draft-ietf-idr-last-as-reservation-05.txt   draft-ietf-idr-last-as-reservation-06.txt 
IDR J. Haas IDR J. Haas
Internet-Draft Juniper Networks Internet-Draft Juniper Networks
Intended status: Informational J. Mitchell Intended status: Informational J. Mitchell
Expires: October 10, 2014 Microsoft Corporation Expires: October 26, 2014 Microsoft Corporation
April 8, 2014 April 24, 2014
Reservation of Last Autonomous System (AS) Numbers Reservation of Last Autonomous System (AS) Numbers
draft-ietf-idr-last-as-reservation-05 draft-ietf-idr-last-as-reservation-06
Abstract Abstract
This document reserves two Autonomous System numbers (ASNs) at the This document reserves two Autonomous System numbers (ASNs) at the
end of the 16 bit and 32 bit ranges, described in this document as end of the 16 bit and 32 bit ranges, described in this document as
"Last ASNs" and provides guidance to implementers and operators on "Last ASNs" and provides guidance to implementers and operators on
their use. their use.
Status of This Memo Status of This Memo
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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 October 10, 2014. This Internet-Draft will expire on October 26, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 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
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bit range, are reserved for use by Well-known communities as bit range, are reserved for use by Well-known communities as
described in [RFC1997] and [IANA.WK]. Although this is not currently described in [RFC1997] and [IANA.WK]. Although this is not currently
true of ASN 4294967295, if there is a future need for another Special true of ASN 4294967295, if there is a future need for another Special
Use ASN that is not designed to be globally routable, or the Use ASN that is not designed to be globally routable, or the
associated BGP communities of such an ASN, ASN 4294967295 could be a associated BGP communities of such an ASN, ASN 4294967295 could be a
valid candidate for such purpose. This document does not prescribe valid candidate for such purpose. This document does not prescribe
any such Special Use to this ASN at the time of publication. any such Special Use to this ASN at the time of publication.
4. Operational Considerations 4. Operational Considerations
Operators SHOULD NOT use these Last ASNs as if they are Private Use Operators SHOULD NOT use these Last ASNs for any other purpose or as
ASNs or for any other purpose. Operational use of these Last ASNs Private Use ASNs. Operational use of these Last ASNs could have
could have undesirable results. For example; use of AS 65535 as if undesirable results. For example; use of AS 65535 as if it were a
it were a Private Use ASN, may result in inadvertent use of BGP Well- Private Use ASN, may result in inadvertent use of BGP Well-known
known Community values [IANA.WK], causing undesireable routing Community values [IANA.WK], causing undesireable routing behavior.
behavior.
These last ASNs MUST NOT be advertised to the global Internet within These last ASNs MUST NOT be advertised to the global Internet within
AS_PATH or AS4_PATH attributes. Operators that choose to do AS_PATH or AS4_PATH attributes. Operators SHOULD filter Last ASNs
filtering of Private Use ASNs within the AS_PATH and AS4_PATH within the AS_PATH and AS4_PATH attributes.
attributes SHOULD also filter these Last ASNs.
5. Implementation Considerations 5. Implementation Considerations
While these Last ASNs are reserved, they remain valid ASNs from a BGP While these Last ASNs are reserved, they remain valid ASNs from a BGP
protocol perspective. Therefore, implementations of BGP [RFC4271] protocol perspective. Therefore, implementations of BGP [RFC4271]
SHOULD NOT treat the use of these Last ASNs as any type of protocol SHOULD NOT treat the use of these Last ASNs as any type of protocol
error. However, implementations MAY generate a local warning message error. However, implementations MAY generate a local warning message
indicating improper use of a reserved ASN. indicating improper use of a reserved ASN.
Implementations that provide tools that filter Private Use ASNs Implementations that provide tools that filter Private Use ASNs
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