Network Working Group                                       M. Bjorklund
Internet-Draft                                            Tail-f Systems
Intended status: Standards Track                          March 28, 2014
Expires: September 29, 2014


                  A YANG Data Model for IP Management
                      draft-ietf-netmod-ip-cfg-14

Abstract

   This document defines a YANG data model for management of IP
   implementations.  The data model includes configuration data and
   state data.

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 September 29, 2014.

Copyright Notice

   Copyright (c) 2014 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.





Bjorklund              Expires September 29, 2014               [Page 1]


Internet-Draft             YANG IP Management                 March 2014


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
     1.2.  Tree Diagrams  . . . . . . . . . . . . . . . . . . . . . .  3
   2.  IP Data Model  . . . . . . . . . . . . . . . . . . . . . . . .  5
   3.  Relationship to IP-MIB . . . . . . . . . . . . . . . . . . . .  7
   4.  IP management YANG Module  . . . . . . . . . . . . . . . . . .  9
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 24
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 25
   7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 27
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 28
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 28
   Appendix A.  Example: NETCONF <get> reply  . . . . . . . . . . . . 30
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 32



































Bjorklund              Expires September 29, 2014               [Page 2]


Internet-Draft             YANG IP Management                 March 2014


1.  Introduction

   This document defines a YANG [RFC6020] data model for management of
   IP implementations.

   The data model covers configuration of per-interface IPv4 and IPv6
   parameters, and mappings of IP addresses to link-layer addresses.  It
   also provides information about which IP addresses are operationally
   used, and which link-layer mappings exist.  Per-interface parameters
   are added through augmentation of the interface data model defined in
   [I-D.ietf-netmod-interfaces-cfg].

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

   The terminology for describing YANG data models is found in
   [RFC6020].

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:




Bjorklund              Expires September 29, 2014               [Page 3]


Internet-Draft             YANG IP Management                 March 2014


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

   o  Abbreviations before data node names: "rw" means configuration
      data (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.






































Bjorklund              Expires September 29, 2014               [Page 4]


Internet-Draft             YANG IP Management                 March 2014


2.  IP Data Model

   This document defines the YANG module "ietf-ip", which augments the
   "interface" and "interface-state" lists defined in the
   "ietf-interfaces" module [I-D.ietf-netmod-interfaces-cfg] with IP
   specific data nodes, and adds IP specific state data.

   The data model has the following structure for IP configuration per
   interface:

      +--rw if:interfaces
         +--rw if:interface* [name]
            ...
            +--rw ipv4!
            |  +--rw enabled?            boolean
            |  +--rw forwarding?         boolean
            |  +--rw mtu?                uint16
            |  +--rw address* [ip]
            |  |  +--rw ip               inet:ipv4-address-no-zone
            |  |  +--rw (subnet)
            |  |     +--:(prefix-length)
            |  |     |  +--rw ip:prefix-length?   uint8
            |  |     +--:(netmask)
            |  |        +--rw ip:netmask?         yang:dotted-quad
            |  +--rw neighbor* [ip]
            |     +--rw ip                    inet:ipv4-address-no-zone
            |     +--rw link-layer-address    yang:phys-address
            +--rw ipv6!
               +--rw enabled?            boolean
               +--rw forwarding?         boolean
               +--rw mtu?                uint32
               +--rw address* [ip]
               |  +--rw ip               inet:ipv6-address-no-zone
               |  +--rw prefix-length    uint8
               +--rw neighbor* [ip]
               |  +--rw ip                    inet:ipv6-address-no-zone
               |  +--rw link-layer-address    yang:phys-address
               +--rw dup-addr-detect-transmits?   uint32
               +--rw autoconf
                  +--rw create-global-addresses?        boolean
                  +--rw create-temporary-addresses?     boolean
                  +--rw temporary-valid-lifetime?       uint32
                  +--rw temporary-preferred-lifetime?   uint32

   The data model defines two configuration containers per interface,
   "ipv4" and "ipv6", representing the IPv4 and IPv6 address families.
   In each container, there is a leaf "enabled" that controls if the
   address family is enabled on that interface, and a leaf "forwarding"



Bjorklund              Expires September 29, 2014               [Page 5]


Internet-Draft             YANG IP Management                 March 2014


   that controls if IP packet forwarding for the address family is
   enabled on the interface.  In each container, there is also a list of
   configured addresses, and a list of configured mappings from IP
   addresses to link-layer addresses.

   The data model has the following structure for IP state per
   interface:

      +--ro if:interfaces-state
         +--ro if:interface* [name]
            ...
            +--ro ipv4!
            |  +--ro forwarding?   boolean
            |  +--ro mtu?          uint16
            |  +--ro address* [ip]
            |  |  +--ro ip               inet:ipv4-address-no-zone
            |  |  +--ro (subnet)?
            |  |  |  +--:(prefix-length)
            |  |  |  |  +--ro prefix-length?   uint8
            |  |  |  +--:(netmask)
            |  |  |     +--ro netmask?         yang:dotted-quad
            |  |  +--ro origin?          ip-address-origin
            |  +--ro neighbor* [ip]
            |     +--ro ip                    inet:ipv4-address-no-zone
            |     +--ro link-layer-address?   yang:phys-address
            |     +--ro origin?               neighbor-origin
            +--ro ipv6!
               +--ro forwarding?   boolean
               +--ro mtu?          uint32
               +--ro address* [ip]
               |  +--ro ip               inet:ipv6-address-no-zone
               |  +--ro prefix-length    uint8
               |  +--ro origin?          ip-address-origin
               |  +--ro status?          enumeration
               +--ro neighbor* [ip]
                  +--ro ip                    inet:ipv6-address-no-zone
                  +--ro link-layer-address?   yang:phys-address
                  +--ro origin?               neighbor-origin
                  +--ro is-router?            empty
                  +--ro state?                enumeration

   The data model defines two state containers per interface, "ipv4" and
   "ipv6", representing the IPv4 and IPv6 address families.  In each
   container, there is a leaf "forwarding" that indicates if IP packet
   forwarding is enabled on that interface.  In each container there is
   also a list of all addresses in use, and a list of known mappings
   from IP addresses to link-layer addresses.




Bjorklund              Expires September 29, 2014               [Page 6]


Internet-Draft             YANG IP Management                 March 2014


3.  Relationship to IP-MIB

   If the device implements IP-MIB [RFC4293], each entry in the "ipv4/
   address" and "ipv6/address" lists is mapped to one ipAddressEntry,
   where the ipAddressIfIndex refers to the "address" entry's interface.

   The IP-MIB defines objects to control IPv6 Router Advertisement.  The
   corresponding YANG data nodes are defined in
   [I-D.ietf-netmod-routing-cfg].

   The entries in "ipv4/neighbor" and "ipv6/neighbor" are mapped to
   ipNetToPhysicalTable.

   The following tables list the YANG data nodes with corresponding
   objects in the IP-MIB.

   +----------------------------------+--------------------------------+
   | YANG data node in                | IP-MIB object                  |
   | /if:interfaces/if:interface      |                                |
   +----------------------------------+--------------------------------+
   | ipv4/enabled                     | ipv4InterfaceEnableStatus      |
   | ipv4/address                     | ipAddressEntry                 |
   | ipv4/address/ip                  | ipAddressAddrType              |
   |                                  | ipAddressAddr                  |
   | ipv4/neighbor                    | ipNetToPhysicalEntry           |
   | ipv4/neighbor/ip                 | ipNetToPhysicalNetAddressType  |
   |                                  | ipNetToPhysicalNetAddressAddr  |
   | ipv4/neighbor/link-layer-address | ipNetToPhysicalPhysAddress     |
   | ipv6/enabled                     | ipv6InterfaceEnableStatus      |
   | ipv6/forwarding                  | ipv6InterfaceForwarding        |
   | ipv6/address                     | ipAddressEntry                 |
   | ipv6/address/ip                  | ipAddressAddrType              |
   |                                  | ipAddressAddr                  |
   | ipv6/neighbor                    | ipNetToPhysicalEntry           |
   | ipv6/neighbor/link-layer-address | ipNetToPhysicalPhysAddress     |
   | ipv6/neighbor/origin             | ipNetToPhysicalType            |
   +----------------------------------+--------------------------------+

    YANG interface configuration data nodes and related IP-MIB objects












Bjorklund              Expires September 29, 2014               [Page 7]


Internet-Draft             YANG IP Management                 March 2014


   +-----------------------------------+-------------------------------+
   | YANG data node in                 | IP-MIB object                 |
   | /if:interfaces-state/if:interface |                               |
   +-----------------------------------+-------------------------------+
   | ipv4                              | ipv4InterfaceEnableStatus     |
   | ipv4/address                      | ipAddressEntry                |
   | ipv4/address/ip                   | ipAddressAddrType             |
   |                                   | ipAddressAddr                 |
   | ipv4/address/origin               | ipAddressOrigin               |
   | ipv4/neighbor                     | ipNetToPhysicalEntry          |
   | ipv4/neighbor/ip                  | ipNetToPhysicalNetAddressType |
   |                                   | ipNetToPhysicalNetAddressAddr |
   | ipv4/neighbor/link-layer-address  | ipNetToPhysicalPhysAddress    |
   | ipv4/neighbor/origin              | ipNetToPhysicalType           |
   | ipv6                              | ipv6InterfaceEnableStatus     |
   | ipv6/forwarding                   | ipv6InterfaceForwarding       |
   | ipv6/address                      | ipAddressEntry                |
   | ipv6/address/ip                   | ipAddressAddrType             |
   |                                   | ipAddressAddr                 |
   | ipv6/address/origin               | ipAddressOrigin               |
   | ipv6/address/status               | ipAddressStatus               |
   | ipv6/neighbor                     | ipNetToPhysicalEntry          |
   | ipv6/neighbor/ip                  | ipNetToPhysicalNetAddressType |
   |                                   | ipNetToPhysicalNetAddressAddr |
   | ipv6/neighbor/link-layer-address  | ipNetToPhysicalPhysAddress    |
   | ipv6/neighbor/origin              | ipNetToPhysicalType           |
   | ipv6/neighbor/state               | ipNetToPhysicalState          |
   +-----------------------------------+-------------------------------+

        YANG interface state data nodes and related IP-MIB objects





















Bjorklund              Expires September 29, 2014               [Page 8]


Internet-Draft             YANG IP Management                 March 2014


4.  IP management YANG Module

   This module imports typedefs from [RFC6991] and
   [I-D.ietf-netmod-interfaces-cfg], and references [RFC0791],
   [RFC0826], [RFC2460], [RFC4861], [RFC4862], [RFC4941] and
   [I-D.ietf-6man-stable-privacy-addresses].

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

   <CODE BEGINS> file "ietf-ip@2014-03-28.yang"

   module ietf-ip {

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

     import ietf-interfaces {
       prefix if;
     }
     import ietf-inet-types {
       prefix inet;
     }
     import ietf-yang-types {
       prefix yang;
     }

     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: Thomas Nadeau
                  <mailto:tnadeau@lucidvision.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
        configuring IP implementations.

        Copyright (c) 2013 IETF Trust and the persons identified as



Bjorklund              Expires September 29, 2014               [Page 9]


Internet-Draft             YANG IP Management                 March 2014


        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.";

     // 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 2014-03-28 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for IP Management";
     }

     /*
      * Features
      */

     feature ipv4-non-contiguous-netmasks {
       description
         "Indicates support for configuring non-contiguous
          subnet masks.";
     }

     feature ipv6-privacy-autoconf {
       description
         "Indicates support for Privacy Extensions for Stateless Address
          Autoconfiguration in IPv6.";
       reference
         "RFC 4941: Privacy Extensions for Stateless Address
                    Autoconfiguration in IPv6";
     }

     /*
      * Typedefs
      */

     typedef ip-address-origin {



Bjorklund              Expires September 29, 2014              [Page 10]


Internet-Draft             YANG IP Management                 March 2014


       type enumeration {
         enum other {
           description
             "None of the following.";
         }
         enum static {
           description
             "Indicates that the address has been statically
              configured, for example using NETCONF or a Command Line
              Interface.";
         }
         enum dhcp {
           description
             "Indicates an address that has been assigned to this
              system by a DHCP server.";
         }
         enum link-layer {
           description
             "Indicates an address created by IPv6 stateless
              auto-configuration that embeds a link-layer address in its
              interface identifier.";
         }
         enum random {
           description
             "Indicates an address chosen by the system at
              random, e.g., an IPv4 address within 169.254/16, an
              RFC 4941 temporary address, or a semantically opaque
              address [I-D.ietf-6man-stable-privacy-addresses]";
         }
       }
       description
         "The origin of an address.";
     }

     typedef neighbor-origin {
       type enumeration {
         enum other {
           description
             "None of the following.";
         }
         enum static {
           description
             "Indicates that the mapping has been statically
              configured, for example using NETCONF or a Command Line
              Interface.";
         }
         enum dynamic {
           description



Bjorklund              Expires September 29, 2014              [Page 11]


Internet-Draft             YANG IP Management                 March 2014


             "Indicates that the mapping has been dynamically resolved
              using e.g., IPv4 ARP or the IPv6 Neighbor Discovery
              protocol.";
         }
       }
       description
         "The origin of a neighbor entry.";
     }

     /*
      * Configuration data nodes
      */

     augment "/if:interfaces/if:interface" {
       description
         "Parameters for configuring IP on interfaces.

          If an interface is not capable of running IP, the server
          must not allow the client to configure these parameters.";

       container ipv4 {
         presence
           "Enables IPv4 unless the 'enabled' leaf
            (which defaults to 'true') is set to 'false'";
         description
           "Parameters for the IPv4 address family.";

         leaf enabled {
           type boolean;
           default true;
           description
             "Controls if IPv4 is enabled or disabled on this
              interface.  When IPv4 is enabled, this interface is
              connected to an IPv4 stack, and the interface can send
              and receive IPv4 packets.";
         }
         leaf forwarding {
           type boolean;
           default false;
           description
             "Controls IPv4 packet forwarding of datagrams received by,
              but not addressed to, this interface.  IPv4 routers
              forward datagrams.  IPv4 hosts do not (except those
              source-routed via the host)";
         }
         leaf mtu {
           type uint16 {
             range "68..max";



Bjorklund              Expires September 29, 2014              [Page 12]


Internet-Draft             YANG IP Management                 March 2014


           }
           units octets;
           description
             "The size, in octets, of the largest IPv4 packet that the
              interface will send and receive.

              The server may restrict the allowed values for this leaf
              depending on the interface's type.

              If this leaf is not configured, the operationally used mtu
              depends on the interface's type.";
           reference
             "RFC 791: Internet Protocol";
         }
         list address {
           key "ip";
           description
             "The list of configured IPv4 addresses on the interface.";

           leaf ip {
             type inet:ipv4-address-no-zone;
             description
               "The IPv4 address on the interface.";
           }
           choice subnet {
             mandatory true;
             description
               "The subnet can be specified as a prefix-length, or,
                if the server supports non-contiguous netmasks, as
                a netmask.";
             leaf prefix-length {
               type uint8 {
                 range "0..32";
               }
               description
                 "The length of the subnet prefix.";
             }
             leaf netmask {
               if-feature ipv4-non-contiguous-netmasks;
               type yang:dotted-quad;
               description
                 "The subnet specified as a netmask.";
             }
           }
         }
         list neighbor {
           key "ip";
           description



Bjorklund              Expires September 29, 2014              [Page 13]


Internet-Draft             YANG IP Management                 March 2014


             "A list of mappings from IPv4 addresses to
              link-layer addresses.

              Entries in this list are used as static entries in the
              ARP cache.";
           reference
             "RFC 826: An Ethernet Address Resolution Protocol";

           leaf ip {
             type inet:ipv4-address-no-zone;
             description
               "The IPv4 address of the neighbor node.";
           }
           leaf link-layer-address {
             type yang:phys-address;
             mandatory true;
             description
               "The link-layer address of the neighbor node.";
           }
         }

       }
       container ipv6 {
         presence
           "Enables IPv6 unless the 'enabled' leaf
            (which defaults to 'true') is set to 'false'";
         description
           "Parameters for the IPv6 address family.";

         leaf enabled {
           type boolean;
           default true;
           description
             "Controls if IPv6 is enabled or disabled on this
              interface.  When IPv6 is enabled, this interface is
              connected to an IPv6 stack, and the interface can send
              and receive IPv6 packets.";
         }
         leaf forwarding {
           type boolean;
           default false;
           description
             "Controls IPv6 packet forwarding of datagrams received by,
              but not addressed to, this interface.  IPv6 routers
              forward datagrams.  IPv6 hosts do not (except those
              source-routed via the host)";
           reference
             "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)



Bjorklund              Expires September 29, 2014              [Page 14]


Internet-Draft             YANG IP Management                 March 2014


                        Section 6.2.1, IsRouter";
         }
         leaf mtu {
           type uint32 {
             range "1280..max";
           }
           units octets;
           description
             "The size, in octets, of the largest IPv6 packet that the
              interface will send and receive.

              The server may restrict the allowed values for this leaf
              depending on the interface's type.

              If this leaf is not configured, the operationally used mtu
              depends on the interface's type.";
           reference
             "RFC 2460: IPv6 Specification
                        Section 5";
         }
         list address {
           key "ip";
           description
             "The list of configured IPv6 addresses on the interface.";

           leaf ip {
             type inet:ipv6-address-no-zone;
             description
               "The IPv6 address on the interface.";
           }
           leaf prefix-length {
             type uint8 {
               range "0..128";
             }
             mandatory true;
             description
               "The length of the subnet prefix.";
           }
         }
         list neighbor {
           key "ip";
           description
             "A list of mappings from IPv6 addresses to
              link-layer addresses.

              Entries in this list are used as static entries in the
              Neighbor Cache.";
           reference



Bjorklund              Expires September 29, 2014              [Page 15]


Internet-Draft             YANG IP Management                 March 2014


             "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)";

           leaf ip {
             type inet:ipv6-address-no-zone;
             description
               "The IPv6 address of the neighbor node.";
           }
           leaf link-layer-address {
             type yang:phys-address;
             mandatory true;
             description
               "The link-layer address of the neighbor node.";
           }
         }
         leaf dup-addr-detect-transmits {
           type uint32;
           default 1;
           description
             "The number of consecutive Neighbor Solicitation messages
              sent while performing Duplicate Address Detection on a
              tentative address.  A value of zero indicates that
              Duplicate Address Detection is not performed on
              tentative addresses.  A value of one indicates a single
              transmission with no follow-up retransmissions.";
           reference
             "RFC 4862: IPv6 Stateless Address Autoconfiguration";
         }
         container autoconf {
           description
             "Parameters to control the autoconfiguration of IPv6
              addresses, as described in RFC 4862.";
           reference
             "RFC 4862: IPv6 Stateless Address Autoconfiguration";

           leaf create-global-addresses {
             type boolean;
             default true;
             description
               "If enabled, the host creates global addresses as
                described in section 5.5 of RFC 4862.";
             reference
               "RFC 4862: IPv6 Stateless Address Autoconfiguration";
           }
           leaf create-temporary-addresses {
             if-feature ipv6-privacy-autoconf;
             type boolean;
             default false;
             description



Bjorklund              Expires September 29, 2014              [Page 16]


Internet-Draft             YANG IP Management                 March 2014


               "If enabled, the host creates temporary addresses as
                described in RFC 4941.";
             reference
               "RFC 4941: Privacy Extensions for Stateless Address
                          Autoconfiguration in IPv6";
           }
           leaf temporary-valid-lifetime {
             if-feature ipv6-privacy-autoconf;
             type uint32;
             units "seconds";
             default 604800;
             description
               "The time period during which the temporary address
                is valid.";
             reference
               "RFC 4941: Privacy Extensions for Stateless Address
                          Autoconfiguration in IPv6
                          - TEMP_VALID_LIFETIME";
           }
           leaf temporary-preferred-lifetime {
             if-feature ipv6-privacy-autoconf;
             type uint32;
             units "seconds";
             default 86400;
             description
               "The time period during which the temporary address is
                preferred.";
             reference
               "RFC 4941: Privacy Extensions for Stateless Address
                          Autoconfiguration in IPv6
                          - TEMP_PREFERRED_LIFETIME";
           }
         }
       }
     }

     /*
      * Operational state data nodes
      */

     augment "/if:interfaces-state/if:interface" {
       description
         "Data nodes for the operational state of IP on interfaces.";

       container ipv4 {
         presence "Present if IPv4 is enabled on this interface";
         config false;
         description



Bjorklund              Expires September 29, 2014              [Page 17]


Internet-Draft             YANG IP Management                 March 2014


           "Interface specific parameters for the IPv4 address family.";

         leaf forwarding {
           type boolean;
           description
             "Indicates if IPv4 packet forwarding is enabled or disabled
              on this interface.";
         }
         leaf mtu {
           type uint16 {
             range "68..max";
           }
           units octets;
           description
             "The size, in octets, of the largest IPv4 packet that the
              interface will send and receive.";
           reference
             "RFC 791: Internet Protocol";
         }
         list address {
           key "ip";
           description
             "The list of IPv4 addresses on the interface.";

           leaf ip {
             type inet:ipv4-address-no-zone;
             description
               "The IPv4 address on the interface.";
           }
           choice subnet {
             description
               "The subnet can be specified as a prefix-length, or,
                if the server supports non-contiguous netmasks, as
                a netmask.";
             leaf prefix-length {
               type uint8 {
                 range "0..32";
               }
               description
                 "The length of the subnet prefix.";
             }
             leaf netmask {
               if-feature ipv4-non-contiguous-netmasks;
               type yang:dotted-quad;
               description
                 "The subnet specified as a netmask.";
             }
           }



Bjorklund              Expires September 29, 2014              [Page 18]


Internet-Draft             YANG IP Management                 March 2014


           leaf origin {
             type ip-address-origin;
             description
               "The origin of this address.";
           }
         }
         list neighbor {
           key "ip";
           description
             "A list of mappings from IPv4 addresses to
              link-layer addresses.

              This list represents the ARP Cache.";
           reference
             "RFC 826: An Ethernet Address Resolution Protocol";

           leaf ip {
             type inet:ipv4-address-no-zone;
             description
               "The IPv4 address of the neighbor node.";
           }
           leaf link-layer-address {
             type yang:phys-address;
             description
               "The link-layer address of the neighbor node.";
           }
           leaf origin {
             type neighbor-origin;
             description
               "The origin of this neighbor entry.";
           }
         }

       }

       container ipv6 {
         presence "Present if IPv6 is enabled on this interface";
         config false;
         description
           "Parameters for the IPv6 address family.";

         leaf forwarding {
           type boolean;
           default false;
           description
             "Indicates if IPv6 packet forwarding is enabled or disabled
              on this interface.";
           reference



Bjorklund              Expires September 29, 2014              [Page 19]


Internet-Draft             YANG IP Management                 March 2014


             "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                        Section 6.2.1, IsRouter";
         }
         leaf mtu {
           type uint32 {
             range "1280..max";
           }
           units octets;
           description
             "The size, in octets, of the largest IPv6 packet that the
              interface will send and receive.";
           reference
             "RFC 2460: IPv6 Specification
                        Section 5";
         }
         list address {
           key "ip";
           description
             "The list of IPv6 addresses on the interface.";

           leaf ip {
             type inet:ipv6-address-no-zone;
             description
               "The IPv6 address on the interface.";
           }
           leaf prefix-length {
             type uint8 {
               range "0..128";
             }
             mandatory true;
             description
               "The length of the subnet prefix.";
           }
           leaf origin {
             type ip-address-origin;
             description
               "The origin of this address.";
           }
           leaf status {
             type enumeration {
               enum preferred {
                 description
                   "This is a valid address that can appear as the
                    destination or source address of a packet.";
               }
               enum deprecated {
                 description
                   "This is a valid but deprecated address that should



Bjorklund              Expires September 29, 2014              [Page 20]


Internet-Draft             YANG IP Management                 March 2014


                    no longer be used as a source address in new
                    communications, but packets addressed to such an
                    address are processed as expected.";
               }
               enum invalid {
                 description
                   "This isn't a valid address and it shouldn't appear
                    as the destination or source address of a packet.";
               }
               enum inaccessible {
                 description
                   "The address is not accessible because the interface
                    to which this address is assigned is not
                    operational.";
               }
               enum unknown {
                 description
                   "The status cannot be determined for some reason.";
               }
               enum tentative {
                 description
                   "The uniqueness of the address on the link is being
                    verified.  Addresses in this state should not be
                    used for general communication and should only be
                    used to determine the uniqueness of the address.";
               }
               enum duplicate {
                 description
                   "The address has been determined to be non-unique on
                    the link and so must not be used.";
               }
               enum optimistic {
                 description
                   "The address is available for use, subject to
                    restrictions, while its uniqueness on a link is
                    being verified.";
               }
             }
             description
               "The status of an address.  Most of the states correspond
                to states from the IPv6 Stateless Address
                Autoconfiguration protocol.";
             reference
               "RFC 4293: Management Information Base for the
                          Internet Protocol (IP)
                          - IpAddressStatusTC
                RFC 4862: IPv6 Stateless Address Autoconfiguration";
           }



Bjorklund              Expires September 29, 2014              [Page 21]


Internet-Draft             YANG IP Management                 March 2014


         }
         list neighbor {
           key "ip";
           description
             "A list of mappings from IPv6 addresses to
              link-layer addresses.

              This list represents the Neighbor Cache.";
           reference
             "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)";

           leaf ip {
             type inet:ipv6-address-no-zone;
             description
               "The IPv6 address of the neighbor node.";
           }
           leaf link-layer-address {
             type yang:phys-address;
             description
               "The link-layer address of the neighbor node.";
           }
           leaf origin {
             type neighbor-origin;
             description
               "The origin of this neighbor entry.";
           }
           leaf is-router {
             type empty;
             description
               "Indicates that the neighbor node acts as a router.";
           }
           leaf state {
             type enumeration {
               enum incomplete {
                 description
                   "Address resolution is in progress and the link-layer
                    address of the neighbor has not yet been
                    determined.";
               }
               enum reachable {
                 description
                   "Roughly speaking, the neighbor is known to have been
                    reachable recently (within tens of seconds ago).";
               }
               enum stale {
                 description
                   "The neighbor is no longer known to be reachable but
                    until traffic is sent to the neighbor, no attempt



Bjorklund              Expires September 29, 2014              [Page 22]


Internet-Draft             YANG IP Management                 March 2014


                    should be made to verify its reachability.";
               }
               enum delay {
                 description
                   "The neighbor is no longer known to be reachable, and
                    traffic has recently been sent to the neighbor.
                    Rather than probe the neighbor immediately, however,
                    delay sending probes for a short while in order to
                    give upper-layer protocols a chance to provide
                    reachability confirmation.";
               }
               enum probe {
                 description
                   "The neighbor is no longer known to be reachable, and
                    unicast Neighbor Solicitation probes are being sent
                    to verify reachability.";
               }
             }
             description
               "The Neighbor Unreachability Detection state of this
                entry.";
             reference
               "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                          Section 7.3.2";
           }
         }
       }
     }
   }

   <CODE ENDS>




















Bjorklund              Expires September 29, 2014              [Page 23]


Internet-Draft             YANG IP Management                 March 2014


5.  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-ip

        Registrant Contact: The NETMOD WG of the IETF.

        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-ip
     namespace:    urn:ietf:params:xml:ns:yang:ietf-ip
     prefix:       ip
     reference:    RFC XXXX
































Bjorklund              Expires September 29, 2014              [Page 24]


Internet-Draft             YANG IP Management                 March 2014


6.  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:

   ipv4/enabled and ipv6/enabled:  These leafs are used to enable or
      disable IPv4 and IPv6 on a specific interface.  By enabling a
      protocol on an interface, an attacker might be able to create an
      unsecured path into a node (or through it if routing is also
      enabled).  By disabling a protocol on an interface, an attacker
      might be able to force packets to be routed through some other
      interface or deny access to some or all of the network via that
      protocol.

   ipv4/address and ipv6/address:  These lists specify the configured IP
      addresses on an interface.  By modifying this information, an
      attacker can cause a node to either ignore messages destined to it
      or accept (at least at the IP layer) messages it would otherwise
      ignore.  The use of filtering or security associations may reduce
      the potential damage in the latter case.

   ipv4/forwarding and ipv6/forwarding:  These leafs allow a client to
      enable or disable the forwarding functions on the entity.  By
      disabling the forwarding functions, an attacker would possibly be
      able to deny service to users.  By enabling the forwarding
      functions, an attacker could open a conduit into an area.  This
      might result in the area providing transit for packets it
      shouldn't or might allow the attacker access to the area bypassing
      security safeguards.

   ipv6/autoconf:  The leafs in this branch control the
      autoconfiguration of IPv6 addresses and in particular whether
      temporary addresses are used or not.  By modifying the
      corresponding leafs, an attacker might impact the addresses used
      by a node and thus indirectly the privacy of the users using the



Bjorklund              Expires September 29, 2014              [Page 25]


Internet-Draft             YANG IP Management                 March 2014


      node.

   ipv4/mtu and ipv6/mtu:  Setting these leafs to very small values can
      be used to slow down interfaces.















































Bjorklund              Expires September 29, 2014              [Page 26]


Internet-Draft             YANG IP Management                 March 2014


7.  Acknowledgments

   The author wishes to thank Jeffrey Lange, Ladislav Lhotka, Juergen
   Schoenwaelder, and Dave Thaler for their helpful comments.















































Bjorklund              Expires September 29, 2014              [Page 27]


Internet-Draft             YANG IP Management                 March 2014


8.  References

8.1.  Normative References

   [I-D.ietf-netmod-interfaces-cfg]
              Bjorklund, M., "A YANG Data Model for Interface
              Configuration", draft-ietf-netmod-interfaces-cfg-12 (work
              in progress), July 2012.

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              September 1981.

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

   [RFC2460]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", RFC 2460, December 1998.

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

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862, September 2007.

   [RFC4941]  Narten, T., Draves, R., and S. Krishnan, "Privacy
              Extensions for Stateless Address Autoconfiguration in
              IPv6", RFC 4941, September 2007.

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

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

   [RFC6991]  Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
              July 2013.

8.2.  Informative References

   [I-D.ietf-6man-stable-privacy-addresses]
              Gont, F., "A Method for Generating Semantically Opaque
              Interface Identifiers with IPv6 Stateless Address



Bjorklund              Expires September 29, 2014              [Page 28]


Internet-Draft             YANG IP Management                 March 2014


              Autoconfiguration (SLAAC)",
              draft-ietf-6man-stable-privacy-addresses-17 (work in
              progress), January 2014.

   [I-D.ietf-netmod-routing-cfg]
              Lhotka, L., "A YANG Data Model for Routing Configuration",
              draft-ietf-netmod-routing-cfg-10 (work in progress),
              July 2012.

   [RFC0826]  Plummer, D., "Ethernet Address Resolution Protocol: Or
              converting network protocol addresses to 48.bit Ethernet
              address for transmission on Ethernet hardware", STD 37,
              RFC 826, November 1982.

   [RFC4293]  Routhier, S., "Management Information Base for the
              Internet Protocol (IP)", RFC 4293, April 2006.

   [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.




























Bjorklund              Expires September 29, 2014              [Page 29]


Internet-Draft             YANG IP Management                 March 2014


Appendix A.  Example: NETCONF <get> reply

   This section gives an example of a reply to the NETCONF <get> request
   for a device that implements the data model defined in this document.

  <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:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
        <interface>
          <name>eth0</name>
          <type>ianaift:ethernetCsmacd</type>
          <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
            <address>
              <ip>192.0.2.1</ip>
              <prefix-length>24</prefix-length>
            </address>
          </ipv4>
          <ipv6 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
            <mtu>1280</mtu>
            <address>
              <ip>2001:db8::10</ip>
              <prefix-length>32</prefix-length>
            </address>
            <dup-addr-detect-transmits>0</dup-addr-detect-transmits>
          </ipv6>
        </interface>
      </interfaces>

      <interfaces-state
          xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces"
          xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
        <interface>
          <name>eth0</name>
          <type>ianaift:ethernetCsmacd</type>
          <!-- other parameters from ietf-interfaces omitted -->

          <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
            <forwarding>false</forwarding>
            <mtu>1500</mtu>
            <address>
              <ip>192.0.2.1</ip>
              <prefix-length>24</prefix-length>
              <origin>static</origin>
            </address>



Bjorklund              Expires September 29, 2014              [Page 30]


Internet-Draft             YANG IP Management                 March 2014


            <neighbor>
              <ip>192.0.2.2</ip>
              <link-layer-address>00:01:02:03:04:05</link-layer-address>
            </neighbor>
          </ipv4>
          <ipv6 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
            <forwarding>false</forwarding>
            <mtu>1500</mtu>
            <address>
              <ip>2001:db8::10</ip>
              <prefix-length>32</prefix-length>
              <origin>static</origin>
              <status>preferred</status>
            </address>
            <address>
              <ip>2001:db8::1:100</ip>
              <prefix-length>32</prefix-length>
              <origin>dhcp</origin>
              <status>preferred</status>
            </address>
            <neighbor>
              <ip>2001:db8::1</ip>
              <link-layer-address>00:01:02:03:04:05</link-layer-address>
              <origin>dynamic</origin>
              <is-router/>
              <state>reachable</state>
            </neighbor>
            <neighbor>
              <ip>2001:db8::4</ip>
              <origin>dynamic</origin>
              <state>incomplete</state>
            </neighbor>
          </ipv6>
        </interface>
      </interfaces-state>
    </data>
  </rpc-reply>














Bjorklund              Expires September 29, 2014              [Page 31]


Internet-Draft             YANG IP Management                 March 2014


Author's Address

   Martin Bjorklund
   Tail-f Systems

   Email: mbj@tail-f.com













































Bjorklund              Expires September 29, 2014              [Page 32]