draft-ietf-bess-pta-flags-03.txt   rfc7902.txt 
BESS Working Group E. Rosen Internet Engineering Task Force (IETF) E. Rosen
Internet-Draft Juniper Networks, Inc. Request for Comments: 7902 Juniper Networks, Inc.
Updates: 6514 (if approved) T. Morin Updates: 6514 T. Morin
Intended status: Standards Track Orange Category: Standards Track Orange
Expires: November 4, 2016 May 3, 2016 ISSN: 2070-1721 June 2016
Registry and Extensions for Registry and Extensions for
P-Multicast Service Interface Tunnel Attribute Flags P-Multicast Service Interface Tunnel Attribute Flags
draft-ietf-bess-pta-flags-03.txt
Abstract Abstract
The BGP-based control procedures for Multicast Virtual Private The BGP-based control procedures for Multicast Virtual Private
Networks make use of a BGP attribute known as the "P-Multicast Networks (MVPNs) make use of a BGP attribute known as the
Service Interface (PMSI) Tunnel" attribute. The attribute contains a "P-Multicast Service Interface (PMSI) Tunnel" attribute. The
one-octet "Flags" field. The purpose of this document is to attribute contains a one-octet "Flags" field. The purpose of this
establish an IANA registry for the assignment of the bits in this document is to establish an IANA registry for the assignment of the
field. Since the Flags field contains only eight bits, this document bits in this field. Since the "Flags" field contains only eight
also defines a new BGP Extended Community, "Additional PMSI Tunnel bits, this document also defines a new BGP Extended Community,
Attribute Flags", that can be used to carry additional flags for the "Additional PMSI Tunnel Attribute Flags", that can be used to carry
PMSI Tunnel attribute. This document updates RFC 6514. additional flags for the "P-Multicast Service Interface (PMSI)
Tunnel" attribute. This document updates RFC 6514.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on November 4, 2016. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7902.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Extending the PMSI Tunnel Attribute Flags Field . . . . . . . 2 2. Extending the "PMSI Tunnel" Attribute "Flags" Field . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. Normative References . . . . . . . . . . . . . . . . . . . . 6
6. Normative References . . . . . . . . . . . . . . . . . . . . 6 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction 1. Introduction
A BGP attribute known as the "P-Multicast Service Interface (PMSI) A BGP attribute, "P-Multicast Service Interface (PMSI) Tunnel"
Tunnel" attribute is defined in [RFC6514]. This attribute contains a attribute is defined in [RFC6514]. This attribute, referred to as
one-octet "Flags" field. Only one flag is defined in that RFC, but the "PMSI Tunnel" attribute in this document, contains a one-octet
there is now a need to define additional flags. However, that RFC "Flags" field. Only one flag is defined in that RFC, but there is
did not create an IANA registry for the assignment of bits in the now a need to define additional flags. However, that RFC did not
"Flags" field. This document creates a registry for that purpose. create an IANA registry for the assignment of bits in the "Flags"
In addition, there may be a need to define more than eight flags. field. This document creates a registry for that purpose. In
addition, there may be a need to define more than eight flags.
Therefore this document defines a new BGP Extended Community, Therefore this document defines a new BGP Extended Community,
"Additional PMSI Tunnel Attribute Flags", that can be used to carry "Additional PMSI Tunnel Attribute Flags", that can be used to carry
additional flags for the PMSI Tunnel attribute. A registry is also additional flags for the "PMSI Tunnel" attribute. A registry is also
created for this Extended Community, allowing IANA to assign flag created for this Extended Community, allowing IANA to assign flag
bits from the Extended Community's six-octet value field. bits from the Extended Community's six-octet value field.
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. Extending the PMSI Tunnel Attribute Flags Field 2. Extending the "PMSI Tunnel" Attribute "Flags" Field
In [RFC6514], only a single octet in the "PMSI Tunnel" attribute is In [RFC6514], only a single octet in the "PMSI Tunnel" attribute is
defined to carry bit flags. This allows eight flags, which is defined to carry bit flags. This allows eight flags, which is
unlikely to be sufficient for all future applications. unlikely to be sufficient for all future applications.
This document defines a new Transitive Opaque Extended Community This document defines a new Transitive Opaque Extended Community
([RFC4360], [RFC7153]), "Additional PMSI Tunnel Attribute Flags". It ([RFC4360] [RFC7153]), "Additional PMSI Tunnel Attribute Flags". It
also defines a new bit flag in the "PMSI Tunnel" attribute Flags also defines a new bit flag in the "PMSI Tunnel" attribute "Flags"
field, called the "Extension" flag. field, called the "Extension" flag.
The "Additional PMSI Tunnel Attribute Flags" Extended Community MUST The "Additional PMSI Tunnel Attribute Flags" Extended Community MUST
NOT be carried by a given BGP UPDATE message unless the following NOT be carried by a given BGP UPDATE message unless the following
conditions both hold: conditions both hold:
o the given BGP UPDATE message is also carrying a "PMSI Tunnel" o the given BGP UPDATE message is also carrying a "PMSI Tunnel"
attribute, and attribute, and
o the "Extension" flag of that "PMSI Tunnel" attribute's "Flags" o the "Extension" flag of that "PMSI Tunnel" attribute's "Flags"
field is set. field is set.
The six-octet value field of the "Additional PMSI Tunnel Attribute The six-octet value field of the "Additional PMSI Tunnel Attribute
Flags" Extended Community is considered to be a string of 48 bit Flags" Extended Community is considered to be a string of 48 one-bit
flags. As shown in Figure 1, the leftmost bit (the most significant flags. As shown in Figure 1, the leftmost bit (the most significant
bit of the most significant octet) is bit 0, and the rightmost bit bit of the most significant octet) is bit 0, and the rightmost bit
(the least significant bit of the least significant octet) is bit 47. (the least significant bit of the least significant octet) is bit 47.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3 4 3 4
2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Value Field of the Additional PMSI Tunnel Attribute Flags Figure 1: Value Field of the "Additional PMSI
Extended Community Tunnel Attribute Flags" Extended Community
A BGP speaker MUST NOT attach more than one "Additional PMSI Tunnel A BGP speaker MUST NOT attach more than one "Additional PMSI Tunnel
Attribute Flags" Extended Community to a given BGP UPDATE. If a Attribute Flags" Extended Community to a given BGP UPDATE. If a
given BGP UPDATE already contains an "Additional PMSI Tunnel given BGP UPDATE already contains an "Additional PMSI Tunnel
Attribute Flags" Extended Community, a BGP speaker MUST NOT attach Attribute Flags" Extended Community, a BGP speaker MUST NOT attach
any additional such Extended Communities. any additional such Extended Communities.
If a BGP speaker receives a BGP UPDATE with more than one "Additional If a BGP speaker receives a BGP UPDATE with more than one "Additional
PMSI Tunnel Attribute Flags" Extended Communities attached, only the PMSI Tunnel Attribute Flags" Extended Communities attached, only the
flag settings in first occurrence of the Extended Community are flag settings in first occurrence of the Extended Community are
skipping to change at page 4, line 11 skipping to change at page 4, line 22
Suppose a BGP speaker receives an UPDATE message that contains a Suppose a BGP speaker receives an UPDATE message that contains a
"PMSI Tunnel" attribute, but does not contain an "Additional PMSI "PMSI Tunnel" attribute, but does not contain an "Additional PMSI
Tunnel Attribute Flags" Extended Community. If the "Extension" flag Tunnel Attribute Flags" Extended Community. If the "Extension" flag
of the "PMSI Tunnel" attribute is set, the UPDATE is considered to be of the "PMSI Tunnel" attribute is set, the UPDATE is considered to be
malformed, and the "treat-as-withdraw" procedure of [RFC7606] MUST be malformed, and the "treat-as-withdraw" procedure of [RFC7606] MUST be
applied. applied.
If a BGP speaker receives an UPDATE message that contains one or more If a BGP speaker receives an UPDATE message that contains one or more
"Additional PMSI Tunnel Attribute Flags" Extended Communities, but "Additional PMSI Tunnel Attribute Flags" Extended Communities, but
either (a) that UPDATE message does not contain a PMSI Tunnel either (a) that UPDATE message does not contain a "PMSI Tunnel"
attribute, or (b) the Extension flag of the PMSI Tunnel attribute is attribute, or (b) the "Extension" flag of the "PMSI Tunnel" attribute
not set, then the Extended Community(ies) SHOULD be removed and is not set, then the Extended Community(ies) SHOULD be removed and
SHOULD NOT be redistributed. The BGP UPDATE message MUST be SHOULD NOT be redistributed. The BGP UPDATE message MUST be
processed (and if necessary, redistributed) as if the Extended processed (and if necessary, redistributed) as if the Extended
Community(ies) had not been present. Community(ies) had not been present.
A BGP speaker that supports the current document, but does not A BGP speaker that supports the current document, but does not
recognize a particular flag (either in the" PMSI Tunnel" attribute recognize a particular flag (either in the" PMSI Tunnel" attribute
"Flags" field or in the "Additional PMSI Tunnel Attribute Flags" "Flags" field or in the "Additional PMSI Tunnel Attribute Flags"
Extended Community) MUST simply ignore that flag. If the BGP speaker Extended Community) MUST simply ignore that flag. If the BGP speaker
propagates either the PMSI Tunnel attribute or the "Additional PMSI propagates either the "PMSI Tunnel" attribute, the "Additional PMSI
Tunnel Attribute Flags" Extended Community or both along with the Tunnel Attribute Flags" Extended Community, or both along with the
UPDATE message, it SHOULD leave the setting of the flag unchanged. UPDATE message, it SHOULD leave the setting of the flag unchanged.
It is possible that a particular application will require all members It is possible that a particular application will require all members
of a particular set of BGP speakers to support a particular flag. of a particular set of BGP speakers to support a particular flag.
How it is determined whether all such BGP speakers support that flag How it is determined whether all such BGP speakers support that flag
is outside the scope of this document. is outside the scope of this document.
In some situations, a BGP speaker may need to modify or replace the In some situations, a BGP speaker may need to modify or replace the
"PMSI Tunnel" attribute before propagating an UPDATE. If the "PMSI Tunnel" attribute before propagating an UPDATE. If the
"Extension" flag of the "PMSI Tunnel" attribute was set before the "Extension" flag of the "PMSI Tunnel" attribute was set before the
attribute is modified or replaced, but that flag is no longer set attribute is modified or replaced, but that flag is no longer set
after the attribute is modified or replaced, any "Additional PMSI after the attribute is modified or replaced, any "Additional PMSI
Tunnel Attribute Flags" Extended Communities MUST be removed before Tunnel Attribute Flags" Extended Communities MUST be removed before
the UPDATE is propagated. If the PMSI Tunnel attribute is removed the UPDATE is propagated. If the "PMSI Tunnel" attribute is removed
entirely before an UPDATE is propagated, the "Additional PMSI Tunnel entirely before an UPDATE is propagated, the "Additional PMSI Tunnel
Attribute Flags" Extended Communities (if any) MUST also be removed. Attribute Flags" Extended Communities (if any) MUST also be removed.
3. IANA Considerations 3. IANA Considerations
IANA is requested to create a new registry called "P-Multicast IANA has created a new registry called "P-Multicast Service Interface
Service Interface (PMSI) Tunnel Attribute Flags" in the "Border (PMSI) Tunnel Attribute Flags" in the "Border Gateway Protocol (BGP)
Gateway Protocol (BGP) Parameters" registry. Parameters" registry.
Per [RFC6514] section 5, a "PMSI Tunnel" attribute contains a "Flags" Per Section 5 of [RFC6514], a "PMSI Tunnel" attribute contains a
octet. The Flags field is a single octet, with bits numbered, left- "Flags" octet. The "Flags" field is a single octet, with bits
to-right, from 0 to 7. IANA is requested to initialize the registry numbered, left-to-right, from 0 to 7. IANA has initialized the
as follows: registry as follows:
Bit Position Description Reference Bit Position Description Reference
(left to right) (left to right)
0 unassigned 0 unassigned
1 Extension This document 1 Extension This document
2 unassigned 2 unassigned
3 unassigned 3 unassigned
4 unassigned 4 unassigned
5 unassigned 5 unassigned
6 unassigned 6 unassigned
7 Leaf Information Required (L) RFC6514 7 Leaf Information Required (L) RFC 6514
PMSI Tunnel Attribute Flags "PMSI Tunnel" Attribute Flags
The registration procedure for this registry is Standards Action. The registration procedure for this registry is Standards Action.
IANA is also requested to assign a codepoint, from the "First Come, IANA has also assigned the codepoint 0x07 from the "First Come, First
First Served" range of the Transitive Opaque Extended Community Sub- Served" range of the "Transitive Opaque Extended Community Sub-Types"
Types registry, for "Additional PMSI Tunnel Attribute Flags". registry for "Additional PMSI Tunnel Attribute Flags".
[TO BE REMOVED: This registration should take place at the following
location: http://www.iana.org/assignments/bgp-extended-communities
/bgp-extended-communities.xhtml#trans-opaque]
IANA is further requested to establish a registry for the bit flags
carried in the "Additional PMSI Tunnel Attribute Flags" Extended
Community. The bits shall be numbered 0-47, with 0 being the most
significant bit and 47 being the least significant bit. The
registration policy for this registry shall be "Standards Action".
[TO BE REMOVED: The creation of the registry should take place at the
following location: http://www.iana.org/assignments/bgp-extended-
communities/bgp-extended-communities.xhtml]
The initial registry should be as follows:
Bit Flag Name Reference IANA has established a registry for the bit flags carried in the
"Additional PMSI Tunnel Attribute Flags" Extended Community. The
bits are numbered 0-47, with 0 being the most significant bit and 47
being the least significant bit. The registration policy for this
registry is "Standards Action".
0-47 unassigned The initial registry should be as follows:
Additional PMSI Tunnel Attribute Flags Bit Flag Name Reference
4. Acknowledgments 0-47 Unassigned
The authors wish to thank Martin Vigoureux for his review of this Additional "PMSI Tunnel" Attribute Flags
document. We also thank Christian Huitema and Alexey Melnikov for
their review and comments.
5. Security Considerations 4. Security Considerations
This document establishes an IANA registry, and defines a new This document establishes an IANA registry, and defines a new
Transitive Opaque Extended Community ([RFC4360], [RFC7153]). Transitive Opaque Extended Community ([RFC4360], [RFC7153]).
Establishment of an IANA registry does not raise any security Establishment of an IANA registry does not raise any security
considerations. considerations.
While this document defines a new Extended Community for carrying bit While this document defines a new Extended Community for carrying bit
flags, it does not define any of the bit flags in that Extended flags, it does not define any of the bit flags in that Extended
Community. Therefore no security considerations are raised. Community. Therefore, no security considerations are raised.
This document defines a new flag, the "Extension" flag, in the "PMSI This document defines a new flag, the "Extension" flag, in the "PMSI
Tunnel" attribute. If a particular UPDATE contains "PMSI Tunnel" Tunnel" attribute. If a particular UPDATE contains a "PMSI Tunnel"
attribute with this flag set, but the UPDATE does not contain an attribute with this flag set, but the UPDATE does not contain an
"Additional PMSI Tunnel Attribute Flags" Extended Community, then the "Additional PMSI Tunnel Attribute Flags" Extended Community, then the
UPDATE is considered to be malformed, and the "treat-as-withdraw" UPDATE is considered to be malformed, and the "treat-as-withdraw"
procedure of [RFC7606] is invoked. Thus one can cause an UPDATE to procedure of [RFC7606] is invoked. Thus, one can cause an UPDATE to
be treated as a withdrawal by incorrectly setting this bit. be treated as a withdrawal by incorrectly setting this bit.
6. Normative References 5. Normative References
[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, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360, Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <http://www.rfc-editor.org/info/rfc4360>. February 2006, <http://www.rfc-editor.org/info/rfc4360>.
skipping to change at page 7, line 5 skipping to change at page 7, line 5
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP [RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153, Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <http://www.rfc-editor.org/info/rfc7153>. March 2014, <http://www.rfc-editor.org/info/rfc7153>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K. [RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages", Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015, RFC 7606, DOI 10.17487/RFC7606, August 2015,
<http://www.rfc-editor.org/info/rfc7606>. <http://www.rfc-editor.org/info/rfc7606>.
Acknowledgments
The authors wish to thank Martin Vigoureux for his review of this
document. We also thank Christian Huitema and Alexey Melnikov for
their review and comments.
Authors' Addresses Authors' Addresses
Eric C. Rosen Eric C. Rosen
Juniper Networks, Inc. Juniper Networks, Inc.
10 Technology Park Drive 10 Technology Park Drive
Westford, Massachusetts 01886 Westford, Massachusetts 01886
United States United States
Email: erosen@juniper.net Email: erosen@juniper.net
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