NETMOD L. Lhotka
Internet-Draft CZ.NIC
Intended status: Standards Track February 20, 2012
Expires: August 21, 2012

A YANG Data Model for Routing Configuration
draft-ietf-netmod-routing-cfg-02

Abstract

This document contains a specification of four YANG modules. Together they form the core routing data model which serves as a basis for configuring a routing subsystem. It is therefore expected that this module will be augmented by additional YANG modules defining data models for individual routing protocols and other related functions. The core routing data model provides 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 August 21, 2012.

Copyright Notice

Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.


Table of Contents

1. Introduction

This document contains a specification of four YANG modules:

The first three 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 three modules can be directly used for simple IP devices with static routing, their main purpose is to provide essential building blocks for more complicated setups involving multiple routing protocols, multicast routing, additional address families, advanced functions such as route filtering or policy routing etc. To this end, it is expected that the core routing data model 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 [RFC6241]:

The following terms are defined in [RFC6020]:

2.1. Glossary of New Terms

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", "ietf-ipv4-unicast-routing-cfg" and "ietf-ipv6-unicast-routing-cfg" modules.
direct route:
a route to a directly connected network.

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.

Prefixes and corresponding YANG modules
Prefix YANG module Reference
eth ex-ethernet [YANG-IF]
if ietf-interfaces [YANG-IF]
ip ietf-ip [YANG-IP]
rip example-rip Appendix Appendix A
rt ietf-routing Section 6
v4ur ietf-ipv4-unicast-routing Section 7
v6ur ietf-ipv6-unicast-routing Section 8
yang ietf-yang-types [RFC6021]
inet ietf-inet-types [RFC6021]

3. Objectives

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

4. The Design of the Core Routing Data Model

The core routing data model consists of three YANG modules. The first module, "ietf-routing", defines the generic components of a routing system. The other two modules, "ietf-ipv4-unicast-routing" and "ietf-ipv6-unicast-routing", augment the "ietf-routing" module with additional data nodes that are needed for IPv4 and IPv6 unicast routing, respectively. The combined data hierarchy is shown in Figure 1, where brackets contain list keys and question marks indicate optional data nodes. Nodes that represent configuration are labeled with "rw" while operational state data have the "ro" label.

+--rw routing
   +--rw router [name]
      +--rw name
      +--rw description?
      +--rw enabled?
      +--rw interfaces
      |  +--rw interface [name]
      |     +--rw name
      |     +--rw v6ur:ipv6-router-advertisements
      |        +--rw v6ur:send-advertisements?
      |        +--rw v6ur:max-rtr-adv-interval?
      |        +--rw v6ur:min-rtr-adv-interval?
      |        +--rw v6ur:managed-flag?
      |        +--rw v6ur:other-config-flag?
      |        +--rw v6ur:link-mtu?
      |        +--rw v6ur:reachable-time?
      |        +--rw v6ur:retrans-timer?
      |        +--rw v6ur:cur-hop-limit?
      |        +--rw v6ur:default-lifetime?
      |        +--rw v6ur:prefix-list
      |           +--rw v6ur:prefix [seqno]
      |              +--rw v6ur:seqno
      |              +--rw v6ur:prefix-spec?
      |              +--rw v6ur:valid-lifetime?
      |              +--rw v6ur:on-link-flag?
      |              +--rw v6ur:preferred-lifetime?
      |              +--rw v6ur:autonomous-flag?
      +--rw routing-protocols
      |  +--rw routing-protocol [name]
      |     +--rw name
      |     +--rw description?
      |     +--rw type
      |     +--rw connected-routing-tables
      |     |  +--rw routing-table [name]
      |     |     +--rw name
      |     |     +--rw import-filter?
      |     |     +--rw export-filter?
      |     +--rw static-routes
      |        +--rw v4ur:ipv4
      |        |  +--rw v4ur:route [seqno]
      |        |     +--rw v4ur:seqno
      |        |     +--rw v4ur:description?
      |        |     +--rw v4ur:outgoing-interface?
      |        |     +--rw v4ur:dest-prefix?
      |        |     +--rw v4ur:next-hop?
      |        +--rw v6ur:ipv6
      |           +--rw v6ur:route [seqno]
      |              +--rw v6ur:seqno
      |              +--rw v6ur:description?
      |              +--rw v6ur:outgoing-interface?
      |              +--rw v6ur:dest-prefix?
      |              +--rw v6ur:next-hop?
      +--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:outgoing-interface?
            |     +--ro v4ur:dest-prefix?
            |     +--ro v4ur:next-hop?
            |     +--ro v6ur:outgoing-interface?
            |     +--ro v6ur:dest-prefix?
            |     +--ro v6ur:next-hop?
            +--rw recipient-routing-tables [recipient-name]
               +--rw recipient-name
               +--rw filter?
	    

As can be seen from Figure 1, the core routing data model introduces several generic components of a routing framework: routers, routing tables containing routes, routing protocols, route filters and RPC operations. The following subsections describe these components in more detail.

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

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

The example in Figure 2 shows a typical (though certainly not the only possible) organization of a more complex routing subsystem. Several of its features are worth mentioning:

4.1. Router

Each router instance in the core routing data model represents a (logical) 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.

Logical network interfaces must be assigned to a router instance in order to be able to participate in packet forwarding, routing protocols and other operations of that router instance. The assignment is accomplished by creating a corresponding entry in the list of router interfaces ("/router/interfaces/interface"). The key of the list entry MUST be the name of a configured logical interface. A logical interface MUST NOT be assigned to more than one router instance.

Apart from the key, each entry of the "/router/interfaces/interface" list MAY contain other configuration or operational state data related to the corresponding logical interface.

4.1.1. Configuration of IPv6 Router Interfaces

The module "ietf-ipv6-unicast-routing" augments the definition of the data node "/router/interfaces/interface" with definitions of the following configuration variables as required by [RFC4861], sec. 6.2.1: Section 8).

The definitions and descriptions of the above parameters can be found in the text of the module "ietf-ipv6-unicast-routing" (

NOTE: The "IsRouter" flag, which is also required by [RFC4861], was omitted. Is is expected that this variable will be implemented in another module, either "ietf-interfaces" or "ietf-ip".

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:

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 state data, for example as entries in routing tables.

4.3. Routing Tables

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

Each routing table may only contain routes of the same address family (AFN and SAFI).

In the core routing data model, the "routing-table" node represents configuration while the descendant list of routes is defined as operational state data. The contents of such lists are controlled by routing protocol operations which may 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 and each supported AFN/SAFI pair:

  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, with the exception of the "direct" pseudo-protocol (Section 4.4): direct routes only appear in the FIB table by default.

The main routing table SHOULD serve as the default 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.

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. Each protocol MUST be assigned a type, which MUST be an identity derived from the "rt:routing-protocol" base identity. The core routing data model defines two identities for the "direct" and "static" pseudo-protocols.

Each routing protocol instance is connected to exactly one routing table. By default, every routing protocol instance SHOULD be connected to the main routing table. An implementation MAY allow any or all routing protocol instances to be configured to use a different routing table.

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:

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

The core routing data model 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 direct routes which are normally supplied by the operating system kernel, based on the detected and configured network interfaces, and they SHOULD by default appear in the FIB routing table. However, using the framework defined in this document, the target routing table for direct routes MAY be changed by connecting the "direct" protocol instance to a non-default routing table. 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 per router.

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 into the core routing framework in the following way :

It is recommended that both per-interface and other configuration data specific to the new protocol be encapsulated in an appropriately named container.

The above steps are implemented by the example YANG module for the RIP routing protocol in Appendix 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.";
}

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

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;
}

Per-interface configuration data are defined by the following "augment" statement:

augment "/rt:routing/rt:router/rt:interfaces/rt:interface" {
  when "../../rt:routing-protocols/rt:routing-protocol/rt:type  = "
     + "'rip:rip'";
  container rip {
    description
      "Per-interface RIP configuration.";
    leaf enabled {
      type boolean;
      default "true";
    }
    leaf metric {
      type rip-metric;
      default "1";
    }
  }
}

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

augment "/rt:routing/rt:router/rt:routing-protocols/"
      + "rt:routing-protocol" {
  when "rt:type = 'rip:rip'";
  container rip {
    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 connected 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 frameworks will be developed separately.

Each route filter is identified by a name which MUST be unique within 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" and "ietf-ipv6-unicast-routing" modules.

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.

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@2012-02-20.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) 2012 IETF Trust and the persons identified as
     authors of the code. All rights reserved.

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

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

  revision 2012-02-20 {
    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 {
        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
          "(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 {
        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";
        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";
      }
      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";
        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>

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@2012-02-20.yang"

module ietf-routing {

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

  prefix "rt";

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

  import ietf-interfaces {
    prefix "if";
  }

  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@nic.cz>
    ";

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

     Copyright (c) 2012 IETF Trust and the persons identified as
     authors of the code. All rights reserved.

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

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

  revision 2012-02-20 {
    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 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.

       A module for an address family should define a specific
       version of this grouping containing 'uses rt:route-content'.
      ";
    leaf outgoing-interface {
      type if:interface-ref;
      description
        "Outgoing interface.";
    }
  }

  /* 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.";
      }
    }
  }

  /* Data Nodes */

  container routing {
    description
      "Routing parameters.";
    list router {
      key "name";
      unique "interfaces/interface/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 interfaces {
        description
          "Router interface parameters.";
        list interface {
          key "name";
          description
            "List of logical interfaces assigned to the router
             instance. Any logical interface can only be assigned to
             one router instance.";
          leaf name {
            type if:interface-ref;
            description
              "A reference to the name of a configured logical
               interface.";
          }
        }
      }
      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
               from the 'routing-protocol' base identity.";
          }
          container connected-routing-tables {
            description
              "Container for connected routing tables.";
            list routing-table {
              must "not(../../../../routing-tables/"
                 + "routing-table[current()/"
                 + "preceding-sibling::routing-table/name]/"
                 + "address-family=../../../../routing-tables/"
                 + "routing-table[current()/name]/"
                 + "address-family and ../../../../routing-tables/"
                 + "routing-table[current()/"
                 + "preceding-sibling::routing-table/name]/safi=../"
                 + "../../../routing-tables/routing-table[current()/"
                 + "name]/safi)" {
                error-message
                  "Each routing protocol may have no more than one
                   connected routing table for each AFN and SAFI.";
                description
                  "For each AFN/SAFI pair there may be at most one
                   connected routing table.";
              }
              key "name";
              description
                "List of routing tables to which the routing protocol
                 instance is connected.

                 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
                  "Reference to 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
                   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 static-routes {
            must "../type='static'" {
              error-message
                "Static routes may be configured only for 'static'
                 routing protocol.";
              description
                "This container is only valid for the 'static'
                 routing protocol.";
            }
            description
              "Configuration of 'static' pseudo-protocol.";
          }
        }
      }
      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 {
          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. This data node must augmented
                 with information specific for routes of each address
                 family.";
              leaf source-protocol {
                type leafref {
                  path "../../../../../routing-protocols/"
                     + "routing-protocol/name";
                }
                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.";
              }
            }
          }
          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@2012-02-20.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";
  }

  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@nic.cz>
    ";

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

     Copyright (c) 2012 IETF Trust and the persons identified as
     authors of the code. All rights reserved.

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

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

  revision 2012-02-20 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A YANG Data Model for Routing Configuration";
  }

  /* Groupings */

  grouping route-content {
    description
      "Parameters of IPv4 unicast routes.";
    uses rt:route-content;
    leaf dest-prefix {
      type inet:ipv4-prefix;
      description
        "IPv4 destination prefix.";
    }
    leaf next-hop {
      type inet:ipv4-address;
      description
        "IPv4 address of the next hop.";
    }
  }

  /* 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.";
    }
    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/rt:static-routes" {
    description
      "This augment defines the configuration of the 'static'
       pseudo-protocol with data specific for IPv4 unicast.";
    container ipv4 {
      description
        "Configuration of a 'static' pseudo-protocol instance
         consists of a list of routes.";
      list route {
        key "seqno";
        ordered-by "user";
        description
          "A user-ordered list of static routes.";
        leaf seqno {
          type uint16;
          description
            "Sequential number of the route.";
        }
        leaf description {
          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>

8. IPv6 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-ipv6-unicast-routing@2012-02-20.yang"

module ietf-ipv6-unicast-routing {

  namespace "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing";

  prefix "v6ur";

  import ietf-routing {
    prefix "rt";
  }

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

  import ietf-interfaces {
    prefix "if";
  }

  import ietf-ip {
    prefix "ip";
  }

  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@nic.cz>
    ";

  description
    "This module augments the 'ietf-routing' module with YANG
     definitions for basic configuration of IPv6 unicast routing.

     Copyright (c) 2012 IETF Trust and the persons identified as
     authors of the code. All rights reserved.

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

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

  revision 2012-02-20 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A YANG Data Model for Routing Configuration";
  }

  /* Groupings */

  grouping route-content {
    description
      "Specific parameters of IPv6 unicast routes.";
    uses rt:route-content;
    leaf dest-prefix {
      type inet:ipv6-prefix;
      description
        "IPv6 destination prefix.";
    }
    leaf next-hop {
      type inet:ipv6-address;
      description
        "IPv6 address of the next hop.";
    }
  }

  /* RPC Methods */

  augment "/rt:get-route/rt:input/rt:destination-address" {
    when "address-family='ipV6' and safi='nlri-unicast'" {
      description
        "This augment is valid only for IPv6 unicast.";
    }
    description
      "The 'address' leaf augments the 'rt:destination-address'
       parameter of the 'rt:get-route' operation.";
    leaf address {
      type inet:ipv6-address;
      description
        "IPv6 destination address.";
    }
  }

  augment "/rt:get-route/rt:output/rt:route" {
    when "address-family='ipV6' and safi='nlri-unicast'" {
      description
        "This augment is valid only for IPv6 unicast.";
    }
    description
      "Contents of the reply to 'rt:get-route' operation.";
    uses route-content;
  }

  /* Data nodes */

  augment "/rt:routing/rt:router/rt:interfaces/rt:interface" {
    when "/if:interfaces/if:interface[name=current()/name] "
       + "/ip:ipv6/ip:enabled='true'" {
      description
        "This augment is only valid for router interfaces with
         enabled IPv6.

         NOTE: Parameter 'is-router' is not included, it is expected
         that it will be implemented by the 'ietf-ip' module.
        ";
    }
    description
      "IPv6-specific parameters of router interfaces.";
    container ipv6-router-advertisements {
      description
        "Parameters of IPv6 Router Advertisements.";
      reference
        "RFC 4861: Neighbor Discovery for IP version 6 (IPv6).

         RFC 4862: IPv6 Stateless Address Autoconfiguration.
        ";
      leaf send-advertisements {
        type boolean;
        default "false";
        description
          "A flag indicating whether or not the router sends periodic
           Router Advertisements and responds to Router
           Solicitations.";
      }
      leaf max-rtr-adv-interval {
        type uint16 {
          range "4..1800";
        }
        units "seconds";
        default "600";
        description
          "The maximum time allowed between sending unsolicited
           multicast Router Advertisements from the interface.";
      }
      leaf min-rtr-adv-interval {
        type uint16 {
          range "3..1350";
        }
        units "seconds";
        description
          "The minimum time allowed between sending unsolicited
           multicast Router Advertisements from the interface.

           Must be no greater than 0.75 * max-rtr-adv-interval.

           Its default value is dynamic:

           - if max-rtr-adv-interval >= 9 seconds, the default value
             is 0.33 * max-rtr-adv-interval;

           - otherwise it is max-rtr-adv-interval.
          ";
      }
      leaf managed-flag {
        type boolean;
        default "false";
        description
          "The boolean value to be placed in the 'Managed address
           configuration' flag field in the Router Advertisement.";
      }
      leaf other-config-flag {
        type boolean;
        default "false";
        description
          "The boolean value to be placed in the 'Other
           configuration' flag field in the Router Advertisement.";
      }
      leaf link-mtu {
        type uint32;
        default "0";
        description
          "The value to be placed in MTU options sent by the router.
           A value of zero indicates that no MTU options are sent.";
      }
      leaf reachable-time {
        type uint32 {
          range "0..3600000";
        }
        units "milliseconds";
        default "0";
        description
          "The value to be placed in the Reachable Time field in the
           Router Advertisement messages sent by the router. The
           value zero means unspecified (by this router).";
      }
      leaf retrans-timer {
        type uint32;
        units "milliseconds";
        default "0";
        description
          "The value to be placed in the Retrans Timer field in the
           Router Advertisement messages sent by the router. The
           value zero means unspecified (by this router).";
      }
      leaf cur-hop-limit {
        type uint8;
        default "64";
        description
          "The default value to be placed in the Cur Hop Limit field
           in the Router Advertisement messages sent by the router.
           The value should be set to the current diameter of the
           Internet. The value zero means unspecified (by this
           router).

           The default should be set to the value specified in IANA
           Assigned Numbers that was in effect at the time of
           implementation.
          ";
        reference
          "IANA: IP Parameters,
           http://www.iana.org/assignments/ip-parameters";
      }
      leaf default-lifetime {
        type uint16 {
          range "0..9000";
        }
        units "seconds";
        description
          "The value to be placed in the Router Lifetime field of
           Router Advertisements sent from the interface, in seconds.
           MUST be either zero or between MaxRtrAdvInterval and 9000
           seconds. A value of zero indicates that the router is not
           to be used as a default router. These limits may be
           overridden by specific documents that describe how IPv6
           operates over different link layers.

           The default value is dynamic and should be set to 3 *
           max-rtr-adv-interval.
          ";
      }
      container prefix-list {
        description
          "A list of prefixes to be placed in Prefix Information
           options in Router Advertisement messages sent from the
           interface.

           Default: all prefixes that the router advertises via
           routing protocols as being on-link for the interface from
           which the advertisement is sent. The link-local prefix
           should not be included in the list of advertised prefixes.
          ";
        list prefix {
          key "seqno";
          unique "prefix-spec";
          description
            "Advertised prefix entry.";
          leaf seqno {
            type uint8;
            description
              "Sequential number of the entry.";
          }
          leaf prefix-spec {
            type inet:ipv6-prefix;
            description
              "IPv6 address prefix.";
          }
          leaf valid-lifetime {
            type uint32;
            units "seconds";
            default "2592000";
            description
              "The value to be placed in the Valid Lifetime in the
               Prefix Information option, in seconds. The designated
               value of all 1's (0xffffffff) represents infinity.

               Implementations may allow valid-lifetime to be
               specified in two ways:

               1. a time that decrements in real time, that is, one
                  that will result in a Lifetime of zero at the
                  specified time in the future,

               2. a fixed time that stays the same in consecutive
                  advertisements.
              ";
          }
          leaf on-link-flag {
            type boolean;
            default "true";
            description
              "The value to be placed in the on-link flag ('L-bit')
               field in the Prefix Information option.";
          }
          leaf preferred-lifetime {
            type uint32;
            units "seconds";
            default "604800";
            description
              "The value to be placed in the Preferred Lifetime in
               the Prefix Information option, in seconds. The
               designated value of all 1's (0xffffffff) represents
               infinity.

               Implementations MAY allow AdvPreferredLifetime to be
               specified in two ways:

               1. a time that decrements in real time, that is, one
                  that will result in a Lifetime of zero at a
                  specified time in the future,

               2. a fixed time that stays the same in consecutive
                  advertisements.
              ";
          }
          leaf autonomous-flag {
            type boolean;
            default "true";
            description
              "The value to be placed in the Autonomous Flag field in
               the Prefix Information option.";
          }
        }
      }
    }
  }

  augment "/rt:routing/rt:router/rt:routing-protocols/"
        + "rt:routing-protocol/rt:static-routes" {
    description
      "This augment defines the configuration of the 'static'
       pseudo-protocol with data specific for IPv6 unicast.";
    container ipv6 {
      description
        "Configuration of a 'static' pseudo-protocol instance
         consists of a list of routes.";
      list route {
        key "seqno";
        ordered-by "user";
        description
          "A user-ordered list of static routes.";
        leaf seqno {
          type uint16;
          description
            "Sequential number of the route.";
        }
        leaf description {
          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='ipV6' and "
       + "../../rt:safi='nlri-unicast'" {
      description
        "This augment is valid only for IPv6 unicast.";
    }
    description
      "This augment defines the content of IPv6 unicast routes.";
    uses route-content;
  }
}

<CODE ENDS>

9. 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:ietf-ipv6-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]:

-------------------------------------------------------------------
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:         ietf-ipv6-unicast-routing
namespace:    urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing
prefix:       v6ur
reference:    RFC XXXX
-------------------------------------------------------------------

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

10. 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:interfaces/rt:interface
This list assigns a logical interface to a router instance and may also specify interface parameters related to routing.
/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.

11. Acknowledgments

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

12. References

12.1. 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.
[RFC4861] Narten, T, Nordmark, E., Simpson, W. and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007.
[RFC6020] Bjorklund, M, "YANG - A Data Modeling Language for Network Configuration Protocol (NETCONF)", RFC 6020, September 2010.
[RFC6021] Schoenwaelder, J., "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", Internet-Draft draft-ietf-netmod-interfaces-cfg-03, February 2012.
[YANG-IP] Bjorklund, M., "A YANG Data Model for IP Configuration", Internet-Draft draft-ietf-netmod-ip-cfg-02, February 2012.

12.2. 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. The YANG module "example-rip" shown below is intended only as an illustration rather than a real definition of a data model for the RIP routing protocol. For the sake of brevity, we do not follow all the guidelines specified in [RFC6087]. See also Section 4.4.1.

<CODE BEGINS> file "example-rip@2012-02-20.yang"

module example-rip {

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

  prefix "rip";

  import ietf-routing {
    prefix "rt";
  }

  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: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;
  }

  augment "/rt:routing/rt:router/rt:interfaces/rt:interface" {
    when "../../rt:routing-protocols/rt:routing-protocol/rt:type = "
       + "'rip:rip'";
    container rip {
      description
        "Per-interface RIP configuration.";
      leaf enabled {
        type boolean;
        default "true";
      }
      leaf metric {
        type rip-metric;
        default "1";
      }
    }
  }

  augment "/rt:routing/rt:router/rt:routing-protocols/"
        + "rt:routing-protocol" {
    when "rt:type = 'rip:rip'";
    container rip {
      leaf update-interval {
        type uint8 {
          range "10..60";
        }
        units "seconds";
        default "30";
        description
          "Time interval between periodic updates.";
      }
    }
  }
}

<CODE ENDS>

Appendix B. Example: 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 (i.e., advertising them in the NETCONF <hello> message) the following YANG modules:

We assume a simple network setup as shown in Figure 14: router "A" uses static default routes with the "ISP" router as the next hop. IPv6 router advertisements are configured only on the "eth1" interface and disabled on the upstream "eth0" interface.

                +-----------------+
                |                 |
                |    Router ISP   |
                |                 |
                +--------+--------+
                         |2001:db8:0:1::2
                         |192.0.2.2
                         |
                         |
                         |2001:db8:0:1::1
                     eth0|192.0.2.1
                +--------+--------+
                |                 |
                |     Router A    |
                |                 |
                +--------+--------+
                     eth1|198.51.100.1
                         |2001:db8:0:2::1
                         |

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

<?xml version="1.0"?>
<rpc-reply
    message-id="101"
    xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
    xmlns:v4ur="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"
    xmlns:v6ur="urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing"
    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">
 <data>
  <if:interfaces>
   <if:interface>
    <if:name>eth0</if:name>
    <if:type>ethernetCsmacd</if:type>
    <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>
    <ip:ipv6>
     <ip:address>
      <ip:ip>2001:0db8:0:1::1</ip:ip>
      <ip:prefix-length>64</ip:prefix-length>
     </ip:address>
     <ip:autoconf>
      <ip:create-global-addresses>false</ip:create-global-addresses>
     </ip:autoconf>
    </ip:ipv6>
   </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>198.51.100.1</ip:ip>
      <ip:prefix-length>24</ip:prefix-length>
     </ip:address>
    </ip:ipv4>
    <ip:ipv6>
     <ip:address>
      <ip:ip>2001:0db8:0:2::1</ip:ip>
      <ip:prefix-length>64</ip:prefix-length>
     </ip:address>
     <ip:autoconf>
      <ip:create-global-addresses>false</ip:create-global-addresses>
     </ip:autoconf>
    </ip:ipv6>
   </if:interface>
  </if:interfaces>
  <rt:routing>
   <rt:router>
    <rt:name>rtr0</rt:name>
    <rt:interfaces>
     <rt:interface>
      <rt:name>eth0</rt:name>
     </rt:interface>
     <rt:interface>
      <rt:name>eth1</rt:name>
      <v6ur:ipv6-router-advertisements>
       <v6ur:send-advertisements>true</v6ur:send-advertisements>
       <v6ur:prefix-list>
        <v6ur:prefix>
         <v6ur:seqno>1</v6ur:seqno>
         <v6ur:prefix-spec>2001:db8:0:2::/64</v6ur:prefix-spec>
        </v6ur:prefix>
       </v6ur:prefix-list>
      </v6ur:ipv6-router-advertisements>
     </rt:interface>
    </rt:interfaces>
    <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>
      <rt:static-routes>
       <v4ur:ipv4>
        <v4ur:route>
         <v4ur:seqno>1</v4ur:seqno>
         <v4ur:dest-prefix>0.0.0.0/0</v4ur:dest-prefix>
         <v4ur:next-hop>192.0.2.2</v4ur:next-hop>
        </v4ur:route>
       </v4ur:ipv4>
       <v6ur:ipv6>
        <v6ur:route>
         <v6ur:seqno>1</v6ur:seqno>
         <v6ur:dest-prefix>::/0</v6ur:dest-prefix>
         <v6ur:next-hop>2001:db8:0:1::2</v6ur:next-hop>
        </v6ur:route>
       </v6ur:ipv6>
      </rt:static-routes>
      <rt:connected-routing-tables>
       <rt:routing-table>
        <rt:name>ipv4-unicast-main</rt:name>
       </rt:routing-table>
       <rt:routing-table>
        <rt:name>ipv6-unicast-main</rt:name>
       </rt:routing-table>
      </rt:connected-routing-tables>
     </rt:routing-protocol>
    </rt:routing-protocols>
    <rt:routing-tables>
     <rt:routing-table>
      <rt:name>ipv4-unicast-fib</rt:name>
      <rt:routes>
       <rt:route>
        <v4ur:dest-prefix>192.0.2.1/24</v4ur:dest-prefix>
        <v4ur:outgoing-interface>eth0</v4ur:outgoing-interface>
        <rt:source-protocol>direct</rt:source-protocol>
        <rt:last-modified>2012-02-20T17:11:27+01:00</rt:last-modified>
       </rt:route>
       <rt:route>
        <v4ur:dest-prefix>198.51.100.0/24</v4ur:dest-prefix>
        <v4ur:outgoing-interface>eth1</v4ur:outgoing-interface>
        <rt:source-protocol>direct</rt:source-protocol>
        <rt:last-modified>2012-02-20T17:11:27+01:00</rt:last-modified>
       </rt:route>
       <rt:route>
        <v4ur:dest-prefix>0.0.0.0/0</v4ur:dest-prefix>
        <v4ur:next-hop>192.0.2.2</v4ur:next-hop>
        <rt:source-protocol>st0</rt:source-protocol>
        <rt:last-modified>2012-02-20T18:02:45+01:00</rt:last-modified>
       </rt:route>
      </rt:routes>
     </rt:routing-table>
     <rt:routing-table>
      <rt:name>ipv6-unicast-fib</rt:name>
      <rt:address-family>ipV6</rt:address-family>
      <rt:safi>nlri-unicast</rt:safi>
      <rt:routes>
       <rt:route>
        <v6ur:dest-prefix>2001:db8:0:1::/64</v6ur:dest-prefix>
        <v6ur:outgoing-interface>eth0</v6ur:outgoing-interface>
        <rt:source-protocol>direct</rt:source-protocol>
        <rt:last-modified>2012-02-20T17:11:27+01:00</rt:last-modified>
       </rt:route>
       <rt:route>
        <v6ur:dest-prefix>2001:db8:0:2::/64</v6ur:dest-prefix>
        <v6ur:outgoing-interface>eth1</v6ur:outgoing-interface>
        <rt:source-protocol>direct</rt:source-protocol>
        <rt:last-modified>2012-02-20T17:11:27+01:00</rt:last-modified>
       </rt:route>
       <rt:route>
        <v6ur:dest-prefix>::/0</v6ur:dest-prefix>
        <v6ur:next-hop>2001:db8:0:1::2</v6ur:next-hop>
        <rt:source-protocol>st0</rt:source-protocol>
        <rt:last-modified>2012-02-20T18:02:45+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>
        <v4ur:dest-prefix>0.0.0.0/0</v4ur:dest-prefix>
        <rt:source-protocol>st0</rt:source-protocol>
        <v4ur:next-hop>192.0.2.2</v4ur:next-hop>
        <rt:last-modified>2012-02-20T18:02:45+01:00</rt:last-modified>
       </rt:route>
      </rt:routes>
     </rt:routing-table>
     <rt:routing-table>
      <rt:name>ipv6-unicast-main</rt:name>
      <rt:address-family>ipV6</rt:address-family>
      <rt:safi>nlri-unicast</rt:safi>
      <rt:recipient-routing-tables>
       <rt:recipient-name>ipv6-unicast-fib</rt:recipient-name>
      </rt:recipient-routing-tables>
      <rt:routes>
       <rt:route>
        <v6ur:dest-prefix>::/0</v6ur:dest-prefix>
        <v6ur:next-hop>2001:db8:0:1::2</v6ur:next-hop>
        <rt:source-protocol>st0</rt:source-protocol>
        <rt:last-modified>2012-02-20T18:02:45+01:00</rt:last-modified>
       </rt:route>
      </rt:routes>
     </rt:routing-table>
    </rt:routing-tables>
   </rt:router>
  </rt:routing>
 </data>
</rpc-reply>

Appendix C. Change Log

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

Appendix C.1. Changes Between Versions -01 and -02

Appendix C.2. Changes Between Versions -00 and -01

Author's Address

Ladislav Lhotka CZ.NIC EMail: lhotka@nic.cz