Internet DRAFT - draft-ymbk-grow-bgp-collector-communities
draft-ymbk-grow-bgp-collector-communities
Network Working Group R. Bush
Internet-Draft Internet Initiative Japan
Obsoletes: 4384 (if approved) E.M.J. Aben
Intended status: Best Current Practice RIPE NCC
Expires: 21 August 2022 17 February 2022
Marking Announcements to BGP Collectors
draft-ymbk-grow-bgp-collector-communities-02
Abstract
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.
Requirements Language
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 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 21 August 2022.
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Copyright Notice
Copyright (c) 2022 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 (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Categories . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Alternative Signaling . . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
BGP route collectors such as RIPE RIS [ris] and Route Views [rviews]
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.
In 2006, [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 [RFC4384].
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2. Rationale
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.
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.
An ISP is expected to announce customer routes to their customers,
and announce customer routes to their external peers and transits.
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.
3. Categories
We consider only three categories of announcements:
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.
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.
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.
4. Signaling
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.
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:
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ASs which do not peer with collectors MAY also choose to use these
markings.
+================+===========+
| Category | Community |
+================+===========+
| Customer Cone | ASN:64994 |
+----------------+-----------+
| External Route | ASN:64995 |
+----------------+-----------+
| Internal Route | ASN:64996 |
+----------------+-----------+
Table 1
Community Markings
5. Alternative Signaling
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.
6. IANA Considerations
As the number of categories is intentionally minimal, an IANA
registry should not be needed.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[ris] "RIPE Routing Information Service (RIS)",
<https://www.ripe.net/analyse/internet-measurements/
routing-information-service-ris/routing-information-
service-ris>.
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[rviews] "University of Oregon Route Views Project",
<http://www.routeviews.org/>.
7.2. Informative References
[RFC4384] Meyer, D., "BGP Communities for Data Collection", BCP 114,
RFC 4384, DOI 10.17487/RFC4384, February 2006,
<https://www.rfc-editor.org/info/rfc4384>.
Authors' Addresses
Randy Bush
Internet Initiative Japan
5147 Crystal Springs
Bainbridge Island, Washington 98110
United States of America
Email: randy@psg.com
Emile Aben
RIPE NCC
Singel 258
1016 AB Amsterdam
Netherlands
Email: emile.aben@ripe.net
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