draft-ietf-idr-bgp-ls-segment-routing-ext-13.txt   draft-ietf-idr-bgp-ls-segment-routing-ext-14.txt 
Inter-Domain Routing S. Previdi Inter-Domain Routing S. Previdi
Internet-Draft Huawei Technologies Internet-Draft Huawei Technologies
Intended status: Standards Track K. Talaulikar, Ed. Intended status: Standards Track K. Talaulikar, Ed.
Expires: October 20, 2019 C. Filsfils Expires: November 9, 2019 C. Filsfils
Cisco Systems, Inc. Cisco Systems, Inc.
H. Gredler H. Gredler
RtBrick Inc. RtBrick Inc.
M. Chen M. Chen
Huawei Technologies Huawei Technologies
April 18, 2019 May 8, 2019
BGP Link-State extensions for Segment Routing BGP Link-State extensions for Segment Routing
draft-ietf-idr-bgp-ls-segment-routing-ext-13 draft-ietf-idr-bgp-ls-segment-routing-ext-14
Abstract Abstract
Segment Routing (SR) allows for a flexible definition of end-to-end Segment Routing (SR) allows for a flexible definition of end-to-end
paths by encoding paths as sequences of topological sub-paths, called paths by encoding paths as sequences of topological sub-paths, called
"segments". These segments are advertised by routing protocols e.g. "segments". These segments are advertised by routing protocols e.g.
by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within
IGP topologies. IGP topologies.
This draft defines extensions to the BGP Link-state address-family in This draft defines extensions to the BGP Link-state address-family in
skipping to change at page 2, line 4 skipping to change at page 2, line 4
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 https://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 October 20, 2019. This Internet-Draft will expire on November 9, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 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
(https://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
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 4 2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 4
2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5 2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5
2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 5 2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 5
2.1.2. SR Capabilities TLV . . . . . . . . . . . . . . . . . 6 2.1.2. SR Capabilities TLV . . . . . . . . . . . . . . . . . 6
2.1.3. SR Algorithm TLV . . . . . . . . . . . . . . . . . . 7 2.1.3. SR Algorithm TLV . . . . . . . . . . . . . . . . . . 7
2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8 2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8
2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 9 2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 10
2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 10 2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 10
2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 10 2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 11
2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 12 2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 12
2.2.3. L2 Bundle Member Attribute TLV . . . . . . . . . . . 14 2.2.3. L2 Bundle Member Attribute TLV . . . . . . . . . . . 14
2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 15 2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 16
2.3.1. Prefix SID TLV . . . . . . . . . . . . . . . . . . . 16 2.3.1. Prefix SID TLV . . . . . . . . . . . . . . . . . . . 17
2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 17 2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 18
2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 18 2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 19
2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 18 2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 19
2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 20 2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 21
2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 21 2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 22
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
3.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 23 3.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 25
4. Manageability Considerations . . . . . . . . . . . . . . . . 24 4. Manageability Considerations . . . . . . . . . . . . . . . . 25
5. Security Considerations . . . . . . . . . . . . . . . . . . . 25 5. Security Considerations . . . . . . . . . . . . . . . . . . . 26
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
8.1. Normative References . . . . . . . . . . . . . . . . . . 27 8.1. Normative References . . . . . . . . . . . . . . . . . . 28
8.2. Informative References . . . . . . . . . . . . . . . . . 28 8.2. Informative References . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
1. Introduction 1. Introduction
Segment Routing (SR) allows for a flexible definition of end-to-end Segment Routing (SR) allows for a flexible definition of end-to-end
paths by combining sub-paths called "segments". A segment can paths by combining sub-paths called "segments". A segment can
represent any instruction, topological or service-based. A segment represent any instruction, topological or service-based. A segment
can have a local semantic to an SR node or global within a domain. can have a local semantic to an SR node or global within a domain.
Within IGP topologies an SR path is encoded as a sequence of Within IGP topologies an SR path is encoded as a sequence of
topological sub-paths, called "IGP segments". These segments are topological sub-paths, called "IGP segments". These segments are
advertised by the link-state routing protocols (IS-IS, OSPFv2 and advertised by the link-state routing protocols (IS-IS, OSPFv2 and
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Table 1: Node Attribute TLVs Table 1: Node Attribute TLVs
These TLVs should only be added to the BGP-LS Attribute associated These TLVs should only be added to the BGP-LS Attribute associated
with the Node NLRI describing the IGP node that is originating the with the Node NLRI describing the IGP node that is originating the
corresponding IGP TLV/sub-TLV described below. corresponding IGP TLV/sub-TLV described below.
2.1.1. SID/Label Sub-TLV 2.1.1. SID/Label Sub-TLV
The SID/Label TLV is used as a sub-TLV by the SR Capabilities The SID/Label TLV is used as a sub-TLV by the SR Capabilities
(Section 2.1.2) and Segment Routing Local Block (SRLB) (Section 2.1.2) and Segment Routing Local Block (SRLB)
(Section 2.1.4) TLVs and has the following format: (Section 2.1.4) TLVs. This information is derived from the protocol
specific advertisements.
o IS-IS, as defined by the SID/Label sub-TLV in
[I-D.ietf-isis-segment-routing-extensions].
o OSPFv2/OSPFv3, as defined by the SID/Label sub-TLV in
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The TLV and 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label (variable) | | SID/Label (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: SID/Label sub-TLV Format Figure 2: SID/Label sub-TLV Format
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The SR Capabilities TLV is used in order to advertise the node's SR The SR Capabilities TLV is used in order to advertise the node's SR
Capabilities including its Segment Routing Global Base (SRGB) Capabilities including its Segment Routing Global Base (SRGB)
range(s). In the case of IS-IS, the capabilities also include the range(s). In the case of IS-IS, the capabilities also include the
IPv4 and IPv6 support for the SR-MPLS forwarding plane. This IPv4 and IPv6 support for the SR-MPLS forwarding plane. This
information is derived from the protocol specific advertisements. information is derived from the protocol specific advertisements.
o IS-IS, as defined by the SR Capabilities sub-TLV in o IS-IS, as defined by the SR Capabilities sub-TLV in
[I-D.ietf-isis-segment-routing-extensions]. [I-D.ietf-isis-segment-routing-extensions].
o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in o OSPFv2/OSPFv3, as defined by the SID/Label Range TLV in
[I-D.ietf-ospf-segment-routing-extensions] and [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3 leverages the
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. same TLV as defined for OSPFv2.
The SR Capabilities TLV has the following format: The SR Capabilities 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | | Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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the first label in the range. Since the SID/Label sub-TLV is the first label in the range. Since the SID/Label sub-TLV is
used to indicate the first label of the SRGB range, only label used to indicate the first label of the SRGB range, only label
encoding is valid under the SR Capabilities TLV. encoding is valid under the SR Capabilities TLV.
2.1.3. SR Algorithm TLV 2.1.3. SR Algorithm TLV
The SR Algorithm TLV is used in order to advertise the SR Algorithms The SR Algorithm TLV is used in order to advertise the SR Algorithms
supported by the node. This information is derived from the protocol supported by the node. This information is derived from the protocol
specific advertisements. specific advertisements.
o IS-IS, as defined by the SR Algorithm sub-TLV in o IS-IS, as defined by the SR-Algorithm sub-TLV in
[I-D.ietf-isis-segment-routing-extensions]. [I-D.ietf-isis-segment-routing-extensions].
o OSPFv2/OSPFv3, as defined by the SR Algorithm TLV in o OSPFv2/OSPFv3, as defined by the SR-Algorithm TLV in
[I-D.ietf-ospf-segment-routing-extensions] and [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3 leverages the
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. same TLV as defined for OSPFv2.
The SR Algorithm TLV has the following format: The SR Algorithm 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Algorithm 1 | Algorithm... | Algorithm N | | | Algorithm 1 | Algorithm... | Algorithm N | |
+- -+ +- -+
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range of local SIDs available, it is required that the node range of local SIDs available, it is required that the node
advertises its SRLB. advertises its SRLB.
This information is derived from the protocol specific This information is derived from the protocol specific
advertisements. advertisements.
o IS-IS, as defined by the SR Local Block sub-TLV in o IS-IS, as defined by the SR Local Block sub-TLV in
[I-D.ietf-isis-segment-routing-extensions]. [I-D.ietf-isis-segment-routing-extensions].
o OSPFv2/OSPFv3, as defined by the SR Local Block TLV in o OSPFv2/OSPFv3, as defined by the SR Local Block TLV in
[I-D.ietf-ospf-segment-routing-extensions] and [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3 leverages the
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. same TLV as defined for OSPFv2.
The SRLB TLV has the following format: The SRLB 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | | Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: SRLB TLV Format Figure 5: SRLB TLV Format
Where: Where:
Type: 1036 Type: 1036
Length: Variable. Minimum length is 12. Length: Variable. Minimum length is 12.
Flags: 1 octet of flags. None are defined at this stage. Flags: 1 octet of flags. The flags are as defined in
[I-D.ietf-isis-segment-routing-extensions] for IS-IS. The flags
are not currently defined for OSPFv2 and OSPFv3 and SHOULD be set
to 0 and MUST be ignored on receipt.
Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on
receipt. receipt.
One or more entries, each of which have the following format: One or more entries, each of which have the following format:
Range Size: 3 octet value indicating the number of labels in Range Size: 3 octet value indicating the number of labels in
the range. the range.
SID/Label sub-TLV (as defined in Section 2.1.1) which encodes SID/Label sub-TLV (as defined in Section 2.1.1) which encodes
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specifies the SRMS functionality along with SRMS preference of the specifies the SRMS functionality along with SRMS preference of the
node advertising the SRMS Prefix-to-SID Mapping ranges. node advertising the SRMS Prefix-to-SID Mapping ranges.
This information is derived from the protocol specific This information is derived from the protocol specific
advertisements. advertisements.
o IS-IS, as defined by the SRMS Preference sub-TLV in o IS-IS, as defined by the SRMS Preference sub-TLV in
[I-D.ietf-isis-segment-routing-extensions]. [I-D.ietf-isis-segment-routing-extensions].
o OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in o OSPFv2/OSPFv3, as defined by the SRMS Preference TLV in
[I-D.ietf-ospf-segment-routing-extensions] and [I-D.ietf-ospf-segment-routing-extensions]. OSPFv3 leverages the
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. same TLV as defined for OSPFv2.
The SRMS Preference TLV has the following format: The SRMS Preference 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference | | Preference |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
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Figure 6: SRMS Preference TLV Format Figure 6: SRMS Preference TLV Format
Where: Where:
Type: 1037 Type: 1037
Length: 1. Length: 1.
Preference: 1 octet. Unsigned 8 bit SRMS preference. Preference: 1 octet. Unsigned 8 bit SRMS preference.
The use of the SRMS Preference TLV is defined in
[I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
2.2. Link Attribute TLVs 2.2. Link Attribute TLVs
The following Link Attribute TLVs are are defined: The following Link Attribute TLVs are are defined:
+------+-----------------------+---------------+ +------+-----------------------+---------------+
| Type | Description | Section | | Type | Description | Section |
+------+-----------------------+---------------+ +------+-----------------------+---------------+
| 1099 | Adjacency SID TLV | Section 2.2.1 | | 1099 | Adjacency SID TLV | Section 2.2.1 |
| 1100 | LAN Adjacency SID TLV | Section 2.2.2 | | 1100 | LAN Adjacency SID TLV | Section 2.2.2 |
| 1172 | L2 Bundle Member TLV | Section 2.2.3 | | 1172 | L2 Bundle Member TLV | Section 2.2.3 |
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Table 2: Link Attribute TLVs Table 2: Link Attribute TLVs
These TLVs should only be added to the BGP-LS Attribute associated These TLVs should only be added to the BGP-LS Attribute associated
with the Link NLRI describing the link of the IGP node that is with the Link NLRI describing the link of the IGP node that is
originating the corresponding IGP TLV/sub-TLV described below. originating the corresponding IGP TLV/sub-TLV described below.
2.2.1. Adjacency SID TLV 2.2.1. Adjacency SID TLV
The Adjacency SID TLV is used in order to advertise information The Adjacency SID TLV is used in order to advertise information
related to an Adjacency SID. This information is originated as in related to an Adjacency SID. This information is derived from Adj-
Adj-SID sub-TLV of IS-IS [I-D.ietf-isis-segment-routing-extensions], SID sub-TLV of IS-IS [I-D.ietf-isis-segment-routing-extensions],
OSPFv2 [I-D.ietf-ospf-segment-routing-extensions] and OSPFv3 OSPFv2 [I-D.ietf-ospf-segment-routing-extensions] and OSPFv3
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Adjacency SID TLV has the following format: The Adjacency SID 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 11, line 28 skipping to change at page 11, line 48
Figure 7: Adjacency SID TLV Format Figure 7: Adjacency SID TLV Format
Where: Where:
Type: 1099 Type: 1099
Length: Variable, 7 or 8 depending on Label or Index encoding of Length: Variable, 7 or 8 depending on Label or Index encoding of
the SID the SID
Flags. 1 octet value which sould be parsed as: Flags. 1 octet value which should be set as:
* IS-IS Adj-SID flags are defined in * IS-IS Adj-SID flags are defined in
[I-D.ietf-isis-segment-routing-extensions] section 2.2.1. [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2 Adj-SID flags are defined in * OSPFv2 Adj-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 6.1. [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3 Adj-SID flags are defined in * OSPFv3 Adj-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 7.1. [I-D.ietf-ospf-segment-routing-extensions].
Weight: Weight used for load-balancing purposes. Weight: Weight used for load-balancing purposes.
Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on
receipt. receipt.
SID/Index/Label: SID/Index/Label:
* IS-IS: Label or index value as defined in * IS-IS: Label or index value as defined in
[I-D.ietf-isis-segment-routing-extensions], [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2: Label or index value as defined in * OSPFv2: Label or index value as defined in
[I-D.ietf-ospf-segment-routing-extensions], [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3: Label or index value as defined in * OSPFv3: Label or index value as defined in
[I-D.ietf-ospf-ospfv3-segment-routing-extensions], [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Flags and, as an extension, the SID/Index/Label fields of this The Flags and, as an extension, the SID/Index/Label fields of this
TLV need to be interpreted accordingly to the respective underlying TLV need to be interpreted accordingly to the respective underlying
IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Link IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS Link
NLRI should be used to determine the underlying protocol NLRI should be used to determine the underlying protocol
specification for parsing these fields. specification for parsing these fields.
2.2.2. LAN Adjacency SID TLV 2.2.2. LAN Adjacency SID TLV
For a LAN, normally a node only announces its adjacency to the IS-IS For a LAN, normally a node only announces its adjacency to the IS-IS
pseudo-node (or the equivalent OSPF Designated and Backup Designated pseudo-node (or the equivalent OSPF Designated and Backup Designated
Routers). The LAN Adjacency Segment TLV allows a node to announce Routers). The LAN Adjacency Segment TLV allows a node to announce
adjacencies to all other nodes attached to the LAN in a single adjacencies to all other nodes attached to the LAN in a single
instance of the BGP-LS Link NLRI. Without this TLV, the instance of the BGP-LS Link NLRI. Without this TLV, the
corresponding BGP-LS link NLRI would need to be originated for each corresponding BGP-LS link NLRI would need to be originated for each
additional adjacency in order to advertise the SR TLVs for these additional adjacency in order to advertise the SR TLVs for these
neighbor adjacencies. neighbor adjacencies.
This information is originated as in LAN Adj-SID sub-TLV of IS-IS This information is derived from LAN-Adj-SID sub-TLV of IS-IS
[I-D.ietf-isis-segment-routing-extensions], OSPFv2 [I-D.ietf-isis-segment-routing-extensions] and LAN Adj-SID sub-TLV of
[I-D.ietf-ospf-segment-routing-extensions] and OSPFv3 OSPFv2 [I-D.ietf-ospf-segment-routing-extensions] and OSPFv3
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The LAN Adjacency SID TLV has the following format: The LAN Adjacency SID 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Weight | Reserved | | Flags | Weight | Reserved |
skipping to change at page 13, line 13 skipping to change at page 13, line 33
Figure 8: LAN Adjacency SID TLV Format Figure 8: LAN Adjacency SID TLV Format
Where: Where:
Type: 1100 Type: 1100
Length: Variable. For IS-IS it would be 13 or 14 depending on Length: Variable. For IS-IS it would be 13 or 14 depending on
Label or Index encoding of the SID. For OSPF it would be 11 or 12 Label or Index encoding of the SID. For OSPF it would be 11 or 12
depending on Label or Index encoding of the SID. depending on Label or Index encoding of the SID.
Flags. 1 octet value which sould be parsed as: Flags. 1 octet value which should be set as:
* IS-IS LAN Adj-SID flags are defined in * IS-IS LAN Adj-SID flags are defined in
[I-D.ietf-isis-segment-routing-extensions] section 2.2.2. [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2 LAN Adj-SID flags are defined in * OSPFv2 LAN Adj-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 6.2. [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3 LAN Adj-SID flags are defined in * OSPFv3 LAN Adj-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 7.3. [I-D.ietf-ospf-segment-routing-extensions].
Weight: Weight used for load-balancing purposes. Weight: Weight used for load-balancing purposes.
Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on
receipt. receipt.
Neighbor ID: 6 octets for IS-IS for the System-ID and 4 octets for Neighbor ID: 6 octets for IS-IS for the System-ID and 4 octets for
OSPF for the OSPF Router-ID of the neighbor. OSPF for the OSPF Router-ID of the neighbor.
SID/Index/Label: SID/Index/Label:
* IS-IS: Label or index value as defined in * IS-IS: Label or index value as defined in
[I-D.ietf-isis-segment-routing-extensions], [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2: Label or index value as defined in * OSPFv2: Label or index value as defined in
[I-D.ietf-ospf-segment-routing-extensions], [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3: Label or index value as defined in * OSPFv3: Label or index value as defined in
[I-D.ietf-ospf-ospfv3-segment-routing-extensions], [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Neighbor ID, Flags and, as an extension, the SID/Index/Label The Neighbor ID, Flags and, as an extension, the SID/Index/Label
fields of this TLV need to be interpreted accordingly to the fields of this TLV need to be interpreted accordingly to the
respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The
Protocol-ID of the BGP-LS Link NLRI should be used to determine the Protocol-ID of the BGP-LS Link NLRI should be used to determine the
underlying protocol specification for parsing these fields. underlying protocol specification for parsing these fields.
2.2.3. L2 Bundle Member Attribute TLV 2.2.3. L2 Bundle Member Attribute TLV
The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member
link which in turn is associated with a parent L3 link. The L3 link link which in turn is associated with a parent L3 link. The L3 link
is described by the Link NLRI defined in [RFC7752] and the L2 Bundle is described by the Link NLRI defined in [RFC7752] and the L2 Bundle
Member Attribute TLV is associated with the Link NLRI. The TLV MAY Member Attribute TLV is associated with the Link NLRI. The TLV MAY
include sub-TLVs which describe attributes associated with the bundle include sub-TLVs which describe attributes associated with the bundle
member. The identified bundle member represents a unidirectional member. The identified bundle member represents a unidirectional
path from the originating router to the neighbor specified in the path from the originating router to the neighbor specified in the
parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be
associated with a Link NLRI. associated with a Link NLRI.
This information is originated as in L2 Bundle Member Attributes TLV This information is derived from L2 Bundle Member Attributes TLV of
of IS-IS [I-D.ietf-isis-l2bundles]. The equivalent functionality has IS-IS [I-D.ietf-isis-l2bundles]. The equivalent functionality has
not been specified as yet for OSPF. not been specified as yet for OSPF.
The L2 Bundle Member Attribute TLV has the following format: The L2 Bundle Member Attribute 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 16, line 8 skipping to change at page 17, line 8
Table 4: Prefix Attribute TLVs Table 4: Prefix Attribute TLVs
These TLVs should only be added to the BGP-LS Attribute associated These TLVs should only be added to the BGP-LS Attribute associated
with the Prefix NLRI describing the prefix of the IGP node that is with the Prefix NLRI describing the prefix of the IGP node that is
originating the corresponding IGP TLV/sub-TLV described below. originating the corresponding IGP TLV/sub-TLV described below.
2.3.1. Prefix SID TLV 2.3.1. Prefix SID TLV
The Prefix SID TLV is used in order to advertise information related The Prefix SID TLV is used in order to advertise information related
to a Prefix SID. This information is originated as in Prefix-SID to a Prefix SID. This information is derived from Prefix-SID sub-TLV
sub-TLV of IS-IS [I-D.ietf-isis-segment-routing-extensions], OSPFv2 of IS-IS [I-D.ietf-isis-segment-routing-extensions] and the Prefix
[I-D.ietf-ospf-segment-routing-extensions] and OSPFv3 SID sub-TLV of OSPFv2 [I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. OSPFv3 [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Prefix SID TLV has the following format: The Prefix SID 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Algorithm | Reserved | | Flags | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 16, line 34 skipping to change at page 17, line 34
Figure 10: Prefix SID TLV Format Figure 10: Prefix SID TLV Format
Where: Where:
Type: 1158 Type: 1158
Length: Variable, 7 or 8 depending on Label or Index encoding of Length: Variable, 7 or 8 depending on Label or Index encoding of
the SID the SID
Flags: 1 octet value which sould be parsed as: Flags: 1 octet value which should be set as:
* IS-IS Prefix SID flags are defined in * IS-IS Prefix SID flags are defined in
[I-D.ietf-isis-segment-routing-extensions] section 2.1. [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2 Prefix SID flags are defined in * OSPFv2 Prefix SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 5. [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3 Prefix SID flags are defined in * OSPFv3 Prefix SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 5. [I-D.ietf-ospf-segment-routing-extensions].
Algorithm: 1 octet value identify the algorithm. Algorithm: 1 octet value identify the algorithm.
Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on Reserved: 2 octets that SHOULD be set to 0 and MUST be ignored on
receipt. receipt.
SID/Index/Label: SID/Index/Label:
* IS-IS: Label or index value as defined in * IS-IS: Label or index value as defined in
[I-D.ietf-isis-segment-routing-extensions], [I-D.ietf-isis-segment-routing-extensions].
* OSPFv2: Label or index value as defined in * OSPFv2: Label or index value as defined in
[I-D.ietf-ospf-segment-routing-extensions], [I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3: Label or index value as defined in * OSPFv3: Label or index value as defined in
[I-D.ietf-ospf-ospfv3-segment-routing-extensions], [I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Flags and, as an extension, the SID/Index/Label fields of this The Flags and, as an extension, the SID/Index/Label fields of this
TLV need to be interpreted accordingly to the respective underlying TLV need to be interpreted accordingly to the respective underlying
IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS IS-IS, OSPFv2 or OSPFv3 protocol. The Protocol-ID of the BGP-LS
Prefix NLRI should be used to determine the underlying protocol Prefix NLRI should be used to determine the underlying protocol
specification for parsing these fields. specification for parsing these fields.
2.3.2. Prefix Attribute Flags TLV 2.3.2. Prefix Attribute Flags TLV
The Prefix Attribute Flags TLV carries IPv4/IPv6 prefix attribute The Prefix Attribute Flags TLV carries IPv4/IPv6 prefix attribute
skipping to change at page 17, line 45 skipping to change at page 18, line 45
Figure 11: Prefix Attribute Flags TLV Format Figure 11: Prefix Attribute Flags TLV Format
Where: Where:
Type: 1170 Type: 1170
Length: variable. Length: variable.
Flags: a variable length flag field (according to the length Flags: a variable length flag field (according to the length
field). Flags are routing protocol specific and are to be parsed field). Flags are routing protocol specific and are to be set as
as below: below:
* IS-IS flags correspond to the IPv4/IPv6 Extended Reachability * IS-IS flags correspond to the IPv4/IPv6 Extended Reachability
Attribute Flags defined in [RFC7794] Attribute Flags defined in [RFC7794]
* OSPFv2 flags correspond to the Flags field of the OSPFv2 * OSPFv2 flags correspond to the Flags field of the OSPFv2
Extended Prefix TLV defined in [RFC7684] Extended Prefix TLV defined in [RFC7684]
* OSPFv3 flags map to the Prefix Options field defined in * OSPFv3 flags map to the Prefix Options field defined in
[RFC5340] and extended via [RFC8362] [RFC5340] and extended via [RFC8362]
The Flags field of this TLV need to be interpreted accordingly to the The Flags field of this TLV need to be interpreted accordingly to the
respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The
Protocol-ID of the BGP-LS Prefix NLRI should be used to determine the Protocol-ID of the BGP-LS Prefix NLRI should be used to determine the
underlying protocol specification for parsing these fields. underlying protocol specification for parsing these fields.
2.3.3. Source Router Identifier (Source Router-ID) TLV 2.3.3. Source Router Identifier (Source Router-ID) TLV
The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the
originator of the Prefix. For IS-IS protocol this is as defined in originator of the Prefix. For the IS-IS protocol this is derived
[RFC7794] IPv4 or IPv6 Router-ID of the originating router. For OSPF from the IPv4/IPv6 Source Router ID sub-TLV as defined in [RFC7794].
protocol, this is as defined in [I-D.ietf-lsr-ospf-prefix-originator] For the OSPF protocol, this is derived from the Prefix Source Router-
and is a 32 bit OSPF Router-ID of the originating router.. ID sub-TLV as defined in [I-D.ietf-lsr-ospf-prefix-originator].
The Source Router-ID TLV has the following format: The Source Router-ID 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// 4 or 6 octet Router-ID // // 4 or 6 octet Router-ID //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 18, line 47 skipping to change at page 19, line 47
Type: 1171 Type: 1171
Length: 4 or 16 in case of IS-IS and 4 in case of OSPF. Length: 4 or 16 in case of IS-IS and 4 in case of OSPF.
Router-ID: the IPv4 or IPv6 Router-ID in case of IS-IS and the Router-ID: the IPv4 or IPv6 Router-ID in case of IS-IS and the
OSPF Router-ID in the case of OSPF. OSPF Router-ID in the case of OSPF.
2.3.4. Range TLV 2.3.4. Range TLV
The range TLV is used in order to advertise a range of prefix-to-SID The Range TLV is used in order to advertise a range of prefix-to-SID
mappings as part of the Segment Routing Mapping Server (SRMS) mappings as part of the Segment Routing Mapping Server (SRMS)
functionality [I-D.ietf-spring-segment-routing-ldp-interop], as functionality [I-D.ietf-spring-segment-routing-ldp-interop], as
defined in the respective underlying IGP SR extensions defined in the respective underlying IGP SR extensions
[I-D.ietf-ospf-segment-routing-extensions], [I-D.ietf-ospf-segment-routing-extensions],
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] and [I-D.ietf-ospf-ospfv3-segment-routing-extensions] and
[I-D.ietf-isis-segment-routing-extensions]. [I-D.ietf-isis-segment-routing-extensions]. The information
advertised in the Range TLV is derived from the SID/Label Binding TLV
in the case of IS-IS and the OSPFv2/OSPFv3 Extended Prefix Range TLV
in the case of OSPFv2/OSPFv3.
A Prefix NLRI, that been advertised with a Range TLV, is considered A Prefix NLRI, that been advertised with a Range TLV, is considered
as a normal routing prefix (i.e. prefix reachability) unless there is as a normal routing prefix (i.e. prefix reachability) unless there is
also an IGP metric TLV (TLV 1095) attached to it. also an IGP metric TLV (TLV 1095) attached to it.
The format of the Range TLV is as follows: The format of the Range TLV is as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 19, line 33 skipping to change at page 20, line 36
Figure 13: Range TLV Format Figure 13: Range TLV Format
Where: Where:
Type: 1159 Type: 1159
Length: Variable, 11 or 12 depending on Label or Index encoding of Length: Variable, 11 or 12 depending on Label or Index encoding of
the SID the SID
Flags: as defined in [I-D.ietf-ospf-segment-routing-extensions], Flags: 1 octet value which should be set as:
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] and
[I-D.ietf-isis-segment-routing-extensions]. * IS-IS SID/Label Binding TLV flags are defined in
[I-D.ietf-isis-segment-routing-extensions].
* OSPFv2 OSPF Extended Prefix Range TLV flags are defined in
[I-D.ietf-ospf-segment-routing-extensions].
* OSPFv3 Extended Prefix Range TLV flags are defined in
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on Reserved: 1 octet that SHOULD be set to 0 and MUST be ignored on
receipt. receipt.
Range Size: 2 octets as defined in Range Size: 2 octets as defined in
[I-D.ietf-ospf-segment-routing-extensions]. [I-D.ietf-ospf-segment-routing-extensions].
The Flags field of this TLV need to be interpreted accordingly to the The Flags field of this TLV need to be interpreted accordingly to the
respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The consumer respective underlying IS-IS, OSPFv2 or OSPFv3 protocol. The consumer
of the BGP-LS interested in this TLV information MUST check the of the BGP-LS interested in this TLV information MUST check the
Protocol-ID of the BGP-LS Prefix NLRI and refer to the underlying Protocol-ID of the BGP-LS Prefix NLRI and refer to the underlying
protocol specification in order to parse this field. protocol specification in order to parse this field.
Within the Range TLV, the prefix-to-SID mappings are advertised using The prefix-to-SID mappings are advertised using sub-TLVs as below:
sub-TLVs as below:
Range TLV
Prefix-SID TLV (used as a sub-TLV in this context)
Where:
o The Range TLV is defined in Section 2.3.4.
o The Prefix-SID TLV (used as sub-TLV in this context) is defined in
Section 2.3.1.
The following sub-sections describe the procedures for mapping of
information from the underlying IGP protocols into the Range TLV.
2.3.4.1. Advertisement Procedure for OSPF
The OSPFv2/OSPFv3 Extended Prefix Range TLV is encoded in the Range
TLV. The flags of the Range TLV have the semantic mapped to the
definition in [I-D.ietf-ospf-segment-routing-extensions] section 4 or
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 4.
Then the prefix-to-SID mapping from the OSPF Prefix SID sub-TLV is IS-IS:
encoded using the BGP-LS Prefix-SID TLV as defined in Section 2.3.1 SID/Label Range TLV
with the flags set according to the definition in Prefix-SID sub-TLV
[I-D.ietf-ospf-segment-routing-extensions] section 5 or
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 5.
2.3.4.2. Advertisement Procedure for IS-IS OSPFv2/OSPFv3:
OSPFv2/OSPFv3 Extended Prefix Range TLV
Prefix SID sub-TLV
The IS-IS SID/Label Binding TLV, when used to signal mapping server BGP-LS:
label bindings, is encoded in the Range TLV. The flags of the Range Range TLV
TLV have the sematic mapped to the definition in Prefix-SID TLV (used as a sub-TLV in this context)
[I-D.ietf-isis-segment-routing-extensions] section 2.4.1.
Then the prefix-to-SID mappings from the IS-IS Prefix SID sub-TLV is The prefix-to-SID mapping information for the BGP-LS Prefix-SID TLV
encoded using the BGP-LS Prefix-SID TLV as defined in Section 2.3.1 (used as sub-TLV in this context) is encoded as described in
with the flags set according to the definition in Section 2.3.1.
[I-D.ietf-isis-segment-routing-extensions] section 2.4.4.1.
2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs 2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs
This section illustrate the IS-IS Segment Routing Extensions TLVs and This section illustrate the IS-IS Segment Routing Extensions TLVs and
sub-TLVs mapped to the ones defined in this document. sub-TLVs mapped to the ones defined in this document.
The following table, illustrates for each BGP-LS TLV, its equivalence The following table, illustrates for each BGP-LS TLV, its equivalence
in IS-IS. in IS-IS.
+------------+------------+-----------------------------------------+ +------------+---------------+--------------------------------------+
| Descriptio | IS-IS TLV | Reference | | Descriptio | IS-IS TLV | Reference |
| n | /sub-TLV | | | n | /sub-TLV | |
+------------+------------+-----------------------------------------+ +------------+---------------+--------------------------------------+
| SR Capabil | 2 | draft-ietf-isis-segment-routing- | | SR Capabil | SR- | [I-D.ietf-isis-segment-routing-exten |
| ities | | extensions section-3.1 | | ities | Capabilities | sions] |
| SR | 19 | draft-ietf-isis-segment-routing- | | | sub-TLV (2) | |
| Algorithm | | extensions section-3.2 | | SR | SR-Algorithm | [I-D.ietf-isis-segment-routing-exten |
| SR Local | 22 | draft-ietf-isis-segment-routing- | | Algorithm | sub-TLV (19) | sions] |
| Block | | extensions section-3.3 | | SR Local | SR Local | [I-D.ietf-isis-segment-routing-exten |
| SRMS | 19 | draft-ietf-isis-segment-routing- | | Block | Block sub-TLV | sions] |
| Preference | | extensions section-3.2 | | | (22) | |
| Adjacency | 31 | draft-ietf-isis-segment-routing- | | SRMS | SRMS | [I-D.ietf-isis-segment-routing-exten |
| SID | | extensions section-2.2.1 | | Preference | Preference | sions] |
| LAN | 32 | draft-ietf-isis-segment-routing- | | | sub-TLV (19) | |
| Adjacency | | extensions section-2.2.2 | | Adjacency | Adj-SID sub- | [I-D.ietf-isis-segment-routing-exten |
| SID | | | | SID | TLV (31) | sions] |
| Prefix SID | 3 | draft-ietf-isis-segment-routing- | | LAN | LAN-Adj-SID | [I-D.ietf-isis-segment-routing-exten |
| | | extensions section-2.1 | | Adjacency | sub-TLV (32) | sions] |
| Range | 149 | draft-ietf-isis-segment-routing- | | SID | | |
| | | extensions section-2.4 | | Prefix SID | Prefix-SID | [I-D.ietf-isis-segment-routing-exten |
| SID/Label | 1 | draft-ietf-isis-segment-routing- | | | sub-TLV (3) | sions] |
| | | extensions section-2.3 | | Range | SID/Label | [I-D.ietf-isis-segment-routing-exten |
| Prefix | 4 | RFC7794 section-2.1 | | | Binding TLV | sions] |
| Attribute | | | | | (149) | |
| Flags | | | | SID/Label | SID/Label | [I-D.ietf-isis-segment-routing-exten |
| Source | 11/12 | RFC7794 section-2.2 | | | sub-TLV (1) | sions] |
| Router-ID | | | | Prefix | Prefix | [RFC7794] |
| L2 Bundle | 25 | draft-ietf-isis-l2bundles section-2 | | Attribute | Attributes | |
| Member | | | | Flags | Flags sub-TLV | |
| Attributes | | | | | (4) | |
+------------+------------+-----------------------------------------+ | Source | IPv4/IPv6 | [RFC7794] |
| Router-ID | Source Router | |
| | ID sub-TLV | |
| | (11/12) | |
| L2 Bundle | L2 Bundle | [I-D.ietf-isis-l2bundles] |
| Member | Member | |
| Attributes | Attributes | |
| | TLV (25) | |
+------------+---------------+--------------------------------------+
Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs
2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs 2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs
This section illustrate the OSPFv2 and OSPFv3 Segment Routing This section illustrate the OSPFv2 and OSPFv3 Segment Routing
Extensions TLVs and sub-TLVs mapped to the ones defined in this Extensions TLVs and sub-TLVs mapped to the ones defined in this
document. document.
The following table, illustrates for each BGP-LS TLV, its equivalence The following table, illustrates for each BGP-LS TLV, its equivalence
in OSPFv2 and OSPFv3. in OSPFv2 and OSPFv3.
+------------+------------+-----------------------------------------+ +------------+-------------+----------------------------------------+
| Descriptio | OSPFv2 TLV | Reference | | Descriptio | OSPFv2 TLV | Reference |
| n | /sub-TLV | | | n | /sub-TLV | |
+------------+------------+-----------------------------------------+ +------------+-------------+----------------------------------------+
| SR Capabil | 9 | draft-ietf-ospf-segment-routing- | | SR Capabil | SID/Label | [I-D.ietf-ospf-segment-routing-extensi |
| ities | | extensions section-3.2 | | ities | Range TLV | ons] |
| SR | 8 | draft-ietf-ospf-segment-routing- | | | (9) | |
| Algorithm | | extensions section-3.1 | | SR | SR- | [I-D.ietf-ospf-segment-routing-extensi |
| SR Local | 14 | draft-ietf-ospf-segment-routing- | | Algorithm | Algorithm | ons] |
| Block | | extensions section-3.3 | | | TLV (8) | |
| SRMS | 15 | draft-ietf-ospf-segment-routing- | | SR Local | SR Local | [I-D.ietf-ospf-segment-routing-extensi |
| Preference | | extensions section-3.4 | | Block | Block TLV | ons] |
| Adjacency | 2 | draft-ietf-ospf-segment-routing- | | | (14) | |
| SID | | extensions section-6.1 | | SRMS | SRMS | [I-D.ietf-ospf-segment-routing-extensi |
| LAN | 3 | draft-ietf-ospf-segment-routing- | | Preference | Preference | ons] |
| Adjacency | | extensions section-6.2 | | | TLV (15) | |
| SID | | | | Adjacency | Adj-SID | [I-D.ietf-ospf-segment-routing-extensi |
| Prefix SID | 2 | draft-ietf-ospf-segment-routing- | | SID | sub-TLV (2) | ons] |
| | | extensions section-5 | | LAN | LAN Adj-SID | [I-D.ietf-ospf-segment-routing-extensi |
| Range | 2 | draft-ietf-ospf-segment-routing- | | Adjacency | sub-TLV (3) | ons] |
| | | extensions section-4 | | SID | | |
| SID/Label | 1 | draft-ietf-ospf-segment-routing- | | Prefix SID | Prefix SID | [I-D.ietf-ospf-segment-routing-extensi |
| | | extensions section-2.1 | | | sub-TLV (2) | ons] |
| Prefix | 4 | RFC7684 section-2.1 | | Range | OSPF | [I-D.ietf-ospf-segment-routing-extensi |
| Attribute | | | | | Extended | ons] |
| Flags | | | | | Prefix | |
| Source | TBD | draft-ietf-lsr-ospf-prefix-originator | | | Range TLV | |
| Router-ID | | section-4 | | | (2) | |
+------------+------------+-----------------------------------------+ | SID/Label | SID/Label | [I-D.ietf-ospf-segment-routing-extensi |
| | sub-TLV (1) | ons] |
| Prefix | Flags of | [RFC7684] |
| Attribute | OSPFv2 | |
| Flags | Extended | |
| | Prefix TLV | |
| | (1) | |
| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator] |
| Router-ID | Source | |
| | Router-ID | |
| | sub-TLV | |
| | (TBD) | |
+------------+-------------+----------------------------------------+
Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs Table 6: OSPFv2 Segment Routing Extensions TLVs/Sub-TLVs
+-----------+------------+------------------------------------------+ +-----------+------------+------------------------------------------+
| Descripti | OSPFv3 TLV | Reference | | Descripti | OSPFv3 TLV | Reference |
| on | /sub-TLV | | | on | /sub-TLV | |
+-----------+------------+------------------------------------------+ +-----------+------------+------------------------------------------+
| SR Capabi | 9 | draft-ietf-ospf-ospfv3-segment-routing- | | SR Capabi | SID/Label | [I-D.ietf-ospf-segment-routing-extension |
| lities | | extensions section-3.2 | | lities | Range TLV | s] |
| SR | 8 | draft-ietf-ospf-ospfv3-segment-routing- | | | (9) | |
| Algorithm | | extensions section-3.1 | | SR | SR- | [I-D.ietf-ospf-segment-routing-extension |
| SR Local | 14 | draft-ietf-ospf-ospfv3-segment-routing- | | Algorithm | Algorithm | s] |
| Block | | extensions section-3.3 | | | TLV (8) | |
| SRMS Pref | 15 | draft-ietf-ospf-ospfv3-segment-routing- | | SR Local | SR Local | [I-D.ietf-ospf-segment-routing-extension |
| erence | | extensions section-3.4 | | Block | Block TLV | s] |
| Adjacency | 5 | draft-ietf-ospf-ospfv3-segment-routing- | | | (14) | |
| SID | | extensions section-6.1 | | SRMS Pref | SRMS | [I-D.ietf-ospf-segment-routing-extension |
| LAN | 6 | draft-ietf-ospf-ospfv3-segment-routing- | | erence | Preference | s] |
| Adjacency | | extensions section-6.2 | | | TLV (15) | |
| SID | | | | Adjacency | Adj-SID | [I-D.ietf-ospf-ospfv3-segment-routing-ex |
| Prefix | 4 | draft-ietf-ospf-ospfv3-segment-routing- | | SID | sub-TLV | tensions] |
| SID | | extensions section-5 | | | (5) | |
| Range | 9 | draft-ietf-ospf-ospfv3-segment-routing- | | LAN | LAN Adj- | [I-D.ietf-ospf-ospfv3-segment-routing-ex |
| | | extensions section-4 | | Adjacency | SID sub- | tensions] |
| SID/Label | 7 | draft-ietf-ospf-ospfv3-segment-routing- | | SID | TLV (6) | |
| | | extensions section-2.1 | | Prefix | Prefix SID | [I-D.ietf-ospf-ospfv3-segment-routing-ex |
| Prefix | 4 | RFC8362 section-3.1 | | SID | sub-TLV | tensions] |
| Attribute | | | | | (4) | |
| Flags | | | | Range | OSPFv3 | [I-D.ietf-ospf-ospfv3-segment-routing-ex |
| Source | TBD | draft-ietf-lsr-ospf-prefix-originator | | | Extended | tensions] |
| Router-ID | | section-4 | | | Prefix | |
| | Range TLV | |
| | (9) | |
| SID/Label | SID/Label | [I-D.ietf-ospf-ospfv3-segment-routing-ex |
| | sub-TLV | tensions] |
| | (7) | |
| Prefix | Prefix | [RFC8362] |
| Attribute | Option | |
| Flags | Fields of | |
| | Prefix TLV | |
| | types | |
| | 3,5,6 | |
| Source | Prefix | [I-D.ietf-lsr-ospf-prefix-originator] |
| Router-ID | Source | |
| | Router-ID | |
| | sub-TLV | |
| | (TBD) | |
+-----------+------------+------------------------------------------+ +-----------+------------+------------------------------------------+
Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs
3. IANA Considerations 3. IANA Considerations
Early allocation of codepoints has been done by IANA for this Early allocation of codepoints has been done by IANA for this
document from the registry "BGP-LS Node Descriptor, Link Descriptor, document from the registry "BGP-LS Node Descriptor, Link Descriptor,
Prefix Descriptor, and Attribute TLVs" based on Table 8. The column Prefix Descriptor, and Attribute TLVs" based on Table 8. The column
"IS-IS TLV/Sub-TLV" defined in the registry does not require any "IS-IS TLV/Sub-TLV" defined in the registry does not require any
skipping to change at page 26, line 6 skipping to change at page 27, line 19
existing set of link attribute information already supported in existing set of link attribute information already supported in
[RFC7752]. [RFC7752].
BGP-LS SR extensions enable traffic engineering use-cases within the BGP-LS SR extensions enable traffic engineering use-cases within the
Segment Routing domain. SR operates within a trusted domain Segment Routing domain. SR operates within a trusted domain
[RFC8402] and its security considerations also apply to BGP-LS [RFC8402] and its security considerations also apply to BGP-LS
sessions when carrying SR information. The SR traffic engineering sessions when carrying SR information. The SR traffic engineering
policies using the SIDs advertised via BGP-LS are expected to be used policies using the SIDs advertised via BGP-LS are expected to be used
entirely within this trusted SR domain (e.g. between multiple AS/ entirely within this trusted SR domain (e.g. between multiple AS/
domains within a single provider network). Therefore, precaution is domains within a single provider network). Therefore, precaution is
necessary to ensure that the SR information collected via BGP-LS is necessary to ensure that the SR information advertised via BGP-LS
limited to specific consumers in a secure manner within this SR sessions is limited to consumers in a secure manner within this
domain. trusted SR domain. BGP peering sessions for address-families other
than Link-State may be setup to routers outside the SR domain. The
The isolation of BGP-LS peering sessions is also required to ensure isolation of BGP-LS peering sessions is recommended to ensure that
that BGP-LS topology information (including the newly added SR BGP-LS topology information (including the newly added SR
information) is not advertised to an external BGP peering session information) is not advertised to an external BGP peering session
outside an administrative domain. outside the SR domain.
6. Contributors 6. Contributors
The following people have substantially contributed to the editing of The following people have substantially contributed to the editing of
this document: this document:
Peter Psenak Peter Psenak
Cisco Systems Cisco Systems
Email: ppsenak@cisco.com Email: ppsenak@cisco.com
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