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Versions: 00 draft-ietf-rtgwg-ni-model

Network Working Group                                          L. Berger
Internet-Draft                                   LabN Consulting, L.L.C.
Intended status: Standards Track                                C. Hopps
Expires: November 18, 2016                              Deutsche Telekom
                                                               A. Lindem
                                                           Cisco Systems
                                                           D. Bogdanovic
                                                            May 17, 2016


                         Network Instance Model
                   draft-rtgyangdt-rtgwg-ni-model-00

Abstract

   This document defines a network instance module.  This module along
   with the logical network element module can be used to manage the
   logical and virtual resource representations that may be present on a
   network device.  Examples of common industry terms for logical
   resource representations are Logical Systems or Logical Routers.
   Examples of common industry terms for virtual resource
   representations are Virtual Routing and Forwarding (VRF) instances
   and Virtual Switch Instances (VSIs).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 18, 2016.

Copyright Notice

   Copyright (c) 2016 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



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   (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  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Status of Work and Open Issues  . . . . . . . . . . . . .   3
   2.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Network Instances . . . . . . . . . . . . . . . . . . . . . .   6
     3.1.  Network Instance Policy . . . . . . . . . . . . . . . . .   6
     3.2.  Network Instance Management . . . . . . . . . . . . . . .   7
     3.3.  Network Instance Instantiation  . . . . . . . . . . . . .   8
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   6.  Network Instance Model  . . . . . . . . . . . . . . . . . . .   8
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Appendix A.  Acknowledgments  . . . . . . . . . . . . . . . . . .  14
   Appendix B.  Contributors . . . . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   This document defines the second of two new modules that are defined
   to support the configuration and operation of network-devices that
   allow for the partitioning of resources from both, or either,
   management and networking perspectives.  Both make use of emerging
   YANG functionality supported by YANG Schema Mount
   [I-D.ietf-netmod-schema-mount].  This document is expected to use
   whatever Schema Mount solution is agreed upon by the Netmod Working
   Group.

   Two forms of resource partitioning are supported:

   The first form, which is defined in [LNE-MODEL], provides a logical
   partitioning of a network device where each partition is separately
   managed as essentially an independent network element which is
   'hosted' by the base network device.  These hosted network elements
   are referred to as logical network elements, or LNEs, and are
   supported by the logical-network-element module defined in
   [LNE-MODEL].  The module is used to identify LNEs and associate
   resources from the network-device with each LNE.  LNEs themselves are



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   represented in YANG as independent network devices; each accessed
   independently.  Optionally, and when supported by the implementation,
   they may also be accessed from the host system.  Examples of vendor
   terminology for an LNE include logical system or logical router, and
   virtual switch, chassis, or fabric.

   The second form, which is defined in this document, provides support
   what is commonly referred to as Virtual Routing and Forwarding (VRF)
   instances as well as Virtual Switch Instances (VSI), see [RFC4026].
   In this form of resource partitioning multiple control plane and
   forwarding/bridging instances are provided by and managed via a
   single (physical or logical) network device.  This form of resource
   partitioning is referred to as Network Instances and are supported by
   the network-instance module defined below.  Configuration and
   operation of each network-instance is always via the network device
   and the network-instance module.

   This document was motivated by, and derived from, [RTG-DEVICE-MODEL].

1.1.  Status of Work and Open Issues

   The top open issues are:

   1.  This document will need to match the evolution and
       standardization of [I-D.openconfig-netmod-opstate] or
       [I-D.ietf-netmod-opstate-reqs] by the Netmod WG.

2.  Overview

   In this document, we consider network devices that support protocols
   and functions defined within the IETF Routing Area, e.g, routers,
   firewalls and hosts.  Such devices may be physical or virtual, e.g.,
   a classic router with custom hardware or one residing within a
   server-based virtual machine implementing a virtual network function
   (VNF).  Each device may sub-divide their resources into logical
   network elements (LNEs) each of which provides a managed logical
   device.  Examples of vendor terminology for an LNE include logical
   system or logical router, and virtual switch, chassis, or fabric.
   Each LNE may also support virtual routing and forwarding (VRF) and
   virtual switching instance (VSI) functions, which are referred to
   below as a network instances (NIs).  This breakdown is represented in
   Figure 1.









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              ,''''''''''''''''''''''''''''''''''''''''''''''`.
              |      Network Device (Physical or Virtual)     |
              | .....................   ..................... |
              | :  Logical Network  :   :  Logical Network  : |
              | :      Element      :   :      Element      : |
              | :+-----+-----+-----+:   :+-----+-----+-----+: |
              | :| Net | Net | Net |:   :| Net | Net | Net |: |
              | :|Inst.|Inst.|Inst.|:   :|Inst.|Inst.|Inst.|: |
              | :+-----+-----+-----+:   :+-----+-----+-----+: |
              | :  | |   | |   | |  :   :  | |   | |   | |  : |
              | :..|.|...|.|...|.|..:   :..|.|...|.|...|.|..: |
              |    | |   | |   | |         | |   | |   | |    |
               `'''|'|'''|'|'''|'|'''''''''|'|'''|'|'''|'|'''''
                   | |   | |   | |         | |   | |   | |
                      Interfaces              Interfaces

   Figure 1: Module Element Relationships

   A model for LNEs is described in [LNE-MODEL] and the model for
   network instances is covered in Section 3.  For more information on
   how these models may be used within an overall device model
   structure, see [RTG-DEVICE-MODEL].

   The interface management model [RFC7223] is an existing model that is
   impacted by the definition of LNEs and network instances.  This
   document and [LNE-MODEL] define augmentations to the interface module
   to support LNEs and NIs.  Similar elements, although perhaps only for
   LNEs, may also need to be included as part of the definition of the
   future hardware and QoS modules.

   Interfaces are a crucial part of any network device's configuration
   and operational state.  They generally include a combination of raw
   physical interfaces, link-layer interfaces, addressing configuration,
   and logical interfaces that may not be tied to any physical
   interface.  Several system services, and layer 2 and layer 3
   protocols may also associate configuration or operational state data
   with different types of interfaces (these relationships are not shown
   for simplicity).  The interface management model is defined by
   [RFC7223].

   The logical-network-element and network-instance modules augment the
   existing interface management model in two ways: The first, by the
   logical-network-element module, adds an identifier which is used on
   physical interface types to identify an associated LNE.  The second,
   by the network-instance module, adds a name which is used on
   interface or sub-interface types to identify an associated network
   instance.  Similarly, this name is also added for IPv4 and IPv6
   types, as defined in [RFC7277].



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   The interface related augmentations are as follows:

       module: ietf-logical-network-element
       augment /if:interfaces/if:interface:
          +--rw bind-lne-name?   string

       module: ietf-network-instance
       augment /if:interfaces/if:interface:
          +--rw bind-network-instance-name?   string
       augment /if:interfaces/if:interface/ip:ipv4:
          +--rw bind-network-instance-name?   string
       augment /if:interfaces/if:interface/ip:ipv6:
          +--rw bind-network-instance-name?   string

   The following is an example of envisioned combined usage.  The
   interfaces container includes a number of commonly used components as
   examples:

             +--rw if:interfaces
             |  +--rw interface* [name]
             |     +--rw name                       string
             |     +--rw bind-lne-name?             string
             |     +--rw ethernet
             |     |  +--rw ni:bind-network-instance-name? string
             |     |  +--rw aggregates
             |     |  +--rw rstp
             |     |  +--rw lldp
             |     |  +--rw ptp
             |     +--rw vlans
             |     +--rw tunnels
             |     +--rw ipv4
             |     |  +--rw ni:bind-network-instance-name? string
             |     |  +--rw arp
             |     |  +--rw icmp
             |     |  +--rw vrrp
             |     |  +--rw dhcp-client
             |     +--rw ipv6
             |        +--rw ni:bind-network-instance-name? string
             |        +--rw vrrp
             |        +--rw icmpv6
             |        +--rw nd
             |        +--rw dhcpv6-client

   The [RFC7223] defined interface model is structured to include all
   interfaces in a flat list, without regard to logical or virtual
   instances (e.g., VRFs) supported on the device.  The bind-lne-name
   and bind-network-instance-name leaves provide the association between
   an interface and its associated LNE and NI (e.g., VRF or VSI).



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3.  Network Instances

   The network instance container is used to represent virtual routing
   and forwarding instances (VRFs) and virtual switching instances
   (VSIs), [RFC4026].  VRFs and VSIs are commonly used to isolate
   routing and switching domains, for example to create virtual private
   networks, each with their own active protocols and routing/switching
   policies.  The model represents both core/provider and virtual
   instances.  Network instances reuse and build on
   [I-D.ietf-netmod-routing-cfg] and are shown below:

       module: ietf-network-instance
          +--rw network-instances
             +--rw network-instance* [name]
                +--rw name                         string
                +--rw type?                        identityref
                +--rw enabled?                     boolean
                +--rw description?                 string
                +--rw network-instance-policy
                |  ...
                +--rw root?                      schema-mount
                |  ...
       augment /if:interfaces/if:interface:
          +--rw bind-network-instance-name?   string
       augment /if:interfaces/if:interface/ip:ipv4:
          +--rw bind-network-instance-name?   string
       augment /if:interfaces/if:interface/ip:ipv6:
          +--rw bind-network-instance-name?   string

   A network instance is identified by a `name` string.  This string is
   used both as an index within the network-instance module and to
   associate resources with a network instance as shown above in the
   interface augmentation.  Type is used to indicate the type NI, such
   as L3-VRF, VPLS, L2-VSI, etc.  Network instance policy and root are
   discussed in greater detail below.

3.1.  Network Instance Policy

   Network instance policies are used to control how NI information is
   represented at the device level, VRF routing policies, and VRF/VSI
   identifiers.  Examples include BGP route targets (RTs) and route
   distinguishers (RDs), virtual network identifiers (VN-IDs), VPLS
   neighbors, etc.  The structure is expected to be:








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       module: ietf-network-instance
          +--rw network-instances
             +--rw network-instance* [name]
                +--rw network-instance-policy
                   (TBD)

3.2.  Network Instance Management

   Modules that may be used to represent network instance specific
   information will be available under `root`.  As with LNEs, actual
   module availability is expected to be implementation dependent.  The
   yang library module [I-D.ietf-netconf-yang-library] is expected to be
   the primary method used to identify supported modules.  Resource
   related control and assignment is expected to be managed at the
   network-device level, not the network instance level, based on the
   `bind-network-instance-name` augmentation mentioned above.

   As an example, consider the case where a network instance with a
   `name` of "green" is defined on a network device.  In this case the
   following structure might be made available:

   +--rw yanglib:modules-state           [I-D.ietf-netconf-yang-library]
   +--rw if:interfaces                   [RFC7223]
   |  +--rw bind-network-instance-name="green" string
   +--rw network-instances
      +--rw network-instance* [name]
         +--rw name="green"    string
         +--rw type?                           identityref
         +--rw enabled=true                    boolean
         +--rw description="The Green VRF"     string
         +--rw network-instance-policy
         |  ... (RT=1000:1, RD=1.2.3.4)
         +--rw root?                           schema-mount
            +--rw yanglib:modules-state  [I-D.ietf-netconf-yang-library]
            +--rw if:intefaces           [RFC7223]
            +--rw mm:network-services
            +--rw nn:oam-protocols
            +--rw oo:routing
            +--rw pp:mpls

   All modules that represent control-plane and data-plane information
   may be present at the `root`, and be accessible via paths modified
   per [I-D.ietf-netmod-schema-mount].  The list of available modules is
   expected to be implementation dependent.  As is the method used by an
   implementation to support NIs.






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3.3.  Network Instance Instantiation

   TBD -- need to resolve if instantiation is based on new list entry
   creation per the pending Schema Mount solution definition.

4.  Security Considerations

   LNE portion is TBD

   NI portion is TBD

5.  IANA Considerations

   This YANG model currently uses a temporary ad-hoc namespace.  If it
   is placed or redirected for the standards track, an appropriate
   namespace URI will be registered in the "IETF XML Registry"
   [RFC3688].  The YANG structure modules will be registered in the
   "YANG Module Names" registry [RFC6020].

6.  Network Instance Model

   The structure of the model defined in this document is described by
   the YANG module below.

   <CODE BEGINS> file "ietf-network-instance@2016-05-01.yang"
   module ietf-network-instance {

     yang-version "1";

     // namespace
     namespace "urn:ietf:params:xml:ns:yang:ietf-network-instance";

     prefix "ni";

     // import some basic types
     import ietf-interfaces {
       prefix if;
     }

     import ietf-ip {
       prefix ip;
     }

     // meta
     organization "IETF RTG YANG Design Team Collaboration
                   with OpenConfig";

     contact



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         "Routing Area YANG Architecture Design Team -
          <rtg-dt-yang-arch@ietf.org>";

     description
       "This module is used to support multiple network instances
        within a single physical or virtual device.  Network
        instances are commonly know as VRFs (virtual routing
        and forwarding) and VSIs (virtual switching instances).";

     revision "2016-05-01" {
       description
         "IETF Routing YANG Design Team Meta-Model";
       reference "TBD";
     }

     // extension statements

     feature bind-network-instance-name {
       description
         "Network Instance to which an interface instance is bound";
     }

     // identity statements

     identity network-instance-type {
         description
            "Base identity from which identities describing
             network instance types are derived.";
     }

      identity ipv4-interface-protocol-type {
         description
             "Base identity for derivation of IPv4 interface
              protocols";
      }

      identity ipv6-interface-protocol-type {
         description
             "Base identity for derivation of IPv6 interface
              protocols";
      }

     // typedef statements

     // grouping statements

     grouping interface-ip-common {
       description



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         "interface-specific configuration for IP interfaces, IPv4 and
         IPv6";

     }

     grouping ipv4-interface-protocols {
         container ipv4-interface-protocols {
             list ipv4-interface-protocol {
                 key "type";
                 leaf type {
                     type identityref {
                         base ipv4-interface-protocol-type;
                     }
                     mandatory true;
                     description
                         "ARP, ICMP, VRRP, DHCP Client, etc.";
                 }
                 description
                     "List of IPv4 protocols configured
                      on an interface";
             }
             description
                 "Container for list of IPv4 protocols configured
                   on an interface";
         }
         description
             "Grouping for IPv4 protocols configured on an interface";
     }

     grouping ipv6-interface-protocols {
         description
             "Grouping for IPv6 protocols configured on
              an interface.";
         container ipv6-interface-protocols {
             description
                 "Container for list of IPv6 protocols configured
                   on an interface.";
             list ipv6-interface-protocol {
                 key "type";
                 description
                     "List of IPv6 protocols configured
                      on an interface";
                 leaf type {
                     type identityref {
                         base ipv6-interface-protocol-type;
                     }
                     mandatory true;
                     description



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                         "ND, ICMPv6, VRRP, DHCPv6 Client, etc.";
                 }
             }
         }
     }

     grouping network-instance-policy {
       description
           "Network instance policies such as route
            distinguisher, route targets, VPLS ID and neighbor,
            Ethernet ID, etc. ";
       reference
           "RFC 4364 - BGP/MPLS Virtual Private Networks (VPNs)
            RFC 6074 - Provisioning, Auto-Discovery, and Signaling
                 in Layer 2 Virtual Private Networks (L2VPNs)
            RFC 7432 - BGP MPLS-Based Ethernet VPN";
       container network-instance-policy {
           description "Network Instance Policy -- details TBD";
       }
     }

     // top level device definition statements
     container network-instances {
         description "Network instances each of which have
                      an independent IP/IPv6 addressing space
                      and protocol instantiations. For layer 3,
                      this consistent with the routing-instance
                      definition in ietf-routing";
         reference "draft-ietf-netmod-routing-cfg";
         list network-instance {
             key name;
             description "List of network-instances";
             leaf name {
                 type string;
                 description "device scoped
                              identifier for the network
                              instance";
             }
             leaf type {
                 type identityref {
                     base network-instance-type;
                 }
                 description
                     "The network instance type -- details TBD
                      Likely types include core, L3-VRF, VPLS,
                      L2-cross-connect, L2-VSI, etc.";
             }
             leaf enabled {



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                 type boolean;
                 default "true";
                 description
                   "Flag indicating whether or not the network
                    instance is enabled.";
             }
             leaf description {
                 type string;
                 description
                   "Description of the network instance
                   and its intended purpose";
             }
             uses network-instance-policy;
             leaf root {
               type schema-mount;
               description "Root for models supported per
                            network instance";
             }
         }
     }

     // augment statements

     augment "/if:interfaces/if:interface" {
       description
           "Add a node for the identification of the logical network
           instance (which is within the interface's identified logical
           network element) associated with the IP information
           configured on an interface";

       leaf bind-network-instance-name {
         type string;
         description
           "Network Instance to which an interface is bound";
       }
     }

     augment "/if:interfaces/if:interface/ip:ipv4" {
       description
           "Add a node for the identification of the logical
           network instance (which is within the interface's
           identified physical or virtual device) associated with
           the IP information configured on an interface";

       leaf bind-network-instance-name {
         type string;
         description
           "Network Instance to which IPv4 interface is bound";



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       }
     }

     augment "/if:interfaces/if:interface/ip:ipv6" {
       description
           "Add a node for the identification of the logical
           network instance (which is within the interface's
           identified physical or virtual device) associated with
           the IP information configured on an interface";

       leaf bind-network-instance-name {
         type string;
         description
           "Network Instance to which IPv6 interface is bound";

       }
     }

     // rpc statements

     // notification statements

   }
   <CODE ENDS>

7.  References

7.1.  Normative References

   [I-D.ietf-netmod-schema-mount]
              Bjorklund, M. and L. Lhotka, "YANG Schema Mount", draft-
              ietf-netmod-schema-mount-01 (work in progress), April
              2016.

   [LNE-MODEL]
              Berger, L., Hopps, C., Lindem, A., and D. Bogdanovic,
              "Logical Network Element Model", draft-rtgyangdt-rtgwg-
              lne-model-00.txt (work in progress), May 2016.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <http://www.rfc-editor.org/info/rfc3688>.

   [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
              Private Network (VPN) Terminology", RFC 4026,
              DOI 10.17487/RFC4026, March 2005,
              <http://www.rfc-editor.org/info/rfc4026>.




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   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC7223]  Bjorklund, M., "A YANG Data Model for Interface
              Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
              <http://www.rfc-editor.org/info/rfc7223>.

   [RFC7277]  Bjorklund, M., "A YANG Data Model for IP Management",
              RFC 7277, DOI 10.17487/RFC7277, June 2014,
              <http://www.rfc-editor.org/info/rfc7277>.

   [RTG-DEVICE-MODEL]
              Lindem, A., Ed., Berger, L., Ed., Bogdanovic, D., and C.
              Hopps, "Network Device YANG Organizational Models", draft-
              rtgyangdt-rtgwg-device-model-04.txt (work in progress),
              May 2016.

7.2.  Informative References

   [I-D.ietf-netconf-yang-library]
              Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module
              Library", draft-ietf-netconf-yang-library-05 (work in
              progress), April 2016.

   [I-D.ietf-netmod-opstate-reqs]
              Watsen, K. and T. Nadeau, "Terminology and Requirements
              for Enhanced Handling of Operational State", draft-ietf-
              netmod-opstate-reqs-03 (work in progress), January 2016.

   [I-D.ietf-netmod-routing-cfg]
              Lhotka, L. and A. Lindem, "A YANG Data Model for Routing
              Management", draft-ietf-netmod-routing-cfg-20 (work in
              progress), October 2015.

   [I-D.openconfig-netmod-opstate]
              Shakir, R., Shaikh, A., and M. Hines, "Consistent Modeling
              of Operational State Data in YANG", draft-openconfig-
              netmod-opstate-01 (work in progress), July 2015.

Appendix A.  Acknowledgments

   The Routing Area Yang Architecture design team members included Acee
   Lindem, Anees Shaikh, Christian Hopps, Dean Bogdanovic, Lou Berger,
   Qin Wu, Rob Shakir, Stephane Litkowski, and Yan Gang.

   The RFC text was produced using Marshall Rose's xml2rfc tool.



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Appendix B.  Contributors

   Contributors' Addresses

      TBD

Authors' Addresses

   Lou Berger
   LabN Consulting, L.L.C.

   Email: lberger@labn.net


   Christan Hopps
   Deutsche Telekom

   Email: chopps@chopps.org


   Acee Lindem
   Cisco Systems
   301 Midenhall Way
   Cary, NC  27513
   USA

   Email: acee@cisco.com


   Dean Bogdanovic

   Email: ivandean@gmail.com



















Berger, et al.          Expires November 18, 2016              [Page 15]


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