IS-IS Working Group                                               F. Wei
Internet-Draft                                                    Y. Qin
Updates: 5301, 5304, 5301 5304 5310                                            Z. Li
(if approved)                                               China Mobile
Intended status: Standards Track                                   T. Li
Expires: December 17, 2010 March 5, 2011                               Cisco Systems, Inc.
                                                                 J. Dong
                                                     Huawei Technologies
                                                           June 15,
                                                       September 1, 2010

             Purge Originator Identification TLV for IS-IS


   At present an IS-IS purge does not contain any information
   identifying the Intermediate System (IS) that generates the purge.
   This makes it difficult to locate the source IS.

   To address this issue, this document defines a TLV to be added to
   purges to record the system ID of the IS generating it.  Since normal
   LSP flooding does not change LSP contents, this TLV should propagate
   with the purge.

Status of this Memo

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

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   This Internet-Draft will expire on December 17, 2010. March 5, 2011.

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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . . . 3
   3.  The Purge Originator Identification (POI) TLV . . . . . . . . . . . . 3
   4.  Using the Dynamic Hostname TLV in Purges  . . . . . . . . . . . 4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   6.  Functional Changes  . . . . . . . . . . . . . . . . . . . . . . 4
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
   8. 4
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5
   8.  Normative References  . . . . . . . . . . . . . . . . . . . . . 5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 6 5

1.  Introduction

   The IS-IS [ISO 10589] routing protocol has been widely used in large-
   scale IP networks because of its strong scalability and fast

   The IS-IS protocol floods purges throughout an area, regardless of
   which IS initiated the purge.  If a network operator would like to
   investigate the cause of the purge, it is difficult to determine the
   origin of the purge.  At present the IS-IS protocol has no mechanism
   to locate the originator of a purge.  To address this problem, this
   document defines a TLV to be added to purges to record the system ID
   of the IS generating the purge.

   Field experience has observed several circumstances where an IS can
   improperly generate a purge.  These are all due to implementation
   deficiencies or implementations that predate [ISO TC1] and generate a
   purge when they receive a corrupted LSP.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

3.  The Purge Originator Identification (POI) TLV

   This document defines a TLV to be included in purges.  If an IS
   generates a purge, it SHOULD include this TLV in the purge with its
   own system ID.  If an IS receives a purge that does not include this
   TLV, then it SHOULD add this TLV with both its own system ID and the
   system ID of the IS that it received the purge from.  This allows ISs
   receiving purges to log the system ID of the originator, or the
   upstream source of the purge.  This makes it much easier for the
   network administrator to locate the origin of the purge and thus the
   cause of the purge.  Similarly, this TLV is helpful to developers in
   lab situations.

   The Purge Originator Identification POI TLV is defined as:

   CODE - 13

   LENGTH - total length of the value field.

   VALUE -
      Number of system IDs carried in this TLV (1 octet) -- Only the
      values 1 and 2 are defined.

      System ID of the Intermediate System that inserted this TLV.

      System ID of the Intermediate System that the purge was received
      from. (optional)

   The POI TLV SHOULD be found in all purges and MUST NOT be found in
   LSPs with a non-zero Remaining Lifetime.

4.  Using the Dynamic Hostname TLV in Purges

   This document also extends the use of the Dynamic hostname TLV (type
   137) [RFC5301].  This TLV MAY also be included in purges.  This will [RFC5301] to further aid in the rapid identification of the
   system that generated the purge.  This TLV MAY be included in purges.
   Implementations SHOULD include the Purge Originator Identification
   TLV in addition to the Dynamic hostname TLV.

5.  Security Considerations

   If the Purge Originator Identification TLV or if the Dynamic hostname POI
   TLV is used in conjunction with IS-IS authentication mechanisms
   [RFC5304][RFC5310], the purge LSP is constructed or modified as
   follows.  First, the original contents included.

5.  Security Considerations

   Use of the LSP are removed,
   leaving only the LSP header, then the Purge Originator Identification
   TLV and/or the Dynamic hostname TLV are added, and then the IS-IS extensions defined here with authentication TLV is added.

   Legacy systems that implement as defined in
   [RFC5304] or [RFC5310] MUST discard will result in the discarding of purges by
   legacy systems which are in strict conformance with these additional TLVs. either of those
   RFCs.  This is not thought to be a
   significant operational issue as may compromise the loss correctness/consistency of purges is typically not

6.  Functional Changes

   This document amends the behavior specified in [RFC5301], [RFC5304]
   and [RFC5310]. routing
   database unless all ISs that receive purges with the Purge Originator
   Identification TLV or in the Dynamic hostname TLV with valid network support these extensions.  NEW
   TEXT: Therefore, all implementations in a domain implementing
   authentication MUST NOT discard the PDU and SHOULD process it
   normally.  The Purge Originator Identification TLV or Dynamic
   hostname TLV MUST NOT be removed from upgraded to receive the purge prior POI TLV before any IS
   is allowed to propagation.
   If multiple purges are received for generate a purge with the same LSP fragment, then POI TLV.

   More interactions between the
   implementation MAY propagate any one of POI TLV, the purges.

7. Dynamic hostname TLV, and
   the Authentication TLV are described in [].

6.  IANA Considerations

   RFC EDITOR NOTE: This section to be removed upon publication.

   This document requests that IANA assign a code point 13 for this the 'Purge
   Originator Identification' TLV from the IS-IS 'TLV Codepoints

8.  The additional values for this TLV should be: IIH:n,
   LSP:y, SNP:n, Purge:y.

7.  Acknowledgments

   Many thanks to Adrian Farrel and Daniel King for your comments to
   improve this document and move it forward.

   The first version of this document was mainly composed by Lianyuan

   Acknowledgments to the discussion in the mailing list.  Some
   improvements of this document are based on the discussion.


8.  Normative References

              Li, T., "IS-IS Registry Extension for Purges",
              draft-li-reg-purge-00 (work in progress), August 2010.

   [ISO 10589]
              ISO, "Intermediate system to Intermediate system routeing
              information exchange protocol for use in conjunction with
              the Protocol for providing the Connectionless-mode Network
              Service (ISO 8473)", ISO/IEC 10589:2002.

   [ISO TC1]  ISO, "Intermediate system to Intermediate system intra-
              domain routeing information exchange protocol for use in
              conjunction with the protocol for providing the
              connectionless-mode Network Service (ISO 8473) --
              Technical Corrigendum 1", ISO/IEC 10589:1992/ Cor.1:1993.

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

   [RFC5301]  McPherson, D. and N. Shen, "Dynamic Hostname Exchange
              Mechanism for IS-IS", RFC 5301, October 2008.

   [RFC5304]  Li, T. and R. Atkinson, "IS-IS Cryptographic
              Authentication", RFC 5304, October 2008.

   [RFC5310]  Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
              and M. Fanto, "IS-IS Generic Cryptographic
              Authentication", RFC 5310, February 2009.

Authors' Addresses

   Fang Wei
   China Mobile
   No. 29, Financial Street, Xicheng District
   Beijing  100032
   P.R. China


   Yue Qin
   China Mobile
   No. 29, Financial Street, Xicheng District
   Beijing  100032
   P.R. China


   Zhenqiang Li
   China Mobile
   Unit2, Dacheng Plaza, No. 28 Xuanwumenxi Ave, Xuanwu District
   Beijing  100053
   P.R. China


   Tony Li
   Cisco Systems, Inc.
   170 W. Tasman Dr.
   San Jose, CA  95134


   Jie Dong
   Huawei Technologies
   KuiKe Building, No.9 Xinxi Rd., Haidian District
   Beijing  100085
   P.R. China