NETMOD                                                         L. Lhotka
Internet-Draft                                                    CESNET
Intended status: Standards Track                          April 27,                      September 23, 2011
Expires: October 29, 2011 March 26, 2012

              A YANG Data Model for Routing Configuration
                    draft-ietf-netmod-routing-cfg-00
                    draft-ietf-netmod-routing-cfg-01

Abstract

   This document contains a specification of two 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 - routing
   processes, routes and router
   instances, routes, routing tables, routing protocol instances protocols and route
   filters.

Status of this Memo

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   This Internet-Draft will expire on October 29, 2011. March 26, 2012.

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   document authors.  All rights reserved.

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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.  Route  Router . . . . . . . . . . . . . . . . . . . . . . . . . .  9 10
     4.2.  Route  . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     4.3.  Routing Tables . . . . . . . . . . . . . . . . . . . . . .  9
     4.3. 11
     4.4.  Routing Protocol Instances Protocols  . . . . . . . . . . . . . . . . 10
       4.3.1. . . . . 12
       4.4.1.  Defining New Routing Protocols . . . . . . . . . . . . 11
     4.4. 13
     4.5.  Route Filters  . . . . . . . . . . . . . . . . . . . . . . 13
     4.5. 15
     4.6.  RPC Operations Operation  . . . . . . . . . . . . . . . . . . . . . . 13 16
   5.  IANA AFN and SAFI YANG Module  . . . . . . . . . . . . . . . . 17
   6.  Routing YANG Module  . . . . . . . . . . . . . . . . . . . . . 15
   6. 25
   7.  IPv4 Unicast Routing YANG Module . . . . . . . . . . . . . . . 24
   7. 34
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 33
   8. 38
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 34
   9. 40
   10. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 35
   10. 41
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 36
     10.1. 42
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 36
     10.2. 42
     11.2. Informative References . . . . . . . . . . . . . . . . . . 36 42
   Appendix A.  Example - Adding a New Routing Protocol . . . . . . . 37 43
     A.1.  Example YANG Module for Routing Information
           Protocol . . . 37 . . . . . . . . . . . . . . . . . . . . . . 43
     A.2.  Sample Reply to the NETCONF <get> Message  . . . . . . . . 38 45
   Appendix B.  Change Log  . . . . . . . . . . . . . . . . . . . . . 50
     B.1.  Changes Between Versions -00 and -01 . . . . . . . . . . . 50
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 44 51

1.  Introduction

   This document contains an initial specification of two three YANG modules,
   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 "ietf-ipv4-unicast-routing", that
      "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 basic essential
   building blocks for more complicated setups involving other address
   families such as IPv6, multicast routing, multiple routing protocols,
   and advanced functions, for example functions such as route filtering and or policy routing.  To
   this end, it is expected that this module will be augmented by
   numerous modules developed by other IETF working groups.

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 [RFC4741]: [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

   o
   active route:  a route which is actually used for packet forwarding.
      If there are multiple candidate routes with the same 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 the their
   standard prefixes prefix associated with the corresponding YANG modules, 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     | ex-ip ietf-ip                   | [YANG-IF] [YANG-IP]  |
            |        |                           |            |
            | rip    | example-rip               | Appendix A |
            |        |                           |            |
            | rt     | ietf-routing              | Section 5 6  |
            |        |                           |            |
            | v4ur   | ietf-ipv4-unicast-routing | Section 6 7  |
            |        |                           |            |
            | yang   | ietf-yang-types           | [RFC6021]  |
            +--------+---------------------------+------------+

             Table 1: Prefixes and corresponding YANG modules

3.  Objectives

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

   o  The data model should be suitable for the common address families,
      in particular IPv4 and IPv6, and for unicast and multicast routing
      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.

4.  The Design of the Core Routing Data Model

   The core routing data model consists of two YANG modules.  The first
   module, "ietf-routing", is rather minimal and provides only a top-
   level container ("routing") and a list of routing processes.  Each
   routing process represents an instance defines the generic components of a (virtual) router with a
   separate forwarding table (FIB, forwarding information base).  For a
   given address family, specified by an Address Family Identifier (AFI)
   [IANA-AFI] and Subsequent Address Family Identifier (SAFI)
   [IANA-SAFI], several independent routing processes may be configured.
   system.  The second YANG module, "ietf-ipv4-unicast-routing", provides a augments the
   "ietf-routing" module with new data
   modeling framework nodes that are needed for IPv4
   unicast routing.

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

      +--rw routing with
         +--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
   several essential
   components: routes, generic components of a routing tables, framework: routers, routing protocol instances,
   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 filling augmenting
   them with appropriate contents defined in other modules, a broad
   range of various
   routing setups can be covered. 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 1: 2: Example setup of the routing subsystem

   Figure 1 2 shows an example of a more complicated setup: 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 defined. configured.

   o  Each routing protocol instance, including the "static" and
      "direct" pseudo-protocol instances, pseudo-protocols, is connected to exactly one routing
      table with which it can exchange routes (in both directions,
      except for the "static" and "direct" pseudo-
      protocols). 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 the figure. 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
   "ietf-ipv4-unicast-routing" module 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, as well as and in operational
   state data, for example as entries in routing tables.

4.2.

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 list contents of routes in routing tables
   is represented (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.

   The "ietf-ipv4-unicast-routing" module requires that at

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

   o  The "ipv4-unicast-fib" table is the forwarding
   router instance:

   1.  Forwarding information base (FIB) contains active routes that are
       used by the operating system kernel for forwarding IPv4 unicast datagrams.

   o  The "ipv4-unicast-main" table is the main

   2.  Main routing table.  By
      default, table to which all IPv4 unicast routing protocols exchange routes with
      this table, and protocol instances are
       connected by default.

   The main routing table SHOULD serve as the source of active routes from
   for the "ipv4-unicast-main" FIB.

   One or more additional routing
      table are installed tables MAY be configured by creating
   new entries in the "ipv4-unicast-fib" table and used "routing-table" list, either being a part of
   factory-default configuration or configured by the client.

   The naming scheme for
      packet forwarding.

   Additional routing tables, as well as restrictions on the
   number and configurability of routing tables MAY be configured. are implementation-
   specific.

   Every routing table MAY can serve as a source of routes for other routing
   tables.  To achieve this, one or more recipient routing tables MAY 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.

4.3.

4.4.  Routing Protocol Instances Protocols

   The "ietf-ipv4-unicast-routing" module core routing data model provides an open-ended framework for
   defining multiple routing protocol instances.  Each of them is
   identified by a name, which is MUST be unique within a routing
   process, 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 is configured. exists.

   Routes learned from the network by a routing protocol instance are passed to
   the connected routing table and vice versa - routes appearing in a
   routing table are passed to all routing protocol 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 4.4) 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-ipv4-unicast-routing" "ietf-routing" module defines two special routing protocols -
   "direct" and "static".  Both are in fact pseudo-
   protocols, 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 routing process 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 kernel, based on the detected and
   configured network interfaces, and they usually appear in the main
   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 can MAY be configured in zero or more multiple instances,
   although
   typically a typical implementation will have exactly one instance suffices.

4.3.1. 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 "v4ur:route" "rt:route" inside "v4ur:routing-table".
      Naturally, route attributes (including the extra attributes) may
      be used "rt:routing-table", and
      possibly to other places in configuration data, too, as demonstrated by the
      "static" pseudo-protocol. data and RPC input or
      output.

   o  The recommended way of defining configuration data specific to the a
      new protocol is to augment the "routing-protocol-instance" "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 added:

   augment "/rt:routing/rt:routing-process/v4ur:ipv4-unicast-routing/"
         + "v4ur:routing-tables/v4ur:routing-table/"
         + "v4ur:routes/v4ur:route" defined in a grouping and then added to route
   definitions appearing in "routing-table" and in the output part of
   "get-route" RPC method:

   grouping route-content {
       when "../../../../v4ur:routing-protocol-instances/"
          + "v4ur:routing-protocol-instance[rt:name="
          + "current()/v4ur:source-protocol]/v4ur:type='rip:rip'";
     description
       "RIP-specific route components."; 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" statement is used to make sure 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
   "v4ur:routing-protocol-instance" "rt:
   routing-protocol" node by using the following "augment" statement,
   which applies only to routing protocol instances whose type is "rip:rip", and which is a part of a routing process
   whose address family is "ipV4" and subsequent address family
   identifier is "nlri-unicast": "rip:
   rip":

   augment "/rt:routing/rt:routing-process/v4ur:ipv4-unicast-routing/"
        + "v4ur:routing-protocol-instances/" "/rt:routing/rt:router/rt:routing-protocols/"
         + "v4ur:routing-protocol-instance" "rt:routing-protocol" {
     when "v4ur:type = 'rip:rip' and ../../../rt:address-family = 'ipV4'"
       + " and ../../../safi "rt:type = 'nlri-unicast'"; '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";
           }
         }

4.4.
       }
       leaf update-interval {
         type uint8 {
           range "10..60";
         }
         units "seconds";
         default "30";
         description
           "Time interval between periodic updates.";
       }
     }
   }

4.5.  Route Filters

   The "ietf-ipv4-unicast-routing" module 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 the "ietf-ipv4-
   unicast-routing" module this document
   allows to establish only the two extreme routing policies in which
   either all routes are allowed or all routes are denied. rejected.  It is
   expected that a real route filtering framework (or
   several alternative frameworks) framework(s) will be developed
   separately.

   Each route filter is identified by a name which is MUST be unique within
   a
   routing process. 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 the "deny all" a route filtering policy.

4.5. policy in which all routes
   are rejected.

4.6.  RPC Operations Operation

   The "ietf-ipv4-unicast-routing-module" "ietf-routing" module defines two RPC operations:

   o  "delete-route" operations allows the client to immediately delete
      specific route(s) from a routing table within a routing process.
      The first input parameter of this operation is the name of the
      routing process, the second parameter is the routing table to act
      upon, and the third (optional) parameter is the "route" container
      with zero or more of the following route attributes: "destination-
      prefix", "next-hop" and "outgoing-interface".  All routes that
      match these attributes MUST be deleted from the selected routing
      table.  If the "route" container is missing or empty, all routes
      from the selected routing table MUST be deleted.

   o "get-route" RPC operation.  It
   is used for querying the forwarding information base of a routing process. router
   instance.  The first input parameter is the name of a
      routing process the router
   instance whose FIB is to be queried, and the second parameter is an IPv4 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 routing process. router
   instance.  Again, modules for particular address families are
   expected to augment the definition of output parameters with AFN/
   SAFI-specific contents.

5.  Routing  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 "ietf-routing@2011-04-27.yang" "iana-afn-safi@2011-09-23.yang"

   module ietf-routing iana-afn-safi {

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

     prefix rt; "ianaaf";

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

     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>";
       "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 contains provides two typedefs containing YANG
        definitions for top-level containers
        for the configuration following IANA-registered enumerations:

        - Address Family Numbers (AFN)

        - Subsequent Address Family Identifiers (SAFI)

        The latest revision of routing together 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 several type
        definitions or
        without modification, is permitted pursuant to, and identities."; 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 2011-04-27 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
         "Identity for the pseudo-protocol providing routes to directly
          connected networks. An implementation MUST preconfigure
          exactly one instance of this pseudo-protocol for each routing
          process."; }

     identity static {
       base routing-protocol;
       description
         "Identity for 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
         "This identity represents a route filter that blocks all
          routes.";
     }

     /* Type definitions */

     typedef address-family {
       type enumeration {
         enum "other" other {
           value 0; "0";
           description
             "none of the following";
         }
         enum "ipV4" ipV4 {
           value 1; "1";
           description
             "IP Version 4";
         }
         enum "ipV6" ipV6 {
           value 2; "2";
           description
             "IP Version 6";
         }
         enum "nsap" nsap {
           value 3; "3";
           description
             "NSAP";
         }
         enum "hdlc" hdlc {
           value 4; "4";
           description
             "(8-bit multidrop)";
         }
         enum "bbn1822" bbn1822 {
           value 5; "5";
           description
             "BBN Report 1822";
         }
         enum "all802" all802 {
           value 6; "6";
           description
             "(includes all 802 media plus Ethernet 'canonical
              format')";
         }
         enum "e163" e163 {
           value 7; "7";
           description
             "E.163";
         }
         enum "e164" e164 {
           value 8; "8";
           description
             "(SMDS, FrameRelay, ATM)";
         }
         enum "f69" f69 {
           value 9; "9";
           description
             "(Telex)";
         }
         enum "x121" x121 {
           value 10; "10";
           description
             "(X.25, Frame Relay)";
         }
         enum "ipx" ipx {
           value 11; "11";
           description
             "IPX (Internet Protocol Exchange)";
         }
         enum "appleTalk" appleTalk {
           value 12; "12";
           description
             "Apple Talk";
         }
         enum "decnetIV" decnetIV {
           value 13; "13";
           description
             "DEC Net Phase IV";
         }
         enum "banyanVines" banyanVines {
           value 14; "14";
           description
             "Banyan Vines";
         }
         enum "e164withNsap" e164withNsap {
           value 15; "15";
           description
             "(E.164 with NSAP format subaddress)";
         }
         enum "dns" dns {
           value 16; "16";
           description
             "(Domain Name System)";
         }
         enum "distinguishedName" distinguishedName {
           value 17; "17";
           description
             "(Distinguished Name, per X.500)";
         }
         enum "asNumber" asNumber {
           value 18; "18";
           description
             "(16-bit quantity, per the AS number space)";
         }
         enum "xtpOverIPv4" xtpOverIPv4 {
           value 19; "19";
           description
             "XTP over IP version 4";
         }
         enum "xtpOverIpv6" xtpOverIpv6 {
           value 20; "20";
           description
             "XTP over IP version 6";
         }
         enum "xtpNativeModeXTP" xtpNativeModeXTP {
           value 21; "21";
           description
             "XTP native mode XTP";
         }
         enum "fibreChannelWWPN" fibreChannelWWPN {
           value 22; "22";
           description
             "Fibre Channel World-Wide Port Name";
         }
         enum "fibreChannelWWNN" fibreChannelWWNN {
           value 23; "23";
           description
             "Fibre Channel World-Wide Node Name";
         }
         enum "gwid" gwid {
           value 24; "24";
           description
             "Gateway Identifier";
         }
         enum "afi" afi {
           value 25; "25";
           description
             "AFI for L2VPN";
         }
       }
       description
         "This typedef is a YANG enumeration of IANA-registered address families.";
          family numbers (AFN).";
       reference
         "http://www.iana.org/assignments/ianaaddressfamilynumbers-mib";
         "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" nlri-unicast {
           value 1; "1";
           description
             "Network Layer Reachability Information used for unicast
              forwarding";
           reference
             "RFC4760";
         }
         enum "nlri-multicast" nlri-multicast {
           value 2; "2";
           description
             "Network Layer Reachability Information used for multicast
              forwarding";
           reference
             "RFC4760";
         }
         enum "nlri-mpls" nlri-mpls {
           value 4; "4";
           description
             "Network Layer Reachability Information (NLRI) with MPLS
              Labels";
           reference
             "RFC3107";
         }
         enum "mcast-vpn" mcast-vpn {
           value 5; "5";
           description
             "MCAST-VPN";

           reference
             "draft-ietf-l3vpn-2547bis-mcast-bgp-08";
         }
         enum "nlri-dynamic-ms-pw" nlri-dynamic-ms-pw {
           value 6; "6";
           status obsolete; "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" tunnel-safi {
           value 64; "64";
           description
             "Tunnel SAFI";
           reference
             "draft-nalawade-kapoor-tunnel-safi-05";
         }
         enum "vpls" vpls {
           value 65; "65";
           description
             "Virtual Private LAN Service (VPLS)";
           reference
             "RFC4761, RFC6074";
         }
         enum "bgp-mdt" bgp-mdt {
           value 66; "66";
           description
             "BGP MDT SAFI";
           reference
             "RFC6037";
         }
         enum "bgp-4over6" bgp-4over6 {
           value 67; "67";
           description
             "BGP 4over6 SAFI";
           reference
             "RFC5747";
         }
         enum "bgp-6over4" bgp-6over4 {
           value 68; "68";
           description
             "BGP 6over4 SAFI";
           reference
             "mailto:cuiyong&tsinghua.edu.cn";
         }
         enum "l1vpn-auto-discovery" l1vpn-auto-discovery {
           value 69; "69";
           description
             "Layer-1 VPN auto-discovery information";
           reference
             "draft-ietf-l1vpn-bgp-auto-discovery-05";
         }
         enum "mpls-vpn" mpls-vpn {
           value 128; "128";
           description
             "MPLS-labeled VPN address";
           reference
             "RFC4364";
         }
         enum "multicast-bgp-mpls-vpn" multicast-bgp-mpls-vpn {
           value 129; "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" route-target-constraints {
           value 132; "132";
           description
             "Route Target constraints";
           reference
             "RFC4684";
         }
         enum "ipv4-diss-flow" ipv4-diss-flow {
           value 133; "133";
           description
             "IPv4 dissemination of flow specification rules";
           reference
             "RFC5575";
         }
         enum "vpnv4-diss-flow" vpnv4-diss-flow {
           value 134; "134";
           description
             "IPv4 dissemination of flow specification rules";
           reference
             "RFC5575";
         }
         enum "vpn-auto-discovery" vpn-auto-discovery {
           value 140; "140";
           description
             "VPN auto-discovery";

           reference
             "draft-ietf-l3vpn-bgpvpn-auto-09";
         }
       }
       description
         "This typedef is a YANG enumeration of IANA-registered
          subsequent address families."; family identifiers (SAFI).";
       reference "http://www.iana.org/assignments/safi-namespace/"
               + "safi-namespace.xml";
     }

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

     }

     /* Data nodes */

     container routing {
       description
         "Routing parameters.";
       list routing-process {
         key "name";
         description
           "Each entry is a container for configuration and operational
            state data of a single (virtual) router for a given address
            family and subsequent address family identifier (SAFI). Each
            entry has a unique name.

            The definitions of data for a particular address family and
            subsequent address family shall be provided via augmentation
            by other modules.";
         leaf name {
           type string;
           description
             "The unique name of the routing process.";
         }
         leaf address-family {
           type address-family;
           default "ipV4";
           description
             "Address family of the routing process.";
         }
         leaf safi {
           type subsequent-address-family;
           default "nlri-unicast";
           description
             "Subsequent address family identifier of the routing
             process.";
         }
         leaf description {
           type string;
           description
             "Textual description of the routing process.";
         }
         leaf enabled {
           type boolean;
           default "true";
           description
             "Enable or disable the routing process. The default value
              is 'true', which means that the process is enabled.";
         }

       }
         "Subsequent Address Family Identifiers (SAFI) Parameters. IANA,
          2011-03-04. <http://www.iana.org/assignments/safi-namespace/
          safi-namespace.xml>
         ";
     }
   }

   <CODE ENDS>

6.  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@2011-04-27.yang" "ietf-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 {

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

     prefix rt;
     } "rt";

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

     import ietf-interfaces iana-afn-safi {
       prefix if; "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>";
        <mailto:lhotka@cesnet.cz>
       ";

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

        It is immediately usable for a device essential components
        that needs just may be used for configuring a single routing table populated with static routes.

        On subsystem.

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

        Redistribution and use in source and binary forms, with or
        without modification, is designed permitted pursuant to, and subject to handle
        arbitrarily complex configurations with any number
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of routing
        tables and various routing protocols (in multiple instances).";

     revision 2011-04-27 {
       description 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.";
     }
     /* 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 routing-process-name afn-safi {
       leaf routing-process-name address-family {
         type rt:routing-process-ref;
         must "/rt:routing/rt:routing-process[rt:name = current()]"
            + "/rt:address-family = 'ipV4' and "
            + "/rt:routing/rt:routing-process[rt:name = current()]"
            + "/rt:safi = 'nlri-unicast'" 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
             "The referred
           "Subsequent address family identifier of routes in the
            routing process must be IPv4 unicast."; 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 a the routing protocol instance from which the
            route comes. This routing process."; protocol must be configured
            (automatically or manually) in the device.";
       }
       leaf last-modified {
         type yang:date-and-time;
         description
         "This grouping defines
           "Time stamp of the first common parameter last modification of both
          RPC operations below."; the route. If the
            route was never modified, it is the time when the route was
            inserted to the routing table.";

       }
     }

     /* RPC operations Methods */

     rpc get-route {
       description
         "Query the forwarding information base of an IPv4 unicast
          routing process a router instance
          whose name is given as the first
          parameter. parameter 'router-name'. The
          second parameter is an IPv4 destination
          address. The server returns '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 {
         uses routing-process-name;
         leaf destination-address router-name {
           type inet:ipv4-address; 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 - IPv4 parameter: destination address."; 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.";
           leaf destination-prefix reply specific for each address family
              should be defined through augmenting.";
           uses route-content;
         }
       }
     }

     /* Data Nodes */

     container routing {
             type inet:ipv4-prefix;
             mandatory true;
       description
               "Destination prefix
         "Routing parameters.";

       list router {
         key "name";
         description
           "Each list entry is a container for configuration and
            operational state data of the returned route.";
           } a single (logical) router.";
         leaf next-hop name {
           type inet:ipv4-address; string;
           description
               "Next hop address of the returned route.";
             "The unique router name.";
         }
         leaf outgoing-interface description {
           type if:interface-ref; string;
           description
             "Textual description
               "Outgoing interface of the returned route.";
           }
         }
       } router.";
         }

     rpc delete-route
         leaf enabled {
           type boolean;
           default "true";
           description

         "Delete all routes that match
             "Enable or disable the given attributes from a
          routing table within a routing process.

          Parameters:
          1. routing process name,
          2. routing table name,
          3. Container 'route' with route attributes.

          <ok> router. The default value is returned by 'true',
              which means that the server upon successful completion.";

       input {
         uses routing-process-name;
         leaf routing-table {
           type leafref {
             path "/rt:routing/rt:routing-process[rt:name=current()/../"
                + "routing-process-name]/ipv4-unicast-routing/"
                + "routing-tables/routing-table/name";
           }
           mandatory true;
           description
             "First parameter."; router is enabled.";
         }
         container route routing-protocols {
           description
             "Second parameter. All routes matching the route
              attributes must be deleted from
             "Container for the list of configured routing table.

              If this container is empty or missing, all routes
              from the selected protocol
              instances.";
           list routing-protocol {
             key "name";
             description
               "An instance of a routing table are deleted."; protocol.";
             leaf destination-prefix name {
               type inet:ipv4-prefix; string;
               description
               "Match destination prefix.";
                 "The name of the routing protocol instance.";
             }
             leaf next-hop description {
               type inet:ipv4-address; string;
               description
               "Match next hop.";
                 "Textual description of the routing protocol
                  instance.";
             }
             leaf outgoing-interface type {
               type if:interface-ref;
             description
               "Match outgoing interface.";
           }
         }
       }
     }

     /* Data nodes */

     augment "/rt:routing/rt:routing-process" {
       when "afi='ipV4' and safi='nlri-unicast'" identityref {
         description
           "IPv4 unicast.";
                 base routing-protocol;
               }
               mandatory "true";
               description
         "Definitions
                 "Type of data nodes that augment a routing process
          for IPv4 unicast.";
       container ipv4-unicast-routing {
         description
           "Container for IPv4 unicast the routing configuration and
            operational state data."; protocol - an identity derived
                  from the 'routing-protocol' base identity.";
             }
             container routing-protocol-instances connected-routing-tables {
               description
                 "Container for the list of configured connected routing protocol
              instances."; tables.";
               list routing-protocol-instance connected-routing-table {
                 key "name";
                 description
               "An instance
                   "List of a routing protocol.";
             container static-routes {
               when "../type='rt:static'" {
                 description
                   "These data nodes are only valid for tables to which the static
                    pseudo-protocol.";

               }
               description
                 "Configuration of a 'static' pseudo-protocol routing protocol
                    instance consists of a list of routes.";
               list static-route {
                 key "id";
                 ordered-by user;
                 description
                   "An user-ordered list of static routes.";
                 leaf id {
                   type string;
                   description
                     "An identification string 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 route.";
                 }
                    corresponding entry is not configured.
                   ";
                 leaf description name {
                   type string;
                   description
                     "Textual leafref {
                     path "../../../../../routing-tables/routing-table/"
                        + "name";
                   }
                   description of
                     "This must be the route."; name of an existing routing
                      table.";
                 }
                 leaf destination-prefix import-filter {
                   type inet:ipv4-prefix;
                   mandatory true; leafref {
                     path "../../../../../route-filters/route-filter/"
                        + "name";
                   }
                   description
                     "The destination prefix
                     "Reference to a route filter that is used for which
                      filtering routes passed from this routing protocol
                      instance to the route may
                      be used.";
                 } routing table specified by the
                      'name' sibling node. If this leaf next-hop {
                   type inet:ipv4-address;
                   description
                     "IPv4 address of is not present,
                      the host or router to which
                      packets whose address matches 'destination-prefix' behavior is protocol-specific, but typically
                      it means that all routes are to be forwarded."; accepted.";
                 }
                 leaf outgoing-interface export-filter {
                   type if:interface-ref;
                   description
                     "Name of the outgoing interface. This attribute
                      is mainly used in direct routes.";
                 }
               }
             }
             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 rt:routing-protocol;
               }
               mandatory true;
               description
                 "Type of the routing protocol - an identity derived
                  from the 'rt:routing-protocol' base identity.";
             }
             leaf routing-table {
               type leafref {
                 path "../../../routing-tables/routing-table/name";
               }
               default "ipv4-unicast-main";
               description
                 "The routing table to which the routing protocol
                  instance is connected. By default it is the
                  'ipv4-unicast-main' table.";
             }
             leaf import-filter {
               type leafref {
                 path "../../../route-filters/route-filter/name";
               } 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
                  'routing-table' 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
                  'routing-table' 'name' sibling node to this
                      routing protocol instance. If this leaf is not
                      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 rt:route-filter;
               }
               default "rt:deny-all-route-filter";
               description
                 "Type 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 {
             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.";

               }
             }
           }
         }
       }
     }
   }

   <CODE ENDS>

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
        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 route-filter - an identity derived
                  from 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 'rt:route-filter' base identity. The default
                  value represents an all-blocking filter.";
             }
           }
         }
         container routing-tables {
           must "routing-table/name='ipv4-unicast-fib'"
        RFC itself for full legal notices.
       ";

     revision 2011-09-23 {
       description
               "IPv4 unicast forwarding information base.";
         "Initial revision.";
       reference
         "RFC XXXX: A YANG Data Model for Routing Configuration";
     }
           must "routing-table/name='ipv4-unicast-main'"

     /* Groupings */

     grouping route-content {
       description
               "The main
         "Specific parameters of IPv4 unicast routing table.";
           }
           description
             "Container for configured routing tables.";

           list routing-table {
             key "name";
             description
               "Each entry represents a configured routing table. At
                least two entries with names 'ipv4-unicast-fib' and
                'ipv4-unicast-main' must exist.";
             container routes {
               config false;
               description
                 "Current contents of the routing table. Note that
                  it is operational state data.";
               list route {
                 description
                   "A routing table entry."; routes.";
       leaf destination-prefix {
         type inet:ipv4-prefix;
         description
                     "Destination
           "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
                     "Name of the outgoing
           "Outgoing interface.";
       }
                 leaf source-protocol
     }

     /* RPC Methods */

     augment "/rt:get-route/rt:input/rt:destination-address" {
                   type leafref
       when "address-family='ipV4' and safi='nlri-unicast'" {
                     path "../../../../../routing-protocol-instances/"
                        + "routing-protocol-instance/name";
         description
           "This augment is valid only for IPv4 unicast.";

       }
       description
                     "Protocol instance from which
         "The 'address' leaf augments the route comes.";
                 } 'rt:destination-address'
          parameter of the 'rt:get-route' operation.";
       leaf last-modified address {
         type yang:date-and-time; inet:ipv4-address;
         description
                     "Time stamp of the last modification of the
                      route. If the route was never modified, it is the
                      time
           "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 route was inserted reply to the routing
                      table.";
                 } '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.";
       }
             leaf name {
               type string;
       description
                 "The name
         "This augment defines the configuration of the routing table.";
             }
             leaf description static
          pseudo-protocol with data specific for IPv4 unicast.";
       container ipv4-unicast-static-routes {
               type string;
               description
                 "Textual
         description
           "Configuration of the routing table.";
             } a 'static' pseudo-protocol instance
            consists of a list recipient-routing-tables of routes.";
         list static-route {
           key "recipient-name"; "id";
           ordered-by "user";
           description
             "A user-ordered list of routing tables that receive routes from
                  the parent routing table."; static routes.";
           leaf recipient-name id {
             type leafref {
                   path "../../../routing-table/name";
                 } string;
             description
                   "The name of
               "An identification string for the recipient routing table."; route.";
           }
           leaf filter description {
             type leafref {
                   path "../../../../route-filters/route-filter/name";
                 } string;
             description
                   "A route filter which is applied to the routes
                    passed on to
               "Textual description of the recipient routing table."; 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>

7.

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 two 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 two the following YANG modules in the YANG Module
   Names registry [RFC6020]:

   -------------------------------------------------------------------
   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
   -------------------------------------------------------------------

8.

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

9.  Security Considerations

   TBD.

9.

   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.

10.  Acknowledgments

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

10.

11.  References

10.1.

11.1.  Normative References

   [IANA-AFI]

   [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.

   [RFC4741]  Enns, R., "NETCONF Configuration Protocol", RFC 4741,
              December 2006.

   [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-bjorklund-netmod-interfaces-cfg-00 draft-ietf-netmod-interfaces-cfg-02 (work
              in progress), December 2010.

10.2. 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.

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 a
   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; "rip";

     import ietf-interfaces ietf-routing {
       prefix if; "rt";
     }

     import ietf-routing ietf-interfaces {
       prefix rt; "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 {
         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:routing-protocol-instances/" "/rt:routing/rt:router/rt:routing-protocols/"
           +
             "rt:routing-protocol-instance" "rt:routing-protocol" {
       when "rt:type='rip:rip'"; "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";
             }
             /* Additional per-interface RIP configuration */
           }
         }
         leaf update-interval {
           type uint8 {
             range "10..60";
           }
           units "seconds";
           default "30";
           description
             "Time interval between periodic updates.";
         }
         /* Additional RIP configuration */
       }
     }
     augment "/rt:routing/rt:routing-tables/rt:routing-table/rt:route" "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/"
           + "rt:routes/rt:route" {
       when "../../../rt:routing-protocol-instances/" "../../../../rt:routing-protocols/"
          +
              "rt:routing-protocol-instance[rt:name=" "rt:routing-protocol[rt:name=current()/rt:source-protocol]/"
          +
              "current()/rt:source-protocol]/rt:type='rip:rip'";
       description
         "RIP-specific route components.";
       leaf metric {
         type rip-metric;
       }
       leaf tag "rt:type='rip:rip'" {
         type uint16;
         default "0";
         description
           "This leaf may be used to carry additional info, e.g. AS
            number."; 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 advertizing advertising in
   <hello>) the
   NETCONF <hello> message) the following YANG modules:

   o  ietf-interfaces [YANG-IF],

   o  ex-ethernet [YANG-IF],

   o  ex-ip [YANG-IF],  ietf-ip [YANG-IP],

   o  ietf-routing (Section 5), 6),

   o  ietf-ipv4-unicast-routing (Section 6), 7),

   o  example-rip (Appendix A.1).

   We assume a simple network setup as shown in Figure 2: 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.

                   +-----------------+
                   |                 |
                   |    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 2: 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="http://example.com/ip"
      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>
      <if:location>05:00.0</if:location>
        <ip:ip>
      <ip:ipv4>
       <ip:address>
        <ip:ip>192.0.2.1</ip:ip>
        <ip:prefix-length>24</ip:prefix-length>
       </ip:address>
        </ip:ip>
      </ip:ipv4>
     </if:interface>
     <if:interface>
      <if:name>eth1</if:name>
      <if:type>ethernetCsmacd</if:type>
      <if:location>05:00.1</if:location>
        <ip:ip>
      <ip:ipv4>
       <ip:address>
        <ip:ip>192.168.1.1</ip:ip>
        <ip:prefix-length>24</ip:prefix-length>
       </ip:address>
        </ip:ip>
      </ip:ipv4>
     </if:interface>
    </if:interfaces>
    <rt:routing>
      <rt:routing-process>
     <rt:router>
      <rt:name>inet-0</rt:name>
        <rt:address-family>ipV4</rt:address-family>
        <rt:safi>nlri-unicast</rt:safi>
        <ipv4-unicast-routing>
          <routing-protocol-instances>
            <routing-protocol-instance>
              <name>direct</name>
              <type>rt:direct</type>
            </routing-protocol-instance>
            <routing-protocol-instance>
              <name>st0</name>
              <description>
      <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.
              </description>
              <type>rt:static</type>
              <static-routes>
        </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>
              </static-routes>
            </routing-protocol-instance>
            <routing-protocol-instance>
              <name>rip0</name>
              <description>
        </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.
              </description>
              <type>rip:rip</type>
              <export-filter>deny-all</export-filter>
        </rt:description>
        <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>
            </routing-protocol-instance>
          </routing-protocol-instances>
          <route-filters>
            <route-filter>
              <name>deny-all</name>
            </route-filter>
          </route-filters>
          <routing-tables>
            <routing-table>
              <name>ipv4-unicast-fib</name>
              <routes>
               <route>
       </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>
                <source-protocol>direct</source-protocol>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth0</outgoing-interface>
                <last-modified>2010-04-01T17:11:27+01:00</last-modified>
               </route>
               <route>
          <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>
                <source-protocol>direct</source-protocol>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth1</outgoing-interface>
                <last-modified>2010-04-01T17:11:27+01:00</last-modified>
               </route>
               <route>
          <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>
                <source-protocol>st0</source-protocol>
          <rt:source-protocol>st0</rt:source-protocol>
          <next-hop>192.168.1.254</next-hop>
                <last-modified>2010-04-01T17:11:32+01:00</last-modified>
               </route>
               <route>
          <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>
                <source-protocol>rip0</source-protocol>
                <next-hop>192.168.1.254</next-hop>
          <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>
                <last-modified>2010-04-01T18:02:45+01:00</last-modified>
               </route>
              </routes>
            </routing-table>
            <routing-table>
              <name>ipv4-unicast-main</name>
              <recipient-routing-tables>
                <recipient-name>ipv4-unicast-fib</recipient-name>
              </recipient-routing-tables>
              <routes>
               <route>
          <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>
                <source-protocol>direct</source-protocol>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth0</outgoing-interface>
                <last-modified>2010-04-01T17:11:27+01:00</last-modified>
               </route>
               <route>
          <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>
                <source-protocol>direct</source-protocol>
          <rt:source-protocol>direct</rt:source-protocol>
          <outgoing-interface>eth1</outgoing-interface>
                <last-modified>2010-04-01T17:11:27+01:00</last-modified>
               </route>
               <route>
          <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>
                <source-protocol>st0</source-protocol>
          <rt:source-protocol>st0</rt:source-protocol>
          <next-hop>192.168.1.254</next-hop>
                <last-modified>2010-04-01T17:11:32+01:00</last-modified>

               </route>
               <route>
          <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>
                <source-protocol>rip0</source-protocol>
                <next-hop>192.168.1.254</next-hop>
          <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>
                <last-modified>2010-04-01T18:02:45+01:00</last-modified>
               </route>
              </routes>
            </routing-table>
          </routing-tables>
        </ipv4-unicast-routing>
      </rt:routing-process>
          <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>

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.

Author's Address

   Ladislav Lhotka
   CESNET

   Email: lhotka@cesnet.cz