[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-ding-netmod-arp-yang-model) 00 01 02 draft-ietf-rtgwg-arp-yang-model

RTGWG                                                            X. Ding
Internet-Draft                                                  F. Zheng
Intended status: Standards Track                                  Huawei
Expires: December 30, 2018                                     R. Wilton
                                                           Cisco Systems
                                                           June 28, 2018


                        YANG Data Model for ARP
                   draft-ding-rtgwg-arp-yang-model-02

Abstract

   This document defines a YANG data model to describe Address
   Resolution Protocol (ARP) configurations.  The data model performs as
   a guideline for configuring ARP capabilities on a system.  It is
   intended this model be used by service providers who manipulate
   devices from different vendors in a standard way.

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 https://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 December 30, 2018.

Copyright Notice

   Copyright (c) 2018 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
   (https://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



Ding, et al.            Expires December 30, 2018               [Page 1]


Internet-Draft               ARP YANG model                    June 2018


   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   2
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Design of the Data Model  . . . . . . . . . . . . . . . . . .   4
     3.1.  ARP Caching . . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  proxy ARP . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.3.  gratuitous ARP  . . . . . . . . . . . . . . . . . . . . .   4
     3.4.  ietf-arp Module . . . . . . . . . . . . . . . . . . . . .   5
   4.  ARP YANG Module . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  Data Model Examples . . . . . . . . . . . . . . . . . . . . .  12
     5.1.  Static ARP Entries  . . . . . . . . . . . . . . . . . . .  12
     5.2.  ARP Dynamic Learning  . . . . . . . . . . . . . . . . . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  14
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   This document defines a YANG [RFC7950] data model for Address
   Resolution Protocol [RFC826] implementation and identification of
   some common properties within a device.  Devices have common
   properties that need to be configured and monitored in a standard
   way.  This document is intended to present universal ARP protocol
   configuration and many vendors can implement it.

   The data model convers configuration of system parameters of ARP,
   such as static ARP entries, timeout for dynamic ARP entries,
   interface ARP, proxy ARP, and so on.  It also provides information
   about running state of ARP implementations.

1.1.  Terminology

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

   The following terms are defined in [RFC6241] and are not redefined
   here:



Ding, et al.            Expires December 30, 2018               [Page 2]


Internet-Draft               ARP YANG model                    June 2018


   o  client

   o  configuration data

   o  server

   o  state data

1.2.  Tree Diagrams

   A simplified graphical representation of the data model is presented
   in Section 3.

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

   o  Abbreviations before data node names: "rw" means configuration
      (read-write) and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node, "!"
      means a presence container, and "*" denotes a list and leaf-list.

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

   Tree diagrams used in this document use the notation defined in
   [RFC8340].

2.  Problem Statement

   This document defines a YANG [RFC7950] configuration data model that
   may be used to configure the ARP feature running on a system.  Data
   model "ietf-ip" [I-D.ietf-netmod-rfc7277bis] covers the address
   mapping functionality.  However, this functionality is strictly
   dependent on IPv4 networks, and many ARP related functionalities are
   missing, e.g. device global ARP entries and control, configuration
   related to dynamic ARP learning, proxy ARP, gratuitous ARP, etc.

   The data model makes use of the YANG "feature" construct which allows
   implementations to support only those ARP features that lie within
   their capabilities.  It is intended this model be used by service
   providers who manipulate devices from different vendors in a standard
   way.






Ding, et al.            Expires December 30, 2018               [Page 3]


Internet-Draft               ARP YANG model                    June 2018


   This model can be used to configure the ARP applications for
   discovering the link layer address associated with a given Internet
   layer address.

3.  Design of the Data Model

   This data model intends to describe the processing that a protocol
   finds the hardware address, also known as Media Access Control (MAC)
   address, of a host from its known IP address.  These tasks include,
   but are not limited to, adding a static entry in the ARP cache,
   configuring dynamic ARP learning, proxy ARP, gratuitous ARP.  There
   are two kind of ARP configurations: global ARP configuration, which
   is across all interfaces on the device, and per interface ARP
   configuration.

3.1.  ARP Caching

   ARP caching is the method of storing network addresses and the
   associated data-link addresses in memory for a period of time as the
   addresses are learned.  This minimizes the use of valuable network
   resources to broadcast for the same address each time a datagram is
   sent.

   There are static ARP cache entries and dynamic ARP cache entries.
   Static entries are manually configured and kept in the cache table on
   a permanent basis.  Dynamic entries are added by vendor software,
   kept for a period of time, and then removed.  We can specify how long
   an entry remains in the ARP cache.  If we specify a timeout of 0
   seconds, entries are never cleared from the ARP cache.

3.2.  proxy ARP

   Proxy ARP [RFC1027] can be configured to enable the switch to respond
   to ARP queries for network addresses by offering its own Ethernet
   media access control (MAC) address.  With proxy ARP enabled, the
   switch captures and routes traffic to the intended destination.

3.3.  gratuitous ARP

   Gratuitous ARP requests help detect duplicate IP addresses.  A
   gratuitous ARP is a broadcast request for a router's own IP address.
   If a router or switch sends an ARP request for its own IP address and
   no ARP replies are received, the router- or switch-assigned IP
   address is not being used by other nodes.  However, if a router or
   switch sends an ARP request for its own IP address and an ARP reply
   is received, the router- or switch-assigned IP address is already
   being used by another node.




Ding, et al.            Expires December 30, 2018               [Page 4]


Internet-Draft               ARP YANG model                    June 2018


3.4.  ietf-arp Module

   This module has one top level container, ARP, which consists of two
   second level containers, which are used for static entries
   configuration and global parameters control.


   module: ietf-arp
       +--rw arp
          +--rw global-static-entries {global-static-entries}?
          |  +--rw static-entry* [ip-address]
          |     +--rw ip-address     inet:ipv4-address-no-zone
          |     +--rw mac-address    yang:mac-address
          +--rw global-control
             +--rw enable-learning?   boolean
             +--rw enable-proxy?      boolean
     augment /if:interfaces/if:interface:
       +--rw arp-dynamic-learning
          +--rw expire-time?     yang:timeticks
          +--rw learn-disable?   boolean
          +--rw proxy
          |  +--rw mode?   enumeration
          +--rw probe
          |  +--rw interval?   uint8
          |  +--rw times?      uint8
          |  +--rw unicast?    boolean
          +--rw gratuitous
          |  +--rw enable?     boolean
          |  +--rw interval?   uint32
          |  +--rw drop?       boolean
          +--ro statistics
             +--ro in-requests-pkts?      uint16
             +--ro in-replies-pkts?       uint16
             +--ro in-gratuitous-pkts?    uint16
             +--ro out-requests-pkts?     uint16
             +--ro out-replies-pkts?      uint16
             +--ro out-gratuitous-pkts?   uint16
     augment /if:interfaces/if:interface/ip:ipv4/ip:neighbor:
       +--ro remaining-expire-time?   uint32


4.  ARP YANG Module

   This section presents the ARP YANG module defined in this document.
   This YANG module imports typedefs from [RFC6991].

<CODE BEGINS>file "ietf-arp@2018-01-27.yang"




Ding, et al.            Expires December 30, 2018               [Page 5]


Internet-Draft               ARP YANG model                    June 2018


module ietf-arp {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-arp";
  prefix arp;

  import ietf-inet-types {
    prefix inet;
        reference "RFC 6991: INET Types Model";
  }

  import ietf-yang-types {
    prefix yang;
        reference "RFC 6991: yang Types Model";
  }

  import ietf-interfaces {
    prefix if;
    description
      "A Network Management Datastore Architecture (NMDA)
       compatible version of the ietf-interfaces module
       is required.";
  }
  import ietf-ip {
    prefix ip;
    description
      "A Network Management Datastore Architecture (NMDA)
       compatible version of the ietf-ip module is
       required.";
  }

  organization
    "IETF Routing Area Working Group (rtgwg)";
  contact
    "WG Web: <http://tools.ietf.org/wg/rtgwg/>
     WG List: <mailto: rtgwg@ietf.org>
     Editor: Xiaojian Ding
         dingxiaojian1@huawei.com
     Editor: Feng Zheng
         habby.zheng@huawei.com
     Editor: Robert Wilton
         rwilton@cisco.com";
  description
    "Address Resolution Protocol (ARP) management, which includes
     static ARP configuration, dynamic ARP learning, ARP entry query,
     and packet statistics collection.";

  revision 2018-01-27 {
    description



Ding, et al.            Expires December 30, 2018               [Page 6]


Internet-Draft               ARP YANG model                    June 2018


      "Init revision";
       //   NOTE TO RFC EDITOR:
     // Please replace the following reference
     // to draft-ding-rtgwg-arp-yang-model-02 with
     // RFC number when published (i.e. RFC xxxx).
    reference
         "draft-ding-rtgwg-arp-yang-model-02";
  }

      /*
      * Features
      */

    feature global-static-entries {
    description
      "This feature indicates that the device allows static entries
       to be configured globally.";
  }


  container arp {
    description
      "Address Resolution Protocol (ARP) management, which includes
        static ARP configuration, dynamic ARP learning, ARP entry
        query, and packet statistics collection.";

    container global-static-entries {
      if-feature "global-static-entries";
      description
        "Set a global static ARP entry, which is independent of the interface.";
      list static-entry {
        key "ip-address";
        description
          "List of ARP static entries that can be configured globally.";
        leaf ip-address {
          type inet:ipv4-address-no-zone;
          description
            "IP address, in dotted decimal notation.";
        }
        leaf mac-address {
          type yang:mac-address;
          mandatory true;
          description
            "MAC address in the format of H-H-H, in which H is
                        a hexadecimal number of 1 to 4 bits.";
        }
      }
    }



Ding, et al.            Expires December 30, 2018               [Page 7]


Internet-Draft               ARP YANG model                    June 2018


    container global-control {
      description
        "Set global control parameters, which are independent of interface.";
        leaf enable-learning {
          type boolean;
                  default "true";
          description
            "Enables or disables global dynamic ARP learning.
                        If 'true', then enforcement is enabled.
                        If 'false', then enforcement is disabled.";
        }
        leaf enable-proxy {
          type boolean;
          default "true";
          description
            "Proxy ARP is enabled by default; perform this
                        task to globally disable proxy ARP on all interfaces.";
        }
    }
        }
   augment "/if:interfaces/if:interface" {
    description
      "Augment interface configuration with parameters of ARP.";
    container arp-dynamic-learning {
      description
        "Support for ARP configuration on interfaces.";
      leaf expire-time {
        type yang:timeticks {
          range "60..86400";
        }
        units "second";
        description
          "Aging time of a dynamic ARP entry.";
      }
      leaf learn-disable {
        type boolean;
        default "false";
        description
          "Whether dynamic ARP learning is disabled on an interface.
                  If the value is True, dynamic ARP learning is disabled.
                  If the value is False, dynamic ARP learning is enabled.";
      }

      container proxy {
        description
          "Configuration parameters for proxy ARP";
                leaf mode {
                  type enumeration {



Ding, et al.            Expires December 30, 2018               [Page 8]


Internet-Draft               ARP YANG model                    June 2018


                        enum DISABLE {
                          description
                                "The system should not respond to ARP requests that
                                do not specify an IP address configured on the local
                                subinterface as the target address.";
                        }
                        enum REMOTE_ONLY {
                          description
                                "The system responds to ARP requests only when the
                                sender and target IP addresses are in different
                                subnets.";
                        }
                        enum ALL {
                          description
                                "The system responds to ARP requests where the sender
                                and target IP addresses are in different subnets, as well
                                as those where they are in the same subnet.";
                        }
                  }
                  default "DISABLE";
                  description
                        "When set to a value other than DISABLE, the local system should
                        respond to ARP requests that are for target addresses other than
                        those that are configured on the local subinterface using its own
                        MAC address as the target hardware address. If the REMOTE_ONLY
                        value is specified, replies are only sent when the target address
                        falls outside the locally configured subnets on the interface,
                        whereas with the ALL value, all requests, regardless of their
                        target address are replied to.";
                  reference "RFC1027: Using ARP to Implement Transparent Subnet Gateways";
       }
      }

      container probe {
        description
          "Common configuration parameters for all ARP probe.";
        leaf interval {
          type uint8 {
            range "1..5";
          }
          units "second";
          description
            "Interval for detecting dynamic ARP entries.";
        }
        leaf times {
          type uint8 {
            range "0..10";
          }



Ding, et al.            Expires December 30, 2018               [Page 9]


Internet-Draft               ARP YANG model                    June 2018


          description
            "Number of aging probe attempts for a dynamic ARP entry.
             If a device does not receive an ARP reply message after
             the number of aging probe attempts reaches a specified
             number,thedynamic ARP entry is deleted.";
        }
        leaf unicast {
          type boolean;
          default "false";
          description
            "Send unicast ARP aging probe messages for a dynamic ARP
             entry.";
        }
      }

      container gratuitous {
        description
          "Configure gratuitous ARP.";
        leaf enable {
          type boolean;
          default "false";
          description
            "Enable or disable sending gratuitous-arp packet on
             interface.";
        }
        leaf interval {
          type uint32 {
            range "1..86400";
          }
          units "second";
          description
            "The interval of sending gratuitous-arp packet on the
             interface.";
        }
        leaf drop {
          type boolean;
          default "false";
          description
            "Drop the receipt of gratuitous ARP packets on the interface.";
        }
      }

      container statistics {
        config false;
        description
          "IP ARP Statistics information on interfaces";
        leaf in-requests-pkts {
          type uint16;



Ding, et al.            Expires December 30, 2018              [Page 10]


Internet-Draft               ARP YANG model                    June 2018


          description
            "Total ARP requests received";
        }
        leaf in-replies-pkts {
          type uint16;
          description
            "Total ARP replies received";
        }
        leaf in-gratuitous-pkts {
          type uint16;
          description
            "Total gratuitous ARP received";
        }
        leaf out-requests-pkts {
          type uint16;
          description
            "Total ARP requests sent";
        }
        leaf out-replies-pkts {
          type uint16;
          description
            "Total ARP replies sent";
        }
        leaf out-gratuitous-pkts {
          type uint16;
          description
            "Total gratuitous ARP sent";
        }
      }
    }
  }


  augment "/if:interfaces/if:interface/ip:ipv4/ip:neighbor" {
    description
      "Augment neighbor list with parameters of ARP,
       eg., support for remaining expire time query on interfaces.";
    leaf remaining-expire-time {
      type uint32;
      config false;
      description
        "Remaining expire time of a dynamic ARP entry. ";
    }
   }


}




Ding, et al.            Expires December 30, 2018              [Page 11]


Internet-Draft               ARP YANG model                    June 2018


5.  Data Model Examples

   This section presents a simple but complete example of configuring
   static ARP entries and dynamic learning, based on the YANG modules
   specified in Section 4.

5.1.  Static ARP Entries

   Requirement:
   Enable static ARP entry global configuration (not rely on interface).
      <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
         <arp xmlns="urn:ietf:params:xml:ns:yang:ietf-arp">
            <static-tables>
               <ip-address> 10.2.2.3 </ip-address>
               <mac-address> 00e0-fc01-0000 </mac-address>
            </static-tables>
         </arp>


   Requirement:
   Enable static ARP entry configuration on interface (defined in
   draft [I-D.ietf-netmod-rfc7277bis]).
      <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
         <ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
            <neighbor>
               <ip-address> 10.2.2.3 </ip-address>
               <mac-address> 00e0-fc01-0000 </mac-address>
               <if-name> GE1/0/1 </if-name>
            </neighbor>
         </ipv4>


5.2.  ARP Dynamic Learning


















Ding, et al.            Expires December 30, 2018              [Page 12]


Internet-Draft               ARP YANG model                    June 2018


Requirement:
Enable ARP dynamic learning configuration.

   <config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
      <arp-dynamic-learning xmlns="urn:ietf:params:xml:ns:yang:ietf-arp-dynamic-learning">
         <if-name> GE1/0/1 </if-name>
         <expire-time>1200</expire-time>
         <learn-disable>false</learn-disable>
         <proxy>
                    <mode>DISABLE</mode>
                 </proxy>
         <probe>
            <interval>5</interval>
            <times>3</times>
            <unicast>false</unicast>
         </probe>
         <gratuitous>
            <gratuitous-enable>false<gratuitous-enable>
            <interval>60</interval>
            <drop>false</drop>
         <gratuitous>
      </arp-dynamic-learning>


6.  Security Considerations

   The YANG module defined in this document is designed to be accessed
   via YANG based management protocols, such as NETCONF [RFC6241] and
   RESTCONF [RFC8040].  Both of these protocols have mandatory-to-
   implement secure transport layers (e.g., SSH, TLS) with mutual
   authentication.

   The NETCONF access control model (NACM) [RFC6536] provides the means
   to restrict access for particular users to a pre-configured subset of
   all available protocol operations and content.

   These are the subtrees and data nodes and their sensitivity/
   vulnerability:

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.






Ding, et al.            Expires December 30, 2018              [Page 13]


Internet-Draft               ARP YANG model                    June 2018


7.  Acknowledgments

   The authors wish to thank Alex Campbell and Reshad Rahman, Qin Wu,
   many others for their helpful comments.

8.  References

8.1.  Normative References

   [I-D.ietf-netmod-rfc7223bis]
              Bjorklund, M., "A YANG Data Model for Interface
              Management", draft-ietf-netmod-rfc7223bis-03 (work in
              progress), January 2018.

   [I-D.ietf-netmod-rfc7277bis]
              Bjorklund, M., "A YANG Data Model for IP Management",
              draft-ietf-netmod-rfc7277bis-03 (work in progress),
              January 2018.

   [RFC1027]  Carl-Mitchell, S. and J. Quarterman, "Using ARP to
              implement transparent subnet gateways", RFC 1027,
              DOI 10.17487/RFC1027, October 1987,
              <https://www.rfc-editor.org/info/rfc1027>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

8.2.  Informative References

   [RFC0826]  Plummer, D., "An Ethernet Address Resolution Protocol: Or
              Converting Network Protocol Addresses to 48.bit Ethernet
              Address for Transmission on Ethernet Hardware", STD 37,
              RFC 826, DOI 10.17487/RFC0826, November 1982,
              <https://www.rfc-editor.org/info/rfc826>.







Ding, et al.            Expires December 30, 2018              [Page 14]


Internet-Draft               ARP YANG model                    June 2018


   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Authors' Addresses

   Xiaojian Ding
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: dingxiaojian1@huawei.com


   Feng Zheng
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: habby.zheng@huawei.com


   Robert Wilton
   Cisco Systems

   Email: rwilton@cisco.com














Ding, et al.            Expires December 30, 2018              [Page 15]

Html markup produced by rfcmarkup 1.127, available from https://tools.ietf.org/tools/rfcmarkup/