Network Working Group                                    Donald Eastlake
INTERNET-DRAFT                                                Weiguo Hao
Intended status: Proposed Standard                                Huawei
Expires: April 11, 2014                                 October 12, 2013



                  TRILL: Nickname and Label Properties
             <draft-eastlake-trill-nick-label-prop-02.txt>


Abstract

   There are a number of current and prospective requirements to
   indicate properties of nicknames, labels, and blocks thereof, for use
   with the TRILL (Transparent Interconnection of Lots of Links, RFC
   6325) protocol. To meet that need, this document specifies IS-IS
   (Intermediate System to Intermediate System) sub-TLVs and some of
   their uses.



Status of This Memo

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

   Distribution of this document is unlimited. Comments should be sent
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Donald Eastlake and Weiguo Hao                                  [Page 1]


INTERNET-DRAFT                                     Nick/Label Properties


Table of Contents

      1. Introduction............................................3
      1.1 Conventions Used in This Document......................3

      2. The Nickname Properties Sub-TLV.........................4

      3. The Label Properties Sub-TLV............................7

      4. IANA Considerations.....................................9

      5. Security Considerations.................................9

      6. Normative References...................................10

      7. Informative References.................................10

      Acknowledgements..........................................11

      Authors' Addresses........................................12
































Donald Eastlake and Weiguo Hao                                  [Page 2]


INTERNET-DRAFT                                     Nick/Label Properties


1. Introduction

   There are a number of current and prospective requirements to
   indicate properties of Nicknames, data Labels, and blocks thereof,
   for use with the TRILL (Transparent Interconnection of Lots of Links
   [RFC6325]) protocol. To meet that need, this document specifies two
   IS-IS (Intermediate System to Intermediate System [ISO-10589]
   [RFC1195]) sub-TLVs and some of their uses.

   These sub-TLVs are used to flag properties of Nicknames and data
   Labels. Provision is made for flags associated with

      o  individual Nicknames,
      o  blocks of Nicknames,
      o  individual Labels, and
      o  blocks of Labels.

   In addition, different sizes of Nicknames and data Labels can be
   accommodated.

   The sub-TLVs specified in this document are used as follows:

   o  They appear only in the IS-IS Router Capability and MT-Capability
      TLVs, which are TLVs number 242 and 144 and are specified in
      [RFC4971] and [RFC6329] respectively.

   o  They can appear multiple times in the same or different Capability
      or MT-Capability TLVs.



1.1 Conventions Used in This Document

   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 [RFC2119].
















Donald Eastlake and Weiguo Hao                                  [Page 3]


INTERNET-DRAFT                                     Nick/Label Properties


2. The Nickname Properties Sub-TLV

   The structure of the Nickname properties (NICK-PROP) sub-TLV is as
   shown below.

         +-+-+-+-+-+-+-+-+
         | Type = TBD    |                (1 byte)
         +-+-+-+-+-+-+-+-+
         | Length        |                (1 byte)
         +-+-+-+-+-+-+-+-+-+-+-+-+...
         | NICK-PROP RECORD 1             (variable)
         +-+-+-+-+-+-+-+-+-+-+-+...
         | NICK-PROP RECORD 2             (variable)
         +-+-+-+-+-+-+-+-+-+-+-+...
         | ...
         +-+-+-+-+-+-+-+-+-+-+-+...
         | NICK-PROP RECORD K
         +-+-+-+-+-+-+-+-+-+-+-+...

                  Figure 1. The Nickname Properties Sub-TLV


   o  Type: NICK-PROP Sub-TLV type, set to TBD.

   o  Length: Variable.

   o  NICK-PROP RECORD: Variable length record as described below.

   Each NICK-PROP RECORD is structured as follows.

         0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
       |NB|  NKSZ  |IN|OK|     RESV                    |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
       | Nickname Information          (variable)
       +-+-+-+-+-+-+-+-+-+-+-+...

   NB: If the NB (Nickname Block) flag is zero, the Nickname Information
       is a single Nickname. If the NB flag is one, the Nickname
       Information consists of an initial and final Nickname that are
       treated as unsigned integers and specify a block of Nicknames
       inclusively.

   NKSZ: The NKSZ field specifies the size of each of the one or two
       Nickname values (see NB bit) that occur in the Nickname
       Information

       The assigned value of NKSZ is as follows:




Donald Eastlake and Weiguo Hao                                  [Page 4]


INTERNET-DRAFT                                     Nick/Label Properties


           NKSZ
           ----
              0    16-bit Nicknames
            1-7    Available for assignment

   IN: The IN flag is ignored unless the NB flag is zero and the
       Nickname Information is a Nickname owned by the RBridge
       advertising the enclosing NICK-PROP sub-TLV. When it is not being
       ignored and is equal to one, the IN flag indicates that the
       Nickname may be used by the advertising RBridge as the ingress
       Nickname for TRILL Data frames it creates.

       TRILL switches may have multiple Nicknames [RFC6325] but there is
       no reason within the TRILL protocol for a TRILL switch to use
       more than one Nickname as the ingress Nickname for TRILL Data
       frames it creates. If a TRILL switch is not using all the
       Nicknames it holds as ingress Nicknames, it SHOULD use the NICK-
       PROP sub-TLV to indicate the Nickname (or Nicknames) it is using
       as ingress. This reduces the amount of Reverse Path Forwarding
       Check (RPFC) state in the campus.  The amount of such state at
       each TRILL switch port is roughly proportional to the product the
       number of ingress Nicknames in use and the number of multi-
       destination distribution trees in use. If a TRILL switch does not
       avertise any ingress Nickname or Nicknames using the IN flag, it
       may use any Nickname it hold as an ingress Nickname.

   OK: The OK flag is only effective if the NB flag is one and the NICK-
       PROP sub-TLV is advertised by the TRILL switch that is highest
       priority to be a tree root. TRILL switches that understand the OK
       flag and see one or more OK flags that are effective and are set
       to one dynamically select their Nickname as specified in
       [RFC6325] and [clearcorrect] except that they do so only from the
       block or blocks of nicknames advertised by NICK-PROP sub-TLV
       NICK-PROP RECORDS with an effective OK flag set to one. Such
       blocks are called the OK Nicknames blocks and a Nickname that is
       included in them is called an OK Nickname. If any Nickname value
       in the range from 0xFFC0 through 0xFFFF or equal to 0x0000 is
       advertised as part of an OK Nickname block they are ignored. For
       example, if 0xE000 through 0xFFFF was advertised as an OK
       Nickname block, it would be treated as if 0xE000 through 0xFFBF
       was advertised.

       If the OK Nickname blocks change such that any TRILL switch is
       holding a Nickname that is no longer OK, that TRILL switch MUST
       allocate a new OK Nickname. To maximize network stability, all
       TRILL switches that might become highest priority tree root
       SHOULD advertise the same OK Nickname blocks.

       Intended uses of this flag are to restrict Nicknames within part
       of a network so as to support some methods to implement


Donald Eastlake and Weiguo Hao                                  [Page 5]


INTERNET-DRAFT                                     Nick/Label Properties


       [multilevel] or [multidatacenter] TRILL.

   RESV: The remaining 10 bits are reserved and MUST be set to zero and
       ignored on receipt.

       Nickname Information: If NB is zero, this information consists of
       a single Nickname. If NB is one, this information consists of an
       initial and final Nickname and represents a block of Nicknames.
       The Nicknames are treated as unsigned integers in network byte
       order. If the final Nickname of a block is less than the initial
       Nickname, the NICK-PROP RECORD is ignored. If the initial and
       final Nicknames are equal, then a block of size one is indicated.
       Otherwise a block of Nickname values with a size greater than one
       is indicated, starting with initial Nickname through and
       including the final Nickname. If the size of each Nickname value
       is not a multiple of 8 bits, the Nickname values are padded with
       initial reserved bits up to the next multiple of 8. These
       reserved bits MUST be sent as zero and ignored on receipt.

   Each NICK-PROP RECORD must fit within the Length of the NICK-PROP
   sub-TLV. If there is a truncated NICK-PROP RECORD at the end of hte
   sub-TLV, that RECORD is ignored.

   For IANA Considerations in assigning values of NKSZ and bits in the
   RESV field, see Section 4.



























Donald Eastlake and Weiguo Hao                                  [Page 6]


INTERNET-DRAFT                                     Nick/Label Properties


3. The Label Properties Sub-TLV

   The structure of the Label properties (LABEL-PROP) sub-TLV is as
   shown below.

         +-+-+-+-+-+-+-+-+
         | Type = TBD    |                (1 byte)
         +-+-+-+-+-+-+-+-+
         | Length        |                (1 byte)
         +-+-+-+-+-+-+-+-+-+-+-+-+...
         | LABEL-PROP RECORD 1            (variable)
         +-+-+-+-+-+-+-+-+-+-+-+...
         | LABEL-PROP RECORD 2            (variable)
         +-+-+-+-+-+-+-+-+-+-+-+...
         | ...
         +-+-+-+-+-+-+-+-+-+-+-+...
         | LABEL-PROP RECORD K
         +-+-+-+-+-+-+-+-+-+-+-+...

                    Figure 2. The Label Properties Sub-TLV

   o  Type: LABEL-PROP Sub-TLV type, set to TBD.

   o  Length: Variable.

   o  LABEL-PROP RECORD: Variable length record as described below.

   Each LABEL-PROP RECORD is structured as follows.

         0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
       |LB|  LBSZ  | SCP |MG|   RESV                   |
       +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
       | Label Information             (variable)
       +-+-+-+-+-+-+-+-+-+-+-+...

   LB: If the LB (Label Block) flag is zero, the Label Information is a
       single Label. If the LB flag is one, the Label Information
       consists of an initial and final Label that are treated as
       unsigned integers and specify a block of Labels inclusively.

   LBSZ: The LBSZ field specifies the size and type of each of the one
       or two Label values (see LB bit) that occur in the Nickname
       Information

       The assigned values of LBSZ are as follows:






Donald Eastlake and Weiguo Hao                                  [Page 7]


INTERNET-DRAFT                                     Nick/Label Properties


           LBSZ
           ----
              0    12-bit VLAN ID
              1    24-bit FGL Label [FGL]
            2-7

   SCP: The SCP or Scope field only has an effect if it is non-zero and
       the LABEL-PROP sub-TLV is advertised by the TRILL switch that is
       highest priority to be a tree root. If indicates the scope of
       propagation of TRILL Data frames having the data label or any of
       the data labels in the block indicated by the PROPERTY RECORD.
       The following values for SCP are currently specified:

          SCP   Meaning
          ---   -------
            0   No scope specified
            1   Available for assignment
            2   Throughout a campus
            3   Local, within part of a campus [TreeDistr]

   MG: The MG bit is used to indicate the management Label. It is only
       effective if the LB flag is zero and the LABEL-PROP sub-TLV is
       advertised by the TRILL switch that is highest priority to be a
       tree root. All TRILL switches that understand this bit MUST
       indicate interest in the listed Label unless this bit is set for
       more than one Label, in which case only the lowest valued such
       Label will be considered the management Label. The failure of a
       TRILL switch to indicate interest in this label will be ignored
       and tree distribution of TRILL data frames with this label will
       not be pruned.

   RESV: The remaining 9 bits are reserved. See Section 4 for IANA
       Considerations.

   Label Information: If LB is zero, this information consists of a
       single Label. If LB is one, this information consists of an
       initial and final Label and represents a block of Labels. The
       Labels are treated as unsigned integers in network byte order. If
       the final Label for a block is less than the initial Label, the
       LABEL-PROP RECORD is ignored. If the initial and final Labels are
       equal, then a block of size one is indicated.  Otherwise a block
       of Label values with a size greater than one is indicated,
       starting with initial Label through and including the final
       Label. If the size of each Label value is not a multiple of 8
       bits, each Label value is padded with initial reserved bits up to
       the next multiple of 8. These reserved bits MUST be sent as zero
       and ignored on receipt. For example, 12-bit Labels are padded
       with four initial zeros.




Donald Eastlake and Weiguo Hao                                  [Page 8]


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4. IANA Considerations

   TBD



5. Security Considerations

   TBD

   For general TRILL security considerations, see [RFC6325].









































Donald Eastlake and Weiguo Hao                                  [Page 9]


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6. Normative References

   [ISO-10589] - ISO/IEC 10589:2002, Second Edition, "Intermediate
         System to Intermediate System Intra-Domain Routing Exchange
         Protocol for use in Conjunction with the Protocol for Providing
         the Connectionless-mode Network Service (ISO 8473)", 2002.

   [RFC1195] - Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and
         Dual Environments", 1990.

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

   [RFC4971] - Vasseur, JP., Ed., Shen, N., Ed., and R. Aggarwal, Ed.,
         "Intermediate System to Intermediate System (IS-IS) Extensions
         for Advertising Router Information", RFC 4971, July 2007

   [RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
         Ghanwani, "Routing Bridges (RBridges): Base Protocol
         Specification", RFC 6325, July 2011.

   [RFC6329] - Fedyk, D., Ed., Ashwood-Smith, P., Ed., Allan, D., Bragg,
         A., and P. Unbehagen, "IS-IS Extensions Supporting IEEE 802.1aq
         Shortest Path Bridging", RFC 6329, April 2012.

   [clearcorrect] - D. Eastlake, M. Zhang, A. Ghanwani, A. Banerjee, V.
         Manral, draft-ietf-trill-clear-correct-06.txt, in RFC Editor's
         queue.

   [FGL] - D. Eastlake, M. Zhang, P. Agarwal, R. Perlman, D. Dutt,
         "TRILL (Transparent Interconnection of Lots of Links): Fine-
         Grained Labeling", draft-ietf-trill-fine-labeling, in RFC
         Editor queue.

         [multilevel] - Perlman, R., D. Eastlake, A. Ghanwani, H. Zhai,
         "Multilevel TRILL (Transparent Interconnection of Lots of
         Links)", draft-perlman-trill-rbridge-multilevel, work in
         progress.




7. Informative References

   [TreeDistr] - draft-wu-trill-lsp-ext-tree-distr-opt, work in
         progress.






Donald Eastlake and Weiguo Hao                                 [Page 10]


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Acknowledgements

   The authors gratefully acknowledge the contributions and review by
   the following:

      tbd

   This document was produced with raw nroff. All macros used were
   defined in the source files.











































Donald Eastlake and Weiguo Hao                                 [Page 11]


INTERNET-DRAFT                                     Nick/Label Properties


Authors' Addresses

   Donald Eastlake
   Huawei R&D USA
   155 Beaver Street
   Milford, MA 01757 USA

   Phone: +1-508-333-2270
   Email: d3e3e3@gmail.com


   Weiguo Hao
   Huawei Technologies
   101 Software Avenue,
   Nanjing 210012, China

   Phone: +86-25-56623144
   Email: haoweiguo@huawei.com


































Donald Eastlake and Weiguo Hao                                 [Page 12]


INTERNET-DRAFT                                     Nick/Label Properties


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Donald Eastlake and Weiguo Hao                                 [Page 13]