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NETMOD                                                         L. Lhotka
Internet-Draft                                                    CESNET
Intended status: Standards Track                      September 23, 2011
Expires: March 26, 2012


              A YANG Data Model for Routing Configuration
                    draft-ietf-netmod-routing-cfg-01

Abstract

   This document contains a specification of three YANG modules that
   together provide a data model for essential configuration of a
   routing subsystem.  It is expected that this module will serve as a
   basis for further development of data models for individual routing
   protocols and other related functions.  The present data model
   defines the common building blocks for such configurations - router
   instances, routes, routing tables, routing protocols and route
   filters.

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 March 26, 2012.

Copyright Notice

   Copyright (c) 2011 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



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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology and Notation . . . . . . . . . . . . . . . . . . .  4
     2.1.  Glossary of New Terms  . . . . . . . . . . . . . . . . . .  4
     2.2.  Prefixes in Data Node Names  . . . . . . . . . . . . . . .  5
   3.  Objectives . . . . . . . . . . . . . . . . . . . . . . . . . .  6
   4.  The Design of the Core Routing Data Model  . . . . . . . . . .  7
     4.1.  Router . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     4.2.  Route  . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     4.3.  Routing Tables . . . . . . . . . . . . . . . . . . . . . . 11
     4.4.  Routing Protocols  . . . . . . . . . . . . . . . . . . . . 12
       4.4.1.  Defining New Routing Protocols . . . . . . . . . . . . 13
     4.5.  Route Filters  . . . . . . . . . . . . . . . . . . . . . . 15
     4.6.  RPC Operation  . . . . . . . . . . . . . . . . . . . . . . 16
   5.  IANA AFN and SAFI YANG Module  . . . . . . . . . . . . . . . . 17
   6.  Routing YANG Module  . . . . . . . . . . . . . . . . . . . . . 25
   7.  IPv4 Unicast Routing YANG Module . . . . . . . . . . . . . . . 34
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 38
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 40
   10. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 41
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 42
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 42
     11.2. Informative References . . . . . . . . . . . . . . . . . . 42
   Appendix A.  Example - Adding a New Routing Protocol . . . . . . . 43
     A.1.  Example YANG Module for Routing Information
           Protocol . . . . . . . . . . . . . . . . . . . . . . . . . 43
     A.2.  Sample Reply to the NETCONF <get> Message  . . . . . . . . 45
   Appendix B.  Change Log  . . . . . . . . . . . . . . . . . . . . . 50
     B.1.  Changes Between Versions -00 and -01 . . . . . . . . . . . 50
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 51















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1.  Introduction

   This document contains an initial specification of three YANG
   modules:

   o  Module "ietf-routing" provides generic components of a routing
      data model.

   o  Module "ietf-ipv4-unicast-routing" augments the "ietf-routing"
      module with additional data specific to IPv4 unicast.

   o  Module "iana-afn-safi" contains two type definitions translating
      IANA registries "Address Family Numbers" [IANA-AFN] and
      "Subsequent Address Family Identifiers" [IANA-SAFI] to YANG
      enumerations.

   ED.  QUESTION: Would it be possible/useful to publish the "iana-afn-
   safi" module as a separate I-D, perhaps together with "iana-if-type"?

   The first two modules together define the so-called core routing data
   model.  This data model will serve as a basis for the development of
   data models for more sophisticated routing configurations.  While
   these two modules can be directly used for simple IPv4-only devices
   with static routing, their main purpose is to provide essential
   building blocks for more complicated setups involving other address
   families such as IPv6, multicast routing, multiple routing protocols,
   and advanced functions such as route filtering or policy routing.  To
   this end, it is expected that this module will be augmented by
   numerous modules developed by other IETF working groups.






















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2.  Terminology and Notation

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

   The following terms are defined in [RFC6241]:

   o  client

   o  message

   o  operation

   o  server

   The following terms are defined in [RFC6020]:

   o  augment

   o  configuration data

   o  container

   o  data model

   o  data node

   o  data type

   o  identity

   o  mandatory node

   o  module

   o  operational state data

   o  prefix

   o  RPC operation

2.1.  Glossary of New Terms








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   active route:  a route which is actually used for packet forwarding.
      If there are multiple candidate routes with a matching destination
      prefix, then it is up to the routing algorithm to select the
      active route.

   core routing data model:  YANG data model resulting from the
      combination of "ietf-routing" and "ietf-ipv4-unicast-routing-cfg"
      modules.

2.2.  Prefixes in Data Node Names

   In this document, names of data nodes are used mostly without a
   prefix, as long as it is clear from the context in which YANG module
   each name is defined.  Otherwise, names are prefixed with their
   standard prefix associated with the corresponding YANG module, as
   shown in Table 1.

            +--------+---------------------------+------------+
            | Prefix | YANG module               | Reference  |
            +--------+---------------------------+------------+
            | eth    | ex-ethernet               | [YANG-IF]  |
            |        |                           |            |
            | if     | ietf-interfaces           | [YANG-IF]  |
            |        |                           |            |
            | inet   | ietf-inet-types           | [RFC6021]  |
            |        |                           |            |
            | ip     | ietf-ip                   | [YANG-IP]  |
            |        |                           |            |
            | rip    | example-rip               | Appendix A |
            |        |                           |            |
            | rt     | ietf-routing              | Section 6  |
            |        |                           |            |
            | v4ur   | ietf-ipv4-unicast-routing | Section 7  |
            |        |                           |            |
            | yang   | ietf-yang-types           | [RFC6021]  |
            +--------+---------------------------+------------+

             Table 1: Prefixes and corresponding YANG modules













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3.  Objectives

   The initial design of the core routing data model was driven by the
   following objectives:

   o  The data model should be suitable for the common address families,
      in particular IPv4 and IPv6, and for unicast and multicast
      routing, as well as Multiprotocol Label Switching (MPLS).

   o  Simple routing setups, such as static routing, should be
      configurable in a simple way, ideally without any need to develop
      additional YANG modules.

   o  On the other hand, the core routing framework must allow for
      complicated setups involving multiple routing tables and multiple
      routing protocols, as well as controlled redistributions of
      routing information.

   o  Device vendors will want to map the data models built on this
      generic framework to their proprietary data models and
      configuration interfaces.  Therefore, the framework should be
      flexible enough to facilitate such a mapping and accommodate data
      models with different logic.




























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4.  The Design of the Core Routing Data Model

   The core routing data model consists of two YANG modules.  The first
   module, "ietf-routing", defines the generic components of a routing
   system.  The second module, "ietf-ipv4-unicast-routing", augments the
   "ietf-routing" module with new data nodes that are needed for IPv4
   unicast routing.

   The combined data hierarchy defined by both YANG modules is shown in
   Figure 1.









































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      +--rw routing
         +--rw router [name]
            +--rw name
            +--rw description?
            +--rw enabled?
            +--rw routing-protocols
            |  +--rw routing-protocol [name]
            |     +--rw name
            |     +--rw description?
            |     +--rw type
            |     +--rw connected-routing-tables
            |     |  +--rw connected-routing-table [name]
            |     |     +--rw name
            |     |     +--rw import-filter?
            |     |     +--rw export-filter?
            |     +--rw v4ur:ipv4-unicast-static-routes
            |        +--rw v4ur:static-route [id]
            |           +--rw v4ur:id
            |           +--rw v4ur:description?
            |           +--rw v4ur:destination-prefix?
            |           +--rw v4ur:next-hop?
            |           +--rw v4ur:outgoing-interface?
            +--rw route-filters
            |  +--rw route-filter [name]
            |     +--rw name
            |     +--rw description?
            |     +--rw type?
            +--rw routing-tables
               +--rw routing-table [name]
                  +--rw name
                  +--rw address-family?
                  +--rw safi?
                  +--rw description?
                  +--ro routes
                  |  +--ro route
                  |     +--ro source-protocol?
                  |     +--ro last-modified?
                  |     +--ro v4ur:destination-prefix?
                  |     +--ro v4ur:next-hop?
                  |     +--ro v4ur:outgoing-interface?
                  +--rw recipient-routing-tables [recipient-name]
                     +--rw recipient-name
                     +--rw filter?

    Figure 1: Data hierarchy of "ietf-routing" and "ietf-ipv4-unicast-
                             routing" modules.

   As can be see from Figure 1, the core routing data model introduces



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   several generic components of a routing framework: routers, routing
   tables containing routes, routing protocols, route filters and RPC
   operations.  The following subsections provide further details about
   these components.

   By combining the components in various ways, and possibly augmenting
   them with appropriate contents defined in other modules, various
   routing setups can be realized.

                           +------------+
                           |    FIB     |
                           +------------+
                                 ^
                                 |
                               +---+
                               | F |
                               +---+
                                 ^
   +--------+                    |
   | direct |    +---+    +--------------+    +---+    +--------------+
   | routes |--->| F |--->|              |<---| F |<---|              |
   +--------+    +---+    |    main      |    +---+    |  additional  |
                          |   routing    |             |   routing    |
   +--------+    +---+    |    table     |    +---+    |    table     |
   | static |--->| F |--->|              |--->| F |--->|              |
   | routes |    +---+    +--------------+    +---+    +--------------+
   +--------+                 ^      |                     ^      |
                              |      v                     |      v
                            +---+  +---+                 +---+  +---+
                            | F |  | F |                 | F |  | F |
                            +---+  +---+                 +---+  +---+
                              ^      |                     ^      |
                              |      v                     |      v
                            +----------+                 +----------+
                            | routing  |                 | routing  |
                            | protocol |                 | protocol |
                            +----------+                 +----------+

             Figure 2: Example setup of the routing subsystem

   Figure 2 shows an example of a more complicated setup.  Several of
   its features are worth mentioning:

   o  Along with the main routing table, which must always be present,
      an additional routing table is configured.

   o  Each routing protocol instance, including the "static" and
      "direct" pseudo-protocols, is connected to exactly one routing



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      table with which it can exchange routes (in both directions,
      except for the "static" and "direct" pseudo-protocols).

   o  Routing tables may also be connected to each other and exchange
      routes in one or both directions.

   o  The forwarding information base (FIB) is a special routing table
      which must always be present.  Typically, the FIB receives the
      active routes from the main routing table and the operating system
      kernel uses this information for packet forwarding.

   o  Route exchanges along all connections may be controlled by means
      of route filters, denoted by "F" in Figure 2.

4.1.  Router

   Each router instance in the core routing data model represents a
   (virtual) router whose configuration and operation is independent of
   other router instances.  Although it it not enforced by the data
   model, different router instances normally do not internally share
   any data.  They may, however, communicate with each other via routing
   protocols.

4.2.  Route

   Routes are basic units of information in a routing system.  The core
   routing data model defines only the following minimal set of route
   attributes:

   o  destination-prefix - IP prefix specifying the set of destination
      addresses for which the route may be used.  This attribute is
      mandatory.

   o  next-hop - IP address of the adjacent router or host to which
      packets with destination addresses belonging to destination-prefix
      should be sent.

   o  outgoing-interface - network interface that should be used for
      sending packets with destination addresses belonging to
      destination-prefix.

   The above list of route attributes is sufficient for a simple static
   routing configuration.  It is expected that future modules defining
   routing protocols will add other route attributes such as metrics or
   preferences.

   Routes and their attributes are used in both configuration data, for
   example as manually configured static routes, and in operational



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   state data, for example as entries in routing tables.

4.3.  Routing Tables

   Routing tables are lists of routes complemented with administrative
   data, namely:

   o  source-protocol - name of the routing protocol from which the
      route was originally obtained.

   o  last-modified - date and time of last modification, or
      installation, of the route.

   In the core routing data model, the contents of routing tables (list
   of routes) are defined as operational state data.  Routing protocol
   operations result in route additions, removals and modifications.
   This also includes manipulations via the "static" pseudo-protocol.

   At least the following two routing tables MUST be configured for each
   router instance:

   1.  Forwarding information base (FIB) contains active routes that are
       used by the operating system kernel for forwarding datagrams.

   2.  Main routing table to which all routing protocol instances are
       connected by default.

   The main routing table SHOULD serve as the source of active routes
   for the FIB.

   One or more additional routing tables MAY be configured by creating
   new entries in the "routing-table" list, either being a part of
   factory-default configuration or configured by the client.

   The naming scheme for routing tables, as well as restrictions on the
   number and configurability of routing tables are implementation-
   specific.

   Every routing table can serve as a source of routes for other routing
   tables.  To achieve this, one or more recipient routing tables may be
   specified in the configuration of the source routing table.  In
   addition, a route filter may be configured for each recipient routing
   table, which selects and/or manipulates the routes that are passed on
   between the source and recipient routing table.







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4.4.  Routing Protocols

   The core routing data model provides an open-ended framework for
   defining multiple routing protocol instances.  Each of them is
   identified by a name, which MUST be unique within a router instance,
   and MUST be assigned a type from a selection which includes all
   routing protocol types supported by the server, such as static, RIP,
   OSPF or BGP.

   Each routing protocol instance is connected to exactly one routing
   table.  By default, every routing protocol instance is connected to
   the main routing table, but any routing protocol instance can be
   configured to use a different routing table, provided such an extra
   table exists.

   Routes learned from the network by a routing protocol are passed to
   the connected routing table and vice versa - routes appearing in a
   routing table are passed to all routing protocols connected to the
   table (except "direct" and "static" pseudo-protocols) and advertised
   by that protocol to the network.

   Two independent route filters (see Section 4.5) may be defined for a
   routing protocol instance to control the exchange of routes in both
   directions between the routing protocol instance and the connected
   routing table:

   o  import filter controls which routes are passed from a routing
      protocol instance to the routing table,

   o  export filter controls which routes the routing protocol instance
      may receive from the connected routing table.

   Note that, for historical reasons, the terms import and export are
   used from the viewpoint of a routing table.

   The "ietf-routing" module defines two special routing protocols -
   "direct" and "static".  Both are in fact pseudo-protocols, which
   means that they are confined to the local device and do not exchange
   any routing information with neighboring routers.  Routes from both
   "direct" and "static" protocol instances are passed to the connected
   routing table (subject to route filters, if any), but an exchange in
   the opposite direction is not allowed.

   Every router instance MUST contain exactly one instance of the
   "direct" pseudo-protocol.  It is the source of routes to directly
   connected networks (so-called direct routes).  Such routes are
   supplied by the operating system kernel, based on the detected and
   configured network interfaces, and they usually appear in the main



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   routing table.  However, using the framework defined in this
   document, the target routing table for direct routes can be changed
   by connecting the "direct" protocol instance to a non-default routing
   table, and the direct routes can also be filtered before they appear
   in the routing table.

   The "static" routing pseudo-protocol allows for specifying routes
   manually.  It MAY be configured in zero or multiple instances,
   although a typical implementation will have exactly one instance.

4.4.1.  Defining New Routing Protocols

   It is expected that future YANG modules will create data models for
   additional routing protocol types.  In order to do so, the new module
   has to define the protocol-specific information and fit it to the
   core routing framework in the following way:

   o  A new identity MUST be defined for the routing protocol and its
      base identity MUST be set to "rt:routing-protocol", or to an
      identity derived from "rt:routing-protocol".

   o  Additional route attributes MAY be defined.  Their definitions
      then have to be inserted as operational state data by augmenting
      the definition of "rt:route" inside "rt:routing-table", and
      possibly to other places in configuration data and RPC input or
      output.

   o  The recommended way of defining configuration data specific to a
      new protocol is to augment the "routing-protocol" list entry with
      a container that encapsulates the configuration hierarchy of the
      new protocol.  The "augment" statement SHOULD be made conditional
      by using a "when" substatement requiring that the new nodes be
      used only if the "type" leaf node is equal to the new protocol's
      identity.

   The above steps are implemented by the example YANG module for the
   RIP routing protocol in Appendix A.  First, the module defines a new
   identity for the RIP protocol:

   identity rip {
     base rt:routing-protocol;
     description "Identity for the RIP routing protocol.";
   }

   Second, new route attributes specific for the RIP protocol ("metric"
   and "tag") are defined in a grouping and then added to route
   definitions appearing in "routing-table" and in the output part of
   "get-route" RPC method:



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   grouping route-content {
     description
       "RIP-specific route content.";
     leaf metric {
       type rip-metric;
     }
     leaf tag {
       type uint16;
       default "0";
       description
         "This leaf may be used to carry additional info, e.g. AS
          number.";
     }
   }

   augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/"
         + "rt:routes/rt:route" {
     when "../../../../rt:routing-protocols/"
        + "rt:routing-protocol[rt:name=current()/rt:source-protocol]/"
        + "rt:type='rip:rip'" {
       description
         "This augment is only valid if the source protocol from which
          the route originated is RIP.";
     }
     description
       "RIP-specific route components.";
     uses route-content;
   }

   augment "/rt:get-route/rt:output/rt:route" {
     description
       "Add RIP-specific route content.";
     uses route-content;
   }

   The "when" substatement in the first "augment" guarantees that the
   new route attributes are only valid when the source protocol is RIP.

   Finally, RIP-specific configuration data are integrated into the "rt:
   routing-protocol" node by using the following "augment" statement,
   which applies only to routing protocol instances whose type is "rip:
   rip":









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   augment "/rt:routing/rt:router/rt:routing-protocols/"
         + "rt:routing-protocol" {
     when "rt:type = 'rip:rip'";
     container rip-configuration {
       container rip-interfaces {
         list rip-interface {
           key "name";
           leaf name {
             type if:interface-ref;
           }
           leaf enabled {
             type boolean;
             default "true";
           }
           leaf metric {
             type rip-metric;
             default "1";
           }
         }
       }
       leaf update-interval {
         type uint8 {
           range "10..60";
         }
         units "seconds";
         default "30";
         description
           "Time interval between periodic updates.";
       }
     }
   }

4.5.  Route Filters

   The core routing data model provides a skeleton for defining route
   filters that can be used to restrict the set of routes being
   exchanged between a routing protocol instance and a routing table, or
   between a source and a recipient routing table.  Route filters may
   also manipulate routes, i.e., add, delete, or modify their
   properties.

   By itself, the route filtering framework defined in this document
   allows to establish only the two extreme routing policies in which
   either all routes are allowed or all routes are rejected.  It is
   expected that real route filtering framework(s) will be developed
   separately.

   Each route filter is identified by a name which MUST be unique within



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   a router instance.  Its type MUST be specified by the "type" identity
   reference - this opens the space for multiple route filtering
   framework implementations.  The default value for route filter type
   is the identity "deny-all-route-filter" defined in the "ietf-routing"
   module, which represents a route filtering policy in which all routes
   are rejected.

4.6.  RPC Operation

   The "ietf-routing" module defines the "get-route" RPC operation.  It
   is used for querying the forwarding information base of a router
   instance.  The first input parameter is the name of the router
   instance whose FIB is to be queried, and the second parameter is a
   destination address.  Modules for particular address families are
   expected to augment the "destination-address" container with the
   "address" leaf, as it is done in the "ietf-ipv4-unicast-routing"
   module.

   The server replies with an active route which is used for forwarding
   datagrams to the destination address within the selected router
   instance.  Again, modules for particular address families are
   expected to augment the definition of output parameters with AFN/
   SAFI-specific contents.




























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5.  IANA AFN and SAFI YANG Module

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number and all occurrences of the revision date below with
   the date of RFC publication (and remove this note).

   <CODE BEGINS> file "iana-afn-safi@2011-09-23.yang"

   module iana-afn-safi {

     namespace "urn:ietf:params:xml:ns:yang:iana-afn-safi";

     prefix "ianaaf";

     organization
       "IANA";

     contact
       "Internet Assigned Numbers Authority

        Postal:
        ICANN
        4676 Admiralty Way, Suite 330
        Marina del Rey, CA 90292
        U. S. A.


        Tel: +1 310 823 9358
        E-Mail: iana&iana.org
       ";

     description
       "This YANG module provides two typedefs containing YANG
        definitions for the following IANA-registered enumerations:

        - Address Family Numbers (AFN)

        - Subsequent Address Family Identifiers (SAFI)

        The latest revision of this YANG module can be obtained from the
        IANA web site.

        Copyright (c) 2011 IETF Trust and the persons identified as
        authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set



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

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

     revision 2011-09-23 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for Routing Configuration";
     }

     typedef address-family {
       type enumeration {
         enum other {
           value "0";
           description
             "none of the following";
         }
         enum ipV4 {
           value "1";
           description
             "IP Version 4";
         }
         enum ipV6 {
           value "2";
           description
             "IP Version 6";
         }
         enum nsap {
           value "3";
           description
             "NSAP";
         }
         enum hdlc {
           value "4";
           description
             "(8-bit multidrop)";
         }
         enum bbn1822 {
           value "5";
           description
             "BBN Report 1822";
         }
         enum all802 {



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           value "6";
           description
             "(includes all 802 media plus Ethernet 'canonical
              format')";
         }
         enum e163 {
           value "7";
           description
             "E.163";
         }
         enum e164 {
           value "8";
           description
             "(SMDS, FrameRelay, ATM)";
         }
         enum f69 {
           value "9";
           description
             "(Telex)";
         }
         enum x121 {
           value "10";
           description
             "(X.25, Frame Relay)";
         }
         enum ipx {
           value "11";
           description
             "IPX (Internet Protocol Exchange)";
         }
         enum appleTalk {
           value "12";
           description
             "Apple Talk";
         }
         enum decnetIV {
           value "13";
           description
             "DEC Net Phase IV";
         }
         enum banyanVines {
           value "14";
           description
             "Banyan Vines";
         }
         enum e164withNsap {
           value "15";
           description



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             "(E.164 with NSAP format subaddress)";
         }
         enum dns {
           value "16";
           description
             "(Domain Name System)";
         }
         enum distinguishedName {
           value "17";
           description
             "(Distinguished Name, per X.500)";
         }
         enum asNumber {
           value "18";
           description
             "(16-bit quantity, per the AS number space)";
         }
         enum xtpOverIPv4 {
           value "19";
           description
             "XTP over IP version 4";
         }
         enum xtpOverIpv6 {
           value "20";
           description
             "XTP over IP version 6";
         }
         enum xtpNativeModeXTP {
           value "21";
           description
             "XTP native mode XTP";
         }
         enum fibreChannelWWPN {
           value "22";
           description
             "Fibre Channel World-Wide Port Name";
         }
         enum fibreChannelWWNN {
           value "23";
           description
             "Fibre Channel World-Wide Node Name";
         }
         enum gwid {
           value "24";
           description
             "Gateway Identifier";
         }
         enum afi {



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           value "25";
           description
             "AFI for L2VPN";
         }
       }
       description
         "This typedef is a YANG enumeration of IANA-registered address
          family numbers (AFN).";
       reference
         "Address Family Numbers. IANA, 2011-01-20.
          <http://www.iana.org/assignments/address-family-numbers/
          address-family-numbers.xml>

          IANA-ADDRESS-FAMILY-NUMBERS-MIB DEFINITIONS
          <http://www.iana.org/assignments/ianaaddressfamilynumbers-mib>
         ";
     }

     typedef subsequent-address-family {
       type enumeration {
         enum nlri-unicast {
           value "1";
           description
             "Network Layer Reachability Information used for unicast
              forwarding";
           reference
             "RFC4760";
         }
         enum nlri-multicast {
           value "2";
           description
             "Network Layer Reachability Information used for multicast
              forwarding";
           reference
             "RFC4760";
         }
         enum nlri-mpls {
           value "4";
           description
             "Network Layer Reachability Information (NLRI) with MPLS
              Labels";
           reference
             "RFC3107";
         }
         enum mcast-vpn {
           value "5";
           description
             "MCAST-VPN";



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           reference
             "draft-ietf-l3vpn-2547bis-mcast-bgp-08";
         }
         enum nlri-dynamic-ms-pw {
           value "6";
           status "obsolete";
           description
             "Network Layer Reachability Information used for Dynamic
              Placement of Multi-Segment Pseudowires (TEMPORARY -
              Expires 2008-08-23)";
           reference
             "draft-ietf-pwe3-dynamic-ms-pw-13";
         }
         enum tunnel-safi {
           value "64";
           description
             "Tunnel SAFI";
           reference
             "draft-nalawade-kapoor-tunnel-safi-05";
         }
         enum vpls {
           value "65";
           description
             "Virtual Private LAN Service (VPLS)";
           reference
             "RFC4761, RFC6074";
         }
         enum bgp-mdt {
           value "66";
           description
             "BGP MDT SAFI";
           reference
             "RFC6037";
         }
         enum bgp-4over6 {
           value "67";
           description
             "BGP 4over6 SAFI";
           reference
             "RFC5747";
         }
         enum bgp-6over4 {
           value "68";
           description
             "BGP 6over4 SAFI";
           reference
             "mailto:cuiyong&tsinghua.edu.cn";
         }



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         enum l1vpn-auto-discovery {
           value "69";
           description
             "Layer-1 VPN auto-discovery information";
           reference
             "draft-ietf-l1vpn-bgp-auto-discovery-05";
         }
         enum mpls-vpn {
           value "128";
           description
             "MPLS-labeled VPN address";
           reference
             "RFC4364";
         }
         enum multicast-bgp-mpls-vpn {
           value "129";
           description
             "Multicast for BGP/MPLS IP Virtual Private Networks
              (VPNs)";
           reference
             "draft-ietf-l3vpn-2547bis-mcast-10,
              draft-ietf-l3vpn-2547bis-mcast-10";
         }
         enum route-target-constraints {
           value "132";
           description
             "Route Target constraints";
           reference
             "RFC4684";
         }
         enum ipv4-diss-flow {
           value "133";
           description
             "IPv4 dissemination of flow specification rules";
           reference
             "RFC5575";
         }
         enum vpnv4-diss-flow {
           value "134";
           description
             "IPv4 dissemination of flow specification rules";
           reference
             "RFC5575";
         }
         enum vpn-auto-discovery {
           value "140";
           description
             "VPN auto-discovery";



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           reference
             "draft-ietf-l3vpn-bgpvpn-auto-09";
         }
       }
       description
         "This typedef is a YANG enumeration of IANA-registered
          subsequent address family identifiers (SAFI).";
       reference
         "Subsequent Address Family Identifiers (SAFI) Parameters. IANA,
          2011-03-04. <http://www.iana.org/assignments/safi-namespace/
          safi-namespace.xml>
         ";
     }
   }

   <CODE ENDS>



































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6.  Routing YANG Module

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number and all occurrences of the revision date below with
   the date of RFC publication (and remove this note).

   <CODE BEGINS> file "ietf-routing@2011-09-23.yang"

   module ietf-routing {

     namespace "urn:ietf:params:xml:ns:yang:ietf-routing";

     prefix "rt";

     import ietf-yang-types {
       prefix "yang";
     }

     import iana-afn-safi {
       prefix "ianaaf";
     }

     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: Ladislav Lhotka
        <mailto:lhotka@cesnet.cz>
       ";

     description
       "This module contains YANG definitions of essential components
        that may be used for configuring a routing subsystem.

        Copyright (c) 2011 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



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

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

     revision 2011-09-23 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for Routing Configuration";
     }

     /* Identities */

     identity routing-protocol {
       description
         "Base identity from which routing protocol identities are
          derived.";
     }

     identity direct {
       base routing-protocol;
       description
         "Routing pseudo-protocol which provides routes to directly
          connected networks.";
     }

     identity static {
       base routing-protocol;
       description
         "Static routing pseudo-protocol.";
     }

     identity route-filter {
       description
         "Base identity from which all route filters are derived.";
     }

     identity deny-all-route-filter {
       base route-filter;
       description
         "Route filter that blocks all routes.";
     }




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     /* Type Definitions */

     typedef router-ref {
       type leafref {
         path "/rt:routing/rt:router/rt:name";
       }
       description
         "This type is used for leafs that reference a router
          instance.";
     }

     /* Groupings */

     grouping afn-safi {
       leaf address-family {
         type ianaaf:address-family;
         default "ipV4";
         description
           "Address family of routes in the routing table.";
       }
       leaf safi {
         type ianaaf:subsequent-address-family;
         default "nlri-unicast";
         description
           "Subsequent address family identifier of routes in the
            routing table.";
       }
       description
         "This grouping provides two parameters specifying address
          family and subsequent address family.";
     }

     grouping route-content {
       description
         "Generic parameters of routes.";
       leaf source-protocol {
         type string;
         description
           "The name of the routing protocol instance from which the
            route comes. This routing protocol must be configured
            (automatically or manually) in the device.";
       }
       leaf last-modified {
         type yang:date-and-time;
         description
           "Time stamp of the last modification of the route. If the
            route was never modified, it is the time when the route was
            inserted to the routing table.";



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       }
     }

     /* RPC Methods */

     rpc get-route {
       description
         "Query the forwarding information base of a router instance
          whose name is given as the first parameter 'router-name'. The
          second parameter 'destination-address' should be augmented in
          order to support destination addresses of all supported
          address families. The server returns the route which is
          currently used for forwarding datagrams to that destination
          address, or an error message, if no such route exists.";
       input {
         leaf router-name {
           type router-ref;
           mandatory "true";
           description
             "First parameter: name of the router instance whose
              forwarding information base is queried.";
         }
         container destination-address {
           uses afn-safi;
           description
             "Second parameter: destination address.

              AFN/SAFI-specific modules must augment this container with
              a leaf named 'address'.
             ";
         }
       }
       output {
         container route {
           uses afn-safi;
           description
             "Contents of the reply specific for each address family
              should be defined through augmenting.";
           uses route-content;
         }
       }
     }

     /* Data Nodes */

     container routing {
       description
         "Routing parameters.";



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       list router {
         key "name";
         description
           "Each list entry is a container for configuration and
            operational state data of a single (logical) router.";
         leaf name {
           type string;
           description
             "The unique router name.";
         }
         leaf description {
           type string;
           description
             "Textual description of the router.";
         }
         leaf enabled {
           type boolean;
           default "true";
           description
             "Enable or disable the router. The default value is 'true',
              which means that the router is enabled.";
         }
         container routing-protocols {
           description
             "Container for the list of configured routing protocol
              instances.";
           list routing-protocol {
             key "name";
             description
               "An instance of a routing protocol.";
             leaf name {
               type string;
               description
                 "The name of the routing protocol instance.";
             }
             leaf description {
               type string;
               description
                 "Textual description of the routing protocol
                  instance.";
             }
             leaf type {
               type identityref {
                 base routing-protocol;
               }
               mandatory "true";
               description
                 "Type of the routing protocol - an identity derived



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                  from the 'routing-protocol' base identity.";
             }
             container connected-routing-tables {
               description
                 "Container for connected routing tables.";
               list connected-routing-table {
                 key "name";
                 description
                   "List of routing tables to which the routing protocol
                    instance is connected. No more than one routing
                    table may be configured for each AFN/SAFI pair.

                    Implementation may provide default routing tables
                    for some AFN/SAFI pairs, which are used if the
                    corresponding entry is not configured.
                   ";
                 leaf name {
                   type leafref {
                     path "../../../../../routing-tables/routing-table/"
                        + "name";
                   }
                   description
                     "This must be the name of an existing routing
                      table.";
                 }
                 leaf import-filter {
                   type leafref {
                     path "../../../../../route-filters/route-filter/"
                        + "name";
                   }
                   description
                     "Reference to a route filter that is used for
                      filtering routes passed from this routing protocol
                      instance to the routing table specified by the
                      'name' sibling node. If this leaf is not present,
                      the behavior is protocol-specific, but typically
                      it means that all routes are accepted.";
                 }
                 leaf export-filter {
                   type leafref {
                     path "../../../../../route-filters/route-filter/"
                        + "name";
                   }
                   description
                     "Reference to a route filter that is used for
                      filtering routes passed from the routing table
                      specified by the 'name' sibling node to this
                      routing protocol instance. If this leaf is not



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                      present, the behavior is protocol-specific -
                      typically it means that all routes are accepted,
                      except for the 'direct' and 'static'
                      pseudo-protocols which accept no routes from any
                      routing table.";
                 }
               }
             }
           }
         }
         container route-filters {
           description
             "Container for configured route filters.";
           list route-filter {
             key "name";
             description
               "Route filters are used for filtering and/or manipulating
                routes that are passed between a routing protocol and a
                routing table or vice versa, or between two routing
                tables. It is expected that other modules augment this
                list with contents specific for a particular route
                filter type.";
             leaf name {
               type string;
               description
                 "The name of the route filter.";
             }
             leaf description {
               type string;
               description
                 "Textual description of the route filter.";
             }
             leaf type {
               type identityref {
                 base route-filter;
               }
               default "deny-all-route-filter";
               description
                 "Type of the route-filter - an identity derived from
                  the 'route-filter' base identity. The default value
                  represents an all-blocking filter.";
             }
           }
         }
         container routing-tables {
           description
             "Container for configured routing tables.";
           list routing-table {



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             key "name";
             description
               "Each entry represents a routing table identified by the
                'name' key. All routes in a routing table must have the
                same AFN and SAFI.";
             leaf name {
               type string;
               description
                 "The name of the routing table.";
             }
             uses afn-safi;
             leaf description {
               type string;
               description
                 "Textual description of the routing table.";
             }
             container routes {
               config "false";
               description
                 "Current contents of the routing table (operational
                  state data).";
               list route {
                 description
                   "A routing table entry. It is expected that this data
                    node will be augmented with information specific for
                    routes of each address family.";
                 uses route-content;
               }
             }
             list recipient-routing-tables {
               key "recipient-name";
               description
                 "A list of routing tables that receive routes from this
                  routing table.";
               leaf recipient-name {
                 type leafref {
                   path "../../../routing-table/name";
                 }
                 description
                   "The name of the recipient routing table.";
               }
               leaf filter {
                 type leafref {
                   path "../../../../route-filters/route-filter/name";
                 }
                 description
                   "A route filter which is applied to the routes passed
                    on to the recipient routing table.";



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               }
             }
           }
         }
       }
     }
   }

   <CODE ENDS>










































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7.  IPv4 Unicast Routing YANG Module

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number and all occurrences of the revision date below with
   the date of RFC publication (and remove this note).

   <CODE BEGINS> file "ietf-ipv4-unicast-routing@2011-09-23.yang"

   module ietf-ipv4-unicast-routing {

     namespace "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing";

     prefix "v4ur";

     import ietf-routing {
       prefix "rt";
     }

     import ietf-inet-types {
       prefix "inet";
     }

     import ietf-interfaces {
       prefix "if";
     }

     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: Ladislav Lhotka
        <mailto:lhotka@cesnet.cz>
       ";

     description
       "This module augments the 'ietf-routing' module with YANG
        definitions for basic configuration of IPv4 unicast routing.

        Copyright (c) 2011 IETF Trust and the persons identified as



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        authors of the code. All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).

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

     revision 2011-09-23 {
       description
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for Routing Configuration";
     }

     /* Groupings */

     grouping route-content {
       description
         "Specific parameters of IPv4 unicast routes.";
       leaf destination-prefix {
         type inet:ipv4-prefix;
         description
           "IPv4 destination prefix.";
       }
       leaf next-hop {
         type inet:ipv4-address;
         description
           "IPv4 address of the next hop.";
       }
       leaf outgoing-interface {
         type if:interface-ref;
         description
           "Outgoing interface.";
       }
     }

     /* RPC Methods */

     augment "/rt:get-route/rt:input/rt:destination-address" {
       when "address-family='ipV4' and safi='nlri-unicast'" {
         description
           "This augment is valid only for IPv4 unicast.";



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       }
       description
         "The 'address' leaf augments the 'rt:destination-address'
          parameter of the 'rt:get-route' operation.";
       leaf address {
         type inet:ipv4-address;
         description
           "IPv4 destination address.";
       }
     }

     augment "/rt:get-route/rt:output/rt:route" {
       when "address-family='ipV4' and safi='nlri-unicast'" {
         description
           "This augment is valid only for IPv4 unicast.";
       }
       description
         "Contents of the reply to 'rt:get-route' operation.";
       uses route-content;
     }

     /* Data nodes */

     augment "/rt:routing/rt:router/rt:routing-protocols/"
           + "rt:routing-protocol" {
       when "rt:type='rt:static'" {
         description
           "The augment is only valid for the 'static'
            pseudo-protocol.";
       }
       description
         "This augment defines the configuration of the static
          pseudo-protocol with data specific for IPv4 unicast.";
       container ipv4-unicast-static-routes {
         description
           "Configuration of a 'static' pseudo-protocol instance
            consists of a list of routes.";
         list static-route {
           key "id";
           ordered-by "user";
           description
             "A user-ordered list of static routes.";
           leaf id {
             type string;
             description
               "An identification string for the route.";
           }
           leaf description {



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             type string;
             description
               "Textual description of the route.";
           }
           uses route-content;
         }
       }
     }

     augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/"
           + "rt:routes/rt:route" {
       when "../../rt:address-family='ipV4' and "
          + "../../rt:safi='nlri-unicast'" {
         description
           "This augment is valid only for IPv4 unicast.";
       }
       description
         "This augment defines the content of IPv4 unicast routes.";
       uses route-content;
     }
   }

   <CODE ENDS>




























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8.  IANA Considerations

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number (and remove this note).

   This document registers the following namespace URIs in the IETF XML
   registry [RFC3688]:

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

   Registrant Contact: The IESG.

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

   ----------------------------------------------------------
   URI: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing

   Registrant Contact: The IESG.

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

   ----------------------------------------------------------
   URI: urn:ietf:params:xml:ns:yang:iana-afn-safi

   Registrant Contact: IANA.

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

   This document registers the following YANG modules in the YANG Module
   Names registry [RFC6020]:

















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   -------------------------------------------------------------------
   name:         ietf-routing
   namespace:    urn:ietf:params:xml:ns:yang:ietf-routing
   prefix:       rt
   reference:    RFC XXXX
   -------------------------------------------------------------------

   -------------------------------------------------------------------
   name:         ietf-ipv4-unicast-routing
   namespace:    urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing
   prefix:       v4ur
   reference:    RFC XXXX
   -------------------------------------------------------------------

   -------------------------------------------------------------------
   name:         iana-afn-safi
   namespace:    urn:ietf:params:xml:ns:yang:iana-afn-safi
   prefix:       ianaaf
   reference:    RFC XXXX
   -------------------------------------------------------------------































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9.  Security Considerations

   The YANG modules defined in this document are 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].

   A number of data nodes defined in the YANG modules are writable/
   creatable/deletable (i.e., "config true" in YANG terms, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations to these data nodes,
   such as "edit-config", can have negative effects on the network if
   the operations are not properly protected.

   The vulnerable "config true" subtrees and data nodes are the
   following:

   /rt:routing/rt:router/rt:routing-protocols/rt:routing-protocol  This
      list specifies the routing protocols configured on a device.

   /rt:routing/rt:router/rt:route-filters/rt:route-filter  This list
      specifies the configured route filters which represent the
      administrative policies for redistributing and modifying routing
      information.

   Unauthorized access to any of these lists can adversely affect the
   routing subsystem of both the local device and the network.  This may
   lead to network malfunctions, delivery of packets to inappropriate
   destinations and other problems.






















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10.  Acknowledgments

   The author wishes to thank Martin Bjorklund, Joel Halpern, Tom Petch
   and Juergen Schoenwaelder for their helpful comments and suggestions.















































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11.  References

11.1.  Normative References

   [IANA-AFN]
              IANA, "Address Family Numbers.", January 2011.

   [IANA-SAFI]
              IANA, "Subsequent Address Family Identifiers (SAFI)
              Parameters.", March 2011.

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

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

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

   [RFC6021]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6021, September 2010.

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

   [YANG-IF]  Bjorklund, M., "A YANG Data Model for Interface
              Configuration", draft-ietf-netmod-interfaces-cfg-02 (work
              in progress), September 2011.

   [YANG-IP]  Bjorklund, M., "A YANG Data Model for IP Configuration",
              draft-ietf-netmod-ip-cfg-00 (work in progress),
              September 2011.

11.2.  Informative References

   [RFC6087]  Bierman, A., "Guidelines for Authors and Reviewers of YANG
              Data Model Documents", RFC 6087, January 2011.

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








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Appendix A.  Example - Adding a New Routing Protocol

   This appendix demonstrates how the core routing data model can be
   extended to support a new routing protocol.  Appendix A.1 contains
   the YANG module which is used for this purpose.  It is intended only
   as an illustration and not as a real definition of a data model for
   the RIP routing protocol.  Also, for the sake of brevity, we do not
   follow all the guidelines specified in [RFC6087].

   Appendix A.2 then contains a complete instance XML document - a reply
   to the NETCONF <get> message from a server that uses the RIP protocol
   as well as static routing.

A.1.  Example YANG Module for Routing Information
      Protocol

   <CODE BEGINS> file "example-rip@2011-09-23.yang"

   module example-rip {

     namespace "http://example.com/rip";

     prefix "rip";

     import ietf-routing {
       prefix "rt";
     }

     import ietf-interfaces {
       prefix "if";
     }

     identity rip {
       base rt:routing-protocol;
       description
         "Identity for the RIP routing protocol.";
     }

     typedef rip-metric {
       type uint8 {
         range "0..16";
       }
     }

     grouping route-content {
       description
         "RIP-specific route content.";
       leaf metric {



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         type rip-metric;
       }
       leaf tag {
         type uint16;
         default "0";
         description
           "This leaf may be used to carry additional info, e.g. AS
            number.";
       }
     }

     augment "/rt:get-route/rt:output/rt:route" {
       description
         "Add RIP-specific route content.";
       uses route-content;
     }

     augment "/rt:routing/rt:router/rt:routing-protocols/"
           + "rt:routing-protocol" {
       when "rt:type = 'rip:rip'";
       container rip-configuration {
         container rip-interfaces {
           list rip-interface {
             key "name";
             leaf name {
               type if:interface-ref;
             }
             leaf enabled {
               type boolean;
               default "true";
             }
             leaf metric {
               type rip-metric;
               default "1";
             }
           }
         }
         leaf update-interval {
           type uint8 {
             range "10..60";
           }
           units "seconds";
           default "30";
           description
             "Time interval between periodic updates.";
         }
       }
     }



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     augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/"
           + "rt:routes/rt:route" {
       when "../../../../rt:routing-protocols/"
          + "rt:routing-protocol[rt:name=current()/rt:source-protocol]/"
          + "rt:type='rip:rip'" {
         description
           "This augment is only valid if the source protocol from which
            the route originated is RIP.";
       }
       description
         "RIP-specific route components.";
       uses route-content;
     }
   }

   <CODE ENDS>

A.2.  Sample Reply to the NETCONF <get> Message

   This section contains a sample reply to the NETCONF <get> message,
   which could be sent by a server supporting (and advertising in the
   NETCONF <hello> message) the following YANG modules:

   o  ietf-interfaces [YANG-IF],

   o  ex-ethernet [YANG-IF],

   o  ietf-ip [YANG-IP],

   o  ietf-routing (Section 6),

   o  ietf-ipv4-unicast-routing (Section 7),

   o  example-rip (Appendix A.1).

   We assume a simple network setup as shown in Figure 3: routers "ISP"
   and "A" use RIP for exchanging routing information whereas static
   routing is used in the private network.  In order to avoid the
   redistribution of the routes to the private subnetworks
   192.168.1.0/24 and 192.168.2.0/24 in RIP, an export filter is used in
   the RIP protocol configuration preventing the routes from the main
   routing table from appearing in RIP updates.









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                   +-----------------+
                   |                 |
                   |    Router ISP   |
                   |                 |
                   +--------+--------+
                            |192.0.2.2
                            |
                            |
                        eth0|192.0.2.1
                   +--------+--------+
                   |                 |
                   |     Router A    |
                   |                 |
                   +--------+--------+
                        eth1|192.168.1.1
                            |
                            |
                            |192.168.1.254
                   +--------+--------+
                   |                 |
                   |     Router B    |
                   |                 |
                   +--------+--------+
                            |192.168.2.1
                            |


                  Figure 3: Example network configuration

   Router "A" then could send the following XML document as its reply to
   the NETCONF <get> message:

  <?xml version="1.0"?>

  <nc:rpc-reply
      message-id="101"
      xmlns="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"
      xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
      xmlns:if="urn:ietf:params:xml:ns:yang:ietf-interfaces"
      xmlns:eth="http://example.com/ethernet"
      xmlns:ip="urn:ietf:params:xml:ns:yang:ietf-ip"
      xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
      xmlns:rip="http://example.com/rip">
   <nc:data>
    <if:interfaces>
     <if:interface>
      <if:name>eth0</if:name>
      <if:type>ethernetCsmacd</if:type>



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      <if:location>05:00.0</if:location>
      <ip:ipv4>
       <ip:address>
        <ip:ip>192.0.2.1</ip:ip>
        <ip:prefix-length>24</ip:prefix-length>
       </ip:address>
      </ip:ipv4>
     </if:interface>
     <if:interface>
      <if:name>eth1</if:name>
      <if:type>ethernetCsmacd</if:type>
      <if:location>05:00.1</if:location>
      <ip:ipv4>
       <ip:address>
        <ip:ip>192.168.1.1</ip:ip>
        <ip:prefix-length>24</ip:prefix-length>
       </ip:address>
      </ip:ipv4>
     </if:interface>
    </if:interfaces>
    <rt:routing>
     <rt:router>
      <rt:name>inet-0</rt:name>
      <rt:routing-protocols>
       <rt:routing-protocol>
        <rt:name>direct</rt:name>
        <rt:type>rt:direct</rt:type>
       </rt:routing-protocol>
       <rt:routing-protocol>
        <rt:name>st0</rt:name>
        <rt:description>
         Static routing is used for the internal network.
        </rt:description>
        <rt:type>rt:static</rt:type>
        <ipv4-unicast-static-routes>
         <static-route>
          <id>id-6378</id>
          <destination-prefix>192.168.2.0/24</destination-prefix>
          <next-hop>192.168.1.254</next-hop>
         </static-route>
        </ipv4-unicast-static-routes>
       </rt:routing-protocol>
       <rt:routing-protocol>
        <rt:name>rip0</rt:name>
        <rt:description>
         RIP is used on the uplink.  Static routes to the
         internal networks are not advertized in RIP.
        </rt:description>



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        <rt:type>rip:rip</rt:type>
        <rt:connected-routing-tables>
         <rt:connected-routing-table>
          <rt:name>ipv4-unicast-main</rt:name>
          <rt:export-filter>deny-all</rt:export-filter>
         </rt:connected-routing-table>
        </rt:connected-routing-tables>
        <rip:rip-configuration>
         <rip:rip-interfaces>
          <rip:rip-interface>
           <rip:name>eth0</rip:name>
          </rip:rip-interface>
         </rip:rip-interfaces>
        </rip:rip-configuration>
       </rt:routing-protocol>
      </rt:routing-protocols>
      <rt:route-filters>
       <rt:route-filter>
        <rt:name>deny-all</rt:name>
       </rt:route-filter>
      </rt:route-filters>
      <rt:routing-tables>
       <rt:routing-table>
        <rt:name>ipv4-unicast-fib</rt:name>
        <rt:routes>
         <rt:route>
          <destination-prefix>192.0.2.1/24</destination-prefix>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth0</outgoing-interface>
          <rt:last-modified>2011-09-23T17:11:27+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>192.168.1.0/24</destination-prefix>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth1</outgoing-interface>
          <rt:last-modified>2011-09-23T17:11:27+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>192.168.2.0/24</destination-prefix>
          <rt:source-protocol>st0</rt:source-protocol>
          <next-hop>192.168.1.254</next-hop>
          <rt:last-modified>2011-09-23T17:11:32+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>0.0.0.0/0</destination-prefix>
          <rt:source-protocol>rip0</rt:source-protocol>
          <next-hop>192.0.2.2</next-hop>
          <rip:metric>2</rip:metric>



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          <rip:tag>64500</rip:tag>
          <rt:last-modified>2011-09-23T18:02:45+01:00</rt:last-modified>
         </rt:route>
        </rt:routes>
       </rt:routing-table>
       <rt:routing-table>
        <rt:name>ipv4-unicast-main</rt:name>
        <rt:recipient-routing-tables>
         <rt:recipient-name>ipv4-unicast-fib</rt:recipient-name>
        </rt:recipient-routing-tables>
        <rt:routes>
         <rt:route>
          <destination-prefix>192.0.2.1/24</destination-prefix>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth0</outgoing-interface>
          <rt:last-modified>2011-09-23T17:11:27+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>192.168.1.0/24</destination-prefix>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth1</outgoing-interface>
          <rt:last-modified>2011-09-23T17:11:27+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>192.168.2.0/24</destination-prefix>
          <rt:source-protocol>st0</rt:source-protocol>
          <next-hop>192.168.1.254</next-hop>
          <rt:last-modified>2011-09-23T17:11:32+01:00</rt:last-modified>
         </rt:route>
         <rt:route>
          <destination-prefix>0.0.0.0/0</destination-prefix>
          <rt:source-protocol>rip0</rt:source-protocol>
          <next-hop>192.0.2.2</next-hop>
          <rip:metric>2</rip:metric>
          <rip:tag>64500</rip:tag>
          <rt:last-modified>2011-09-23T18:02:45+01:00</rt:last-modified>
         </rt:route>
        </rt:routes>
       </rt:routing-table>
      </rt:routing-tables>
     </rt:router>
    </rt:routing>
   </nc:data>
  </nc:rpc-reply>







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Appendix B.  Change Log

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

B.1.  Changes Between Versions -00 and -01

   o  AFN/SAFI-independent stuff was moved to the "ietf-routing" module.

   o  Typedefs for AFN and SAFI were placed in a separate "iana-afn-
      safi" module.

   o  Names of some data nodes were changed, in particular "routing-
      process" is now "router".

   o  The restriction of a single AFN/SAFI per router was lifted.

   o  RPC operation "delete-route" was removed.

   o  Illegal XPath references from "get-route" to the datastore were
      fixed.

   o  Section "Security Considerations" was written.





























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Author's Address

   Ladislav Lhotka
   CESNET

   Email: lhotka@cesnet.cz













































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