draft-collector-comm/draft-ymbk-grow-bgp-collector-communities.xml
2022-02-17 13:10:18 -08:00

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<?xml version="1.0"?>
<!-- <!DOCTYPE rfc SYSTEM "rfc2629.dtd"> -->
<?rfc comments="yes"?>
<?rfc compact="yes"?>
<?rfc inline="yes"?>
<?rfc sortrefs="yes"?>
<?rfc subcompact="yes"?>
<?rfc symrefs="yes"?>
<?rfc toc="yes"?>
<?rfc tocdepth="3"?>
<?rfc tocindent="yes"?>
<?rfc tocompact="yes"?>
<rfc consensus="yes" category="bcp" submissionType="IETF" docName="draft-ymbk-grow-bgp-collector-communities-02" ipr="trust200902" obsoletes="4384">
<front>
<title>Marking Announcements to BGP Collectors</title>
<author fullname="Randy Bush" initials="R." surname="Bush">
<organization>Internet Initiative Japan</organization>
<address>
<postal>
<street>5147 Crystal Springs</street>
<city>Bainbridge Island</city>
<region>Washington</region>
<code>98110</code>
<country>US</country>
</postal>
<email>randy@psg.com</email>
</address>
</author>
<author fullname="Emile Aben" initials="E.M.J." surname="Aben">
<organization>RIPE NCC</organization>
<address>
<postal>
<street>Singel 258</street>
<city>Amsterdam</city>
<!-- <region>NL.NH</region> -->
<code>1016 AB</code>
<country>NL</country>
</postal>
<email>emile.aben@ripe.net</email>
</address>
</author>
<date />
<abstract>
<t>When BGP route collectors such as RIPE RIS and Route Views are
used by operators and researchers, currently one can not tell if the
collection of paths announced to a collector represents the ISP's
customer cone, includes internal routes, includes paths learned from
peerings or transits. This greatly reduces the utility of the
collected data. This document specifies the use of BGP communities
to differentiate the kinds of views being presented to the
collectors.</t>
</abstract>
<note title="Requirements Language">
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when,
and only when, they appear in all capitals, as shown here.</t>
</note>
</front>
<middle>
<section anchor="intro" title="Introduction">
<t>BGP route collectors such as <xref target="ris">RIPE RIS</xref>
and <xref target="rviews">Route Views</xref> are used by both
operators and researchers. Unfortunately, one can not tell paths
announced to a collector are solely from the ISP's customer cone
(one's own prefixes and the closure of those to whom transit is
provided; i.e. what one would announce to a peer), include internal
routes (e.g. inter-router links), or external paths learned via
peering or transit. This greatly reduces the utility of the
collected data, and has been a cause of much pain over the years.
This document suggests the use of BGP communities to differentiate
between these categories.</t>
<t>In 2006, <xref target="RFC4384"/> attempted a similar goal but
failed to gain traction in the operational community. We believe
this was due to its unnecessary complexity. This document proposes
two much simpler marking schemes and, if published, will obsolete
<xref target="RFC4384"/>.</t>
</section>
<section anchor="rationale" title="Rationale">
<t>When an operator uses a collector to look at an ISP's
announcement of a prefix, it is very useful to know if the ISP also
announced it to their customers and/or peers/transits. Researchers
want to differentiate similarly in order to understand expected
route propagation.</t>
<t>One usually wishes to ignore any internal-only routes, e.g.
inter-router point-to-point links, an ISP may announce to the
collector, as they would not be announcing them to peers, transits,
or customers. I.e. they would not be used operationally.</t>
<t>An ISP is expected to announce customer routes to their
customers, and announce customer routes to their external peers and
transits.</t>
<t>In general, one does not need to differentiate whether the ISP
will announce to peers or transits; and the ISP may not wish to
expose the business relationships with external providers. So this
document do not propose to differentiate peers from transit
providers.</t>
</section>
<section anchor="categories" title="Categories">
<t>We consider only three categories of announcements:
<list style="hanging">
<t hangText="Customer Cone:">
One's own prefixes and the closure of those to whom transit is
provided including routes announced by BGP customers, static
prefixes used for non-BGP customers, datacenter routes,
etc.</t>
<t hangText="External Routes:">
Routes learned from peers and transit providers which the ISP
would normally announce to customers but not to peers. Often,
ISPs do not announce such routes to collectors. But, as there
is no general practice, this category is important to mark.</t>
<t hangText="Internal Routes:">
ISPs occasionally announce to the collector Internal point to
point and other routes they would not normally announce to
customers, peers, or transit providers.</t>
</list>
</t>
</section>
<section anchor="signal" title="Signaling">
<t>BGP announcements to route collectors SHOULD be marked with
communities indicating into which category the announcement falls.
As most collector peers already use community markings similar to
these, but ad hoc, the additional effort should be trivial.</t>
<t>The ASN in the marking SHOULD be that of the collector peer. The
communities were selected from community values which were unused at
the time of this document and SHOULD be as follows:</t>
<t>ASs which do not peer with collectors MAY also choose to use
these markings.</t>
<texttable anchor='markings'>
<preamble></preamble>
<ttcol align='left'>Category</ttcol>
<ttcol align='left'>Community</ttcol>
<c>Customer Cone</c> <c>ASN:64994</c>
<c>External Route</c> <c>ASN:64995</c>
<c>Internal Route</c> <c>ASN:64996</c>
<postamble>Community Markings</postamble>
</texttable>
</section>
<section anchor="alt" title="Alternative Signaling">
<t>Alternatively, should marking at the path granularity be
considered too revealing, the collector peer could announce a single
well-known prefix, for example 10.10.10.10/10, with one or more of
the community markings as above, describing the set of paths being
announced to the collector.</t>
</section>
<section anchor="iana" title="IANA Considerations">
<t>As the number of categories is intentionally minimal, an IANA
registry should not be needed.</t>
</section>
</middle>
<back>
<references title="Normative References">
<?rfc include="reference.RFC.2119.xml"?>
<?rfc include="reference.RFC.8174.xml"?>
<reference anchor="ris" target="https://www.ripe.net/analyse/internet-measurements/routing-information-service-ris/routing-information-service-ris">
<front>
<title>RIPE Routing Information Service (RIS)</title>
<author/>
<date/>
</front>
</reference>
<reference anchor="rviews" target="http://www.routeviews.org/">
<front>
<title>University of Oregon Route Views Project</title>
<author/>
<date/>
</front>
</reference>
</references>
<references title="Informative References">
<?rfc include="reference.RFC.4384.xml"?>
</references>
</back>
</rfc>