draft-ietf-grow-collection-communities-04.txt   draft-ietf-grow-collection-communities-05.txt 
INTERNET-DRAFT D. Meyer INTERNET-DRAFT D. Meyer
draft-ietf-grow-collection-communities-04.txt draft-ietf-grow-collection-communities-05.txt
Category Best Current Practice Category Best Current Practice
Expires: September 2004 March 2004 Expires: March 2005 September 2004
BGP Communities for Data Collection BGP Communities for Data Collection
<draft-ietf-grow-collection-communities-04.txt> <draft-ietf-grow-collection-communities-05.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is subject to all provisions Status of this Memo
of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering This document is an Internet-Draft and is subject to all
Task Force (IETF), its areas, and its working groups. Note that provisions of section 3 of RFC 3667. By submitting this
other groups may also distribute working documents as Internet- Internet-Draft, each author represents that any applicable
Drafts. patent or other IPR claims of which he or she is aware have
been or will be disclosed, and any of which he or she become
aware will be disclosed, in accordance with RFC 3668.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are working documents of the Internet
and may be updated, replaced, or obsoleted by other documents at any Engineering Task Force (IETF), its areas, and its working
time. It is inappropriate to use Internet-Drafts as reference groups. Note that other groups may also distribute working
material or to cite them other than as "work in progress." documents as Internet-Drafts.
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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed
http://www.ietf.org/shadow.html at http://www.ietf.org/shadow.html.
This document is a product of the GROW WG. Comments should be This document is a product of the GROW WG. Comments should be
addressed to the authors, or the mailing list at addressed to the authors, or the mailing list at
grow@lists.uoregon.edu. grow@lists.uoregon.edu.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved. Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract Abstract
skipping to change at page 3, line 13 skipping to change at page 3, line 13
route collectors. route collectors.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Peers and Peering . . . . . . . . . . . . . . . . . . . . . 5 2.1. Peers and Peering . . . . . . . . . . . . . . . . . . . . . 5
2.2. Customer Routes . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Customer Routes . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Peer Routes . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Peer Routes . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Internal Routes . . . . . . . . . . . . . . . . . . . . . . 5 2.4. Internal Routes . . . . . . . . . . . . . . . . . . . . . . 5
2.5. Internal More Specific Routes . . . . . . . . . . . . . . . 6 2.5. Internal More Specific Routes . . . . . . . . . . . . . . . 5
2.6. Special Purpose Routes. . . . . . . . . . . . . . . . . . . 6 2.6. Special Purpose Routes. . . . . . . . . . . . . . . . . . . 6
2.7. Upstream Routes . . . . . . . . . . . . . . . . . . . . . . 6 2.7. Upstream Routes . . . . . . . . . . . . . . . . . . . . . . 6
2.8. National Routes . . . . . . . . . . . . . . . . . . . . . . 6 2.8. National Routes . . . . . . . . . . . . . . . . . . . . . . 6
2.9. Regional Routes . . . . . . . . . . . . . . . . . . . . . . 6 2.9. Regional Routes . . . . . . . . . . . . . . . . . . . . . . 6
3. RFC 1997 Community Encoding and Values . . . . . . . . . . . . 7 3. RFC 1997 Community Encoding and Values . . . . . . . . . . . . 7
3.1. Community Values for BGP Data Collection. . . . . . . . . . 7 3.1. Community Values for BGP Data Collection. . . . . . . . . . 7
4. Extended Communities . . . . . . . . . . . . . . . . . . . . . 9 4. Extended Communities . . . . . . . . . . . . . . . . . . . . . 9
4.1. Four-octet AS specific extended communities . . . . . . . . 10 4.1. Four-octet AS specific extended communities . . . . . . . . 11
5. Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . 10 5. Note on BGP Update Packing . . . . . . . . . . . . . . . . . . 11
6. Security Considerations. . . . . . . . . . . . . . . . . . . . 12 6. Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Total Path Attribute Length . . . . . . . . . . . . . . . . 12 7. Security Considerations. . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 12 7.1. Total Path Attribute Length . . . . . . . . . . . . . . . . 13
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 8. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 13
8.1. Normative References. . . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.2. Informative References. . . . . . . . . . . . . . . . . . . 13 9.1. Normative References. . . . . . . . . . . . . . . . . . . . 14
9. Author's Addresses . . . . . . . . . . . . . . . . . . . . . . 14 9.2. Informative References. . . . . . . . . . . . . . . . . . . 14
10. Full Copyright Statement. . . . . . . . . . . . . . . . . . . 14 10. Author's Addresses. . . . . . . . . . . . . . . . . . . . . . 15
11. Intellectual Property . . . . . . . . . . . . . . . . . . . . 15
12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
BGP communities [RFC1997] are used by service providers for many BGP communities [RFC1997] are used by service providers for many
purposes, including tagging of customer, peer, and geographically purposes, including tagging of customer, peer, and geographically
originated routes. Such tagging is typically used to control the originated routes. Such tagging is typically used to control the
scope of redistribution of routes within a providers network, and to scope of redistribution of routes within a providers network, and to
its customers and peers. Communities are also used for a wide variety its customers and peers. Communities are also used for a wide variety
of other applications, such as allowing customers to set attributes of other applications, such as allowing customers to set attributes
such as LOCAL_PREF [RFC1771] by sending appropriate communities to such as LOCAL_PREF [RFC1771] by sending appropriate communities to
skipping to change at page 4, line 40 skipping to change at page 4, line 40
implement this scheme (as there is a large amount of existing data as implement this scheme (as there is a large amount of existing data as
well as many legacy peerings). well as many legacy peerings).
The remainder of this document is organized as follows. Section 2 The remainder of this document is organized as follows. Section 2
provides both the definition of terms used as well as the semantics provides both the definition of terms used as well as the semantics
of the communities used for BGP data collection, and section 3 of the communities used for BGP data collection, and section 3
defines the corresponding encodings for RFC 1997 [RFC1997] defines the corresponding encodings for RFC 1997 [RFC1997]
communities. Finally, section 4 defines the encodings for use with communities. Finally, section 4 defines the encodings for use with
extended communities [EXTCOMM]. extended communities [EXTCOMM].
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 BCP 14, RFC 2119
[RFC2119].
2. Definitions 2. Definitions
In this section, we define the terms used and the categories of In this section, we define the terms used and the categories of
routes that may be tagged with communities. This tagging is often routes that may be tagged with communities. This tagging is often
referred to coloring, and we refer to a route's "color" as its referred to coloring, and we refer to a route's "color" as its
community value. The categories defined here are loosely modeled on community value. The categories defined here are loosely modeled on
those described in [WANG] and [HUSTON]. those described in [WANG] and [HUSTON].
2.1. Peers and Peering 2.1. Peers and Peering
skipping to change at page 6, line 7 skipping to change at page 5, line 37
propagated to the service provider's customers. propagated to the service provider's customers.
2.4. Internal Routes 2.4. Internal Routes
Internal routes are those routes that a service provider originates Internal routes are those routes that a service provider originates
and passes to its peers and customers. These routes are frequently and passes to its peers and customers. These routes are frequently
taken out of the address space allocated to a provider. taken out of the address space allocated to a provider.
2.5. Internal More Specific Routes 2.5. Internal More Specific Routes
Internal more specific routes are those routes which are frequently Internal more-specific routes are those routes which are frequently
used for circuit load balancing purposes, IGP route reduction, and used for circuit load balancing purposes, IGP route reduction, and
also may correspond to customer services which are not visible also may correspond to customer services which are not visible
outside the service provider's network. Internal more specific routes outside the service provider's network. Internal more specific routes
are not exported to any external peer. are not exported to any external peer.
2.6. Special Purpose Routes 2.6. Special Purpose Routes
Special purpose routes are those routes which do not fall into any of Special purpose routes are those routes which do not fall into any of
the other classes described here. In those cases in which such routes the other classes described here. In those cases in which such routes
need to be distinguished, a service provider may color such routes need to be distinguished, a service provider may color such routes
skipping to change at page 6, line 36 skipping to change at page 6, line 30
2.8. National Routes 2.8. National Routes
These are route sets that are sourced from and/or received within a These are route sets that are sourced from and/or received within a
particular country. particular country.
2.9. Regional Routes 2.9. Regional Routes
Several global backbones implement regional policy based on their Several global backbones implement regional policy based on their
deployed footprint, and on strategic and business imperatives. deployed footprint, and on strategic and business imperatives.
Service providers often have settlement free interconnections with an Service providers often have settlement-free interconnections with an
AS in one region, and that same AS is a customer in another region. AS in one region, and that same AS is a customer in another region.
This mandates use of regional routing, including community attributes This mandates use of regional routing, including community attributes
set by the network in question to allow easy discrimination among set by the network in question to allow easy discrimination among
regional routes. For example, service providers may treat a route set regional routes. For example, service providers may treat a route set
received from another service provider in Europe differently than the received from another service provider in Europe differently than the
same route set received in North America, as it is common practice to same route set received in North America, as it is common practice to
sell transit in one region while peering in the other. sell transit in one region while peering in the other.
3. RFC 1997 Community Encoding and Values 3. RFC 1997 Community Encoding and Values
skipping to change at page 7, line 29 skipping to change at page 7, line 24
order two octets to represent the providers AS number, and the low order two octets to represent the providers AS number, and the low
order two octets to represent the classification of the route, as order two octets to represent the classification of the route, as
depicted below: depicted below:
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| <AS> | <Value> | | <AS> | <Value> |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where <AS> 16 bit AS number, and <Value> is the encoding of the where <AS> 16 bit AS number. For example, the encoding 0x2A7C029A
value. For example, the encoding 0x2A7C029A would represent the AS would represent the AS 10876 with value 666.
10876 with value 666.
3.1. Community Values for BGP Data Collection 3.1. Community Values for BGP Data Collection
In this section we define the RFC 1997 community encoding for the In this section we define the RFC 1997 community encoding for the
route types described above for use in BGP data collection. It is route types described above for use in BGP data collection. It is
anticipated that a service provider's internal community values will anticipated that a service provider's internal community values will
be converted to these standard values for output to a route be converted to these standard values for output to a route
collector. collector.
This document follows the best current practice of using the basic This document follows the best current practice of using the basic
skipping to change at page 8, line 14 skipping to change at page 8, line 14
Category Value Category Value
=============================================================== ===============================================================
Reserved <AS>:0000000000000000 Reserved <AS>:0000000000000000
Customer Routes <AS>:0000000000000001 Customer Routes <AS>:0000000000000001
Peer Routes <AS>:0000000000000010 Peer Routes <AS>:0000000000000010
Internal Routes <AS>:0000000000000011 Internal Routes <AS>:0000000000000011
Internal More Specific Routes <AS>:0000000000000100 Internal More Specific Routes <AS>:0000000000000100
Special Purpose Routes <AS>:0000000000000101 Special Purpose Routes <AS>:0000000000000101
Upstream Routes <AS>:0000000000000110 Upstream Routes <AS>:0000000000000110
Reserved <AS>:0000000000000011- Reserved <AS>:0000000000000111-
<AS>:0000111111111111 <AS>:0000011111111111
National and Regional Routes <AS>:0001000000000000- National and Regional Routes <AS>:0000100000000000-
<AS>:1111111111111111 <AS>:1111111111111111
Africa (AF) <AS>:0001<X><CC> Africa (AF) <AS>:<R><X><CC>
Oceania (OC) <AS>:0010<X><CC> Oceania (OC) <AS>:<R><X><CC>
Asia (AS) <AS>:0011<X><CC> Asia (AS) <AS>:<R><X><CC>
Antarctica (AQ) <AS>:0100<X><CC> Antarctica (AQ) <AS>:<R><X><CC>
Europe (EU) <AS>:0101<X><CC> Europe (EU) <AS>:<R><X><CC>
Latin America/Caribbean islands (LAC) <AS>:0110<X><CC> Latin America/Caribbean islands (LAC) <AS>:<R><X><CC>
North America (NA) <AS>:0111<X><CC> North America (NA) <AS>:<R><X><CC>
Reserved <AS>:1000000000000000- Reserved <AS>:0100000000000000-
<AS>:1111111111111111 <AS>:1111111111111111
In the above table, Where
<AS> is the 16-bit AS <AS> is the 16-bit AS
<R> is the 5-bit Region <R> is the 5-bit Region Identifier
<X> is 1-bit satellite link indication (1 if satellite link, 0 otherwise) <X> is the 1-bit satellite link indication
X = 1 for satellite links, 0 otherwise
<CC> is the 10-bit ISO-3166-2 country code <CC> is the 10-bit ISO-3166-2 country code
and <R> takes the values:
Africa (AF) 00001
Oceania (OC) 00010
Asia (AS) 00011
Antarctica (AQ) 00100
Europe (EU) 00101
Latin America/Caribbean Islands (LAC) 00110
North America (NA) 00111
Reserved 01000-11111
That is: That is:
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| <AS> | <R> |X| <CC> | | <AS> | <R> |X| <CC> |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
For example, the encoding for a national route over a terrestrial For example, the encoding for a national route over a terrestrial
link in AS 10876 from the Fiji Islands would be: link in AS 10876 from the Fiji Islands would be:
<AS> = 10876 = 0x2A7B <AS> = 10876 = 0x2A7C
<R> = OC = 0010 <R> = 00010
<X> = 0x0 <X> = 0
<CC> = Fiji Islands Country Code = 242 = 0011110010 <CC> = Fiji Islands Country Code = 242 = 0011110010
so that the low order 16 bits look like 001000011110010 = 0x10F2. In this case, the low order 16 bits are 0001000011110010 = 0x10F2
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x2A7C | 0x10F2 | | 0x2A7C | 0x10F2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note that a configuration language might allow the specification of Note that a configuration language might allow the specification of
this community as 10876:4338 (0x1F2 == 4338 decimal). this community as 10876:4338 (0x10F2 == 4338 decimal).
Finally, note that these categories are not intended to be mutually Finally, note that these categories are not intended to be mutually
exclusive, and multiple communities can be attached where exclusive, and multiple communities can be attached where
appropriate. appropriate.
4. Extended Communities 4. Extended Communities
In some cases, the encoding described in section 3.1 may clash with a In some cases, the encoding described in section 3.1 may clash with a
service provider's existing community assignments. Extended service provider's existing community assignments. Extended
communities [EXTCOMM] provide a convenient mechanism that can be used communities [EXTCOMM] provide a convenient mechanism that can be used
skipping to change at page 10, line 41 skipping to change at page 11, line 20
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 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 | 0x05 | Global Administrator | | 0x02 | 0x05 | Global Administrator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Global Administrator (cont.) | 0x10F2 | | Global Administrator (cont.) | 0x10F2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In this case, the 4 octet Global Administrator sub-field contains a In this case, the 4 octet Global Administrator sub-field contains a
4-octets Autonomous System number assigned by the IANA. 4-octets Autonomous System number assigned by the IANA.
5. Acknowledgments 5. Note on BGP Update Packing
Note that data collection communities have the potential of making
the attribute set of a specific route more unique than it would be
otherwise (since each route collects data that is specific to it's
path inside one or more ASes). This, in turn, can affect whether
multiple routes can be grouped in the same BGP update message, and
may lead to increased use of bandwidth, router CPU cycles, and
memory.
6. Acknowledgments
The community encoding described in this document germinated from an The community encoding described in this document germinated from an
interesting suggestion from Akira Kato at WIDE. In particular, the interesting suggestion from Akira Kato at WIDE. In particular, the
idea would be to use the collection community values to select paths idea would be to use the collection community values to select paths
that would result in (hopefully) more efficient access to various that would result in (hopefully) more efficient access to various
services. For example, in the case of RFC 3258 [RFC3258] based DNS services. For example, in the case of RFC 3258 [RFC3258] based DNS
anycast service, BGP routers may see multiple paths to the same anycast service, BGP routers may see multiple paths to the same
prefix, and others might be coming from the same origin with prefix, and others might be coming from the same origin with
different paths, but others might be from different region/country different paths, but others might be from different region/country
(with the same origin AS). (with the same origin AS).
Joe Abley, Randy Bush, Sean Donelan, Xenofontas Dimitropoulos, Vijay Joe Abley, Randy Bush, Sean Donelan, Xenofontas Dimitropoulos, Vijay
Gill, John Heasley, Geoff Huston, Steve Huter, Olivier Marce, Ryan Gill, John Heasley, Geoff Huston, Steve Huter, Michael Patton,
McDowell, Rob Rockell, Rob Thomas, Pekka Savola, and Patrick Verkaik Olivier Marce, Ryan McDowell, Rob Rockell, Rob Thomas, Pekka Savola,
all made many insightful comments on early versions of this draft. Patrick Verkaik and Alex Zinin all made many insightful comments on
Henk Uijterwaal suggested the use of the ISO-3166-2 country codes. early versions of this draft. Henk Uijterwaal suggested the use of
the ISO-3166-2 country codes.
6. Security Considerations 7. Security Considerations
While this document introduces no additional security considerations While this document introduces no additional security considerations
into the BGP protocol, the information contained in the communities into the BGP protocol, the information contained in the communities
defined in this document may in some cases reveal network structure defined in this document may in some cases reveal network structure
that was not previously visible outside the provider's network. As a that was not previously visible outside the provider's network. As a
result, care should be taken when exporting such communities to route result, care should be taken when exporting such communities to route
collectors. Finally, routes exported to a route collector should also collectors. Finally, routes exported to a route collector should also
be tagged with the NO_EXPORT community (0xFFFFFF01). be tagged with the NO_EXPORT community (0xFFFFFF01).
6.1. Total Path Attribute Length 7.1. Total Path Attribute Length
The communities described in this document are intended for use on The communities described in this document are intended for use on
egress to a route collector. Hence an operator may choose to egress to a route collector. Hence an operator may choose to
overwrite its internal communities with the values specified in this overwrite its internal communities with the values specified in this
document when exporting routes to a route collector. However, document when exporting routes to a route collector. However,
operators should in general ensure that the behavior of their BGP operators should in general ensure that the behavior of their BGP
implementation is well-defined when the addition of an attribute implementation is well-defined when the addition of an attribute
causes a PDU to exceed 4096 octets. For example, since it is common causes a PDU to exceed 4096 octets. For example, since it is common
practice to use community attributes to implement policy (among other practice to use community attributes to implement policy (among other
functionality such as allowing customers to set attributes such as functionality such as allowing customers to set attributes such as
LOCAL_PREF), the behavior of an implementation when the attribute LOCAL_PREF), the behavior of an implementation when the attribute
space overflows is crucial. Among other behaviors, an implementation space overflows is crucial. Among other behaviors, an implementation
might usurp the intended attribute data or otherwise cause might usurp the intended attribute data or otherwise cause
indeterminate failures. These behaviors can result in unanticipated indeterminate failures. These behaviors can result in unanticipated
community attribute sets, and hence result in unintended policy community attribute sets, and hence result in unintended policy
implications. implications.
7. IANA Considerations 8. IANA Considerations
This document assigns a new Sub-Type for the AS specific extended This document assigns a new Sub-Type for the AS specific extended
community type. In particular, the IANA should assign Sub-type 0x05, community type. In particular, the IANA should assign Sub-type 0x05,
using the "First Come First Served" policy defined in RFC 2434 using the "First Come First Served" policy defined in RFC 2434
[RFC2434], for the Sub-Type defined in Section 4. This corresponds to [RFC2434], for the Sub-Type defined in Section 4. This corresponds to
a Type Field value of 0x0005. a Type Field value of 0x0005.
8. References 9. References
8.1. Normative References 9.1. Normative References
[EXTCOMM] Sangali, S., D. Tappan and Y. Rekhter, "BGP Extended [EXTCOMM] Sangali, S., D. Tappan and Y. Rekhter, "BGP Extended
Communities Attribute", draft-ietf-idr-bgp-ext-communities-06.txt, Communities Attribute", draft-ietf-idr-bgp-ext-communities-07.txt,
Work in progress. Work in progress.
[ISO-3166-2] http://www.iso.org/iso/en/prods-services/iso3166ma/index.html [ISO-3166-2] http://www.iso.org/iso/en/prods-services/iso3166ma/index.html
[RIS-ISO-3166] ftp://ftp.ripe.net/iso3166-countrycodes.txt [RIS-ISO-3166] ftp://ftp.ripe.net/iso3166-countrycodes.txt
[RFC1771] Rekhter, Y. and T. Li (Editors), "A Border [RFC1771] Rekhter, Y. and T. Li (Editors), "A Border
Gateway Protocol (BGP-4)", RFC 1771, March 1995. Gateway Protocol (BGP-4)", RFC 1771, March 1995.
[RFC1997] Chandra, R. and P. Traina, "BGP Communities [RFC1997] Chandra, R. and P. Traina, "BGP Communities
Attribute", RFC 1997, August 1996. Attribute", RFC 1997, August 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to 9.2. Informative References
Indicate Requirement Levels", BCP 14, RFC 2119,
March 1997.
8.2. Informative References
[HUSTON] Huston, G., "Interconnection, Peering, and Settlements", [HUSTON] Huston, G., "Interconnection, Peering, and Settlements",
http://www.isoc.org/inet99/proceedings/1e/1e_1.htm http://www.isoc.org/inet99/proceedings/1e/1e_1.htm
[RFC2028] Hovey, R. and S. Bradner, "The Organizations [RFC2028] Hovey, R. and S. Bradner, "The Organizations
Involved in the IETF Standards Process", BCP 11, Involved in the IETF Standards Process", BCP 11,
RFC 2028, October 1996. RFC 2028, October 1996.
[RFC2434] Narten, T., and H. Alvestrand, "Guidelines for [RFC2434] Narten, T., and H. Alvestrand, "Guidelines for
Writing an IANA Considerations Section in RFCs", Writing an IANA Considerations Section in RFCs",
BCP 26, RFC 2434, October 1998. BCP 26, RFC 2434, October 1998.
[RFC3258] Hardie, T., "Distributing Authoritative Name [RFC3258] Hardie, T., "Distributing Authoritative Name
Servers via Shared Unicast Addresses", RFC 3258, Servers via Shared Unicast Addresses", RFC 3258,
April 2002. April 2002.
[RIS] "Routing Information Service", http://www.ripe.net/ris [RIS] "Routing Information Service", http://www.ripe.net/ris
[ROUTEVIEWS] "The Routeviews Project", http://www.routeviews.org [ROUTEVIEWS] "The Routeviews Project", http://www.routeviews.org
[VPLS] Kompella, K., et al., "Virtual Private LAN [VPLS] Kompella, K., et al., "Virtual Private LAN
Service", draft-ietf-l2vpn-vpls-bgp-01.txt, Service", draft-ietf-l2vpn-vpls-bgp-02.txt,
Work in Progress. Work in Progress.
[WANG] Wang, F. and L. Gao, "Inferring and Characterizing [WANG] Wang, F. and L. Gao, "Inferring and Characterizing
Internet Routing Policies", ACM SIGCOMM Internet Internet Routing Policies", ACM SIGCOMM Internet
Measurement Conference 2003. Measurement Conference 2003.
9. Author's Addresses 10. Author's Addresses
David Meyer David Meyer
EMail: dmm@1-4-5.net EMail: dmm@1-4-5.net
10. Full Copyright Statement Intellectual Property Statement
Copyright (C) The Internet Society (2004). 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 translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS 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 WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
11. Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights 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 might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an 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 attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf- this standard. Please address the information to the IETF at
ipr@ietf.org. ietf-ipr@ietf.org.
12. Acknowledgement Disclaimer of Validity
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 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
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2004). 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.
Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/