draft-ietf-bier-ospf-bier-extensions-07.txt   draft-ietf-bier-ospf-bier-extensions-08.txt 
OSPF P. Psenak, Ed. OSPF P. Psenak, Ed.
Internet-Draft N. Kumar Internet-Draft N. Kumar
Intended status: Standards Track IJ. Wijnands Intended status: Standards Track IJ. Wijnands
Expires: January 4, 2018 Cisco Expires: April 6, 2018 Cisco
A. Dolganow A. Dolganow
Nokia Nokia
T. Przygienda T. Przygienda
J. Zhang J. Zhang
Juniper Networks, Inc. Juniper Networks, Inc.
S. Aldrin S. Aldrin
Google, Inc. Google, Inc.
July 3, 2017 October 3, 2017
OSPF Extensions for BIER OSPF Extensions for BIER
draft-ietf-bier-ospf-bier-extensions-07.txt draft-ietf-bier-ospf-bier-extensions-08.txt
Abstract Abstract
Bit Index Explicit Replication (BIER) is an architecture that Bit Index Explicit Replication (BIER) is an architecture that
provides multicast forwarding through a "BIER domain" without provides multicast forwarding through a "BIER domain" without
requiring intermediate routers to maintain multicast related per-flow requiring intermediate routers to maintain multicast related per-flow
state. Neither does BIER require an explicit tree-building protocol state. Neither does BIER require an explicit tree-building protocol
for its operation. A multicast data packet enters a BIER domain at a for its operation. A multicast data packet enters a BIER domain at a
"Bit-Forwarding Ingress Router" (BFIR), and leaves the BIER domain at "Bit-Forwarding Ingress Router" (BFIR), and leaves the BIER domain at
one or more "Bit-Forwarding Egress Routers" (BFERs). The BFIR router one or more "Bit-Forwarding Egress Routers" (BFERs). The BFIR router
skipping to change at page 1, line 45 skipping to change at page 1, line 45
with MPLS encapsulation. with MPLS encapsulation.
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.
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 https://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 January 4, 2018. This Internet-Draft will expire on April 6, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 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 (https://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.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Flooding of the BIER Information in OSPF . . . . . . . . . . 3 2. Flooding of the BIER Information in OSPF . . . . . . . . . . 3
2.1. BIER Sub-TLV . . . . . . . . . . . . . . . . . . . . . . 3 2.1. BIER Sub-TLV . . . . . . . . . . . . . . . . . . . . . . 3
2.2. BIER MPLS Encapsulation Sub-TLV . . . . . . . . . . . . . 4 2.2. BIER MPLS Encapsulation Sub-TLV . . . . . . . . . . . . . 4
2.3. Optional BIER Tree Type Sub-TLV . . . . . . . . . . . . . 5 2.3. Optional BIER Tree Type Sub-TLV . . . . . . . . . . . . . 5
2.4. Optional BIER sub-domain BSL conversion Sub-TLV . . . . . 6 2.4. Optional BIER sub-domain BSL conversion Sub-TLV . . . . . 6
2.5. Flooding scope of BIER Information . . . . . . . . . . . 7 2.5. Flooding scope of BIER Information . . . . . . . . . . . 7
3. Security Considerations . . . . . . . . . . . . . . . . . . . 7 3. Security Considerations . . . . . . . . . . . . . . . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. BIER Tree Type Registry . . . . . . . . . . . . . . . . . 8
6. Normative References . . . . . . . . . . . . . . . . . . . . 8 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 6. Normative References . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. Introduction
Bit Index Explicit Replication (BIER) is an architecture that Bit Index Explicit Replication (BIER) is an architecture that
provides optimal multicast forwarding through a "BIER domain" without provides optimal multicast forwarding through a "BIER domain" without
requiring intermediate routers to maintain any multicast related per- requiring intermediate routers to maintain any multicast related per-
flow state. Neither does BIER explicitly require a tree-building flow state. Neither does BIER explicitly require a tree-building
protocol for its operation. A multicast data packet enters a BIER protocol for its operation. A multicast data packet enters a BIER
domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the
BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs). BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs).
skipping to change at page 4, line 4 skipping to change at page 4, line 4
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-domain-ID | MT-ID | BFR-id | | Sub-domain-ID | MT-ID | BFR-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) | | Sub-TLVs (variable) |
+- -+ +- -+
| | | |
Type: TBD1 Type: TBD1
Length: variable Length: Variable, dependent on sub-TLVs.
Sub-domain-ID: Unique value identifying the BIER sub-domain within Sub-domain-ID: Unique value identifying the BIER sub-domain within
the BIER domain, as described in section 1 of the BIER domain, as described in section 1 of
[I-D.ietf-bier-architecture]. [I-D.ietf-bier-architecture].
MT-ID: Multi-Topology ID (as defined in [RFC4915]) that identifies MT-ID: Multi-Topology ID (as defined in [RFC4915]) that identifies
the topology that is associated with the BIER sub-domain. the topology that is associated with the BIER sub-domain.
BFR-id: A 2 octet field encoding the BFR-id, as documented in BFR-id: A 2 octet field encoding the BFR-id, as documented in
section 2 of [I-D.ietf-bier-architecture]. If the BFR is not section 2 of [I-D.ietf-bier-architecture]. If the BFR is not
skipping to change at page 4, line 49 skipping to change at page 4, line 49
The BIER MPLS Encapsulation Sub-TLV has the following format: The BIER MPLS Encapsulation Sub-TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Lbl Range Size | Label Range Base | |Lbl Range Size | Label Range Base |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BS Length | Reserved | |BS Len | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: TBD2 Type: TBD2
Length: 4 octets Length: 4 octets
Label Range Size: A 1 octet field encoding the label range size of Label Range Size: A 1 octet field encoding the label range size of
the label range. It MUST be greater then 0, otherwise the the label range. It MUST be greater then 0, otherwise the
advertising router MUST be treated as if it did not advertise a advertising router MUST be treated as if it did not advertise a
BIER sub-TLV. BIER sub-TLV.
Label Range Base: A 3 octet field, where the 20 rightmost bits Label Range Base: A 3 octet field, where the 20 rightmost bits
represent the first label in the label range. represent the first label in the label range. The 4 leftmost bits
MUST be ignored.
Bit String Length: A 1 octet field encoding the supported Bit String Length: A 4 bits field encoding the supported BitString
BitString length associated with this BFR-prefix. The values length associated with this BFR-prefix. The values allowed in
allowed in this field are specified in section 2 of this field are specified in section 2 of
[I-D.ietf-bier-mpls-encapsulation]. [I-D.ietf-bier-mpls-encapsulation].
The "label range" is the set of labels beginning with the label The "label range" is the set of labels beginning with the label
range base and ending with ((label range base)+(label range size)- range base and ending with ((label range base)+(label range size)-
1). A unique label range is allocated for each BitStream length 1). A unique label range is allocated for each BitStream length
and Sub-domain-ID. These labels are used for BIER forwarding as and Sub-domain-ID. These labels are used for BIER forwarding as
described in [I-D.ietf-bier-architecture] and described in [I-D.ietf-bier-architecture] and
[I-D.ietf-bier-mpls-encapsulation]. [I-D.ietf-bier-mpls-encapsulation].
The size of the label range is determined by the number of Set The size of the label range is determined by the number of Set
skipping to change at page 6, line 28 skipping to change at page 6, line 28
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tree Type | | Tree Type |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Type: TBD3. Type: TBD3.
Length: 1 octet. Length: 1 octet.
Tree Type: 1 octet Tree Type: 1 octet field describing the Tree Type. The following
value is defined by this document:
0: Shortest Path First (SPF) algorithm based on IGP link
metric. This is the standard shortest path algorithm as
computed by the OSPF protocol.
2.4. Optional BIER sub-domain BSL conversion Sub-TLV 2.4. Optional BIER sub-domain BSL conversion Sub-TLV
The BIER sub-domain BSL conversion Sub-TLV is a Sub-TLV of the BIER The BIER sub-domain BSL conversion Sub-TLV is a Sub-TLV of the BIER
Sub-TLV. This sub-TLV indicates whether the BFR is capable of Sub-TLV. This sub-TLV indicates whether the BFR is capable of
imposing a different Bit String Length (BSL) than the one it received imposing a different Bit String Length (BSL) than the one it received
in a BIER encapsulated packet. Such a capability may allow future, in a BIER encapsulated packet. Such a capability may allow future,
advanced tree types which ensure simple migration procedures from one advanced tree types which ensure simple migration procedures from one
BSL to another in a given MT-ID and Sub-domain-ID or prevent stable BSL to another in a given MT-ID and Sub-domain-ID or prevent stable
blackholes in scenarios where not all routers support the same set of blackholes in scenarios where not all routers support the same set of
skipping to change at page 7, line 20 skipping to change at page 7, line 22
Type: TBD4. Type: TBD4.
Length: 0 octets. Length: 0 octets.
2.5. Flooding scope of BIER Information 2.5. Flooding scope of BIER Information
The flooding scope of the OSPF Extended Prefix Opaque LSA [RFC7684] The flooding scope of the OSPF Extended Prefix Opaque LSA [RFC7684]
that is used for advertising the BIER Sub-TLV is set to area-local. that is used for advertising the BIER Sub-TLV is set to area-local.
To allow BIER deployment in a multi-area environment, OSPF must To allow BIER deployment in a multi-area environment, OSPF must
propagate BIER information between areas. The following procedure is propagate BIER information between areas.
used in order to propagate BIER related information between areas:
( ) ( ) ( )
( ) ( ) ( )
R1 Area 1 R2 Area 0 R3 Area 2 R4
( ) ( ) ( )
( ) ( ) ( )
Figure 1: BIER propagation between areas
The following procedure is used in order to propagate BIER related
information between areas:
When an OSPF Area Border Router (ABR) advertises a Type-3 Summary When an OSPF Area Border Router (ABR) advertises a Type-3 Summary
LSA from an intra-area or inter-area prefix to all its attached LSA from an intra-area or inter-area prefix to all its attached
areas, it will also originate an Extended Prefix Opaque LSA, as areas, it will also originate an Extended Prefix Opaque LSA, as
described in [RFC7684]. The flooding scope of the Extended Prefix described in [RFC7684]. The flooding scope of the Extended Prefix
Opaque LSA type will be set to area-local. The route-type in the Opaque LSA type will be set to area-local. The route-type in the
OSPF Extended Prefix TLV is set to inter-area. When determining OSPF Extended Prefix TLV is set to inter-area. When determining
whether a BIER Sub-TLV should be included in this LSA, an OSPF ABR whether a BIER Sub-TLV should be included in this LSA, an OSPF ABR
will: will:
- Examine its best path to the prefix in the source area and - Examine its best path to the prefix in the source area and
find the advertising router associated with the best path to find the advertising router associated with the best path to
that prefix. that prefix.
- Determine if such advertising router advertised a BIER Sub- - Determine if such advertising router advertised a BIER Sub-
TLV for the prefix. If yes, the ABR will copy the information TLV for the prefix. If yes, the ABR will copy the information
from such BIER MPLS Sub-TLV when advertising BIER MPLS Sub-TLV from such BIER Sub-TLV when advertising BIER Sub-TLV to each
to each attached area. attached area.
In the Figure 1, R1 advertises a prefix 192.0.0.1/32 in Area 1.
It also advertises Extended Prefix Opaque LSA for prefix
192.0.0.1/32 and includes BIER Sub-TLV in it. Area Border Router
(ABR) R2 calculates the reachability for prefix 192.0.0.1/32
inside Area 1 and propagates it to Area 0. When doing so, it
copies the entire BIER Sub-TLV (including all its Sub-TLVs) it
received from R1 in Area 1 and includes it in the Extended Prefix
Opaque LSA it generates for 192.0.0.1/32 in Area 0. ABR R3
calculates the reachability for prefix 192.0.0.1/32 inside Area 0
and propagates it to Area 2. When doing so, it copies the entire
BIER Sub-TLV (including all its Sub-TLVs) it received from R2 in
Area 0 and includes it in the Extended Prefix Opaque LSA it
generates for 192.0.0.1/32 in Area 2.
3. Security Considerations 3. Security Considerations
Implementations must assure that malformed TLV and Sub-TLV Implementations must assure that malformed TLV and Sub-TLV
permutations do not result in errors which cause hard OSPF failures. permutations do not result in errors which cause hard OSPF failures.
4. IANA Considerations 4. IANA Considerations
The document requests three new allocations from the OSPF Extended The document requests three new allocations from the OSPF Extended
Prefix sub-TLV registry as defined in [RFC7684]. Prefix sub-TLV registry as defined in [RFC7684].
skipping to change at page 8, line 4 skipping to change at page 8, line 32
Implementations must assure that malformed TLV and Sub-TLV Implementations must assure that malformed TLV and Sub-TLV
permutations do not result in errors which cause hard OSPF failures. permutations do not result in errors which cause hard OSPF failures.
4. IANA Considerations 4. IANA Considerations
The document requests three new allocations from the OSPF Extended The document requests three new allocations from the OSPF Extended
Prefix sub-TLV registry as defined in [RFC7684]. Prefix sub-TLV registry as defined in [RFC7684].
BIER Sub-TLV: TBD1 BIER Sub-TLV: TBD1
BIER MPLS Encapsulation Sub-TLV: TBD2 BIER MPLS Encapsulation Sub-TLV: TBD2
BIER Tree Type Sub-TLV: TBD3 BIER Tree Type Sub-TLV: TBD3
BIER sub-domain BSL conversion Sub-TLV BIER sub-domain BSL conversion Sub-TLV
4.1. BIER Tree Type Registry
IANA is requested to set up a registry called "BIER Tree Type". The
registration policy for this registry is "Standards Action"
([RFC8126] and [RFC7120]).
Values in this registry must come from the range 0-255.
The initial value in the BIER Tree Type registry is:
0: Shortest Path First (SPF) algorithm based on standard IGP link
metric.
5. Acknowledgments 5. Acknowledgments
The authors would like to thank Rajiv Asati, Christian Martin, Greg The authors would like to thank Rajiv Asati, Christian Martin, Greg
Shepherd and Eric Rosen for their contribution. Shepherd and Eric Rosen for their contribution.
6. Normative References 6. Normative References
[I-D.ietf-bier-architecture] [I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit S. Aldrin, "Multicast using Bit Index Explicit
skipping to change at page 8, line 33 skipping to change at page 9, line 28
[I-D.ietf-bier-mpls-encapsulation] [I-D.ietf-bier-mpls-encapsulation]
Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J., Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J.,
Aldrin, S., and I. Meilik, "Encapsulation for Bit Index Aldrin, S., and I. Meilik, "Encapsulation for Bit Index
Explicit Replication in MPLS and non-MPLS Networks", Explicit Replication in MPLS and non-MPLS Networks",
draft-ietf-bier-mpls-encapsulation-07 (work in progress), draft-ietf-bier-mpls-encapsulation-07 (work in progress),
June 2017. June 2017.
[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>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
RFC 4915, DOI 10.17487/RFC4915, June 2007, RFC 4915, DOI 10.17487/RFC4915, June 2007,
<http://www.rfc-editor.org/info/rfc4915>. <https://www.rfc-editor.org/info/rfc4915>.
[RFC7120] Cotton, M., "Early IANA Allocation of Standards Track Code
Points", BCP 100, RFC 7120, DOI 10.17487/RFC7120, January
2014, <https://www.rfc-editor.org/info/rfc7120>.
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <http://www.rfc-editor.org/info/rfc7684>. 2015, <https://www.rfc-editor.org/info/rfc7684>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
Authors' Addresses Authors' Addresses
Peter Psenak (editor) Peter Psenak (editor)
Cisco Cisco
Apollo Business Center Apollo Business Center
Mlynske nivy 43 Mlynske nivy 43
Bratislava 821 09 Bratislava 821 09
Slovakia Slovakia
Email: ppsenak@cisco.com Email: ppsenak@cisco.com
Nagendra Kumar Nagendra Kumar
 End of changes. 20 change blocks. 
25 lines changed or deleted 80 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/