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RFC 7188 - Optimized Link State Routing Protocol Version 2 (OLSR


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Internet Engineering Task Force (IETF)                       C. Dearlove
Request for Comments: 7188                               BAE Systems ATC
Updates: 6130, 7181                                           T. Clausen
Category: Standards Track                       LIX, Ecole Polytechnique
ISSN: 2070-1721                                               April 2014

      Optimized Link State Routing Protocol Version 2 (OLSRv2) and
      MANET Neighborhood Discovery Protocol (NHDP) Extension TLVs

Abstract

   This specification describes extensions to definitions of TLVs used
   by the Optimized Link State Routing Protocol version 2 (OLSRv2) and
   the MANET Neighborhood Discovery Protocol (NHDP) to increase their
   abilities to accommodate protocol extensions.  This document updates
   RFC 7181 (OLSRv2) and RFC 6130 (NHDP).

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 5741.

   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/rfc7188.

Copyright Notice

   Copyright (c) 2014 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
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Applicability Statement . . . . . . . . . . . . . . . . . . .   3
   4.  TLV Values  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Unrecognized TLV Values . . . . . . . . . . . . . . . . .   4
     4.2.  TLV Value Lengths . . . . . . . . . . . . . . . . . . . .   5
     4.3.  Undefined TLV Values  . . . . . . . . . . . . . . . . . .   5
       4.3.1.  NHDP TLVs: LOCAL_IF, LINK_STATUS, and OTHER_NEIGHB  .   6
       4.3.2.  OLSRv2 TLVs: MPR and NBR_ADDR_TYPE  . . . . . . . . .   6
       4.3.3.  Unspecified TLV Values  . . . . . . . . . . . . . . .   6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  LOCAL_IF Address Block TLVs . . . . . . . . . . . . . . .   7
       5.1.1.  New Registry  . . . . . . . . . . . . . . . . . . . .   7
       5.1.2.  Modification to Existing Registry . . . . . . . . . .   8
     5.2.  LINK_STATUS Address Block TLVs  . . . . . . . . . . . . .   8
       5.2.1.  New Registry  . . . . . . . . . . . . . . . . . . . .   8
       5.2.2.  Modification to Existing Registry . . . . . . . . . .   9
     5.3.  OTHER_NEIGHB Address Block TLVs . . . . . . . . . . . . .  10
       5.3.1.  Create New Registry . . . . . . . . . . . . . . . . .  10
       5.3.2.  Modification to Existing Registry . . . . . . . . . .  11
     5.4.  MPR Address Block TLVs  . . . . . . . . . . . . . . . . .  11
       5.4.1.  New Registry  . . . . . . . . . . . . . . . . . . . .  11
       5.4.2.  Modification to Existing Registry . . . . . . . . . .  12
     5.5.  NBR_ADDR_TYPE Address Block TLVs  . . . . . . . . . . . .  12
       5.5.1.  New Registry  . . . . . . . . . . . . . . . . . . . .  12
       5.5.2.  Modification to Existing Registry . . . . . . . . . .  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  15
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  15
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  15

1.  Introduction

   The MANET Neighborhood Discovery Protocol (NHDP) [RFC6130] and the
   Optimized Link State Routing Protocol version 2 (OLSRv2) [RFC7181]
   are protocols for use in Mobile Ad Hoc Networks (MANETs) [RFC2501],
   based on the Generalized MANET Packet/Message Format [RFC5444].

   This document updates [RFC6130] and [RFC7181], specifically their use
   of TLV (Type-Length-Value) elements, to increase the extensibility of
   these protocols and to enable some improvements in their
   implementation.

   This specification reduces the latitude of implementations of
   [RFC6130] and [RFC7181] to consider some messages, which will not be
   created by implementations simply following those specifications, as
   a reason to consider the message as "badly formed", and thus as a
   reason to reject the message.  This gives greater latitude to the
   creation of extensions of these protocols, in particular extensions
   that will interoperate with unextended implementations of those
   protocols.  As part of that, it indicates how TLVs with unexpected
   value fields must be handled, and adds some additional options to
   those TLVs.

   Note that TLVs with unknown type or type extension are already
   specified as to be ignored by [RFC6130] and [RFC7181] and also are
   not a reason to reject a message.

2.  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
   [RFC2119].

   Additionally, this document uses the terminology of [RFC5444],
   [RFC6130], and [RFC7181].

3.  Applicability Statement

   This document updates the specification of the protocols described in
   [RFC6130] and [RFC7181].

   Specifically, this specification updates [RFC6130] and [RFC7181] in
   the following ways:

   o  Removes the latitude of rejecting a message with a TLV with a
      known type, but with an unexpected TLV Value field, for the TLV
      Types defined in [RFC6130] and [RFC7181].

   o  Specifies the handling of a TLV Value field with unexpected
      length.

   o  Sets up IANA registries for TLV Values for the Address Block TLVs:

      *  LOCAL_IF, defined in [RFC6130].

      *  LINK_STATUS, defined in [RFC6130].

      *  OTHER_NEIGHB, defined in [RFC6130].

      *  MPR, defined in [RFC7181], now considered as a bit field.

      *  NBR_ADDR_TYPE, defined in [RFC7181], now considered as a bit
         field.

   o  Defines a well-known TLV Value for "UNSPECIFIED" for the Address
      Block TLV Types LOCAL_IF, LINK_STATUS, and OTHER_NEIGHB, all
      defined in [RFC6130].

4.  TLV Values

   NHDP [RFC6130] and OLSRv2 [RFC7181] define a number of TLVs within
   the framework of [RFC5444].  These TLVs define the meaning of only
   some of the contents that can be found in a TLV Value field.  This
   limitation may be either defining only certain TLV Values or
   considering only some lengths of the TLV Value fields (or a single-
   value field in a multivalue Address-Block TLV).  This specification
   describes how NHDP [RFC6130] and OLSRv2 [RFC7181] are to handle TLVs
   with other TLV Value fields.

4.1.  Unrecognized TLV Values

   NHDP and OLSRv2 specify that, in addition to well-defined reasons (in
   the respective protocol specifications), an implementation of these
   protocols MAY recognize a message as "badly formed" and therefore
   "invalid for processing" for other reasons (Section 12.1 of [RFC6130]
   and Section 16.3.1 of [RFC7181]).  These sections could be
   interpreted as allowing rejection of a message because a TLV Value
   field is unrecognized.  This specification removes that latitude:

   o  An implementation MUST NOT reject a message because it contains an
      unrecognized TLV value.  Instead, any unrecognized TLV Value field
      MUST be processed or ignored by an unextended implementation of
      NHDP or OLSRv2, as described in the following sections.

   o  Hence, this specification removes the 7th, 10th, and 11th bullets
      in Section 12.1 of [RFC6130].

   It should be stressed that this is not a change to [RFC6130] or
   [RFC7181], except with regard to not allowing this to be a reason for
   rejection of a message.  [RFC6130] or [RFC7181] are specified in
   terms such as "if an address is associated with a value of LOST by a
   LINK_STATUS TLV".  Association with an unrecognized value has no
   effect on any implementation strictly following such a specification.

4.2.  TLV Value Lengths

   The TLVs specified in [RFC6130] and [RFC7181] may be either single-
   value or multivalue TLVs.  In either case, the length of each item of
   information encoded in the TLV Value field is the "single-length",
   defined and calculated as in Section 5.4.1 of [RFC5444].  All TLVs
   specified in [RFC6130] and [RFC7181] have a one- or two-octet single-
   length.  These are considered the expected single-lengths of such a
   received TLV.

   Other single-length TLV Value fields may be introduced by extensions
   to [RFC6130] and [RFC7181].  This document specifies how
   implementations of [RFC6130] and [RFC7181], or extensions thereof,
   MUST behave on receiving TLVs of the TLV types defined in [RFC6130]
   and [RFC7181], but with TLV Value fields with other single-length
   values.

   The following principles apply:

   o  If the received single-length is greater than the expected single-
      length, then the excess octets MUST be ignored.

   o  If the received single-length is less than the expected single-
      length, then the absent octets MUST be considered to have all bits
      cleared (0).

   Exception:

   o  A received CONT_SEQ_NUM with a single-length < 2 SHOULD be
      considered an error.

4.3.  Undefined TLV Values

   [RFC6130] and [RFC7181] define a number of TLVs, but for some of
   these TLVs they specify meanings for only some TLV Values.  This
   document establishes IANA registries for these TLV Values, with
   initial registrations reflecting those used by [RFC6130] and
   [RFC7181], and as specified in Section 4.3.3.

   There are different cases of TLV Values with different
   characteristics.  These cases are considered in this section.

4.3.1.  NHDP TLVs: LOCAL_IF, LINK_STATUS, and OTHER_NEIGHB

   For the Address-Block TLVs LOCAL_IF, LINK_STATUS, and OTHER_NEIGHB
   TLVs, defined in [RFC6130], only a limited number of values are
   specified for each.  These are converted, by this specification, into
   extensible registries with initial registrations for values defined
   and used by [RFC6130] -- see Section 5.

   An implementation of [RFC6130] that receives a LOCAL_IF, LINK_STATUS,
   or OTHER_NEIGHB TLV with any TLV Value other than the values that are
   defined in [RFC6130] MUST ignore that TLV Value, as well as any
   corresponding attribute association to the address.

4.3.2.  OLSRv2 TLVs: MPR and NBR_ADDR_TYPE

   The Address-Block TLVs MPR and NBR_ADDR_TYPE, defined in [RFC7181],
   are similar to those defined in [RFC6130] in having only limited
   values specified (1, 2, and 3): 1 and 2 represent the presence of two
   different attributes associated to an address, and 3 represents "both
   1 and 2".

   These TLV Value fields are, by this specification, converted to bit
   fields and MUST be interpreted as such.  As the existing definitions
   of values 1, 2, and 3 behave in that manner, it is likely that this
   will involve no change to an implementation, but any test of (for
   example) Value = 1 or Value = 3 MUST be converted to a test of (for
   example) Value bitand 1 = 1, where "bitand" denotes a bitwise AND
   operation.

   This specification creates registries for recording reservations of
   the individual bits in these bit fields, with initial registrations
   for values defined and used by [RFC7181] -- see Section 5.

   Other TLVs defined by [RFC7181] are not affected by this
   specification.

4.3.3.  Unspecified TLV Values

   The registries defined in Section 5 for the LOCAL_IF, LINK_STATUS,
   and OTHER_NEIGHB TLVs each include an additional TLV Value
   UNSPECIFIED.  This TLV Value represents a defined value that, like
   currently undefined TLV Values, indicates that no information is
   associated with this address; the defined value will always have this
   meaning.  Such a TLV Value may be used to enable the creation of more
   efficient multivalue Address Block TLVs or to simplify an
   implementation.

   The similar requirement for the MPR and NBR_ADDR_TYPES TLVs is
   already satisfied by the TLV Value zero, provided that each bit in
   the TLV Value is defined as set ('1') when indicating the presence of
   an attribute, or clear ('0') when indicating the absence of an
   attribute.  Therefore, this is required for registrations from the
   relevant registries; see Section 5.

   For the LINK_METRIC TLV, this is already possible by clearing the
   most significant bits (0 to 3) of the first octet of the TLV Value.
   It is RECOMMENDED that in this case the remaining bits of the TLV
   Value are either all clear ('0') or all set ('1').

5.  IANA Considerations

   IANA has completed the ten actions set out in the following sections.

5.1.  LOCAL_IF Address Block TLVs

5.1.1.  New Registry

   IANA has created a new sub-registry called "LOCAL_IF TLV Values"
   within the "Mobile Ad hoc NETwork (MANET) Parameters" registry.

   IANA has populated this registry as specified in Table 1.

   +---------+-------------+-------------------------------+-----------+
   | Value   | Name        | Description                   | Reference |
   +---------+-------------+-------------------------------+-----------+
   | 0       | THIS_IF     | The network address is        | RFC 7188  |
   |         |             | associated with this local    |           |
   |         |             | interface of the sending      |           |
   |         |             | router                        |           |
   |         |             |                               |           |
   | 1       | OTHER_IF    | The network address is        | RFC 7188  |
   |         |             | associated with another local |           |
   |         |             | interface of the sending      |           |
   |         |             | router                        |           |
   |         |             |                               |           |
   | 2-223   |             | Unassigned                    |           |
   |         |             |                               |           |
   | 224-254 |             | Reserved for Experimental Use | RFC 7188  |
   |         |             |                               |           |
   | 255     | UNSPECIFIED | No information about this     | RFC 7188  |
   |         |             | network address is provided   |           |
   +---------+-------------+-------------------------------+-----------+

                       Table 1: LOCAL_IF TLV Values

   New assignments are to be made by Expert Review [RFC5226].

   The Designated Experts are required to use the guidelines specified
   in [RFC6130] and [RFC7181].

5.1.2.  Modification to Existing Registry

   IANA maintains a sub-registry called "LOCAL_IF Address Block TLV Type
   Extensions" within the "Mobile Ad hoc NETwork (MANET) Parameters"
   registry.  This sub-registry already had an entry for value 0.  IANA
   has replaced the entry in the Description column for this value with
   the text "This value is to be interpreted according to the registry
   LOCAL_IF TLV Values".  The resulting table is as specified in
   Table 2.

   +-----------+-----------------------------------------+-------------+
   | Type      | Description                             | Reference   |
   | Extension |                                         |             |
   +-----------+-----------------------------------------+-------------+
   | 0         | This value is to be interpreted         | RFC 6130,   |
   |           | according to the registry LOCAL_IF TLV  | RFC 7188    |
   |           | Values                                  |             |
   |           |                                         |             |
   | 1-255     | Unassigned                              |             |
   +-----------+-----------------------------------------+-------------+

     Table 2: LOCAL_IF Address Block TLV Type Extensions Modifications

5.2.  LINK_STATUS Address Block TLVs

5.2.1.  New Registry

   IANA has created a new sub-registry called "LINK_STATUS TLV Values"
   within the "Mobile Ad hoc NETwork (MANET) Parameters" registry.

   IANA has populated this registry as specified in Table 3.

   +---------+-------------+-------------------------------+-----------+
   | Value   | Name        | Description                   | Reference |
   +---------+-------------+-------------------------------+-----------+
   | 0       | LOST        | The link on this interface    | RFC 7188  |
   |         |             | from the router with that     |           |
   |         |             | network address has been lost |           |
   |         |             |                               |           |
   | 1       | SYMMETRIC   | The link on this interface    | RFC 7188  |
   |         |             | from the router with that     |           |
   |         |             | network address has the       |           |
   |         |             | status of symmetric           |           |
   |         |             |                               |           |
   | 2       | HEARD       | The link on this interface    | RFC 7188  |
   |         |             | from the router with that     |           |
   |         |             | network address has the       |           |
   |         |             | status of heard               |           |
   |         |             |                               |           |
   | 3-223   |             | Unassigned                    |           |
   |         |             |                               |           |
   | 224-254 |             | Reserved for Experimental Use | RFC 7188  |
   |         |             |                               |           |
   | 255     | UNSPECIFIED | No information about this     | RFC 7188  |
   |         |             | network address is provided   |           |
   +---------+-------------+-------------------------------+-----------+

                      Table 3: LINK_STATUS TLV Values

   New assignments are to be made by Expert Review [RFC5226].

   The Designated Experts are required to use the guidelines specified
   in [RFC6130] and [RFC7181].

5.2.2.  Modification to Existing Registry

   IANA maintains a sub-registry called "LINK_STATUS Address Block TLV
   Type Extensions" within the "Mobile Ad hoc NETwork (MANET)
   Parameters" registry.  This sub-registry already had an entry for
   value 0.  IANA has replaced the entry in the Description column for
   this value with the text "This value is to be interpreted according
   to the registry LINK_STATUS TLV Values".  The resulting table is as
   specified in Table 4.

   +-----------+------------------------------------------+------------+
   | Type      | Description                              | Reference  |
   | Extension |                                          |            |
   +-----------+------------------------------------------+------------+
   | 0         | This value is to be interpreted          | RFC 6130,  |
   |           | according to the registry LINK_STATUS    | RFC 7188   |
   |           | TLV Values                               |            |
   |           |                                          |            |
   | 1-255     | Unassigned                               |            |
   +-----------+------------------------------------------+------------+

   Table 4: LINK_STATUS Address Block TLV Type Extensions Modifications

5.3.  OTHER_NEIGHB Address Block TLVs

5.3.1.  Create New Registry

   IANA has created a new sub-registry called "OTHER_NEIGHB TLV Values"
   within the "Mobile Ad hoc NETwork (MANET) Parameters" registry.

   IANA has populated this registry as specified in Table 5.

   +---------+-------------+-------------------------------+-----------+
   | Value   | Name        | Description                   | Reference |
   +---------+-------------+-------------------------------+-----------+
   | 0       | LOST        | The neighbor relationship     | RFC 7188  |
   |         |             | with the router with that     |           |
   |         |             | network address has been lost |           |
   |         |             |                               |           |
   | 1       | SYMMETRIC   | The neighbor relationship     | RFC 7188  |
   |         |             | with the router with that     |           |
   |         |             | network address is symmetric  |           |
   |         |             |                               |           |
   | 2-223   |             | Unassigned                    |           |
   |         |             |                               |           |
   | 224-254 |             | Reserved for Experimental Use | RFC 7188  |
   |         |             |                               |           |
   | 255     | UNSPECIFIED | No information about this     | RFC 7188  |
   |         |             | network address is provided   |           |
   +---------+-------------+-------------------------------+-----------+

              Table 5: OTHER_NEIGHB Address Block TLV Values

   New assignments are to be made by Expert Review [RFC5226].

   The Designated Experts are required to use the guidelines specified
   in [RFC6130] and [RFC7181].

5.3.2.  Modification to Existing Registry

   IANA maintains a sub-registry called "OTHER_NEIGHB Address Block TLV
   Type Extensions" within the "Mobile Ad hoc NETwork (MANET)
   Parameters" registry.  This sub-registry already had an entry for
   value 0.  IANA has replaced the entry in the Description column for
   this value with the text "This value is to be interpreted according
   to the registry OTHER_NEIGHB TLV Values".  The resulting table is as
   specified in Table 6.

   +-----------+------------------------------------------+------------+
   | Type      | Description                              | Reference  |
   | Extension |                                          |            |
   +-----------+------------------------------------------+------------+
   | 0         | This value is to be interpreted          | RFC 6130,  |
   |           | according to the registry OTHER_NEIGHB   | RFC 7188   |
   |           | TLV Values                               |            |
   |           |                                          |            |
   | 1-255     | Unassigned                               |            |
   +-----------+------------------------------------------+------------+

   Table 6: OTHER_NEIGHB Address Block TLV Type Extensions Modifications

5.4.  MPR Address Block TLVs

5.4.1.  New Registry

   IANA has created a new sub-registry called "MPR TLV Bit Values"
   within the "Mobile Ad hoc NETwork (MANET) Parameters" registry.

   IANA has populated this registry as specified in Table 7.

   +-----+-------+----------+------------------------------+-----------+
   | Bit | Value | Name     | Description                  | Reference |
   +-----+-------+----------+------------------------------+-----------+
   | 7   | 0x01  | Flooding | The neighbor with that       | RFC 7188  |
   |     |       |          | network address has been     |           |
   |     |       |          | selected as flooding MPR     |           |
   |     |       |          |                              |           |
   | 6   | 0x02  | Routing  | The neighbor with that       | RFC 7188  |
   |     |       |          | network address has been     |           |
   |     |       |          | selected as routing MPR      |           |
   |     |       |          |                              |           |
   | 0-5 |       |          | Unassigned                   |           |
   +-----+-------+----------+------------------------------+-----------+

                 Table 7: MPR Address Block TLV Bit Values

   New assignments are to be made by Expert Review [RFC5226].

   The Designated Experts are required to use the guidelines specified
   in [RFC6130] and [RFC7181].  Additionally, the Designated Experts are
   required to ensure that the following sense is preserved:

   o  For each bit in the field, a set bit (1) means that the address
      has the designated property, while an unset bit (0) means that no
      information about the designated property is provided.  In
      particular, an unset bit must not be used to convey any specific
      information about the designated property.

5.4.2.  Modification to Existing Registry

   IANA maintains a sub-registry called "MPR Address Block TLV Type
   Extensions" within the "Mobile Ad hoc NETwork (MANET) Parameters"
   registry.  This sub-registry already had an entry for value 0.  IANA
   has replaced the entry in the Description column for this value with
   the text "This value is to be interpreted according to the registry
   MPR TLV Bit Values".  The resulting table is as specified in Table 8.

   +-----------+-----------------------------------------+-------------+
   | Type      | Description                             | Reference   |
   | Extension |                                         |             |
   +-----------+-----------------------------------------+-------------+
   | 0         | This value is to be interpreted         | RFC 7181,   |
   |           | according to the registry MPR TLV Bit   | RFC 7188    |
   |           | Values                                  |             |
   |           |                                         |             |
   | 1-255     | Unassigned                              |             |
   +-----------+-----------------------------------------+-------------+

       Table 8: MPR Address Block TLV Type Extensions Modifications

5.5.  NBR_ADDR_TYPE Address Block TLVs

5.5.1.  New Registry

   IANA has created a new sub-registry called "NBR_ADDR_TYPE Address
   Block TLV Bit Values" within the "Mobile Ad hoc NETwork (MANET)
   Parameters" registry.

   IANA has populated this registry as specified in Table 9.

   +-----+-------+------------+----------------------------+-----------+
   | Bit | Value | Name       | Description                | Reference |
   +-----+-------+------------+----------------------------+-----------+
   | 7   | 0x01  | ORIGINATOR | The network address is an  | RFC 7188  |
   |     |       |            | originator address         |           |
   |     |       |            | reachable via the          |           |
   |     |       |            | originating router         |           |
   |     |       |            |                            |           |
   | 6   | 0x02  | ROUTABLE   | The network address is a   | RFC 7188  |
   |     |       |            | routable address reachable |           |
   |     |       |            | via the originating router |           |
   |     |       |            |                            |           |
   | 0-5 |       |            | Unassigned                 |           |
   +-----+-------+------------+----------------------------+-----------+

            Table 9: NBR_ADDR_TYPE Address Block TLV Bit Values

   New assignments are to be made by Expert Review [RFC5226].

   The Designated Experts are required to use the guidelines specified
   in [RFC6130] and [RFC7181].  Additionally, the Designated Experts are
   required to ensure that the following sense is preserved:

   o  For each bit in the field, a set bit (1) means that the address
      has the designated property, while an unset bit (0) means that no
      information about the designated property is provided.  In
      particular, an unset bit must not be used to convey any specific
      information about the designated property.

5.5.2.  Modification to Existing Registry

   IANA maintains a sub-registry called "NBR_ADDR_TYPE Address Block TLV
   Type Extensions" within the "Mobile Ad hoc NETwork (MANET)
   Parameters" registry.  This sub-registry already had an entry for
   value 0.  IANA has replaced the entry in the Description column for
   this value with the text "This value is to be interpreted according
   to the registry NBR_ADDR_TYPE TLV Bit Values".  The resulting table
   is as specified in Table 10.

   +-----------+-------------------------------------------+-----------+
   | Type      | Description                               | Reference |
   | Extension |                                           |           |
   +-----------+-------------------------------------------+-----------+
   | 0         | This value is to be interpreted according | RFC 7181, |
   |           | to the registry NBR_ADDR_TYPE Address     | RFC 7188  |
   |           | Block TLV Bit Values                      |           |
   |           |                                           |           |
   | 1-255     | Unassigned                                |           |
   +-----------+-------------------------------------------+-----------+

         Table 10: NBR_ADDR_TYPE Address Block TLV Type Extensions
                               Modifications

6.  Security Considerations

   The updates made to [RFC6130] and [RFC7181] have the following
   implications on the security considerations:

   o  Created IANA registries for retaining TLV values for TLVs, already
      defined in the already published specifications of the two
      protocols, and with initial registrations for the TLV values
      defined by these specifications.  This does not give rise to any
      additional security considerations.

   o  Enabled protocol extensions for registering TLV values in the
      created IANA registries.  Such extensions MUST specify appropriate
      security considerations.

   o  Created, in some registries, a registration for "UNSPECIFIED"
      values for more efficient use of multivalue Address Block TLVs.
      The interpretation of an address being associated with a TLV of a
      given type and with the value "UNSPECIFIED" is identical to that
      address not being associated with a TLV of that type.  Thus, this
      update does not give rise to any additional security
      considerations.

   o  Reduced the latitude of implementations of the two protocols to
      reject a message as "badly formed" due to the value field of a TLV
      being unexpected.  These protocols are specified in terms such as
      "if an address is associated with a value of LOST by a LINK_STATUS
      TLV".  Association with an unknown value (or a value newly defined
      to mean no link status information) has no effect on such a
      specification.  Thus, this update does not give rise to any
      additional security considerations.

   o  Did not introduce any opportunities for attacks on the protocols
      through signal modification that are not already present in the
      two protocols.

7.  Acknowledgments

   The authors would like to gratefully acknowledge the following people
   for intense technical discussions, early reviews, and comments on the
   specification (listed alphabetically): Ulrich Herberg (Fujitsu
   Laboratories of America) and Henning Rogge (Frauenhofer FKIE).

   The authors would also like to express their gratitude to Adrian
   Farrel for his assistance and contributions to the successful and
   timely completion of this specification.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5444]  Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
              "Generalized MANET Packet/Message Format", RFC 5444,
              February 2009.

   [RFC6130]  Clausen, T., Dean, J., and C. Dearlove, "Mobile Ad Hoc
              Network (MANET) Neighborhood Discovery Protocol (NHDP)",
              RFC 6130, April 2011.

   [RFC7181]  Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
              "The Optimized Link State Routing Protocol Version 2", RFC
              7181, April 2014.

8.2.  Informative References

   [RFC2501]  Macker, J. and S. Corson, "Mobile Ad hoc Networking
              (MANET): Routing Protocol Performance Issues and
              Evaluation Considerations", RFC 2501, January 1999.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

Authors' Addresses

   Christopher Dearlove
   BAE Systems Advanced Technology Centre
   West Hanningfield Road
   Great Baddow, Chelmsford
   United Kingdom

   Phone: +44 1245 242194
   EMail: chris.dearlove@baesystems.com
   URI:   http://www.baesystems.com/

   Thomas Heide Clausen
   LIX, Ecole Polytechnique

   Phone: +33 6 6058 9349
   EMail: T.Clausen@computer.org
   URI:   http://www.ThomasClausen.org/

 

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