Network Working Group Yakov Rekhter (Juniper Networks)
Internet Draft Srihari R. Sangli (Cisco Systems)
Expiration Date: May 2009 Daniel Tappan (Cisco Systems)
Intended Status: Proposed Standard
Four-octet AS Specific BGP Extended Community
draft-ietf-l3vpn-as4octet-ext-community-02.txt
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Abstract
This document defines a new type of a BGP extended community - four-
octet AS specific extended community. This community allows to carry
4 octet autonomous system numbers.
Specification of Requirements
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 RFC 2119 [RFC2119].
1. Introduction
This document defines a new type of BGP extended community
([RFC4360]) - four-octet AS specific extended community. This type of
extended community is similar to the two-octet AS specific extended
community, except that it can carry a four octets autonomous system
number.
2. Four-octet AS specific extended community
This is an extended type with Type Field comprising of 2 octets and
Value Field comprising of 6 octets.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x02 or 0x42 | Sub-Type | Global Administrator :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: Global Administrator (cont.) | Local Administrator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The value of the high-order octet of this extended type is either
0x02 (for transitive communities) or 0x42 (for non-transitive commu-
nities). The low-order octet of this extended type is used to indi-
cate sub-types.
The Value Field consists of two sub-fields:
Global Administrator sub-field: 4 octets
This sub-field contains a 4-octets Autonomous System number
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assigned by IANA.
Local Administrator sub-field: 2 octets
The organization identified by Autonomous System number in the
Global Administrator sub-field, can encode any information in
this sub-field. The format and meaning of the value encoded in
this sub-field should be defined by the sub-type of the commu-
nity.
3. Considerations for two-octet Autonomous Systems
As per [RFC4893], a two-octet Autonomous System number can be con-
verted into a 4-octet Autonomous System number by setting the two
high-order octets of the 4-octet field to zero.
As a consequence, at least in principle an autonomous system that
uses a two-octet Autonomous System number could use either two-octet
or four-octet AS specific extended communities. This is undesirable,
as both communities would be treated as different, even if they had
the same Sub-Type and Local Administrator values.
Therefore, for backward compatibility with existing deployments, and
to avoid inconsistencies between two-octet and four-octet specific
extended communities, autonomous systems that use two-octet
Autonomous System numbers SHOULD use two-octet AS specific extended
communities rather than four-octet AS specific extended communities.
4. IANA Considerations
This document defines a class of extended communities called four-
octet AS specific extended community for which the IANA is to create
and maintain a registry entitled Four-octet AS Specific Extended Com-
munity. All the communities in this class are of extended Types.
Future assignment are to be made using the "First Come First Served"
policy defined in [RFC5226]. The Type values for the transitive com-
munities of the four-octet AS specific extended community class are
0x0200-0x02ff, and for the non-transitive communities of that class
are 0x4200-0x42ff. Assignments consist of a name and the value.
This document makes the following assignments for the four-octet AS
specific extended community:
Name Type Value
---- ----------
four-octet AS specific Route Target 0x0202
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four-octet AS specific Route Origin 0x0203
5. Security Considerations
All the security considerations for BGP Extended Communities apply
here.
6. Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any assur-
ances of licenses to be made available, or the result of an attempt
made to obtain a general license or permission for the use of such
proprietary rights by implementers or users of this specification can
be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
7. Copyright Notice
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
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Internet Draftdraft-ietf-l3vpn-as4octet-ext-community-02.txtNovember 2008
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
8. Disclaimer of validity:
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. Copies of IPR disclosures made to the
IETF Secretariat and any assurances of licenses to be made available,
or the result of an attempt made to obtain a general license or
permission for the use of such proprietary rights by implementers or
users of this specification can be obtained from the IETF on-line IPR
repository at http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
9. Acknowledgements
Thanks to Bruno Decraene for his contributions to this document.
10. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5226] Narten, T., Alvestrand, H., "Guidelines for Writing an IANA
Considerations Section in RFCs", RFC5226, May 2008.
[RFC4360] Srihari R. Sangli, Daniel Tappan, Yakov Rekhter, "BGP
Extended Communities Attribute", RFC 4360, February 2006.
[RFC4893] Vohra, Q., Chen, E., "BGP Support for Four-octet AS Number
Space", RFC 4893, May 2007.
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11. Non-normative References
12. Author Information
Yakov Rekhter
Juniper Networks, Inc.
e-mail: yakov@juniper.net
Srihari R. Sangli
Cisco Systems, Inc.
e-mail: rsrihari@cisco.com
Dan Tappan
Cisco Systems, Inc.
250 Apollo Drive
Chelmsford, MA 01824
e-mail: tappan@cisco.com
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