draft-ietf-grow-va-auto-03.txt   draft-ietf-grow-va-auto-04.txt 
Network Working Group P. Francis Network Working Group P. Francis
Internet-Draft MPI-SWS Internet-Draft MPI-SWS
Intended status: Informational X. Xu Intended status: Informational X. Xu
Expires: August 26, 2011 Huawei Expires: January 2, 2012 Huawei
H. Ballani H. Ballani
Cornell U. Cornell U.
D. Jen D. Jen
UCLA UCLA
R. Raszuk R. Raszuk
Cisco Cisco
L. Zhang L. Zhang
UCLA UCLA
February 22, 2011 July 1, 2011
Auto-Configuration in Virtual Aggregation Auto-Configuration in Virtual Aggregation
draft-ietf-grow-va-auto-03.txt draft-ietf-grow-va-auto-04.txt
Abstract Abstract
Virtual Aggregation as specified in [I-D.ietf-grow-va] requires Virtual Aggregation as specified in [I-D.ietf-grow-va] requires
configuration of a static "VP-List" on all routers. The VP-List configuration of a static "VP-List" on all routers. The VP-List
allows routers to know which prefixes may or may not be FIB- allows routers to know which prefixes may or may not be FIB-
installed. This draft specified an optional method of determining installed. This draft specified an optional method of determining
this that requires far less configuration. Specifically, it requires this that requires far less configuration. Specifically, it requires
the configuration of a "VP-Range" in ASBRs connected to transit and the configuration of a "VP-Range" in ASBRs connected to transit and
peer ISPs. An Extended Communities Attribute is used to convey to peer ISPs. A Non-transitive Extended Communities Attribute is used
other routers that a given route can be FIB-suppressed. This draft to convey to other routers that a given route can be FIB-suppressed.
has no changes from the 02 draft.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF 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 August 26, 2011. This Internet-Draft will expire on January 2, 2012.
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
skipping to change at page 2, line 23 skipping to change at page 2, line 23
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.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements notation . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . . 3
2. Specification . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Specification . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
5.1. Normative References . . . . . . . . . . . . . . . . . . . 4 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2. Informative References . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction 1. Introduction
As the current VA specification stands ([I-D.ietf-grow-va]), routers As the current VA specification stands ([I-D.ietf-grow-va]), routers
have to know which prefixes they must FIB-install and and which they have to know which prefixes they must FIB-install and which they need
need not FIB-install. The VP-List tells them this: they must FIB- not FIB-install. The VP-List tells them this: they must FIB-install
install routes to Virtual Prefixes (VP), and they need not FIB- routes to Virtual Prefixes (VP), and they need not FIB-install routes
install routes to prefixes that fall within VPs for which they are to prefixes that fall within VPs for which they are not an
not an Aggregation Point Router (APR). The same VP-List must be Aggregation Point Router (APR). The same VP-List must be installed
installed in every router. in every router.
This draft specifies an optional alternative to the VP-List that This draft specifies an optional alternative to the VP-List that
requires far less configuration. Specifically, a list of one or more requires far less configuration. Specifically, a list of one or more
"VP-Ranges" is configured in ASBRs --- typically ASBRs that do not "VP-Ranges" is configured in ASBRs --- typically ASBRs that do not
connect to customer networks. These ASBRs then simply tag routes as connect to customer networks. These ASBRs then simply tag routes as
to whether the route can be suppressed. This is simpler than the to whether the route can be suppressed. This is simpler than the
current configured VP-List approach in two regards. First, fewer current configured VP-List approach in two regards. First, fewer
routers need to be configured. Second, the VP-Range is simpler than routers need to be configured. Second, the VP-Range is simpler than
the VP-List. In most cases, once an ISP is past its initial VA roll- the VP-List. In most cases, once an ISP is past its initial VA roll-
out phase, the VP-Range consists of a single 0/0 entry. out phase, the VP-Range consists of a single 0/0 entry.
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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. Specification 2. Specification
With the "VP-Range" approach to determining suppressability, certain With the "VP-Range" approach to determining suppressability, certain
ASBRs are designated as "tagging routers". Tagging routers ASBRs are designated as "tagging routers". Tagging routers
explicitly tag routes with an Extended Communities Attribute that explicitly tag routes with a Non-transitive Extended Communities
indicates whether the route can be FIB-suppressed. All ASBRs that Attribute that indicates whether the route can be FIB-suppressed.
connect to one or more transit provider ISPs MUST be tagging routers. All ASBRs that connect to one or more transit provider ISPs MUST be
ASBRs that connect to one or more peer ISPs SHOULD be tagging tagging routers. ASBRs that connect to one or more peer ISPs SHOULD
routers. ASBRs that connect to customer networks SHOULD NOT be be tagging routers. ASBRs that connect to customer networks SHOULD
tagging routers. NOT be tagging routers.
Tagging routers are configured with a "VP-Range" list. This consists Tagging routers are configured with a "VP-Range" list. This consists
of the ranges of IP address that are collectively covered by all VPs of the ranges of IP address that are collectively covered by all VPs
in the AS. In a mature deployment of VA, the range would amount to in the AS. In a mature deployment of VA, the range would amount to
all IP addresses, in which case the VP-Range is simply 0/0. Early in all IP addresses, in which case the VP-Range is simply 0/0. Early in
VA deployment, when an ISP is still in the testing or roll-out phase, VA deployment, when an ISP is still in the testing or roll-out phase,
the VP-Range may consist of multiple entries. the VP-Range may consist of multiple entries.
Tagging routers SHOULD tag any route whose prefix falls within the Tagging routers SHOULD tag any route whose prefix falls within the
VP-Range with a "can-suppress" tag, with the following exceptions: VP-Range with a "can-suppress" tag, with the following exceptions:
1. Tagging routers MUST NOT tag VP routes with can-suppress (where a 1. Tagging routers MUST NOT tag VP routes with can-suppress (where a
VP route is that route to the VP that the router originates in VP route is that route to the VP that the router originates in
its role as an APR). its role as an APR).
2. If the ISP has a policy of FIB-installing customer routes, then 2. If the ISP has a policy of FIB-installing customer routes, then
routes received from customers SHOULD NOT be tagged with can- routes received from customers SHOULD NOT be tagged with can-
suppress. suppress.
The can-suppress tag itself is an Extended Communities Attribute The can-suppress tag itself is an Extended Communities Attribute
[RFC4360] to be assigned by IANA. The Transitive Bit MUST be set to [RFC4360] to be assigned by IANA from the "well-known" pool define in
value 1 (the community is non-transitive across ASes). [I-D.ietf-idr-reserved-extended-communities]. The Transitive Bit
MUST be set to value 1 (the community is non-transitive across ASes).
Routers install or suppress FIB entries according to the following Routers install or suppress FIB entries according to the following
rules. Note that tagging routers conceptually follow these rules rules. Note that tagging routers conceptually follow these rules
after tagging (or not tagging) the route. Note also that these rules after tagging (or not tagging) the route. Note also that these rules
apply only to the route used by the router as the best route. In apply only to the route used by the router as the best route. In
other words, if a router receives two routes for the same prefix, and other words, if a router receives two routes for the same prefix, and
one route is tagged can-suppress and the other is not, the router one route is tagged can-suppress and the other is not, the router
follows these rules only with respect to the route that it selects as follows these rules only with respect to the route that it selects as
the best route. the best route.
1. Routes without the can-suppress tag MUST be FIB-installed. 1. Routes without the can-suppress tag MUST be FIB-installed.
2. APRs MUST FIB-install routes for sub-prefixes that fall within 2. APRs MUST FIB-install routes for sub-prefixes that fall within
the APR's VPs, whether or not the route is tagged can-suppress. the APR's VPs, whether or not the route is tagged can-suppress.
3. Otherwise, routers MAY FIB-suppress routes tagged as can- 3. Otherwise, routers MAY FIB-suppress routes tagged as can-
suppress. suppress.
3. IANA Considerations 3. IANA Considerations
IANA must assign type values for the Extended Communities Attributes IANA is requested to assign, from the registry "BGP Assigned non-
that convey the tags. transitive extended communities", a value TBD for "VA can suppress":
Registry Name: BGP Assigned non-transitive extended
communities
Name Type Value
---- ----------
VA can suppress TBD
4. Security Considerations 4. Security Considerations
As of this writing, there are no known new security threats As of this writing, there are no known new security threats
introduced by this draft. introduced by this draft.
5. References 5. Acknowledgements
5.1. Normative References The authors would like to thank Wes George and Bruno Decraene for
their reviews and suggestions.
6. References
6.1. Normative References
[I-D.ietf-grow-va] [I-D.ietf-grow-va]
Francis, P., Xu, X., Ballani, H., Jen, D., Raszuk, R., and Francis, P., Xu, X., Ballani, H., Jen, D., Raszuk, R., and
L. Zhang, "FIB Suppression with Virtual Aggregation", L. Zhang, "FIB Suppression with Virtual Aggregation",
draft-ietf-grow-va-01 (work in progress), Oct 2009. draft-ietf-grow-va-04 (work in progress), Oct 2009.
[I-D.ietf-idr-reserved-extended-communities]
Decraene, B. and P. Francois, "Assigned BGP extended
communities",
draft-ietf-idr-reserved-extended-communities-01 (work in
progress), May 2011.
[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.
5.2. Informative References 6.2. Informative References
Authors' Addresses Authors' Addresses
Paul Francis Paul Francis
Max Planck Institute for Software Systems Max Planck Institute for Software Systems
Gottlieb-Daimler-Strasse Gottlieb-Daimler-Strasse
Kaiserslautern 67633 Kaiserslautern 67633
Germany Germany
Phone: +49 631 930 39600 Phone: +49 631 930 39600
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