





Internet Engineering Task Force (IETF)                      T. Manderson
Request for Comments: 6397                                         ICANN
Category: Standards Track                                   October 2011
ISSN: 2070-1721


   Multi-Threaded Routing Toolkit (MRT) Border Gateway Protocol (BGP)
     Routing Information Export Format with Geo-Location Extensions

Abstract

   This document updates the Multi-threaded Routing Toolkit (MRT) export
   format for Border Gateway Protocol (BGP) routing information by
   extending it to include optional terrestrial coordinates of a BGP
   collector and its BGP peers.

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/rfc6397.

Copyright Notice

   Copyright (c) 2011 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.







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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
   2.  Requirements Notation . . . . . . . . . . . . . . . . . . . . . 2
   3.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   4.  Geo-Location-Aware MRT Routing Information Subtype  . . . . . . 3
     4.1.  GEO_PEER_TABLE  . . . . . . . . . . . . . . . . . . . . . . 3
     4.2.  GEO_PEER_TABLE and Peer Entry Values  . . . . . . . . . . . 5
   5.  BGP Collector Construction  . . . . . . . . . . . . . . . . . . 5
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . . . 6
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 6
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
   9.  Security Considerations . . . . . . . . . . . . . . . . . . . . 7
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     10.1. Normative References  . . . . . . . . . . . . . . . . . . . 7
     10.2. Informative References  . . . . . . . . . . . . . . . . . . 8

1.  Introduction

   Researchers and engineers often wish to analyze network behavior by
   studying routing protocol transactions and routing information base
   snapshots in relation to geographical topologies.  Usually, the
   Border Gateway Protocol [RFC4271] is the subject of study, and the
   analysis can be significantly aided by the availability and extension
   of the "Multi-Threaded Routing Toolkit (MRT) Routing Information
   Export Format" [RFC6396].  The MRT format was originally defined in
   the MRT Programmer's Guide [MRT-GUIDE].

   The addition of geo-location coordinates (longitude and latitude)
   pertaining to the geographical location of both the BGP collector and
   its BGP peers to BGP export data enables a researcher or enquiring
   individual to gain a terrestrial insight to the routes seen by a BGP
   speaker.  Such data may ultimately aid researchers in understanding
   any disparity between the geographical location of networks and the
   topological location of networks in addition to the relationships
   between geographical position and routing anomalies.  Such insight
   could provide future input into network design and network security.

   This memo documents an optional extension to the MRT format [RFC6396]
   and introduces an additional definition of an MRT Subtype field that
   includes the terrestrial coordinates of a BGP collector and its BGP
   peers.

2.  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 [RFC2119].



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3.  Definitions

   Coordinates: The geographic latitude and longitude specifying a
   location on the earth.

   BGP Speaker: A network device that exchanges network routing
   information using BGP.

   Geo-location: Assigning a set of coordinates to a specific artifact,
   in this case a BGP speaker.

   BGP Collector: A BGP speaker (usually passive) that stores and
   archives BGP routing data from active BGP peers for analysis.

   BGP Peer: Either an internal or external BGP peer [RFC4271].

   Not A Number (NAN): Numeric data type representing an undefined or
   unrepresentable value, as defined in the IEEE Standard for Floating-
   Point Arithmetic [IEEE754].

4.  Geo-Location-Aware MRT Routing Information Subtype

   An additional subtype (GEO_PEER_TABLE) is defined for the
   TABLE_DUMP_V2 format, extending TABLE_DUMP_V2 Type.

4.1.  GEO_PEER_TABLE

   The GEO_PEER_TABLE Subtype updates the TABLE_DUMP_V2 Types to include
   geo-location information in the form of the World Geodetic System
   1984 (WGS84) [WGS-84] formatted coordinates.

   The document adds the 7th subtype number and name below.  The first 6
   subtypes are defined by the MRT format [RFC6396].

   Subtype Number       Subtype Name
   ----------------------------------
       7               GEO_PEER_TABLE

   The GEO_PEER_TABLE MRT record provides the BGP ID of the collector,
   its latitude and longitude in WGS84 [WGS-84] format, and a list of
   indexed peers and their respective latitudes and longitudes in WGS84
   [WGS-84] format.

   The format and function of the Collector BGP ID and Peer Count are as
   defined by the TABLE_DUMP_V2, PEER_INDEX_TABLE format [RFC6396].






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   The Collector Latitude and Collector Longitude are the geographical
   coordinates of the collector in WGS84 [WGS-84] datum decimal degrees
   format stored as a single precision float in the 32 bits allocated to
   the Collector Latitude and Collector Longitude.  The latitude and
   longitude MAY be a Not A Number (NAN) [IEEE754] for situations where
   the geo-location of the collector is considered private.  The
   Collector Latitude and Collector Longitude MUST NOT be a mix of WGS84
   [WGS-84] datum coordinates and NAN values.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Collector BGP ID                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Collector Latitude                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Collector Longitude                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Peer Count           |  Peer Entries (variable)
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Format of the GEO_PEER_TABLE

   The format of the Peer Entries is shown below.  The Peer Type and the
   Peer BGP ID are as defined in the TABLE_DUMP_V2 MRT, PEER_INDEX_TABLE
   format [RFC6396].  The order of the Peer Entries in the
   GEO_PEER_TABLE MUST match the order and number as existing in the
   PEER_INDEX_TABLE.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Peer Type   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Peer BGP ID                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Peer Latitude                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Peer Longitude                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                          Format of Peer Entries

   The Peer Latitude and Peer Longitude are the geographical coordinates
   of the peer in WGS84 [WGS-84] datum decimal degrees format stored as
   a single precision float in the 32 bits allocated to the Peer
   Latitude and Peer Longitude.  The latitude and longitude MAY be a Not
   A Number (NAN) [IEEE754] for situations where the geo-location of the



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   peer is considered private.  The Peer Latitude and Peer Longitude
   MUST NOT be a mix of WGS84 [WGS-84] datum coordinates and NAN values
   for a single peer.

4.2.  GEO_PEER_TABLE and Peer Entry Values

   Collector BGP ID: Defined in the MRT format [RFC6396].

   Collector Latitude: Geographic latitude of the BGP collector in WGS84
   [WGS-84] datum decimal degrees format stored as a single precision
   float.

   Collector Longitude: Geographic longitude of the BGP collector in
   WGS84 [WGS-84] datum decimal degrees format stored as a single
   precision float.

   Peer Count: Defined in the MRT format [RFC6396].

   Peer Entries: Defined in the MRT format [RFC6396].

   Peer Type: Defined in the MRT format [RFC6396].

   Peer BGP ID: Defined in the MRT format [RFC6396].

   Peer Latitude: Geographic latitude of the BGP peer in WGS84 [WGS-84]
   datum decimal degrees format stored as a single precision float.

   Peer Longitude: Geographic longitude of the BGP peer in WGS84
   [WGS-84] datum decimal degrees format stored as a single precision
   float.

5.  BGP Collector Construction

   This section aids the reader in understanding the function of a BGP
   collector.

   The BGP collector is a hardware- or software-based device that speaks
   the Border Gateway Protocol.  Its intended function is to store (and
   archive) the BGP routing data it receives from other BGP speakers
   with which it has peering relationships, providing data for later
   analysis.  The general nature of a BGP collector is that it is a
   passive device in that it listens to route updates and does not
   announce or propagate any information it knows or receives.  It
   should be noted that this is not always the case; network operators
   sometimes enable the collection of BGP routing data on active BGP
   speakers to obtain a situational view of the routing system as they
   see it at a particular point in time.




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   As a fully fledged BGP speaker, the BGP collector can fit into any
   BGP topology including Internal BGP (iBGP), External BGP (eBGP), and
   so on.  The implementation of a BGP collector in a network topology
   is therefore limited by that network's use of BGP.

6.  Privacy Considerations

   The GEOPRIV [RFC6280] architecture requires that privacy rules
   attached to a location object be transmitted alongside the location
   information in the object.  If a BGP collector adds location
   coordinates to an MRT record based on GEOPRIV location objects, then
   it would have to include privacy rules as well.  Since the MRT geo-
   location format does not support the provision of privacy rules, each
   location entry in an MRT object is assigned the following default
   privacy rules [RFC4119]:

   -- retransmission-allowed: True
   -- retention-expires: 100 years from timestamp of the MRT object
   -- ruleset-reference: Empty
   -- note-well: Empty

   Location information derived from a location object with more
   restrictive privacy rules MUST NOT be included in an MRT geo-location
   record unless there are non-technical measures in place that enforce
   and communicate the constraints on the use of the location
   information in the MRT geo-location format (e.g., contractual
   agreements between peers).

7.  Acknowledgements

   Thanks to Andrew Clark, Ernest Foo, Dave Meyer, Larry Blunk, Richard
   Barnes, and Jeffrey Haas for reviewing this document.

   This document describes a small portion of the research towards the
   author's Ph.D.

8.  IANA Considerations

   Per this section, the Internet Assigned Numbers Authority (IANA) has
   registered the additional Subtype code value as:

       7    GEO_PEER_TABLE

   in the MRT format [RFC6396] and Subtype code values related to the
   TABLE_DUMP_V2 Type in the MRT namespace.






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9.  Security Considerations

   This extension to the MRT format [RFC6396] defines fields that are of
   a descriptive nature and provides information that is useful in the
   analysis of routing systems.  As such, the author believes that they
   do not constitute an additional network-based security risk.  It is
   recommended that the operators of the BGP collector and BGP peers
   consider their own privacy and security concerns before supplying
   geographical coordinates to BGP data collection systems.  Special
   attention should be given to the physical security of an organization
   before supplying geographical coordinates, especially if the
   resulting BGP data with geo-location extensions is made public.

   Entities that operate BGP collectors, and users of data provided by
   BGP collectors, should be aware that the geo-location data supplied
   by a peer can only be taken at face value.  It is possible that a BGP
   peer may supply coordinates that are purposefully misleading or
   inaccurate.  It is therefore up to the BGP collector whether or not
   to include this information or use its own methods to either trust or
   validate the data provided.  It is not recommended that a BGP
   collector use geographical coordinates not supplied by a BGP peer.

10.  References

10.1.  Normative References

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

   [RFC4119]    Peterson, J., "A Presence-based GEOPRIV Location Object
                Format", RFC 4119, December 2005.

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

   [RFC6280]    Barnes, R., Lepinski, M., Cooper, A., Morris, J.,
                Tschofenig, H., and H. Schulzrinne, "An Architecture for
                Location and Location Privacy in Internet Applications",
                BCP 160, RFC 6280, July 2011.

   [RFC6396]    Blunk, L., Karir, M., and C. Labovitz, "Multi-Threaded
                Routing Toolkit (MRT) Routing Information Export
                Format", RFC 6396, October 2011.








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10.2.  Informative References

   [IEEE754]    IEEE 754, "IEEE Standard for Floating-Point Arithmetic",
                August 2008, <http://ieeexplore.ieee.org/servlet/
                opac?punumber=4610933>.

   [MRT-GUIDE]  Labovitz, C., "MRT Programmer's Guide", November 1999,
                <http://www.merit.edu/networkresearch/
                mrtprogrammer.pdf>.

   [WGS-84]     Geodesy and Geophysics Department, DoD., "World Geodetic
                System 1984", January 2000, <http://earth-info.nga.mil/
                GandG/publications/tr8350.2/wgs84fin.pdf>.

Author's Address

   Terry Manderson
   ICANN

   EMail: terry.manderson@icann.org































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