admin-status>up</admin-status>
         <oper-status>up</oper-status>
         <if-index>1</if-index>
         <statistics>
           <discontinuity-time>2013-04-01T03:00:00Z</discontinuity-time>
           <!-- counters now shown here -->
         </statistics>
       </interface>

     </interfaces-state>
   </data>
 </rpc-reply>
































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Appendix E.  Examples: Interface Naming Schemes

   This section gives examples of some implementation strategies.

   The examples make use of the example data model "ex-vlan" (see
   Appendix C) to show how logical interfaces can be configured.

E.1.  Router with Restricted Interface Names

   In this example, a router has support for 4 line cards, each with 8
   ports.  The slots for the cards are physically numbered from 0 to 3,
   and the ports on each card from 0 to 7.  Each card has fast- or
   gigabit-ethernet ports.

   The device-specific names for these physical interfaces are
   "fastethernet-N/M" or "gigabitethernet-N/M".

   The name of a vlan interface is restricted to the form
   "<physical-interface-name>.<subinterface-number>".

   It is assumed that the operator is aware of this naming scheme.  The
   implementation auto-initializes the value for "type" based on the
   interface name.

   The NETCONF server does not advertise the 'arbitrary-names' feature
   in the <hello> message.

   An operator can configure a physical interface by sending an
   <edit-config> containing:

     <interface nc:operation="create">
       <name>fastethernet-1/0</name>
     </interface>

   When the server processes this request, it will set the leaf "type"
   to "ethernetCsmacd".  Thus, if the client performs a <get-config>
   right after the <edit-config> above, it will get:

     <interface>
       <name>fastethernet-1/0</name>
       <type>ethernetCsmacd</type>
     </interface>

   The client can configure a vlan interface by sending an <edit-config>
   containing:






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     <interface nc:operation="create">
       <name>fastethernet-1/0.10005</name>
       <type>l2-vlan</type>
       <vlan:base-interface>fastethernet-1/0</vlan:base-interface>
       <vlan:vlan-id>5</vlan:vlan-id>
     </interface>

   If the client tries to change the type of the physical interface with
   an <edit-config> containing:

     <interface nc:operation="merge">
       <name>fastethernet-1/0</name>
       <type>tunnel</type>
     </interface>

   then the server will reply with an "invalid-value" error, since the
   new type does not match the name.

E.2.  Router with Arbitrary Interface Names

   In this example, a router has support for 4 line cards, each with 8
   ports.  The slots for the cards are physically numbered from 0 to 3,
   and the ports on each card from 0 to 7.  Each card has fast- or
   gigabit-ethernet ports.

   The device-specific names for these physical interfaces are
   "fastethernet-N/M" or "gigabitethernet-N/M".

   The implementation does not restrict the logical interface names.
   This allows to more easily apply the interface configuration to a
   different interface.  However, the additional level of indirection
   also makes it a bit more complex to map interface names found in
   other protocols to configuration entries.

   The NETCONF server advertises the 'arbitrary-names' feature in the
   <hello> message.

   Physical interfaces are configured as in Appendix E.1.

   An operator can configure a logical interface by sending an
   <edit-config> containing:

     <interface nc:operation="create">
       <name>acme-interface</name>
       <type>l2-vlan</type>
       <vlan:base-interface>fastethernet-1/0</vlan:base-interface>
       <vlan:vlan-id>5</vlan:vlan-id>
     </interface>



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   If necessary, the operator can move the configuration named
   "acme-interface" over to a different physical interface with an
   <edit-config> containing:

     <interface nc:operation="merge">
       <name>acme-interface</name>
       <vlan:base-interface>fastethernet-1/1</vlan:base-interface>
     </interface>

E.3.  Ethernet Switch with Restricted Interface Names

   In this example, an ethernet switch has a number of ports, each port
   identified by a simple port number.

   The device-specific names for the physical interfaces are numbers
   that match the physical port number.

   An operator can configure a physical interface by sending an
   <edit-config> containing:

     <interface nc:operation="create">
       <name>6</name>
     </interface>

   When the server processes this request, it will set the leaf "type"
   to "ethernetCsmacd".  Thus, if the client performs a <get-config>
   right after the <edit-config> above, it will get:

     <interface>
       <name>6</name>
       <type>ethernetCsmacd</type>
     </interface>

E.4.  Generic Host with Restricted Interface Names

   In this example, a generic host has interfaces named by the kernel.
   The system identifies the physical interface by the name assigned by
   the operating system to the interface.

   The name of a vlan interface is restricted to the form
   "<physical-interface-name>:<vlan-number>".

   The NETCONF server does not advertise the 'arbitrary-names' feature
   in the <hello> message.

   An operator can configure an interface by sending an <edit-config>
   containing:




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     <interface nc:operation="create">
       <name>eth8</name>
     </interface>

   When the server processes this request, it will set the leaf "type"
   to "ethernetCsmacd".  Thus, if the client performs a <get-config>
   right after the <edit-config> above, it will get:

     <interface>
       <name>eth8</name>
       <type>ethernetCsmacd</type>
     </interface>

   The client can configure a vlan interface by sending an <edit-config>
   containing:

     <interface nc:operation="create">
       <name>eth8:5</name>
       <type>l2-vlan</type>
       <vlan:base-interface>eth8</vlan:base-interface>
       <vlan:vlan-id>5</vlan:vlan-id>
     </interface>

E.5.  Generic Host with Arbitrary Interface Names

   In this example, a generic host has interfaces named by the kernel.
   The system identifies the physical interface by the name assigned by
   the operating system to the interface.

   The implementation does not restrict the logical interface names.
   This allows to more easily apply the interface configuration to a
   different interface.  However, the additional level of indirection
   also makes it a bit more complex to map interface names found in
   other protocols to configuration entries.

   The NETCONF server advertises the 'arbitrary-names' feature in the
   <hello> message.

   Physical interfaces are configured as in Appendix E.4.

   An operator can configure a logical interface by sending an
   <edit-config> containing:

     <interface nc:operation="create">
       <name>acme-interface</name>
       <type>l2-vlan</type>
       <vlan:base-interface>eth8</vlan:base-interface>
       <vlan:vlan-id>5</vlan:vlan-id>



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     </interface>

   If necessary, the operator can move the configuration named
   "acme-interface" over to a different physical interface with an
   <edit-config> containing:

     <interface nc:operation="merge">
       <name>acme-interface</name>
       <vlan:base-interface>eth3</vlan:base-interface>
     </interface>









































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Appendix F.  ChangeLog

   RFC Editor: remove this section upon publication as an RFC.

F.1.  Version -11

   o  Separated the operational state from the configuration.

   o  Removed 'location', and instead use the name to identify physical
      interfaces.

   o  Added the feature 'pre-provisioning'.

   o  Made 'oper-status' and 'if-index' mandatory in the data model.

   o  Added 'admin-status'.

   o  Clarified why description can be mapped to ifAlias.

   o  Clarified that 64-bit counters only are used, where there exist
      64-bit and 32-bit counters in IF-MIB.

   o  Updated Security Considerations section with a reference to NACM.

F.2.  Version -08

   o  Removed the mtu leaf.

   o  Added examples of different interface naming schemes.

F.3.  Version -07

   o  Made leaf speed config false.

F.4.  Version -06

   o  Added oper-status leaf.

   o  Added leaf-lists higher-layer-if and lower-layer-if, that show the
      interface layering.

   o  Added container statistics with counters.

F.5.  Version -05

   o  Added an Informative References section.





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   o  Updated the Security Considerations section.

   o  Clarified the behavior of an NETCONF server when invalid values
      are received.

F.6.  Version -04

   o  Clarified why ifPromiscuousMode is not part of this data model.

   o  Added a table that shows the mapping between this YANG data model
      and IF-MIB.

F.7.  Version -03

   o  Added the section Relationship to the IF-MIB.

   o  Changed if-index to be a leaf instead of leaf-list.

   o  Explained the notation used in the data model tree picture.

F.8.  Version -02

   o  Editorial fixes

F.9.  Version -01

   o  Changed leaf "if-admin-status" to leaf "enabled".

   o  Added Security Considerations






















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Author's Address

   Martin Bjorklund
   Tail-f Systems

   Email: mbj@tail-f.com













































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