[Search] [txt|pdf|bibtex] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-acee-ospf-rfc4970bis)  00 01 02         Standards Track
          03 04 05 06 07 rfc7770                                        
Network Working Group                                     A. Lindem, Ed.
Internet-Draft                                                   N. Shen
Obsoletes: 4970 (if approved)                                 J. Vasseur
Intended status: Standards Track                           Cisco Systems
Expires: March 27, 2016                                      R. Aggarwal
                                                                  Arktan
                                                              S. Shaffer
                                                                  Akamai
                                                      September 24, 2015


    Extensions to OSPF for Advertising Optional Router Capabilities
                   draft-ietf-ospf-rfc4970bis-04.txt

Abstract

   It is useful for routers in an OSPFv2 or OSPFv3 routing domain to
   know the capabilities of their neighbors and other routers in the
   routing domain.  This document proposes extensions to OSPFv2 and
   OSPFv3 for advertising optional router capabilities.  The Router
   Information (RI) Link State Advertisement (LSA) is defined for this
   purpose.  In OSPFv2, the RI LSA will be implemented with an opaque
   LSA type ID.  In OSPFv3, the RI LSA will be implemented with a unique
   LSA type function code.  In both protocols, the RI LSA can be
   advertised at any of the defined flooding scopes (link, area, or
   autonomous system (AS)).  This document obsoletes RFC 4970 by
   providing a revised specification including support for advertisement
   of multiple instances of the RI LSA and a TLV for functional
   capabilities.

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 March 27, 2016.





Lindem, et al.           Expires March 27, 2016                 [Page 1]


Internet-Draft         OSPF Capability Extensions         September 2015


Copyright Notice

   Copyright (c) 2015 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Notation . . . . . . . . . . . . . . . . . .   3
     1.2.  Summary of Changes from RFC 4970  . . . . . . . . . . . .   3
   2.  OSPF Router Information (RI) LSA  . . . . . . . . . . . . . .   3
     2.1.  OSPFv2 Router Information (RI) Opaque LSA . . . . . . . .   4
     2.2.  OSPFv3 Router Information (RI) Opaque LSA . . . . . . . .   6
     2.3.  OSPF Router Informational Capabilities TLV  . . . . . . .   6
     2.4.  Assigned OSPF Router Informational Capability Bits  . . .   7
     2.5.  OSPF Router Functional Capabilities TLV . . . . . . . . .   8
     2.6.  Flooding Scope of the Router Information LSA  . . . . . .   9
   3.  Backward Compatibility  . . . . . . . . . . . . . . . . . . .  10
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Appendix A.  Acknowledgments  . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   It is useful for routers in an OSPFv2 [OSPF] or OSPFv3 [OSPFV3]
   routing domain to know the capabilities of their neighbors and other
   routers in the routing domain.  This can be useful for both the
   advertisement and discovery of OSPFv2 and OSPFv3 capabilities.
   Throughout this document, OSPF will be used when the specification is
   applicable to both OSPFv2 and OSPFv3.  Similarly, OSPFv2 or OSPFv3
   will be used when the text is protocol specific.

   OSPF uses the options field in LSAs and hello packets to advertise
   optional router capabilities.  In the case of OSPFv2, all the bits in



Lindem, et al.           Expires March 27, 2016                 [Page 2]


Internet-Draft         OSPF Capability Extensions         September 2015


   this field have been allocated so additional optional capabilities
   cannot be advertised.  This document describes extensions to OSPF to
   advertise these optional capabilities via opaque LSAs in OSPFv2 and
   LSAs with a unique type in OSPFv3.  For existing OSPF capabilities,
   backward-compatibility issues dictate that this advertisement is used
   primarily for informational purposes.  For future OSPF extensions,
   this advertisement MAY be used as the sole mechanism for
   advertisement and discovery.

   This document obsoletes RFC 4970 by providing a revised specification
   including support for advertisement of multiple instances of the RI
   LSA and a TLV for functional capabilities.

1.1.  Requirements Notation

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

1.2.  Summary of Changes from RFC 4970

   This document includes the following changes from RFC 4970 [RFC4970]:

   1.  The main change is that an OSPF router will be able to advertise
       multiple instances of the OSPF Router Information LSA.  This
       change permeates through much of the document

   2.  Additionally, Section 2.5 includes an additional TLV for
       functional capabilities.  This is in contrast to the existing TLV
       which is used to advertise capabilities for informational
       purposes only.

   3.  The IANA allocation policy for the OSPFv3 LSA Function Code
       registry and all the OSPF Router Information IANA registeries has
       been changed from "Standards Action" to "IETF Review"
       [IANA-GUIDE].

   4.  Finally, references have been updated for drafts that have become
       RFCs and RFCs that have been obsoleted since the publication of
       RFC 4970.

2.  OSPF Router Information (RI) LSA

   OSPFv2 routers will advertise a link scoped, area-scoped, or AS-
   scoped Opaque-LSA [OPAQUE].  The OSPFv2 Router Information (RI) LSA
   has an Opaque type of 4 and the Opaque ID is the RI LSA instance ID.
   The first Opaque ID, i.e., 0, SHOULD always contain the Router
   Informational Capabilities TLV and, if advertised, the Router



Lindem, et al.           Expires March 27, 2016                 [Page 3]


Internet-Draft         OSPF Capability Extensions         September 2015


   Functional Capabilities TLV.  RI LSAs subsequence to the first can be
   used for information that doesn't fit in the first instance.

2.1.  OSPFv2 Router Information (RI) Opaque LSA

   OSPFv2 routers will advertise a link scoped, area-scoped, or AS-
   scoped Opaque-LSA [OPAQUE].  The OSPFv2 Router Information LSA has an
   Opaque type of 4 and Opaque ID specifies the LSA instance ID with the
   first instance always having an Instance ID of 0.


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            LS age             |     Options   |  9, 10, or 11 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       4       |     Opaque ID (Instance ID)                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+d-+-+-+-+-+-+-+-+-+-+-+
      |                     Advertising Router                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     LS sequence number                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |         LS checksum           |             length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-                            TLVs                             -+
      |                             ...                               |


                   OSPFv2 Router Information Opaque LSA


   The format of the TLVs within the body of an RI LSA is the same as
   the format used by the Traffic Engineering Extensions to OSPF [TE].
   The LSA payload consists of one or more nested Type/Length/Value
   (TLV) triplets.  The format of each TLV is:


      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |              Type             |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                            Value...                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                                TLV Format



Lindem, et al.           Expires March 27, 2016                 [Page 4]


Internet-Draft         OSPF Capability Extensions         September 2015


   The Length field defines the length of the value portion in octets
   (thus a TLV with no value portion would have a length of 0).  The TLV
   is padded to 4-octet alignment; padding is not included in the length
   field (so a 3-octet value would have a length of 3, but the total
   size of the TLV would be 8 octets).  Nested TLVs are also 32-bit
   aligned.  For example, a 1-byte value would have the length field set
   to 1, and 3 octets of padding would be added to the end of the value
   portion of the TLV.  The padding is composed of zeros.  Unrecognized
   types are ignored.










































Lindem, et al.           Expires March 27, 2016                 [Page 5]


Internet-Draft         OSPF Capability Extensions         September 2015


2.2.  OSPFv3 Router Information (RI) Opaque LSA

   The OSPFv3 Router Information LSA has a function code of 12 while the
   S1/S2 bits are dependent on the desired flooding scope for the LSA.
   The U bit will be set indicating that the OSPFv3 RI LSA should be
   flooded even if it is not understood.  The Link State ID (LSID) value
   for this LSA is the instance ID.  The first instance ID, i.e., 0,
   SHOULD always contain the Router Informational Capabilities TLV and,
   if advertised, the Router Functional Capabilities TLV.  OSPFv3 Router
   Information LSAs subsequence to the first can be used for information
   that doesn't fit in the first instance.  OSPFv3 routers MAY advertise
   multiple RI LSAs per flooding scope.


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            LS age             |1|S12|          12             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Link State ID (Instance ID)             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Advertising Router                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       LS sequence number                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        LS checksum           |             Length             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-                            TLVs                             -+
      |                             ...                               |


                       OSPFv3 Router Information LSA

   The format of the TLVs within the body of an RI LSA is as defined in
   Section 2.1

   When a new Router Information LSA TLV is defined, the specification
   MUST explicitly state whether the TLV is applicable to OSPFv2 only,
   OSPFv3 only, or both OSPFv2 and OSPFv3.

2.3.  OSPF Router Informational Capabilities TLV

   An OSPF router advertising an OSPF RI LSA MAY include the Router
   Informational Capabilities TLV.  If included, it MUST be the first
   TLV in the first instance, i.e., instance 0, of the OSPF RI LSA.
   Additionally, the TLV MUST accurately reflect the OSPF router's
   capabilities in the scope advertised.  However, the informational



Lindem, et al.           Expires March 27, 2016                 [Page 6]


Internet-Draft         OSPF Capability Extensions         September 2015


   capabilities advertised have no impact on the OSPF's operation, they
   are advertised purely for informational purposes.

   The format of the Router Informational Capabilities TLV is as
   follows:


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Type             |             Length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Informational Capabilities                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      Type     A 16-bit field set to 1.

      Length   A 16-bit field that indicates the length of the value
               portion in octets and will be a multiple of 4 octets
               dependent on the number of capabilities advertised.
               Initially, the length will be 4, denoting 4 octets of
               informational capability bits.

      Value    A variable length sequence of capability bits rounded
               to a multiple of 4 octets padded with undefined bits.
               Initially, there are 4 octets of capability bits.  Bits
               are numbered left-to-right starting with the most
               significant bit being bit 0.


                OSPF Router Informational Capabilities TLV

   The Router Informational Capabilities TLV MAY be followed by optional
   TLVs that further specify a capability.

2.4.  Assigned OSPF Router Informational Capability Bits

   The following informational capability bits are assigned:












Lindem, et al.           Expires March 27, 2016                 [Page 7]


Internet-Draft         OSPF Capability Extensions         September 2015


      Bit       Capabilities

      0         OSPF graceful restart capable [GRACE]
      1         OSPF graceful restart helper  [GRACE]
      2         OSPF Stub Router support [STUB]
      3         OSPF Traffic Engineering support [TE]
      4         OSPF point-to-point over LAN [P2PLAN]
      5         OSPF Experimental TE [EXP-TE]
      6-31      Unassigned (IETF Review)

                OSPF Router Informational Capabilities Bits

   References for [GRACE], [STUB], [TE], [P2PLAN], and [EXP-TE] are
   included herein.

2.5.  OSPF Router Functional Capabilities TLV

   This specification also defines the Router Functional Capabilities
   TLV for advertisement within the OSPF Router Information LSA.  An
   OSPF router advertising an OSPF RI LSA MAY include the Router
   Functional Capabilities TLV.  If included, it MUST be the included in
   the first instance of the LSA.  Additionally, the TLV MUST be used to
   reflect OSPF router functional capabilities.  If the TLV is not
   included or the length doesn't include the assigned OSPF functional
   capability bit, the corresponding OSPF functional capability is
   implicitly advertised as not being supported by the advertising OSPF
   router.

   The format of the Router Functional Capabilities TLV is as follows:






















Lindem, et al.           Expires March 27, 2016                 [Page 8]


Internet-Draft         OSPF Capability Extensions         September 2015


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Type             |             Length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Functional Capabilities                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      Type     A 16-bit field set to IANA TBD (Suggested value 2).

      Length   A 16-bit field that indicates the length of the value
               portion in octets and will be a multiple of 4 octets
               dependent on the number of capabilities advertised.
               Initially, the length will be 4, denoting 4 octets of
               informational capability bits.

      Value    A variable length sequence of capability bits rounded
               to a multiple of 4 octets padded with undefined bits.
               Initially, there are 4 octets of capability bits.  Bits
               are numbered left-to-right starting with the most
               significant bit being bit 0.

                  OSPF Router Functional Capabilities TLV

   The Router Functional Capabilities TLV MAY be followed by optional
   TLVs that further specify a capability.  In contrast to the Router
   Informational Capabilities TLV, the OSPF extensions advertised in
   this TLV MAY be used by other OSPF routers to dictate protocol
   operation.  The specifications for functional capabilities advertised
   in this TLV MUST describe protocol behavior and address backward
   compatibility.

2.6.  Flooding Scope of the Router Information LSA

   The flooding scope for a Router Information LSA is determined by the
   LSA type.  For OSPFv2, type 9 (link-scoped), type 10 (area-scoped),
   or a type 11 (AS-scoped) opaque LSA may be flooded.  For OSPFv3, the
   S1 and S2 bits in the LSA type determine the flooding scope.  If AS-
   wide flooding scope is chosen, the originating router should also
   advertise area-scoped LSA(s) into any attached Not-So-Stubby Area
   (NSSA) area(s).  An OSPF router MAY advertise different capabilities
   when both NSSA area scoped LSA(s) and an AS-scoped LSA are
   advertised.  This allows functional capabilities to be limited in
   scope.  For example, a router may be an area border router but only
   support traffic engineering (TE) in a subset of its attached areas.





Lindem, et al.           Expires March 27, 2016                 [Page 9]


Internet-Draft         OSPF Capability Extensions         September 2015


   The choice of flooding scope is made by the advertising router and is
   a matter of local policy.  The originating router MAY advertise
   multiple RI LSAs with the same instance ID as long as the flooding
   scopes differ.  TLV flooding scope rules will be specified on a per-
   TLV basis and MUST be specified in the accompanying specifications
   for future Router Information LSA TLVs.

3.  Backward Compatibility

   For backward compatibility, previously advertised Router Information
   TLVs SHOULD continue to be advertised in the first instance, i.e., 0,
   of the Router Information LSA.  If a Router Information TLV is
   advertised in multiple Router Information LSA instances and the
   multiple instance processing is not explicitly specified in the RFC
   defining that Router Information TLV, the Router Instance TLV in the
   Router Information LSA with the numerically smallest Instance ID will
   be used and subsequent instances will be ignored.

4.  Security Considerations

   This document describes both a generic mechanism for advertising
   router capabilities and a TLV for advertising informational and
   functional capability bits.  The capability TLVs are less critical
   than the topology information currently advertised by the base OSPF
   protocol.  The security considerations for the generic mechanism are
   dependent on the future application and, as such, should be described
   as additional capabilities are proposed for advertisement.  Security
   considerations for the base OSPF protocol are covered in [OSPF] and
   [OSPFV3].

5.  IANA Considerations

   The following IANA assignment was made from an existing registry:

      The OSPFv2 opaque LSA type 4 has been reserved for the OSPFv2 RI
      opaque LSA.

   The following registries have been defined for the following
   purposes:

   1.  Registry for OSPFv3 LSA Function Codes - This top-level registry
       will be comprised of the fields Value, LSA function code name,
       and Document Reference.  The OSPFv3 LSA function code is defined
       in section A.4.2.1 of [OSPFV3].  The OSPFv3 LSA function code 12
       has been reserved for the OSPFv3 Router Information (RI) LSA.






Lindem, et al.           Expires March 27, 2016                [Page 10]


Internet-Draft         OSPF Capability Extensions         September 2015


                     +-----------+-------------------------------------+
                     | Range     | Assignment Policy                   |
                     +-----------+-------------------------------------+
                     | 0         | Reserved (not to be assigned)       |
                     |           |                                     |
                     | 1-11      | Already assigned                    |
                     |           |                                     |
                     | 12        | OSPFv3 RI LSA (Assigned herein)     |
                     |           |                                     |
                     | 13-15     | Already assigned                    |
                     |           |                                     |
                     | 16-255    | Unassigned (IETF Review)            |
                     |           |                                     |
                     | 256-8175  | Reserved (No assignments)           |
                     |           |                                     |
                     | 8176-8183 | Experimentation (No assignments)    |
                     |           |                                     |
                     | 8184-8190 | Vendor Private Use (No assignments) |
                     |           |                                     |
                     | 8191      | Reserved (not to be assigned)       |
                     +-----------+-------------------------------------+

                         OSPFv3 LSA Function Codes

       *  OSPFv3 LSA function codes in the range 16-255 are not be
          assigned subject to IETF Review.  New values are assigned only
          through RFCs that have been shepherded through the IESG as AD-
          Sponsored or IETF WG Documents [IANA-GUIDE].

       *  OSPFv3 LSA function codes in the range 8176-8181 are for
          experimental use; these will not be registered with IANA and
          MUST NOT be mentioned by RFCs.

       *  OSPFv3 LSAs with an LSA Function Code in the Vendor Private
          Use range 8184-8190 MUST include the Vendor Enterprise Code as
          the first 4 octets following the 20 octets of LSA header.

       *  If a new LSA Function Code is documented, the documentation
          MUST include the valid combinations of the U, S2, and S1 bits
          for the LSA.  It SHOULD also describe how the Link State ID is
          to be assigned.

       Changes to the OSPFv3 LSA Function Code registry from RFC 4970
       include changing the allocation policy for the range 16-255 from
       "Standard Action" to "IETF Review" and reservation of the
       maxiumum value (8191).





Lindem, et al.           Expires March 27, 2016                [Page 11]


Internet-Draft         OSPF Capability Extensions         September 2015


   2.  Registry for OSPF RI TLVs - This top-level registry will be
       comprised of the fields Value, TLV Name, and Document Reference.
       The value of 1 for the informational capabilities TLV is defined
       herein.  The value IANA TBD (suggested value 2) for the Router
       Functional Capabilities TLV is also defined herein.

                     +-------------+-----------------------------------+
                     | Range       | Assignment Policy                 |
                     +-------------+-----------------------------------+
                     | 0           | Reserved (not to be assigned)     |
                     |             |                                   |
                     | 1           | Informational Capabilities        |
                     |             |                                   |
                     | 2           | Unassigned (IETF Review)          |
                     |             |                                   |
                     | TBD         | Functional Capabilities           |
                     |             |                                   |
                     | 3-9         | Already Assigned                  |
                     |             |                                   |
                     | 10-32767    | Unassigned (IETF Review)          |
                     |             |                                   |
                     | 32768-32777 | Experimentation (No assignments)  |
                     |             |                                   |
                     | 32778-65535 | Reserved (Not to be assigned)     |
                     +-----------+-------------------------------------+

                               OSPF RI TLVs

       *  Types in the range 2, 10-32767 are to be assigned subject to
          IETF Review.  New values are assigned only through RFCs that
          have been shepherded through the IESG as AD-Sponsored or IETF
          WG Documents [IANA-GUIDE].

       *  Types in the range 32778-65535 are reserved and are not to be
          assigned at this time.  Before any assignments can be made in
          this range, there MUST be a Standards Track RFC that specifies
          IANA Considerations that covers the range being assigned.

       The only change to OSPF RI TLV registry from RFC 4970 is a change
       to the allocation policy for the range 10-32767 from "Standard
       Action" to "IETF Review".

   3.  Registry for OSPF Router Informational Capability Bits - This
       sub-registry of the OSPF RI TLV registry will be comprised of the
       fields Bit Number, Capability Name, and Document Reference.  The
       values are defined in Section 2.4.  All Router Informational
       Capability TLV additions are to be assigned through IETF Review.




Lindem, et al.           Expires March 27, 2016                [Page 12]


Internet-Draft         OSPF Capability Extensions         September 2015


       This is changed from RFC 4970 where the allocation policy was
       Standards Action.

   4.  Registry for OSPF Router Functional Capability Bits - This sub-
       registry of the OSPF RI TLV registry will be comprised of the
       fields Bit Number, Capability Name, and Document Reference.
       Initially, the sub-registry will be empty but will be available
       for future capabilities.  All Router Functional Capability TLV
       additions are to be assigned through IETF Review.  This is
       registery is added since RFC 4970 and will be added to the "OSPF
       Shortest Path First v2 (OSPFv2) Parameters" group.

6.  References

6.1.  Normative References

   [OPAQUE]   Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
              OSPF Opaque LSA Option", RFC 5250, July 2008.

   [OSPF]     Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.

   [OSPFV3]   Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
              for IPv6", RFC 5340, July 2008.

   [RFC-KEYWORDS]
              Bradner, S., "Key words for use in RFC's to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4970]  Lindem, A., Shen, N., Vasseur, J., Aggarwal, R., and S.
              Shaffer, "Extensions to OSPF for Advertising Optional
              Router Capabilities", RFC 4970, July 2007.

   [TE]       Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              Extensions to OSPF", RFC 3630, September 2003.

6.2.  Informative References

   [EXP-TE]   Srisuresh, P. and P. Joseph, "OSPF-xTE: Experimental
              Extension to OSPF for Traffic Engineering", RFC 4973, July
              2007.

   [GRACE]    Moy, J., Pillay-Esnault, P., and A. Lindem, "Graceful OSPF
              Restart", RFC 3623, November 2003.

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




Lindem, et al.           Expires March 27, 2016                [Page 13]


Internet-Draft         OSPF Capability Extensions         September 2015


   [P2PLAN]   Shen, N. and A. Zinin, "Point-to-point operation over LAN
              in link-state routing protocols", RFC 5309, October 2008.

   [STUB]     Retana, A., Nguyen, L., White, R., Zinin, A., and D.
              McPherson, "OSPF Stub Router Advertisement", RFC 6987,
              September 2013.

Appendix A.  Acknowledgments

   The idea for this work grew out of a conversation with Andrew Partan
   and we would like to thank him for his contribution.  The authors
   would like to thanks Peter Psenak for his review and helpful comments
   on early versions of the document.

   Comments from Abhay Roy, Vishwas Manral, Vivek Dubey, and Adrian
   Farrel have been incorporated into later versions.

   Thanks to Yingzhen Qu for acting as document shepherd.

   Thanks to Chris Bowers, Alia Atlas, Shraddha Hegde, and Tom Petch for
   review of the BIS version of this document.

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

Authors' Addresses

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

   Email: acee@cisco.com


   Naiming Shen
   Cisco Systems
   225 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: naiming@cisco.com









Lindem, et al.           Expires March 27, 2016                [Page 14]


Internet-Draft         OSPF Capability Extensions         September 2015


   Jean-Philippe Vasseur
   Cisco Systems
   1414 Massachusetts Avenue
   Boxborough, MA  01719
   USA

   Email: jpv@cisco.com


   Rahul Aggarwal
   Arktan

   Email: raggarwa_1@yahoo.com


   Scott Shaffer
   Akamai
   8 Cambridge Center
   Cambridge, MA  02142
   USA

   Email: sshaffer@akamai.com





























Lindem, et al.           Expires March 27, 2016                [Page 15]