draft-ietf-idr-reserved-extended-communities-00.txt   draft-ietf-idr-reserved-extended-communities-01.txt 
Network Working Group B. Decraene Network Working Group B. Decraene
Internet-Draft France Telecom - Orange Internet-Draft France Telecom - Orange
Intended status: Standards Track P. Francois Intended status: Standards Track P. Francois
Expires: August 11, 2011 UCL Expires: November 24, 2011 Universite catholique de Louvain
February 07, 2011 May 23, 2011
Reserved BGP extended communities Assigned BGP extended communities
draft-ietf-idr-reserved-extended-communities-00 draft-ietf-idr-reserved-extended-communities-01
Abstract Abstract
This document assigns two BGP extended community types, one This document defines two IANA registries in order to assign
transitive and one non-transitive. It also defines two IANA transitive and non-transitive extended communities from. These are
registries in order to allow the allocation of reserved transitive similar to the existing well-known BGP communities defined in RFC
and non-transitive extended communities. These are similar to the 1997 but provide an easier control of inter-AS community
existing reserved (formerly Well-known) BGP communities defined in
RFC 1997 but provides an easier control of inter-AS community
advertisement as a community could be chosen as transitive or non- advertisement as a community could be chosen as transitive or non-
transitive across ASes. transitive across ASes.
For that purpose, this document defines the use of the reserved AS
number 0 for the transitive and non-transitive generic four-octet AS
specific extended community types.
Requirements Language Requirements Language
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 RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
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.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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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 August 11, 2011. This Internet-Draft will expire on November 24, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
skipping to change at page 2, line 17 skipping to change at page 2, line 19
(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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
1. Introduction 1. Introduction
[RFC1997] defines the BGP community attribute and some BGP Well known [RFC1997] defines the BGP community attribute and some BGP well-known
communities whose meaning SHALL be understood by all compliant communities whose meaning SHALL be understood by all compliant
implementations. New reserved communities can be registered in the implementations. New communities can be registered in the IANA "BGP
IANA "BGP Well-known Communities" registry but it can't be assumed Well-known Communities" registry but it can't be assumed anymore that
anymore that they will be known by all BGP implementations. they will be known by all BGP implementations. Implementations or
Implementations or BGP policies which recognize them will behave as BGP policies which recognize them will behave as specified.
specified. Implementation which do not recognize those new reserved Implementations which do not recognize those new reserved communities
communities will propagate them from BGP neighbor to BGP neighbor and will propagate them from BGP neighbor to BGP neighbor and from AS to
from AS to AS with an unlimited scope. AS with an unlimited scope.
There is currently no agreed way to reserve a non transitive well There is currently no agreed way to register a non transitive well-
known community: known community:
o [RFC1997] defines BGP Well-known communities with no structure to On one hand, [RFC1997] defines BGP Well-known communities with no
set their transitiveness across ASes. Without structure, non structure to set their transitiveness across ASes. Without
transitive communities can only be filtered by explicitly structure, communities can only be filtered by explicitly enumerating
enumerating all community values that will be denied or allowed to all community values that will be denied or allowed to BGP speakers
BGP speakers in neighboring ASes. This is not satisfactory as in neighboring ASes. This is not satisfactory as this would require
this would require upgrading all border routers to understand this upgrading all border routers to understand this community before its
community before its first usage. first usage.
o [RFC4360] defines the BGP extended community attribute with a
structure including a type and a transitive bit "T". The
transitive bit, when set, allows to restrict the scope of the
community within an AS. But their is no IANA registry to allocate
a (single) well known extended community. RFC 4360 [RFC4360]
defines IANA registries to allocate BGP Extended Communities
types. Each type is able to encode 2^48 or 2^56 values depending
on the type being extended or regular. Therefore, one needing to
reserve a single non-transitive extended community would need to
reserve an extended subtype which represents 2^48 communities,
while a single value is used. This would both waste the resources
and disable the ability to define global policies on reserved
communities, such as to filter them out.
To address this limitation, this document assigns two BGP extended
community types, one transitive and one non-transitive. It also
defines two IANA registries in order to allow the allocation of
reserved transitive and non-transitive extended communities. These
are similar to the existing Well-known BGP communities defined in RFC
1997 but provides a control on inter-AS community advertisement as a
community could be chosen as transitive or non-transitive across
ASes.
2. IANA Considerations On the other hand, [RFC4360] defines the BGP extended community
attribute with a structure including a type and a transitive bit "T".
This transitive bit, when set, allows to restrict the scope of the
community within an AS. But their is no IANA registry to allocate
one well-known extended community. [RFC4360] defines IANA registries
to allocate BGP Extended Communities types. Each type is able to
encode 2^48 or 2^56 values depending on the type being extended or
regular. Therefore, one needing to reserve a single non-transitive
extended community would need to reserve an extended subtype which
represents 2^48 communities, while a single value is used. This
would both waste the resources and disable the ability to define
global policies on reserved communities, such as to accept them or to
filter them out.
IANA is requested to assign, from the registry "BGP Extended To address this limitation, this document defines two IANA registries
Communities Type - extended, transitive type", a type value TBD for in order to allow the registration of transitive and non-transitive
"BGP Reserved transitive extended communities": extended communities. These are similar to the existing Well-known
BGP communities defined in [RFC1997] but provides a control on
inter-AS community advertisement as a community could be chosen as
transitive or non-transitive across ASes.
Registry Name: BGP Extended Communities Type - extended, transitive 2. Assigned extended communities
Name Type Value [I-D.ietf-idr-as4octet-extcomm-generic-subtype] defines a generic
---- ---------- sub-type for the four-octet AS specific extended community. The
BGP Reserved transitive extended communities TBD (e.g. 0x9000) value of the four-octets Global Administrator sub-field contains a
four-octet Autonomous System number. The value of their two-octet
Local Administrator sub-field has semantics defined by the Autonomous
System set in the Global Administrator sub-field.
IANA is requested to assign, from the registry "BGP Extended This document updates [I-D.ietf-idr-as4octet-extcomm-generic-subtype]
Communities Type - extended, non-transitive", a type value TBD for and defines the use of the Local Administrator sub-field when the AS
"BGP Reserved non-transitive extended communities": number encoded in the Global Administrator sub-field has the reserved
value 0.
Registry Name: BGP Extended Communities Type - extended, non-transitive When the AS number encoded in the Global Administrator sub-field has
the reserved value 0, the communities have global significance. The
lists of those communities are maintained by the IANA in the
registries "Assigned transitive extended communities" for the
"transitive generic four-octet AS specific" extended community type
and "Assigned non-transitive extended communities" for the "non-
transitive generic four-octet AS specific" extended community type.
Name Type Value Note that this use of the reserved AS number 0 in the AS field of the
---- ---------- communities is similar to the one defined by [RFC1997] for the BGP
BGP Reserved non-transitive extended communities TBD (e.g. 0xd000) Well-Known communities.
Note to the IANA: suggested value for the two reserved BGP Extended 3. IANA Considerations
Communities extended type are 0x9000 and 0xd000. Otherwise, both
values should be identical, except for their T - Transitive bit (bit
1 as defined in [RFC4360]).
The IANA is requested to create and maintain a registry entitled "BGP The IANA is requested to create and maintain a registry entitled
Reserved transitive extended communities": "Assigned transitive extended communities" with the following
registration procedure:
Registry Name: BGP Reserved transitive extended communities Registry Name: Assigned transitive extended communities
Range Registration Procedures Range Registration Procedures
--------------------------- ------------------------- ----------- -------------------------
0x000000000000-FFFFFFFEFFFF Reserved 0x0000-8000 First Come First Served
0xFFFFFFFF0000-00FFFFFF8000 First Come First Served 0x8001-FFFF Standards Action/Early IANA Allocation
0x00FFFFFF8001-FFFFFFFFFFFF Standards Action/Early IANA Allocation
The IANA is requested to create and maintain a registry entitled "BGP The IANA is requested to create and maintain a registry entitled
Reserved non-transitive extended communities": "Assigned non-transitive extended communities" with the following
registration procedure:
Registry Name: BGP Reserved non-transitive extended communities Registry Name: Assigned non-transitive extended communities
Range Registration Procedures Range Registration Procedures
--------------------------- ------------------------- ----------- -------------------------
0x000000000000-FFFFFFFEFFFF Reserved 0x0000-8000 First Come First Served
0xFFFFFFFF0000-00FFFFFF8000 First Come First Served 0x8001-FFFF Standards Action/Early IANA Allocation
0x00FFFFFF8001-FFFFFFFFFFFF Standards Action/Early IANA Allocation
An application may need both a transitive and non-transitive reserved An application may need both a transitive and a non-transitive
community. It may be beneficial to have the same value for both community and it may be beneficial to have the same value for both
communities. (Note that both extended community will still be communities. (Note that both extended communities will still be
different as they will differ from their T bit). The IANA SHOULD try different as they will differ from their T bit). The IANA SHOULD try
to accommodate such request to have both a transitive and non- to accommodate such request to get both a transitive and non-
transitive reserved community with the same value for both. transitive assigned community with the same value for both.
3. Security Considerations 4. Security Considerations
This document defines IANA actions. In itself, it has no impact on This document defines IANA actions. In itself, it has no impact on
the security of the BGP protocol. the security of the BGP protocol.
4. Normative References 5. Normative References
[I-D.ietf-idr-as4octet-extcomm-generic-subtype]
Rao, D., Mohapatra, P., and J. Haas, "Generic Subtype for
BGP Four-octet AS specific extended community",
draft-ietf-idr-as4octet-extcomm-generic-subtype-03 (work
in progress), October 2010.
[RFC1997] Chandrasekeran, R., Traina, P., and T. Li, "BGP [RFC1997] Chandrasekeran, R., Traina, P., and T. Li, "BGP
Communities Attribute", RFC 1997, August 1996. Communities Attribute", RFC 1997, August 1996.
[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.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, February 2006. Communities Attribute", RFC 4360, February 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
Authors' Addresses Authors' Addresses
Bruno Decraene Bruno Decraene
France Telecom - Orange France Telecom - Orange
38-40 rue du General Leclerc 38 rue du General Leclerc
Issy Moulineaux cedex 9 92794 Issy Moulineaux cedex 9 92794
France France
Email: bruno.decraene@orange-ftgroup.com Email: bruno.decraene@orange-ftgroup.com
Pierre Francois Pierre Francois
UCL Universite catholique de Louvain
Place Ste Barbe, 2 Place Ste Barbe, 2
Louvain-la-Neuve 1348 Louvain-la-Neuve 1348
BE BE
Email: francois@info.ucl.ac.be Email: francois@info.ucl.ac.be
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