One document matched: draft-ietf-idr-as0-06.xml

<?xml version="1.0" encoding="US-ASCII"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd">
<!-- WK: Set category, IPR, docName -->
<rfc category="std" docName="draft-ietf-idr-as0-06" ipr="trust200902"
     updates="4271">
  <?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>

  <?rfc toc="yes" ?>

  <?rfc symrefs="yes" ?>

  <?rfc sortrefs="yes"?>

  <?rfc iprnotified="no" ?>

  <?rfc strict="yes"?>

  <?rfc compact="yes" ?>

  <front>
    <!-- WK: Set long title. -->

    <title abbrev="as0-processing">Codification of AS 0 processing.</title>

    <author fullname="Warren Kumari" initials="W." surname="Kumari">
      <organization>Google</organization>

      <address>
        <postal>
          <street>1600 Amphitheatre Parkway</street>

          <city>Mountain View, CA</city>

          <code>94043</code>

          <country>US</country>
        </postal>

        <email>warren@kumari.net</email>
      </address>
    </author>

    <author fullname="Randy Bush" initials="R." surname="Bush">
      <organization>Internet Initiative Japan</organization>

      <address>
        <postal>
          <street>5147 Crystal Springs</street>

          <city>Bainbridge Island, WA</city>

          <code>98110</code>

          <country>US</country>
        </postal>

        <email>randy@psg.com</email>
      </address>
    </author>

    <author fullname="Heather Schiller" initials="H." surname="Schiller">
      <organization>Verizon</organization>

      <address>
        <postal>
          <street>22001 Loudoun County Parkway</street>

          <city>Ashburn</city>

          <code>20147</code>

          <country>US</country>
        </postal>

        <email>heather.schiller@verizon.com</email>
      </address>
    </author>

    <author fullname="Keyur Patel" initials="K." surname="Patel">
      <organization>Cisco Systems</organization>

      <address>
        <postal>
          <street>170 W. Tasman Drive</street>

          <city>San Jose</city>

          <region>CA</region>

          <code>95134</code>

          <country>USA</country>
        </postal>

        <phone></phone>

        <facsimile></facsimile>

        <email>keyupate@cisco.com</email>

        <uri></uri>
      </address>
    </author>

    <date day="26" month="August" year="2012" />

    <area>int</area>

    <workgroup>idr</workgroup>

    <abstract>
      <t>This document updates RFC 4271 and proscribes the use of Autonomous
      System (AS) 0 in the Border Gateway Protocol (BGP) OPEN and AS_PATH /
      AS4_PATH BGP attribute.</t>
    </abstract>
  </front>

  <middle>
    <section title="Introduction">
      <t>Autonomous System 0 is listed in the IANA Autonomous System Number
      Registry as "Reserved - May be use to identify non-routed networks"
      (<xref target="IANA.AS_Numbers"></xref>).</t>

      <t><xref target="RFC6491"></xref> specifies that AS number zero in a
      Route Origin Attestation (ROA) is used to mark a prefix and all its more
      specific prefixes as not to be used in a routing context. This allows a
      resource holder to signal that a prefix (and the more specifics) should
      not be routed by publishing a ROA listing AS0 as the only origin. To
      respond to this signal requres that BGP implementations do not accept or
      propagate routes containing AS0.</t>

      <t>No clear statement that AS 0 was proscribed could be found in any BGP
      specification. This document corrects this omission, most importantly in
      the case of the AS_PATH. This represents an update to the error handling
      procedures given in <xref target="RFC4271"></xref> Sections 6.2 and 6.3
      by specifying the behavior in the presence of AS0.</t>

      <t>At least two implementations discard routes containing AS 0, and this
      document codifies this behavior.</t>

      <section title="Requirements notation">
        <t>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 <xref
        target="RFC2119"></xref>.</t>
      </section>
    </section>

    <section title="Behavior">
      <t>A BGP speaker MUST NOT originate or propagate a route with an AS
      number of zero in the AS_PATH, AS4_PATH, AGGREGATOR or AS4_AGGREGATOR
      attributes.</t>

      <t>An UPDATE message that contains the AS number of zero in the AS_PATH
      or AGGREGATOR attribute MUST be considered as malformed, and be handled
      by the procedures specified in <xref
      target="I-D.ietf-idr-error-handling"></xref>.</t>

      <t>An UPDATE message that contains the AS number of zero in the AS4_PATH
      or AS4_AGGREGATOR attribute MUST be considered as malformed, and be
      handled by the procedures specified in <xref
      target="I-D.ietf-idr-rfc4893bis"></xref>.</t>

      <t>If a BGP speaker receives zero as the peer AS in an OPEN message, it
      MUST abort the connection and send a NOTIFICATION with Error Code "OPEN
      Message Error" and subcode "Bad Peer AS" (see <xref
      target="RFC4271"></xref> Section 6.2). A router MUST NOT initiate a
      connection claiming to be AS number zero.</t>

      <t>Authors of future protocol extensions that carry the Autonomous
      System number are encouraged to keep in mind that AS number zero is
      reserved and to provide clear direction on how to handle AS number
      zero.</t>
    </section>

    <section title="IANA Considerations">
      <t>The IANA is requested to update the Reference for number 0 in the
      "Autonomous System (AS) Numbers" registry to reference this
      document.</t>
    </section>

    <section anchor="security" title="Security Considerations">
      <t>By allowing a Resource Public Key Infrastructure (RPKI) resource
      holder to issue a ROA saying that AS 0 is the only valid origin for a
      route, we allow them to state that a particular address resource is not
      in use. By ensuring that all implementations that see AS 0 in a route
      ignore that route, we prevent a malicious party from announcing routes
      containing AS 0 in an attempt to hijack those resources.</t>

      <t>In addition, by standardizing the behavior upon reception of an
      AS_PATH (or AS4_PATH) containing AS 0, this document makes the behavior
      better defined.</t>
    </section>

    <section title="Acknowledgements">
      <t>The authors wish to thank Elwyn Davies, Enke Chen, Brian Dickson,
      Bruno Decraene, Robert Raszuk, Jakob Heitz, Danny McPherson, Chris
      Morrow, iLya, John Scudder, Jeff Tantsura, Daniel Ginsburg and Susan
      Hares. Apologies to those we may have missed, it was not
      intentional.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include='reference.RFC.2119.xml'?>

      <?rfc include='reference.RFC.4271.xml'?>

      <?rfc include='reference.I-D.draft-ietf-idr-error-handling-01.xml'?>

      <?rfc include='reference.I-D.draft-ietf-idr-rfc4893bis-06.xml'?>

      <reference anchor="IANA.AS_Numbers"
                 target="http://www.iana.org/assignments/as-numbers">
        <front>
          <title abbrev="Autonomous System (AS) Numbers">Autonomous System
          (AS) Numbers</title>

          <author>
            <organization>IANA</organization>
          </author>

          <date />
        </front>
      </reference>
    </references>

    <references title="Informative References">
      <?rfc include='reference.RFC.6491.xml'?>
    </references>

    <section title="Changes / Author Notes.">
      <t>[RFC Editor: Please remove this section before publication ]</t>

      <t>Draft accepted as IDR Doc, notes reset. Please see notes for
      draft-wkumari-idr-as0.xml for prior comments.</t>

      <t>Changes -00.</t>

      <t><list style="symbols">
          <t>Added AS4_PATH -- Robert Raszuk.</t>

          <t>Change "bgp listener" to "bgp speaker" -- Enke Chen</t>

          <t>Consistent use of AS_PATH (v., AS-PATH and AS PATH) -- Danny
          McPherson</t>

          <t>New text for Sec 2 P1 -- Enke / Keyur / Scudder,
          http://www.ietf.org/mail-archive/web/idr/current/msg05786.html</t>

          <t>I made a boo boo -- I had the file open in 2 editors, made
          changes in one and overwrote them by saving on the "other, then
          checked the broken one into SVN. Apologies to all whose comments I
          may have missed...</t>
        </list></t>

      <t>Changes -01</t>

      <t><list style="symbols">
          <t>The WG thread
          http://www.ietf.org/mail-archive/web/idr/current/msg05685.html
          showed a very strong preference for separating the error definition
          and handling -- the chairs also showed a prefernce to Publish this
          and point to the error handling that Enke will write.</t>

          <t>The originally suggested text ("An UPDATE message that contains
          the AS number of zero in the AS-PATH attribute MUST be...") only
          referenced the AS-PATH, readded AS4_PATH, *AGGREGATOR as suggested
          by Robert Raszak and Danny.</t>
        </list></t>

      <t>Changes -02</t>

      <t><list style="symbols">
          <t>Fixed the reference for *AGGREGATOR. This required breaking it
          out into two sentences / clauses.</t>

          <t>Added text on other places where an AS can show up (e.g: "4-Octet
          AS specific Extended Community" [5668]) -- thanks to Keyur.</t>
        </list></t>

      <t>Changes - 03<list style="symbols">
          <t>Removed text on other places where an AS can show up (e.g:
          "4-Octet AS specific Extended Community" [5668]).</t>

          <t>Added *very* generic "Authors of future protocol extensions..."
          text</t>
        </list></t>

      <t>Changes -04</t>

      <t><list style="symbols">
          <t>Looks like the draft needs an 'Updates: RFC 4271' header. Can you
          make the change? -- JGS.</t>

          <t>"You have things a bit scrambled in these two paragraphs" -- JGS
          (whoops!).</t>

          <t>Editorial: I suggest dropping the parentheses in... JGS.</t>

          <t>Added "This document updates rfc 4271" to keep IDNITs
          happy...</t>

          <t>Bumped refs: draft-ietf-sidr-iana-objects has been published as
          RFC 6491, idr-error is now -01, 4893bis is now -06</t>
        </list></t>

      <t>Changes - 05</t>

      <t><list style="symbols">
          <t>Added something to the intro saying what we update and why. This
          was in the abstract, but I didn't have it in the intro. Stupid.</t>
        </list></t>

      <t>Changes - 06<list style="symbols">
          <t>Incorporated some comments / clarifications from Gen-ART review
          (Elwyn Davies)</t>

          <t>Expaned acronyms.</t>

          <t>RFC 6491 fix - clarified what it actually said and what
          implications are.</t>
        </list></t>
    </section>
  </back>
</rfc>