tech-invite   World Map     

IETF     RFCs     Groups     SIP     ABNFs    |    3GPP     Specs     Gloss.     Arch.     IMS     UICC    |    Misc.    |    search     info

RFC 7939

Proposed STD
Pages: 72
Top     in Index     Prev     Next
in Group Index     Prev in Group     No Next: Highest Number in Group     Group: MANET

Definition of Managed Objects for the Neighborhood Discovery Protocol

Part 1 of 4, p. 1 to 11
None       Next Section

Obsoletes:    6779


Top       ToC       Page 1 
Internet Engineering Task Force (IETF)                        U. Herberg
Request for Comments: 7939
Obsoletes: 6779                                                  R. Cole
Category: Standards Track                                 US Army CERDEC
ISSN: 2070-1721                                              I. Chakeres
                                                                  Delvin
                                                              T. Clausen
                                                     Ecole Polytechnique
                                                             August 2016


 Definition of Managed Objects for the Neighborhood Discovery Protocol

Abstract

   This document replaces RFC 6779; it contains revisions and extensions
   to the original document.  It defines a portion of the Management
   Information Base (MIB) for use with network management protocols in
   the Internet community.  In particular, it describes objects for
   configuring parameters of the Neighborhood Discovery Protocol (NHDP)
   process on a router.  The extensions described in this document add
   objects and values to support the NHDP optimization specified in RFC
   7466.  The MIB module defined in this document, denoted NHDP-MIB,
   also reports state, performance information, and notifications about
   NHDP.  This additional state and performance information is useful to
   troubleshoot problems and performance issues during neighbor
   discovery.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7939.

[Page 2] 
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 (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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Differences from RFC 6779 . . . . . . . . . . . . . . . .   3
   2.  The Internet-Standard Management Framework  . . . . . . . . .   3
   3.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Terms . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.2.  Notation  . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Structure of the MIB Module . . . . . . . . . . . . . . . . .   4
     5.1.  Notifications . . . . . . . . . . . . . . . . . . . . . .   5
       5.1.1.  Introduction  . . . . . . . . . . . . . . . . . . . .   5
       5.1.2.  Notification Generation . . . . . . . . . . . . . . .   5
       5.1.3.  Limiting Frequency of Notifications . . . . . . . . .   5
     5.2.  The Configuration Group . . . . . . . . . . . . . . . . .   7
     5.3.  The State Group . . . . . . . . . . . . . . . . . . . . .   7
     5.4.  The Performance Group . . . . . . . . . . . . . . . . . .   8
     5.5.  Tables and Indexing . . . . . . . . . . . . . . . . . . .   8
   6.  Relationship to Other MIB Modules . . . . . . . . . . . . . .  10
     6.1.  Relationship to the SNMPv2-MIB  . . . . . . . . . . . . .  10
     6.2.  Relationship to Routing Protocol MIB Modules Relying on
           the NHDP-MIB Module . . . . . . . . . . . . . . . . . . .  10
     6.3.  Relationship to the If-MIB  . . . . . . . . . . . . . . .  10
     6.4.  MIB Modules Required for IMPORTS  . . . . . . . . . . . .  11
   7.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .  11
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  66
   9.  Applicability Statement . . . . . . . . . . . . . . . . . . .  68
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  69
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  69
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  69
     11.2.  Informative References . . . . . . . . . . . . . . . . .  71
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  72
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  72

Top      ToC       Page 3 
1.  Introduction

   This document defines a portion of the Management Information Base
   (MIB) for use with network management protocols in the Internet
   community.  In particular, it describes objects for configuring
   parameters of the Mobile Ad Hoc Network (MANET) Neighborhood
   Discovery Protocol (NHDP) [RFC6130] process on a router.  The MIB
   module defined in this document, denoted NHDP-MIB, also reports
   state, performance information, and notifications about NHDP.  This
   additional state and performance information is useful to
   troubleshoot problems and performance issues during neighbor
   discovery.

1.1.  Differences from RFC 6779

   This document obsoletes [RFC6779], replacing that document as the
   specification of the MIB module for [RFC6130].  This revision to
   [RFC6779] is necessitated by the update to [RFC6130] specified in
   [RFC7466].

   The MIB module for [RFC6130], specified in this document, captures
   the new information and states for each symmetric 2-hop neighbor,
   recorded in the Neighbor Information Base of a router and to be
   reflected in the appropriate tables, introduced by [RFC7466],
   specifically:

   o  Addition of objects nhdpIib2HopSetN2Lost and
      nhdpIfPerfCounterDiscontinuityTime.

   o  Addition of extra value (notconsidered) to nhdp2HopNbrState.

   o  Revised full compliance state.

2.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).  This memo specifies a MIB
   module that is compliant to the SMIv2, which is described in STD 58,
   RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
   [RFC2580].

Top      ToC       Page 4 
3.  Conventions

   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
   [RFC2119].

4.  Overview

   [RFC6130] allows a router to discover and track topological
   information of routers up to two hops away by virtue of exchanging
   HELLO messages.  This information is useful for routers running
   various routing and multicast flooding protocols developed within the
   IETF MANET Working Group.

4.1.  Terms

   The following definitions apply throughout this document:

   o  Notification Objects - triggers and associated notification
      messages allowing for asynchronous tracking of predefined events
      on the managed router.

   o  Configuration Objects - switches, tables, and objects that are
      initialized to default settings or set through the management
      interface defined by this MIB module.

   o  State Objects - automatically generated values that define the
      current operating state of the NHDP instance in the router.

   o  Performance Objects - automatically generated values that help to
      assess the performance of the NHDP instance on the router and the
      overall discovery performance within the MANET.

4.2.  Notation

   The same notations as defined in [RFC6130] are used throughout this
   document.

5.  Structure of the MIB Module

   This section presents the structure of the NHDP-MIB module.  The MIB
   module is arranged into the following structure:

   o  nhdpNotifications - objects defining NHDP-MIB notifications.

Top      ToC       Page 5 
   o  nhdpObjects - defining objects within this MIB module.  The
      objects are arranged into the following groups:

      *  Configuration Group - defining objects related to the
         configuration of the NHDP instance on the router.

      *  State Group - defining objects that reflect the current state
         of the NHDP instance running on the router.

      *  Performance Group - defining objects that are useful to a
         management station when characterizing the performance of NHDP
         on the router and in the MANET.

   o  nhdpConformance - defining the minimal and maximal conformance
      requirements for implementations of this MIB module.

5.1.  Notifications

   This section describes the use of notifications and mechanisms to
   enhance the ability to manage NHDP routing domains.

5.1.1.  Introduction

   Notifications can be emitted by a router running an instance of this
   specification as a reaction to a specific event.  This allows an
   observer of these events to efficiently determine the source of
   problems or significant changes of configuration or topology, instead
   of polling a possibly large number of routers.

5.1.2.  Notification Generation

   When an exception event occurs, the application notifies the local
   agent, which sends a notification to the appropriate SNMP management
   stations.  The message includes the notification type and may include
   a list of notification-specific variables.  Section 7 contains the
   notification definitions, which includes the variable lists.  At
   least one IP address of the router that originates the notification
   is included in the variable list so that the source of the
   notification may be determined.

5.1.3.  Limiting Frequency of Notifications

   To limit the frequency of notifications, the following additional
   mechanisms are suggested, similar to those in [RFC4750].

Top      ToC       Page 6 
5.1.3.1.  Ignoring Initial Activity

   The majority of critical events occur when NHDP is first enabled on a
   router, at which time, the symmetric neighbors and 2-hop neighbors of
   the router are discovered.  During this initial period, a potential
   flood of notifications is unnecessary since the events are expected.
   To avoid unnecessary notifications, a router SHOULD NOT originate
   expected notifications until a predefined and administratively
   configured time interval has elapsed.  It is RECOMMENDED that this
   time interval be at least 3 times nhdpHelloInterval so that symmetric
   neighbors are discovered.  The suppression window for notifications
   is started when the nhdpIfStatus transitions from its default value
   of 'false(2)' to 'true(1)'.

5.1.3.2.  Throttling Notifications

   The mechanism for throttling the notifications is the same as in
   [RFC4750] (i.e., the number of transmitted notifications per time is
   bounded).

   Appropriate values for the window time and upper bound are to be
   administratively configured and depend on the deployment of the
   MANET.  If NHDP is deployed on a lossy, wireless medium, sending too
   many notifications in a short time interval may lead to collisions
   and dropped packets.  In particular, in dense deployments of routers
   running NHDP (i.e., where each router has many neighbors), a change
   of the local topology may trigger many notifications at the same
   time.  [RFC4750] recommends "7 traps with a window time of 10
   seconds" as the upper bound.  As NHDP is expected to be deployed in
   more lossy channels than OSPF, it is RECOMMENDED to choose a lower
   threshold for the number of notifications per time than that.
   Specifically, it is RECOMMENDED that the threshold value for the
   objects reflecting the change be set to a value of '10' and the
   DEFAULT values for these objects within the Notifications Group be
   set to this value.  Further, a time window for the change objects is
   defined within this MIB module.  If the number of occurrences exceeds
   the change threshold within the previous change window, then it is
   RECOMMENDED that the notification be sent.  Furthermore, it is
   RECOMMENDED that the value for this window be set to at least 5 times
   the nhdpHelloInterval.

   The following objects are used to define the thresholds and time
   windows for specific notifications defined in the NHDP-MIB module:
   nhdpNbrStateChangeThreshold, nhdpNbrStateChangeWindow,
   nhdp2HopNbrStateChangeThreshold, and nhdp2HopNbrStateChangeWindow.

Top      ToC       Page 7 
5.1.3.3.  One Notification per Event

   Similar to the mechanism in [RFC4750], only one notification is sent
   per event.

5.2.  The Configuration Group

   The router running NHDP is configured with a set of controls.  The
   authoritative list of configuration controls within the NHDP-MIB
   module are found within the MIB module itself.  Generally, an attempt
   was made in developing the NHDP-MIB module to support all
   configuration objects defined in [RFC6130].  For all of the
   configuration parameters, the same constraints and default values of
   these parameters as defined in [RFC6130] are followed.  Refer to
   [RFC5148] for guidance on setting jitter-related parameters, e.g.,
   nhdpMaxJitter.

5.3.  The State Group

   The State Group reports current state information of a router running
   NHDP.  The NHDP-MIB State Group tables were designed to contain the
   complete set of state information defined within the information
   bases specified in Sections 6, 7, and 8 of [RFC6130].

   Two constructs, i.e., TEXTUAL-CONVENTIONs, are defined to support the
   tables in the State Group.  NHDP stores and indexes information
   through sets of (dynamically defined) addresses, i.e., address sets.
   Within SMIv2, it is not possible to index tables with variably
   defined address sets.  Hence, these TEXTUAL-CONVENTIONs are defined
   to provide a local mapping between NHDP-managed address sets and
   SMIv2 table indexing.  These constructs are the NeighborIfIndex and
   NeighborRouterIndex.  These are locally (to the router) defined,
   unique identifiers of virtual neighbors and neighbor interfaces.  Due
   to the nature of NHDP, the local router may have identified distinct
   address sets but is not able to associate these as a single
   interface.  Hence, two or more NeighborIfIndexes pointing to multiple
   distinct address sets may, in fact, be related to a common neighbor
   interface.  This ambiguity may also hold with respect to the
   assignment of the NeighborRouterIndex.  The local MIB agent is
   responsible for managing, aggregating, and retiring the defined
   indexes and for updating MIB tables using these indexes as the local
   router learns more about its neighbors' topologies.  These constructs
   are used to define indexes to the appropriate State Group tables and
   to correlate table entries to address sets, virtual neighbor
   interfaces, and virtual neighbors within the MANET.

Top      ToC       Page 8 
5.4.  The Performance Group

   The Performance Group reports values relevant to system performance.
   Unstable neighbors or 2-hop neighbors and frequent changes of sets
   can have a negative influence on the performance of NHDP.  This MIB
   module defines several objects that can be polled in order to, e.g.,
   calculate histories or monitor frequencies of changes.  This may help
   an observer determining unusual topology changes or other changes
   that affect stability and reliability of the MANET.

5.5.  Tables and Indexing

   The NHDP-MIB module contains a number of tables that record data
   related to:

   o  the local router,

   o  a local MANET interface on the router,

   o  other routers that are one hop removed from the local router,

   o  interfaces on other routers that are one hop removed from the
      local router, and

   o  other routers that are two hops removed from the local router.

   The NHDP-MIB module's tables are indexed via the following
   constructs:

   o  nhdpIfIndex - the IfIndex of the local router on which NHDP is
      configured.

   o  nhdpDiscIfIndex - a locally managed index representing a known
      interface on a neighboring router.

   o  nhdpDiscRouterIndex - a locally managed index representing an ID
      of a known neighboring router.

   These tables and their indexing are:

   o  nhdpInterfaceTable - describes the configuration of the interfaces
      of this router.  This table has INDEX { nhdpIfIndex }.

   o  nhdpLibLocalIfSetTable - records all network addresses that are
      defined as local interface network addresses on this router.  This
      table has INDEX { nhdpLibLocalIfSetIndex }.

Top      ToC       Page 9 
   o  nhdpLibRemovedIfAddrSetTable - records network addresses that were
      recently used as local interface network addresses on this router
      but have been removed.  This table has INDEX
      { nhdpLibRemovedIfAddrSetIndex }.

   o  nhdpInterfaceStateTable - records state information related to
      specific interfaces of this router.  This table has INDEX
      { nhdpIfIndex }.

   o  nhdpDiscIfSetTable - includes the nhdpDiscRouterIndex of the
      discovered router, the nhdpDiscIfIndex of the discovered
      interface, and the current set of addresses associated with this
      neighbor interface.  This table has INDEX { nhdpDiscIfSetIndex }.

   o  nhdpIibLinkSetTable - for each local interface, records all links
      belonging to other routers that are, or recently were, 1-hop
      neighbors to this router.  This table has INDEX { nhdpIfIndex,
      nhdpDiscIfIndex }.

   o  nhdpIib2HopSetTable - for each local interface, records network
      addresses (one at a time) of symmetric 2-hop neighbors and the
      symmetric links to symmetric 1-hop neighbors of this router
      through which these symmetric 2-hop neighbors can be reached.
      This table has INDEX { nhdpIfIndex, nhdpDiscIfIndex,
      nhdpIib2HopSetIpAddressType, nhdpIib2HopSetIpAddress }.

   o  nhdpNibNeighborSetTable - records all network addresses of each
      1-hop neighbor to this router.  This table has INDEX
      { nhdpDiscRouterIndex }.

   o  nhdpNibLostNeighborSetTable - records network addresses of other
      routers that were recently symmetric 1-hop neighbors to this
      router but are now advertised as lost.  This table has INDEX
      { nhdpDiscRouterIndex }.

   o  nhdpInterfacePerfTable - records performance objects that are
      measured for each local NHDP interface on this router.  This table
      has INDEX { nhdpIfIndex }.

   o  nhdpDiscIfSetPerfTable - records performance objects that are
      measured for each discovered interface of a neighbor of this
      router.  This table has INDEX { nhdpDiscIfIndex }.

   o  nhdpDiscNeighborSetPerfTable - records performance objects that
      are measured for discovered neighbors of this router.  This table
      has INDEX { nhdpDiscRouterIndex }.

Top      ToC       Page 10 
   o  nhdpIib2HopSetPerfTable - records performance objects that are
      measured for discovered 2-hop neighbors of this router.  This
      table has INDEX { nhdpDiscRouterIndex }.

6.  Relationship to Other MIB Modules

   This section specifies the relationship of the MIB module contained
   in this document to other standards, particularly to standards
   containing other MIB modules.  MIB modules and specific definitions
   imported from MIB modules that SHOULD be implemented in conjunction
   with the MIB module contained within this document are identified in
   this section.

6.1.  Relationship to the SNMPv2-MIB

   The System Group in the SNMPv2-MIB module [RFC3418] is defined as
   being mandatory for all systems, and the objects apply to the entity
   as a whole.  The System Group provides identification of the
   management entity and certain other system-wide data.  The NHDP-MIB
   module does not duplicate those objects.

6.2.  Relationship to Routing Protocol MIB Modules Relying on the NHDP-
      MIB Module

   [RFC6130] allows routing protocols to rely on the neighborhood
   information that is discovered by means of HELLO message exchange.
   In order to allow for troubleshooting, fault isolation, and
   management of such routing protocols through a routing protocol MIB
   module, it may be desired to align the State Group tables of the
   NHDP-MIB module and the routing protocol MIB module.  This is
   accomplished through the definition of two TEXTUAL-CONVENTIONs in the
   NHDP-MIB module: the NeighborIfIndex and the NeighborRouterIndex.
   These object types are used to develop indexes into common NHDP-MIB
   module and routing protocol State Group tables.  These objects are
   locally significant but should be locally common to the NHDP-MIB
   module and the routing protocol MIB module implemented on a common
   networked router.  This will allow for improved cross-referencing of
   information across the two MIB modules.

6.3.  Relationship to the If-MIB

   The nhdpInterfaceTable in this MIB module describes the configuration
   of the interfaces of this router that are intended to use MANET
   control protocols.  As such, this table 'sparse augments' the
   ifTable [RFC2863] specifically when NHDP is to be configured to
   operate over this interface.  The interface is identified by the
   ifIndex from the Interfaces Group defined in the Interfaces Group MIB
   module [RFC2863].

Top      ToC       Page 11 
   A conceptual row in the nhdpInterfaceTable exists if and only if
   either the row has been administratively created or there is an
   interface on the managed device that supports and runs NHDP.  This
   implies that for each entry in the nhdpInterfaceTable, there is a
   corresponding entry in the Interface Table where nhdpIfIndex and
   ifIndex are equal.  If that corresponding entry in the Interface
   Table is deleted, then the entry in nhdpInterfaceTable is
   automatically deleted, NHDP is disabled on this interface, and all
   configuration and state information related to this interface is to
   be removed from memory.

6.4.  MIB Modules Required for IMPORTS

   The following NHDP-MIB module IMPORTS objects from SNMPv2-SMI
   [RFC2578], SNMPv2-TC [RFC2579], SNMPv2-CONF [RFC2580], IF-MIB
   [RFC2863], SNMP-FRAMEWORK-MIB [RFC3411], INET-ADDRESS-MIB [RFC4001],
   and FLOAT-TC-MIB [RFC6340].



(page 11 continued on part 2)

Next Section