Network working group                                          Q. Zeng
Internet Draft                                                 J. Dong
Intended status: Standards Track                   Huawei Technologies
Expires: April 2011                                           Z. Huang
                                                         China Telecom
                                                      October 22, 2010


       One-time Address-Prefix Based Outbound Route Filter for BGP-4

                   draft-zeng-one-time-prefix-orf-01.txt


Abstract

   This document defines a new Outbound Router Filter (ORF) type for
   BGP, termed "One-time Address Prefix Outbound Route Filter", which
   would allow a BGP speaker to send to its BGP peer a route refresh
   request with a set of address-prefix-based filters to make the peer
   re-advertise only the specific routes matching the filters to the
   speaker. This ORF-type enables a BGP speaker to recover some
   specific "problematic" routes without requiring its peer to re-
   advertise the whole Adj-RIB-Out of specific address family, which
   makes the trouble shooting operation (such as packets tracking) more
   efficient and reduces the impact on network stability. This filter
   does not change the outbound route filters on BGP peers and should
   only be used for one-time filtering.

Status of this Memo

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

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   http://www.ietf.org/shadow.html.




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   This Internet-Draft will expire on April 22, 2011.

Copyright Notice

   Copyright (c) 2010 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.

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 RFC-2119 [RFC2119].

Table of Contents

   1. Introduction................................................2
   2. One-time Address Prefix ORF-Type............................3
   3. Operation...................................................4
   4. Security Considerations.....................................4
   5. IANA Considerations.........................................4
   6. Acknowledgments.............................................4
   7. References..................................................4
      7.1. Normative References...................................4
   Authors' Addresses.............................................6

   1. Introduction

   The Outbound Route Filtering Capability defined in [RFC5291]
   provides a mechanism for a BGP speaker to send to its BGP peer a set
   of Outbound Route Filters (ORFs) that can be used by its peer to
   filter its outbound routing updates to the speaker.

   During some network maintenance, BGP speaker only needs to retrieve
   some specific "problematic" routes from its peer if the routes are
   possibly lost or contain some problematic attributes for some reason,
   but send ROUTE-REFRESH will lead to the peer re-advertising its



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   whole Adj-RIB-Out. Such large numbers of updates include a lot of
   unnecessary routes which would make trouble shooting operation (such
   as packets tracking) more difficult, and is a waste of processing
   resources and bandwidth. With the increase of IPV6 deployment, this
   problem could be more significant. Even configured with ORF
   mechanism as defined in [RFC5291], on receipt of a ROUTE-REFRESH
   message, the peer will re-advertise all the routes matching current
   outbound route filters, i.e., the whole Adj-Rib-Out for this BGP
   speaker. Since in this case the BGP speaker does not want to change
   the outbound route filters on its peer, this problem cannot be
   solved by current ORF mechanism.

   This document defines a new Outbound Router Filter (ORF) type for
   BGP, termed "One-time Address Prefix Outbound Route Filter", which
   would allow a BGP speaker to send to its BGP peer a route refresh
   request with a set of address-prefix-based filters to make the peer
   re-advertise only the specific routes matching the filters to the
   speaker. This ORF-type enables a BGP speaker to recover some
   specific "problematic" routes without requiring its peer to re-
   advertise the whole Adj-RIB-Out of specific address family, which
   makes the trouble shooting operation (such as packets tracking) more
   efficient and reduces the impact on network stability. This filter
   does not change the outbound route filters on BGP peers and should
   only be used for one-time filtering.

   2. One-time Address Prefix ORF-Type

   This document defines a new ORF type: One-time Address Prefix ORF.

   As specified in the [RFC5291], an ORF entry is a tuple of the form
   <AFI/SAFI, ORF-Type, Action, Match, ORF-value> an ORF consists of
   one or more ORF entries that have a common AFI/SAFI and ORF-Type. An
   ORF is identified by <AFI/SAFI, ORF-Type>.

   The format of One-time Address Prefix ORF-Type entry is the same as
   the encoding of Address Prefix ORF in [RFC5292], the specific fields
   are defined as follows:

   Since the semantics of this new ORF-Type is always "one-time
   filtering" and has no impact on existing ORFs, so the Action field
   MUST be ignored.

   The matching rules of the One-time Address Prefix ORF are the same
   as defined in Address-Prefix-Based ORF [RFC-5292].





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   The ORF entries of this type are used as one-time filters that MUST
   not change any previously installed ORF entry on the remote peer.

   3. Operation

   The capability negotiation of <AFI/SAFI, One-time Address Prefix
   ORF> MUST NOT delay the advertisement of routes with this AFI/SAFI.

   The received One-time Address Prefix ORF entries SHOULD only be used
   for one-time route filtering and MUST NOT be saved locally. The
   received One-time Address Prefix ORF entries MUST NOT modify the
   outbound route filters on the receiver (either locally configured or
   received from peer through ORF).

   On receipt of ROUTE-REFRESH message with One-time Address Prefix ORF
   entries, the receiver SHOULD re-advertise to the peer the routes
   from the Adj-RIB-Out associated with the peer which pass the entries
   carried in the One-time Address Prefix ORF and taking into account
   the locally saved ORFs (if any) received from the peer.

   4. Security Considerations

   This extension to BGP does not change the underlying security issues
   in [RFC4271].

   5. IANA Considerations

   This document specifies a new Outbound Route Filtering (ORF) type,
   One-time Address-Prefix ORF. The value of the ORF-type needs to be
   assigned by the IANA.

   6. Acknowledgments

   The authors would like to thank Keyur Patel, Enke Chen, Rob Shakir,
   Susan Hares, Haibo Wang, Jiawei Dong, Yaqun Xiao, Mach Chen for
   their valuable suggestions and comments to this document.

   7. References

      7.1. Normative References

   [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
             Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918,
             September 2000.



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   [RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering
             Capability for BGP-4", RFC 5291, August 2008.

   [RFC5292] Chen, E. and S. Sangli, "Address-Prefix-Based Outbound
             Route Filter for BGP-4", RFC 5292, August 2008.

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

   [RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of
             Standards Track Code Points", BCP 100, RFC 4020, February
             2005.

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
































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Authors' Addresses

   Qing Zeng
      Huawei Technologies Co.,Ltd.
      Huawei Building, No.3 Xinxi Rd.,
      Hai-Dian District
      Beijing, 100085
      P.R. China

      Email: zengqing@huawei.com

   Jie Dong
      Huawei Technologies Co.,Ltd.
      Huawei Building, No.3 Xinxi Rd.,
      Hai-Dian District
      Beijing, 100085
      P.R. China

      Email: dongjie_dj@huawei.com

   ZhiLan Huang
     China Telecom
     109 West Zhongshan Ave,
     Tianhe District, Guanghou, 510630, P.R.C

     Email: huangzl@gsta.com

















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