draft-ietf-idr-as0-03.txt   draft-ietf-idr-as0-04.txt 
idr W. Kumari idr W. Kumari
Internet-Draft Google Internet-Draft Google
Intended status: Standards Track R. Bush Updates: 4271 (if approved) R. Bush
Expires: July 19, 2012 Internet Initiative Japan Intended status: Standards Track Internet Initiative Japan
H. Schiller Expires: November 8, 2012 H. Schiller
Verizon Verizon
K. Patel K. Patel
Cisco Systems Cisco Systems
January 16, 2012 May 7, 2012
Codification of AS 0 processing. Codification of AS 0 processing.
draft-ietf-idr-as0-03 draft-ietf-idr-as0-04
Abstract Abstract
This document proscribes the use of AS 0 in BGP OPEN and AS_PATH / This document updates RFC 4271 and proscribes the use of AS 0 in BGP
AS4_PATH BGP attribute. OPEN and AS_PATH / AS4_PATH BGP attribute.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 19, 2012. This Internet-Draft will expire on November 8, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 11 skipping to change at page 3, line 11
6.2. Informative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . . 5
Appendix A. Changes / Author Notes. . . . . . . . . . . . . . . . 5 Appendix A. Changes / Author Notes. . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
Autonomous System 0 is listed in the IANA Autonomous System Number Autonomous System 0 is listed in the IANA Autonomous System Number
Registry as "Reserved - May be use to identify non-routed networks" Registry as "Reserved - May be use to identify non-routed networks"
([IANA.AS_Numbers]). ([IANA.AS_Numbers]).
[I-D.ietf-sidr-iana-objects] specifies that AS number zero in a ROA [RFC6491] specifies that AS number zero in a ROA is used to mark an
is used to mark an NLRI which is to be marked as Invalid. NLRI which is to be marked as Invalid.
No clear statement that AS 0 was proscribed could be found in any BGP No clear statement that AS 0 was proscribed could be found in any BGP
specification. specification.
As at least two implementations discard routes containing AS 0 (and As at least two implementations discard routes containing AS 0, and
to allow approaches such as the above) this document codifies this to allow approaches such as the above, this document codifies this
behavior. behavior.
1.1. Requirements notation 1.1. Requirements notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
2. Behavior 2. Behavior
A BGP speaker MUST NOT originate or propagate a route with an AS 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 number of zero in the AS_PATH, AS4_PATH, AGGREGATOR or AS4_AGGREGATOR
attributes. attributes.
An UPDATE message that contains the AS number of zero in the AS_PATH An UPDATE message that contains the AS number of zero in the AS_PATH
or AS4_PATH attribute MUST be considered as malformed, and be handled or AGGREGATOR attribute MUST be considered as malformed, and be
by the procedures specified in [I-D.ietf-idr-error-handling]. handled by the procedures specified in [I-D.ietf-idr-error-handling].
An UPDATE message that contains the AS number of zero in the An UPDATE message that contains the AS number of zero in the AS4_PATH
AGGREGATOR or AS4_AGGREGATOR attribute MUST be considered as or AS4_AGGREGATOR attribute MUST be considered as malformed, and be
malformed, and be handled by the procedures specified in handled by the procedures specified in [I-D.ietf-idr-rfc4893bis].
[I-D.ietf-idr-rfc4893bis].
If a BGP speaker receives zero as the peer AS in an OPEN message, it 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 MUST abort the connection and send a NOTIFICATION with Error Code
"OPEN Message Error" and subcode "Bad Peer AS" (see [RFC4271] Section "OPEN Message Error" and subcode "Bad Peer AS" (see [RFC4271] Section
6.2). A router MUST NOT initiate a connection claiming to be AS 6.2). A router MUST NOT initiate a connection claiming to be AS
number zero. number zero.
Authors of future protocol extensions that carry the Autonomous Authors of future protocol extensions that carry the Autonomous
System number are encouraged keep in mind that AS number zero is System number are encouraged keep in mind that AS number zero is
reserved and to provide clear direction on how to handle AS number reserved and to provide clear direction on how to handle AS number
zero. zero.
3. IANA Considerations 3. IANA Considerations
The IANA is requested to update the Reference for number 0 in the The IANA is requested to update the Reference for number 0 in the
"Autonomous System (AS) Numbers" registry to reference this document. "Autonomous System (AS) Numbers" registry to reference this document.
4. Security Considerations 4. Security Considerations
By allowing resource holders to say that AS 0 is the only valid By allowing a RPKI resource holder to issue a ROA saying that AS 0 is
origin for a route, we allow them to state that a particular address the only valid origin for a route, we allow them to state that a
resource is not in use. By ensuring that all implementations that particular address resource is not in use. By ensuring that all
see AS 0 in a route ignore that route, we prevent a malicious party implementations that see AS 0 in a route ignore that route, we
from announcing routes containing AS 0 in an attempt to hijack those prevent a malicious party from announcing routes containing AS 0 in
resources. an attempt to hijack those resources.
In addition, by standardizing the behavior upon reception of an In addition, by standardizing the behavior upon reception of an
AS_PATH (or AS4_PATH) containing AS 0, this document makes the AS_PATH (or AS4_PATH) containing AS 0, this document makes the
behavior better defined, and security gotchas often lurk in the behavior better defined, and security gotchas often lurk in the
undefined spaces. undefined spaces.
5. Acknowledgements 5. Acknowledgements
The authors wish to thank Enke Chen, Brian Dickson, Bruno Decraene, The authors wish to thank Enke Chen, Brian Dickson, Bruno Decraene,
Robert Raszuk, Jakob Heitz, Danny McPherson, Chris Morrow, iLya, John Robert Raszuk, Jakob Heitz, Danny McPherson, Chris Morrow, iLya, John
Scudder, Jeff Tantsura, Daniel Ginsburg and Susan Hares. Apologies Scudder, Jeff Tantsura, Daniel Ginsburg and Susan Hares. Apologies
to those we may have missed, it was not intentional. to those we may have missed, it was not intentional.
6. References 6. References
6.1. Normative References 6.1. Normative References
[I-D.ietf-idr-error-handling] [I-D.ietf-idr-error-handling]
Scudder, J., Chen, E., Mohapatra, P., and K. Patel, Scudder, J., Chen, E., Mohapatra, P., and K. Patel,
"Revised Error Handling for BGP UPDATE Messages", "Revised Error Handling for BGP UPDATE Messages",
draft-ietf-idr-error-handling-00 (work in progress), draft-ietf-idr-error-handling-01 (work in progress),
November 2011. December 2011.
[I-D.ietf-idr-rfc4893bis] [I-D.ietf-idr-rfc4893bis]
Vohra, Q. and E. Chen, "BGP Support for Four-octet AS Vohra, Q. and E. Chen, "BGP Support for Four-octet AS
Number Space", draft-ietf-idr-rfc4893bis-04 (work in Number Space", draft-ietf-idr-rfc4893bis-06 (work in
progress), July 2011. progress), April 2012.
[IANA.AS_Numbers] [IANA.AS_Numbers]
IANA, "Autonomous System (AS) Numbers", IANA, "Autonomous System (AS) Numbers",
<http://www.iana.org/assignments/as-numbers>. <http://www.iana.org/assignments/as-numbers>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006. Protocol 4 (BGP-4)", RFC 4271, January 2006.
6.2. Informative References 6.2. Informative References
[I-D.ietf-sidr-iana-objects] [RFC6491] Manderson, T., Vegoda, L., and S. Kent, "Resource Public
Manderson, T., Vegoda, L., and S. Kent, "RPKI Objects Key Infrastructure (RPKI) Objects Issued by IANA",
issued by IANA", draft-ietf-sidr-iana-objects-03 (work in RFC 6491, February 2012.
progress), May 2011.
Appendix A. Changes / Author Notes. Appendix A. Changes / Author Notes.
[RFC Editor: Please remove this section before publication ] [RFC Editor: Please remove this section before publication ]
Draft accepted as IDR Doc, notes reset. Please see notes for Draft accepted as IDR Doc, notes reset. Please see notes for
draft-wkumari-idr-as0.xml for prior comments. draft-wkumari-idr-as0.xml for prior comments.
Changes -00. Changes -00.
o Added AS4_PATH -- Robert Raszuk. o Added AS4_PATH -- Robert Raszuk.
o Change "bgp listener" to "bgp speaker" -- Enke Chen o Change "bgp listener" to "bgp speaker" -- Enke Chen
o Consistent use of AS_PATH (v., AS-PATH and AS PATH) -- Danny o Consistent use of AS_PATH (v., AS-PATH and AS PATH) -- Danny
McPherson McPherson
o New text for Sec 2 P1 -- Enke / Keyur / Scudder, o New text for Sec 2 P1 -- Enke / Keyur / Scudder,
http://www.ietf.org/mail-archive/web/idr/current/msg05786.html http://www.ietf.org/mail-archive/web/idr/current/msg05786.html
o I made a boo boo -- I had the file open in 2 editors, made changes o 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 in one and overwrote them by saving on the "other, then checked
broken one into SVN. Apologies to all whose comments I may have the broken one into SVN. Apologies to all whose comments I may
missed... have missed...
Changes -01 Changes -01
o The WG thread o The WG thread
http://www.ietf.org/mail-archive/web/idr/current/msg05685.html http://www.ietf.org/mail-archive/web/idr/current/msg05685.html
showed a very strong preference for separating the error showed a very strong preference for separating the error
definition and handling -- the chairs also showed a prefernce to definition and handling -- the chairs also showed a prefernce to
Publish this and point to the error handling that Enke will write. Publish this and point to the error handling that Enke will write.
o The originally suggested text ("An UPDATE message that contains o The originally suggested text ("An UPDATE message that contains
the AS number of zero in the AS-PATH attribute MUST be...") only the AS number of zero in the AS-PATH attribute MUST be...") only
referenced the AS-PATH, readded AS4_PATH, *AGGREGATOR as suggested referenced the AS-PATH, readded AS4_PATH, *AGGREGATOR as suggested
by Robert Raszak and Danny. by Robert Raszak and Danny.
Changes -02 Changes -02
o Fixed the reference for *AGGREGATOR. This required breaking it o Fixed the reference for *AGGREGATOR. This required breaking it
out into two sentences / clauses. out into two sentences / clauses.
o Added text on other places where an AS can show up (e.g: "4-Octet o Added text on other places where an AS can show up (e.g: "4-Octet
AS specific Extended Community" [RFC5668]) -- thanks to Keyur. AS specific Extended Community" [5668]) -- thanks to Keyur.
Changes - 03 Changes - 03
o Removed text on other places where an AS can show up (e.g: o Removed text on other places where an AS can show up (e.g:
"4-Octet AS specific Extended Community" [RFC5668]). "4-Octet AS specific Extended Community" [5668]).
o Added *very* generic "Authors of future protocol extensions..." o Added *very* generic "Authors of future protocol extensions..."
text text
Changes -04
o Looks like the draft needs an 'Updates: RFC 4271' header. Can you
make the change? -- JGS.
o "You have things a bit scrambled in these two paragraphs" -- JGS
(whoops!).
o Editorial: I suggest dropping the parentheses in... JGS.
o Added "This document updates rfc 4271" to keep IDNITs happy...
o Bumped refs: draft-ietf-sidr-iana-objects has been published as
RFC 6491, idr-error is now -01, 4893bis is now -06
Authors' Addresses Authors' Addresses
Warren Kumari Warren Kumari
Google Google
1600 Amphitheatre Parkway 1600 Amphitheatre Parkway
Mountain View, CA 94043 Mountain View, CA 94043
US US
Email: warren@kumari.net Email: warren@kumari.net
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