draft-ietf-ospf-segment-routing-extensions-12.txt   draft-ietf-ospf-segment-routing-extensions-13.txt 
Open Shortest Path First IGP P. Psenak, Ed. Open Shortest Path First IGP P. Psenak, Ed.
Internet-Draft S. Previdi, Ed. Internet-Draft S. Previdi, Ed.
Intended status: Standards Track C. Filsfils Intended status: Standards Track C. Filsfils
Expires: September 9, 2017 Cisco Systems, Inc. Expires: November 5, 2017 Cisco Systems, Inc.
H. Gredler H. Gredler
RtBrick Inc. RtBrick Inc.
R. Shakir R. Shakir
Google, Inc. Google, Inc.
W. Henderickx W. Henderickx
Nokia Nokia
J. Tantsura J. Tantsura
Individual Individual
March 8, 2017 May 4, 2017
OSPF Extensions for Segment Routing OSPF Extensions for Segment Routing
draft-ietf-ospf-segment-routing-extensions-12 draft-ietf-ospf-segment-routing-extensions-13
Abstract Abstract
Segment Routing (SR) allows a flexible definition of end-to-end paths Segment Routing (SR) allows a flexible definition of end-to-end paths
within IGP topologies by encoding paths as sequences of topological within IGP topologies by encoding paths as sequences of topological
sub-paths, called "segments". These segments are advertised by the sub-paths, called "segments". These segments are advertised by the
link-state routing protocols (IS-IS and OSPF). link-state routing protocols (IS-IS and OSPF).
This draft describes the OSPF extensions required for Segment This draft describes the OSPF extensions required for Segment
Routing. Routing.
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 http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 9, 2017. This Internet-Draft will expire on November 5, 2017.
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 (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 38 skipping to change at page 2, line 38
3.2. SID/Label Range TLV . . . . . . . . . . . . . . . . . . . 6 3.2. SID/Label Range TLV . . . . . . . . . . . . . . . . . . . 6
3.3. SR Local Block Sub-TLV . . . . . . . . . . . . . . . . . 8 3.3. SR Local Block Sub-TLV . . . . . . . . . . . . . . . . . 8
3.4. SRMS Preference Sub-TLV . . . . . . . . . . . . . . . . . 9 3.4. SRMS Preference Sub-TLV . . . . . . . . . . . . . . . . . 9
4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 10 4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 10
5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 12 5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 12
6. SID/Label Binding Sub-TLV . . . . . . . . . . . . . . . . . . 16 6. SID/Label Binding Sub-TLV . . . . . . . . . . . . . . . . . . 16
6.1. ERO Metric Sub-TLV . . . . . . . . . . . . . . . . . . . 17 6.1. ERO Metric Sub-TLV . . . . . . . . . . . . . . . . . . . 17
6.2. ERO Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . 18 6.2. ERO Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . 18
6.2.1. IPv4 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 18 6.2.1. IPv4 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 18
6.2.2. Unnumbered Interface ID ERO Sub-TLV . . . . . . . . . 19 6.2.2. Unnumbered Interface ID ERO Sub-TLV . . . . . . . . . 19
6.2.3. IPv4 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 20 6.2.3. IPv4 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 21
6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV . . . . . 21 6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV . . . . . 22
7. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 22 7. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 23
7.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 23 7.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 23
7.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 24 7.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 25
8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 26 8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 26
8.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 26 8.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 26
8.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 27 8.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 27
8.3. SID for External Prefixes . . . . . . . . . . . . . . . . 28 8.3. Segment Routing for External Prefixes . . . . . . . . . . 28
8.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 28 8.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 29
8.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 28 8.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 29
8.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 29 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 29
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
9.1. OSPF OSPF Router Information (RI) TLVs Registry . . . . . 29 9.1. OSPF OSPF Router Information (RI) TLVs Registry . . . . . 29
9.2. OSPF Extended Prefix LSA TLV Registry . . . . . . . . . . 29 9.2. OSPF Extended Prefix LSA TLV Registry . . . . . . . . . . 30
9.3. OSPF Extended Prefix LSA Sub-TLV Registry . . . . . . . . 29 9.3. OSPF Extended Prefix LSA Sub-TLV Registry . . . . . . . . 30
9.4. OSPF Extended Link LSA Sub-TLV Registry . . . . . . . . . 30 9.4. OSPF Extended Link LSA Sub-TLV Registry . . . . . . . . . 30
10. Implementation Status . . . . . . . . . . . . . . . . . . . . 30 10. Implementation Status . . . . . . . . . . . . . . . . . . . . 30
11. Security Considerations . . . . . . . . . . . . . . . . . . . 32 11. Security Considerations . . . . . . . . . . . . . . . . . . . 32
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 32 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 32
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 32
14.1. Normative References . . . . . . . . . . . . . . . . . . 32 14.1. Normative References . . . . . . . . . . . . . . . . . . 32
14.2. Informative References . . . . . . . . . . . . . . . . . 33 14.2. Informative References . . . . . . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34
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segment is typically a multi-hop path while an adjacency segment, in segment is typically a multi-hop path while an adjacency segment, in
most cases, is a one-hop path. SR's control-plane can be applied to most cases, is a one-hop path. SR's control-plane can be applied to
both IPv6 and MPLS data-planes, and does not require any additional both IPv6 and MPLS data-planes, and does not require any additional
signalling (other than IGP extensions). The IPv6 data plane is out signalling (other than IGP extensions). The IPv6 data plane is out
of the scope of this specification - it is not applicable to OSPFv2 of the scope of this specification - it is not applicable to OSPFv2
which only supports the IPv4 address-family. For example, when used which only supports the IPv4 address-family. For example, when used
in MPLS networks, SR paths do not require any LDP or RSVP-TE in MPLS networks, SR paths do not require any LDP or RSVP-TE
signalling. However, SR can interoperate in the presence of LSPs signalling. However, SR can interoperate in the presence of LSPs
established with RSVP or LDP. established with RSVP or LDP.
There are additional segment types, e.g., Binding SID defined in
[I-D.ietf-spring-segment-routing].
This draft describes the OSPF extensions required for Segment This draft describes the OSPF extensions required for Segment
Routing. Routing.
Segment Routing architecture is described in Segment Routing architecture is described in
[I-D.ietf-spring-segment-routing]. [I-D.ietf-spring-segment-routing].
Segment Routing use cases are described in Segment Routing use cases are described in
[I-D.filsfils-spring-segment-routing-use-cases]. [I-D.filsfils-spring-segment-routing-use-cases].
2. Segment Routing Identifiers 2. Segment Routing Identifiers
Segment Routing defines various types of Segment Identifiers (SIDs): Segment Routing defines various types of Segment Identifiers (SIDs):
Prefix-SID, Adjacency-SID, LAN Adjacency SID and Binding SID. Prefix-SID, Adjacency-SID, LAN Adjacency SID, and Binding SID.
For the purpose of the advertisements of various SID values, new Extended Prefix/Link Opaque LSAs defined in [RFC7684] are used for
Opaque LSAs [RFC5250] are defined in [RFC7684]. These LSAs are advertisements of the various SID types.
generic containers that can be used to advertise any additional
attributes associated with a prefix or link. These Opaque LSAs are
complementary to the existing LSAs and are not aimed to replace any
of the existing LSAs.
2.1. SID/Label Sub-TLV 2.1. SID/Label Sub-TLV
The SID/Label Sub-TLV appears in multiple TLVs or Sub-TLVs defined The SID/Label Sub-TLV appears in multiple TLVs or Sub-TLVs defined
later in this document. It is used to advertise the SID or label later in this document. It is used to advertise the SID or label
associated with a prefix or adjacency. The SID/Label TLV has associated with a prefix or adjacency. The SID/Label TLV has
following format: 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) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD, suggested value 1 Type: TBD, suggested value 1
Length: variable, 3 or 4 octet Length: Variable, 3 or 4 octet
SID/Label: If length is set to 3, then the 20 rightmost bits SID/Label: If length is set to 3, then the 20 rightmost bits
represent a label. If length is set to 4, then the value represent a label. If length is set to 4, then the value
represents a 32-bit SID. represents a 32-bit SID.
The receiving router MUST ignore SID/Label Sub-TLV if the length The receiving router MUST ignore the SID/Label Sub-TLV if the
is other then 3 or 4. length is other then 3 or 4.
3. Segment Routing Capabilities 3. Segment Routing Capabilities
Segment Routing requires some additional router capabilities to be Segment Routing requires some additional router capabilities to be
advertised to other routers in the area. advertised to other routers in the area.
These SR capabilities are advertised in the Router Information Opaque These SR capabilities are advertised in the Router Information Opaque
LSA (defined in [RFC7770]). LSA (defined in [RFC7770]).
3.1. SR-Algorithm TLV 3.1. SR-Algorithm TLV
The SR-Algorithm TLV is a top-level TLV of the Router Information The SR-Algorithm TLV is a top-level TLV of the Router Information
Opaque LSA (defined in [RFC7770]). Opaque LSA (defined in [RFC7770]).
The SR-Algorithm Sub-TLV is optional. It MAY only be advertised once The SR-Algorithm TLV is optional. It MUST only be advertised once in
in the Router Information Opaque LSA. If the SID/Label Range TLV, as the Router Information Opaque LSA. If the SID/Label Range TLV, as
defined in Section 3.2, is advertised, then the SR-Algorithm TLV MUST defined in Section 3.2, is advertised, then the SR-Algorithm TLV MUST
also be advertised. If the SR-Algorithm TLV is not advertised by the also be advertised. If the SR-Algorithm TLV is not advertised by the
node, such node is considered as not being segment routing capable. node, such node is considered as not being segment routing capable.
An SR Router may use various algorithms when calculating reachability An SR Router may use various algorithms when calculating reachability
to OSPF routers or prefixes in an OSPF area. Examples of these to OSPF routers or prefixes in an OSPF area. Examples of these
algorithms are metric based Shortest Path First (SPF), various algorithms are metric based Shortest Path First (SPF), various
flavors of Constrained SPF, etc. The SR-Algorithm TLV allows a flavors of Constrained SPF, etc. The SR-Algorithm TLV allows a
router to advertise the algorithms currently used by the router to router to advertise the algorithms currently used by the router to
other routers in an OSPF area. The SR-Algorithm TLV has following other routers in an OSPF area. The SR-Algorithm TLV has following
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Algorithm 1 | Algorithm... | Algorithm n | | | Algorithm 1 | Algorithm... | Algorithm n | |
+- -+ +- -+
| | | |
+ + + +
where: where:
Type: TBD, suggested value 8 Type: TBD, suggested value 8
Length: variable Length: Variable
Algorithm: Single octet identifying the algorithm. The following Algorithm: Single octet identifying the algorithm. The following
values are defined by this document: values are defined by this document:
0: Shortest Path First (SPF) algorithm based on link metric. 0: Shortest Path First (SPF) algorithm based on link metric.
This is the standard shortest path algorithm as computed by the This is the standard shortest path algorithm as computed by the
OSPF protocol. Consistent with the deployed practice for link- OSPF protocol. Consistent with the deployed practice for link-
state protocols, Algorithm 0 permits any node to overwrite the state protocols, Algorithm 0 permits any node to overwrite the
SPF path with a different path based on its local policy. If SPF path with a different path based on its local policy. If
the SR-Algorithm Sub-TLV is advertised, Algorithm 0 MUST be the SR-Algorithm TLV is advertised, Algorithm 0 MUST be
included. included.
1: Strict Shortest Path First (SPF) algorithm based on link 1: Strict Shortest Path First (SPF) algorithm based on link
metric. The algorithm is identical to Algorithm 0 but metric. The algorithm is identical to Algorithm 0 but
Algorithm 1 requires that all nodes along the path will honor Algorithm 1 requires that all nodes along the path will honor
the SPF routing decision. Local policy at the node claiming the SPF routing decision. Local policy at the node claiming
support for Algorithm 1 MUST NOT alter the SPF paths computed support for Algorithm 1 MUST NOT alter the SPF paths computed
by Algorithm 1. by Algorithm 1.
When multiple SR-Algorithm sub-TLVs are received from a given router When multiple SR-Algorithm TLVs are received from a given router, the
the receiver SHOULD use the first occurrence of the sub-TLV in the receiver SHOULD use the first occurrence of the TLV in the Router
Router Information LSA. If the SR-Algorithm sub-TLV appears in Information LSA. If the SR-Algorithm TLV appears in multiple Router
multiple Router Information LSAs that have different flooding scopes, Information LSAs that have different flooding scopes, the SR-
the SR-Algorithm sub-TLV in the Router Information LSA with the Algorithm TLV in the Router Information LSA with the narrowest
lowest flooding scope SHOULD be used. If the SR-Algorithm sub-TLV flooding scope SHOULD be used. If the SR-Algorithm TLV appears in
appears in multiple Router Information LSAs that have the same multiple Router Information LSAs that have the same flooding scope,
flooding scope, the SR-Algorithm sub-TLV in the Router Information the SR-Algorithm TLV in the Router Information LSA with the
LSA with the numerically smallest Instance ID SHOULD be used and numerically smallest Instance ID SHOULD be used and subsequent
subsequent instances of the SR-Algorithm sub-TLV SHOULD be ignored. instances of the SR-Algorithm TLV SHOULD be ignored.
The RI LSA can be advertised at any of the defined opaque flooding The RI LSA can be advertised at any of the defined opaque flooding
scopes (link, area, or Autonomous System (AS)). For the purpose of scopes (link, area, or Autonomous System (AS)). For the purpose of
SR-Algorithm TLV advertisement, area scope flooding is required. SR-Algorithm TLV advertisement, area scope flooding is required.
3.2. SID/Label Range TLV 3.2. SID/Label Range TLV
The SID/Label Range TLV is a top-level TLV of the Router Information The SID/Label Range TLV is a top-level TLV of the Router Information
Opaque LSA (defined in [RFC7770]). Opaque LSA (defined in [RFC7770]).
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) | | Sub-TLVs (variable) |
+- -+ +- -+
| | | |
+ + + +
where: where:
Type: TBD, suggested value 9 Type: TBD, suggested value 9
Length: variable Length: Variable
Range Size: 3 octets of the SID/label range Range Size: 3-octet SID/label range size (i.e., the number of SIDs
or labels in the range including the first SID/label). It MUST be
greater than 0.
Initially, the only supported Sub-TLV is the SID/Label TLV as defined Initially, the only supported Sub-TLV is the SID/Label TLV as defined
in Section 2.1. The SID/Label advertised in the SID/Label TLV in Section 2.1. The SID/Label advertised in the SID/Label TLV
represents the first SID/Label in the advertised range. represents the first SID/Label in the advertised range.
Multiple occurrences of the SID/Label Range TLV MAY be advertised, in Multiple occurrences of the SID/Label Range TLV MAY be advertised, in
order to advertise multiple ranges. In such case: order to advertise multiple ranges. In such case:
o The originating router MUST encode each range into a different o The originating router MUST encode each range into a different
SID/Label Range TLV. SID/Label Range TLV.
o The originating router decides the order in which the set of SID/ o The originating router decides the order in which the set of SID/
Label Range TLVs are advertised inside the Router Information Label Range TLVs are advertised inside the Router Information
Opaque LSA. The originating router MUST ensure the order is the Opaque LSA. The originating router MUST ensure the order is the
same after a graceful restart (using checkpointing, non-volatile same after a graceful restart (using checkpointing, non-volatile
storage or any other mechanism) in order to assure the SID/label storage, or any other mechanism) in order to assure the SID/label
range and SID index correspondence is preserved across graceful range and SID index correspondence is preserved across graceful
restarts. restarts.
o The receiving router must adhere to the order in which the ranges o The receiving router MUST adhere to the order in which the ranges
are advertised when calculating a SID/label from a SID index. are advertised when calculating a SID/label from a SID index.
The following example illustrates the advertisement of multiple The following example illustrates the advertisement of multiple
ranges: ranges:
The originating router advertises following ranges: The originating router advertises the following ranges:
Range 1: [100, 199] Range 1: [100, 199]
Range 2: [1000, 1099] Range 2: [1000, 1099]
Range 3: [500, 599] Range 3: [500, 599]
The receiving routers concatenate the ranges and build the Segment The receiving routers concatenate the ranges and build the Segment
Routing Global Block (SRGB) as follows: Routing Global Block (SRGB) as follows:
SRGB = [100, 199] SRGB = [100, 199]
[1000, 1099] [1000, 1099]
[500, 599] [500, 599]
skipping to change at page 8, line 9 skipping to change at page 8, line 9
... ...
The RI LSA can be advertised at any of the defined flooding scopes The RI LSA can be advertised at any of the defined flooding scopes
(link, area, or autonomous system (AS)). For the purpose of SID/ (link, area, or autonomous system (AS)). For the purpose of SID/
Label Range TLV advertisement, area scope flooding is required. Label Range TLV advertisement, area scope flooding is required.
3.3. SR Local Block Sub-TLV 3.3. SR Local Block Sub-TLV
The SR Local Block (SRLB) Sub-TLV contains the range of labels the The SR Local Block (SRLB) Sub-TLV contains the range of labels the
node has reserved for local SIDs. Local SIDs are used, e.g., for node has reserved for local SIDs. Local SIDs are used, e.g., for
Adjacency-SIDs, and may also be allocated by other components than Adjacency-SIDs, and may also be allocated by components other than
OSPF protocol. As an example, an application or a controller may the OSPF protocol. As an example, an application or a controller may
instruct the router to allocate a specific local SID. Therefore, in instruct the router to allocate a specific local SID. Therefore, in
order for such applications or controllers to know what are the local order for such applications or controllers to know what local SIDs
SIDs available in the router, it is required that the router are available on the router, it is required that the router
advertises its SRLB. The SRLB Sub-TLV is used for that purpose. advertises its SRLB. The SRLB Sub-TLV is used for that purpose.
The SR Local Block (SRLB) Sub-TLV is a top-level TLV of the Router The SR Local Block (SRLB) Sub-TLV is a top-level TLV of the Router
Information Opaque LSA (defined in [RFC7770]). Information Opaque LSA (defined in [RFC7770]).
The SR Local Block Sub-TLV MAY appear multiple times in the Router The SR Local Block Sub-TLV MAY appear multiple times in the Router
Information Opaque LSA and has the following format: Information Opaque LSA 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
skipping to change at page 8, line 38 skipping to change at page 8, line 38
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) | | Sub-TLVs (variable) |
+- -+ +- -+
| | | |
+ + + +
where: where:
Type: TBD, suggested value 12 Type: TBD, suggested value 12
Length: variable Length: Variable
Range Size: 3 octets of the SID/label range. MUST be higher then Range Size: 3-octet SID/label range size (i.e., the number of SIDs
0. or labels in the range including the first SID/label). It MUST be
greater than 0.
Initially, the only supported Sub-TLV is the SID/Label TLV as defined Initially, the only supported Sub-TLV is the SID/Label TLV as defined
in Section 2.1. The SID/Label advertised in the SID/Label TLV in Section 2.1. The SID/Label advertised in the SID/Label TLV
represents the first SID/Label in the advertised range. represents the first SID/Label in the advertised range.
The originating router MUST NOT advertise overlapping ranges. The originating router MUST NOT advertise overlapping ranges.
Each time a SID from the SRLB is allocated, it SHOULD also be Each time a SID from the SRLB is allocated, it SHOULD also be
reported to all components (e.g.: controller or applications) in reported to all components (e.g., controller or applications) in
order for these components to have an up-to-date view of the current order for these components to have an up-to-date view of the current
SRLB allocation. This is required to avoid collision between SRLB allocation. This is required to avoid collisions between
allocation instructions. allocation instructions.
Within the context of OSPF, the reporting of local SIDs is done Within the context of OSPF, the reporting of local SIDs is done
through OSPF Sub-TLVs such as the Adjacency-SID (Section 7). through OSPF Sub-TLVs such as the Adjacency-SID (Section 7).
However, the reporting of allocated local SIDs may also be done However, the reporting of allocated local SIDs may also be done
through other means and protocols which mechanisms are outside the through other means and protocols which are outside the scope of this
scope of this document. document.
A router advertising the SRLB TLV may also have other label ranges, A router advertising the SRLB TLV may also have other label ranges,
outside of the SRLB, used for its local allocation purposes which are outside of the SRLB, used for its local allocation purposes which are
NOT advertised in the SRLB. For example, it is possible that an NOT advertised in the SRLB. For example, it is possible that an
Adjacency-SID is allocated using a local label that is not part of Adjacency-SID is allocated using a local label that is not part of
the SRLB. the SRLB.
The RI LSA can be advertised at any of the defined flooding scopes The RI LSA can be advertised at any of the defined flooding scopes
(link, area, or autonomous system (AS)). For the purpose of SR Local (link, area, or autonomous system (AS)). For the purpose of SR Local
Block Sub-TLV TLV advertisement, area scope flooding is required. Block Sub-TLV TLV advertisement, area scope flooding is required.
3.4. SRMS Preference Sub-TLV 3.4. SRMS Preference Sub-TLV
The Segment Routing Mapping Server (SRMS) Preference sub-TLV is used The Segment Routing Mapping Server (SRMS) Preference sub-TLV is used
to advertise a preference associated with the node that acts as a SR to advertise a preference associated with the node that acts as an SR
Mapping Server. SRMS preference is defined in Mapping Server. SRMS preference is defined in
[I-D.ietf-spring-conflict-resolution]. [I-D.ietf-spring-conflict-resolution].
The SRMS Preference Sub-TLV is a top-level TLV of the Router The SRMS Preference Sub-TLV is a top-level TLV of the Router
Information Opaque LSA (defined in [RFC7770]). Information Opaque LSA (defined in [RFC7770]).
The SRMS Preference Sub-TLV MAY only be advertised once in the Router The SRMS Preference Sub-TLV MAY only be advertised once in the Router
Information Opaque LSA and has the following format: Information Opaque LSA and has the following format:
0 1 2 3 0 1 2 3
skipping to change at page 10, line 6 skipping to change at page 10, line 6
where: where:
Type: TBD, suggested value 13 Type: TBD, suggested value 13
Length: 4 octets Length: 4 octets
Preference: 1 octet. SRMS preference value from 0 to 255. Preference: 1 octet. SRMS preference value from 0 to 255.
When multiple SRMS Preference sub-TLVs are received from a given When multiple SRMS Preference sub-TLVs are received from a given
router the receiver SHOULD use the first occurrence of the sub-TLV in router, the receiver SHOULD use the first occurrence of the sub-TLV
the Router Information LSA. If the SRMS Preference sub-TLV appears in the Router Information LSA. If the SRMS Preference sub-TLV
in multiple Router Information LSAs that have different flooding appears in multiple Router Information LSAs that have different
scopes, the SRLB sub-TLV in the Router Information LSA with the flooding scopes, the SRLB sub-TLV in the Router Information LSA with
lowest flooding scope SHOULD be used. If the SRMS Preference sub-TLV the narrowest flooding scope SHOULD be used. If the SRMS Preference
appears in multiple Router Information LSAs that have the same sub-TLV appears in multiple Router Information LSAs that have the
flooding scope, the SRMS Preference sub-TLV in the Router Information same flooding scope, the SRMS Preference sub-TLV in the Router
LSA with the numerically smallest Instance ID SHOULD be used and Information LSA with the numerically smallest Instance ID SHOULD be
subsequent instances of the SRMS Preference sub-TLV SHOULD be used and subsequent instances of the SRMS Preference sub-TLV SHOULD
ignored. be ignored.
The RI LSA can be advertised at any of the defined flooding scopes The RI LSA can be advertised at any of the defined flooding scopes
(link, area, or autonomous system (AS)). For the purpose of the SRMS (link, area, or autonomous system (AS)). For the purpose of the SRMS
Preference Sub-TLV advertisement, AS scope flooding is required. If Preference Sub-TLV advertisement, AS scope flooding is required. If
the SRMS advertisements from the SRMS server are only used inside the the SRMS advertisements from the SRMS server are only used inside the
area to which the SRMS server is attached, area scope flooding may be area to which the SRMS server is attached, area scope flooding may be
used. used.
4. OSPF Extended Prefix Range TLV 4. OSPF Extended Prefix Range TLV
In some cases it is useful to advertise attributes for a range of In some cases it is useful to advertise attributes for a range of
prefixes. The Segment Routing Mapping Server, which is described in prefixes. The Segment Routing Mapping Server, which is described in
[I-D.filsfils-spring-segment-routing-ldp-interop], is an example [I-D.filsfils-spring-segment-routing-ldp-interop], is an example
where we need a single advertisement to advertise SIDs for multiple where we need a single advertisement to advertise SIDs for multiple
prefixes from a contiguous address range. prefixes from a contiguous address range.
The OSPF Extended Prefix Range TLV, which is a new top level TLV of The OSPF Extended Prefix Range TLV, which is a top level TLV of the
the Extended Prefix LSA described in [RFC7684] is defined for this Extended Prefix LSA described in [RFC7684] is defined for this
purpose. purpose.
Multiple OSPF Extended Prefix Range TLVs MAY be advertised in each Multiple OSPF Extended Prefix Range TLVs MAY be advertised in each
OSPF Extended Prefix Opaque LSA, but all prefix ranges included in a OSPF Extended Prefix Opaque LSA, but all prefix ranges included in a
single OSPF Extended Prefix Opaque LSA MUST have the same flooding single OSPF Extended Prefix Opaque LSA MUST have the same flooding
scope. The OSPF Extended Prefix Range TLV has the following format: scope. The OSPF Extended Prefix Range 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 11, line 28 skipping to change at page 11, line 28
| | | |
where: where:
Type: TBD, suggested value 2. Type: TBD, suggested value 2.
Length: Variable Length: Variable
Prefix length: Length of the prefix Prefix length: Length of the prefix
AF: 0 - IPv4 unicast AF: Address family for the prefix. Currently, the only supported
value is 0 for IPv4 unicast. The inclusion of address family in
this TLV allows for future extension.
Range size: Represents the number of prefixes that are covered by Range size: Represents the number of prefixes that are covered by
the advertisement. The Range Size MUST NOT exceed the number of the advertisement. The Range Size MUST NOT exceed the number of
prefixes that could be satisfied by the prefix length without prefixes that could be satisfied by the prefix length without
including the IPv4 multicast address range (224.0.0.0/3). including the IPv4 multicast address range (224.0.0.0/3).
Flags: Single octet field. The following flags are defined: Flags: Single octet field. The following flags are defined:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+ +--+--+--+--+--+--+--+--+
|IA| | | | | | | | |IA| | | | | | | |
+--+--+--+--+--+--+--+--+ +--+--+--+--+--+--+--+--+
where: where:
IA-Flag: Inter-Area flag. If set, advertisement is of inter- IA-Flag: Inter-Area flag. If set, advertisement is of inter-
area type. The ABR that is advertising the OSPF Extended area type. An ABR that is advertising the OSPF Extended Prefix
Prefix Range TLV between areas MUST set this bit. Range TLV between areas MUST set this bit.
This bit is used to prevent redundant flooding of Prefix Range This bit is used to prevent redundant flooding of Prefix Range
TLVs between areas as follows: TLVs between areas as follows:
An ABR always prefers intra-area Prefix Range advertisements An ABR always prefers intra-area Prefix Range advertisements
over inter-area advertisements. over inter-area advertisements.
An ABR does not consider inter-area Prefix Range An ABR does not consider inter-area Prefix Range
advertisements coming from non-backbone areas. advertisements coming from non-backbone areas.
An ABR only propagates an inter-area Prefix Range An ABR only propagates an inter-area Prefix Range
advertisement from the backbone area to connected non- advertisement from the backbone area to connected non-
backbone areas if the advertisement is considered to be the backbone areas if the advertisement is considered to be the
best one. best one.
Address Prefix: The prefix, encoded as an even multiple of 32-bit Address Prefix: The prefix, encoded as 32-bit value, padded with
words, padded with zero bits as necessary. This encoding consumes zero bits as necessary. The prefix represents the first prefix in
((PrefixLength + 31) / 32) 32-bit words. The Address Prefix the prefix range.
represents the first prefix in the prefix range.
5. Prefix SID Sub-TLV 5. Prefix SID Sub-TLV
The Prefix SID Sub-TLV is a Sub-TLV of the OSPF Extended Prefix TLV The Prefix SID Sub-TLV is a Sub-TLV of the OSPF Extended Prefix TLV
described in [RFC7684] and the OSPF Extended Prefix Range TLV described in [RFC7684] and the OSPF Extended Prefix Range TLV
described in Section 4. It MAY appear more than once in the parent described in Section 4. It MAY appear more than once in the parent
TLV and has the following format: 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
skipping to change at page 13, line 49 skipping to change at page 13, line 49
SID/Index/Label: According to the V and L flags, it contains SID/Index/Label: According to the V and L flags, it contains
either: either:
A 32-bit index defining the offset in the SID/Label space A 32-bit index defining the offset in the SID/Label space
advertised by this router. advertised by this router.
A 24-bit label where the 20 rightmost bits are used for A 24-bit label where the 20 rightmost bits are used for
encoding the label value. encoding the label value.
If multiple Prefix-SIDs are advertised for the same prefix, the If multiple Prefix-SIDs are advertised for the same prefix, the
receiving router MUST use the first encoded SID and MAY use the receiving router MUST use the first encoded SID and MAY use
subsequent SIDs. subsequent SIDs.
When propagating Prefix-SIDs between areas, if multiple prefix-SIDs When propagating Prefix-SIDs between areas, if multiple prefix-SIDs
are advertised for a prefix, an implementation SHOULD preserve the are advertised for a prefix, an implementation SHOULD preserve the
original order when advertising prefix-SIDs to other areas. This original order when advertising prefix-SIDs to other areas. This
allows implementations that only support a single Prefix-SID to have allows implementations that only support a single Prefix-SID to have
a consistent view across areas. a consistent view across areas.
When calculating the outgoing label for the prefix, the router MUST When calculating the outgoing label for the prefix, the router MUST
take into account the E and P flags advertised by the next-hop router take into account the E and P flags advertised by the next-hop router
if that router advertised the SID for the prefix. This MUST be done if that router advertised the SID for the prefix. This MUST be done
regardless of whether the next-hop router contributes to the best regardless of whether the next-hop router contributes to the best
path to the prefix. path to the prefix.
The NP-Flag (No-PHP) MUST be set for Prefix-SIDs allocated to inter- The NP-Flag (No-PHP) MUST be set for Prefix-SIDs allocated to inter-
area prefixes that are originated by the ABR based on intra-area or area prefixes that are originated by the ABR based on intra-area or
inter-area reachability between areas. When the inter-area prefix is inter-area reachability between areas. When the inter-area prefix is
generated based on a prefix which is directly attached to the ABR, generated based on a prefix which is directly attached to the ABR,
the NP-Flag SHOULD NOT be set. the NP-Flag SHOULD NOT be set.
The NP-Flag (No-PHP) MUST be be set for the Prefix-SIDs allocated to The NP-Flag (No-PHP) MUST be be set for Prefix-SIDs allocated to
redistributed prefixes, unless the redistributed prefix is directly redistributed prefixes, unless the redistributed prefix is directly
attached to the ASBR, in which case the NP-flag SHOULD NOT be set. attached to the ASBR, in which case the NP-flag SHOULD NOT be set.
If the NP-Flag is not set, then any upstream neighbor of the Prefix- If the NP-Flag is not set, then any upstream neighbor of the Prefix-
SID originator MUST pop the Prefix-SID. This is equivalent to the SID originator MUST pop the Prefix-SID. This is equivalent to the
penultimate hop popping mechanism used in the MPLS dataplane. In penultimate hop popping mechanism used in the MPLS dataplane. In
such case, MPLS EXP bits of the Prefix-SID are not preserved for the such case, MPLS EXP bits of the Prefix-SID are not preserved for the
final destination (the Prefix-SID being removed). If the NP-flag is final destination (the Prefix-SID being removed). If the NP-flag is
not set then the received E-flag is ignored. not set then the received E-flag is ignored.
skipping to change at page 15, line 7 skipping to change at page 15, line 7
label. This is useful, e.g., when the originator of the Prefix- label. This is useful, e.g., when the originator of the Prefix-
SID is the final destination for the related prefix and the SID is the final destination for the related prefix and the
originator wishes to receive the packet with the original EXP originator wishes to receive the packet with the original EXP
bits. bits.
When the M-Flag is set, the NP-flag and the E-flag MUST be ignored at When the M-Flag is set, the NP-flag and the E-flag MUST be ignored at
reception. reception.
As the Mapping Server does not specify the originator of a prefix As the Mapping Server does not specify the originator of a prefix
advertisement, it is not possible to determine PHP behavior solely advertisement, it is not possible to determine PHP behavior solely
based on the Mapping Server advertisement. However, PHP behavior may based on the Mapping Server advertisement. However, PHP behavior
safely be done in following cases: SHOULD be done in following cases:
The Prefix is intra-area type and the downstream neighbor is the The Prefix is intra-area type and the downstream neighbor is the
originator of the prefix. originator of the prefix.
The Prefix is inter-area type and downstream neighbor is an ABR, The Prefix is inter-area type and downstream neighbor is an ABR,
which is advertising the prefix reachability and is also which is advertising prefix reachability and is also generating
generating the Extended Prefix TLV with the A-flag set for this the Extended Prefix TLV with the A-flag set for this prefix as
prefix as described in section 2.1 of [RFC7684]. described in section 2.1 of [RFC7684].
The Prefix is external type and downstream neighbor is an ASBR, The Prefix is external type and downstream neighbor is an ASBR,
which is advertising the prefix reachability and is also which is advertising prefix reachability and is also generating
generating the Extended Prefix TLV with the A-flag set for this the Extended Prefix TLV with the A-flag set for this prefix as
prefix as described in section 2.1 of [RFC7684]. described in section 2.1 of [RFC7684].
When a Prefix-SID is advertised in an Extended Prefix Range TLV, then When a Prefix-SID is advertised in an Extended Prefix Range TLV, then
the value advertised in Prefix SID Sub-TLV is interpreted as a the value advertised in the Prefix SID Sub-TLV is interpreted as a
starting SID value. starting SID value.
Example 1: If the following router addresses (loopback addresses) Example 1: If the following router addresses (loopback addresses)
need to be mapped into the corresponding Prefix SID indexes: need to be mapped into the corresponding Prefix SID indexes:
Router-A: 192.0.2.1/32, Prefix-SID: Index 1 Router-A: 192.0.2.1/32, Prefix-SID: Index 1
Router-B: 192.0.2.2/32, Prefix-SID: Index 2 Router-B: 192.0.2.2/32, Prefix-SID: Index 2
Router-C: 192.0.2.3/32, Prefix-SID: Index 3 Router-C: 192.0.2.3/32, Prefix-SID: Index 3
Router-D: 192.0.2.4/32, Prefix-SID: Index 4 Router-D: 192.0.2.4/32, Prefix-SID: Index 4
skipping to change at page 16, line 12 skipping to change at page 16, line 12
10.1.6/24, Prefix-SID: Index 56 10.1.6/24, Prefix-SID: Index 56
10.1.7/24, Prefix-SID: Index 57 10.1.7/24, Prefix-SID: Index 57
then the Prefix field in the Extended Prefix Range TLV would be set then the Prefix field in the Extended Prefix Range TLV would be set
to 10.1.1.0, Prefix Length would be set to 24, Range Size would be 7, to 10.1.1.0, Prefix Length would be set to 24, Range Size would be 7,
and the Index value in the Prefix-SID Sub-TLV would be set to 51. and the Index value in the Prefix-SID Sub-TLV would be set to 51.
6. SID/Label Binding Sub-TLV 6. SID/Label Binding Sub-TLV
The SID/Label Binding Sub-TLV is used to advertise a SID/Label The SID/Label Binding Sub-TLV is used to advertise a SID/Label
mapping for a path to the prefix. mapping for a path to the a prefix.
The SID/Label Binding Sub-TLV MAY be originated by any router in an The SID/Label Binding Sub-TLV MAY be originated by any router in an
OSPF domain. The router may advertise a SID/Label binding to a FEC OSPF domain. The router may advertise a SID/Label binding to a FEC
along with at least a single 'nexthop style' anchor. The protocol along with at least a single 'nexthop style' anchor. The protocol
supports more than one 'nexthop style' anchor to be attached to a supports more than one 'nexthop style' anchor to be attached to a
SID/Label binding, which results in a simple path description SID/Label binding, which results in a simple path description
language. In analogy to RSVP, the terminology for this is called an language. Analogous to RSVP, the terminology for this is called an
'Explicit Route Object' (ERO). Since ERO style path notation allows 'Explicit Route Object' (ERO). Since ERO-style path notation allows
anchoring SID/label bindings to both link and node IP addresses, any anchoring SID/label bindings to both link and node IP addresses, any
Label Switched Path (LSP) can be described. Additionally, SID/Label Label Switched Path (LSP) can be described. Additionally, SID/Label
Bindings from external protocols can be easily re-advertised. Bindings from external protocols can be easily re-advertised.
The SID/Label Binding Sub-TLV may be used for advertising SID/Label The SID/Label Binding Sub-TLV may be used for advertising SID/Label
Bindings and their associated Primary and Backup paths. In a single Bindings and their associated Primary and Backup paths. In a single
TLV, a primary ERO Path, backup ERO Path, or both can be advertised. TLV, a primary ERO Path, backup ERO Path, or both can be advertised.
If a router wants to advertise multiple parallel paths, then it can If a router wants to advertise multiple parallel paths, then it can
generate several TLVs for the same Prefix/FEC. Each occurrence of a generate several TLVs for the same Prefix/FEC. Each occurrence of a
Binding TLV for a given FEC Prefix will add a new path. Binding TLV for a given FEC Prefix will add a new path.
skipping to change at page 17, line 19 skipping to change at page 17, line 19
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|M| | |M| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
M-bit - When the bit is set, the binding represents a mirroring M-bit - When the bit is set, the binding represents a mirroring
context as defined in context as defined in
[I-D.minto-rsvp-lsp-egress-fast-protection]. [I-D.minto-rsvp-lsp-egress-fast-protection].
Other bits: Reserved. These MUST be zero when sent and are
ignored when received.
MT-ID: Multi-Topology ID (as defined in [RFC4915]). MT-ID: Multi-Topology ID (as defined in [RFC4915]).
Weight: Weight used for load-balancing purposes. The use of the Weight: 8 bits of weight used for load-balancing purposes. The
weight is defined in [I-D.ietf-spring-segment-routing]. use of the weight is defined in [I-D.ietf-spring-segment-routing].
The SID/Label Binding Sub-TLV supports the following Sub-TLVs: The SID/Label Binding Sub-TLV supports the following Sub-TLVs:
SID/Label Sub-TLV as described in Section 2.1. This Sub-TLV MUST SID/Label Sub-TLV as described in Section 2.1. This Sub-TLV MUST
appear in the SID/Label Binding Sub-TLV and it SHOULD only appear appear in the SID/Label Binding Sub-TLV and it SHOULD only appear
once. If the SID/Label Sub-TLV is not included in the SID/Label once. If the SID/Label Sub-TLV is not included in the SID/Label
Binding Sub-TLV, the SID/Label Binding Sub-TLV MUST be ignored. Binding Sub-TLV, the SID/Label Binding Sub-TLV MUST be ignored.
If the SID/Label Sub-TLV appears in the SID/Label Binding Sub-TLV If the SID/Label Sub-TLV appears in the SID/Label Binding Sub-TLV
more than once, instances other than the first will be ignored and more than once, instances other than the first SHOULD be ignored
the condition SHOULD be logged for possible action by the network and the condition SHOULD be logged for possible action by the
operator. network operator.
ERO Metric Sub-TLV as defined in Section 6.1. ERO Metric Sub-TLV as defined in Section 6.1.
ERO Sub-TLVs as defined in Section 6.2. ERO Sub-TLVs as defined in Section 6.2.
6.1. ERO Metric Sub-TLV 6.1. ERO Metric Sub-TLV
The ERO Metric Sub-TLV is a Sub-TLV of the SID/Label Binding TLV. The ERO Metric Sub-TLV is a Sub-TLV of the SID/Label Binding TLV.
The ERO Metric Sub-TLV advertises the cost of an ERO path. It is The ERO Metric Sub-TLV advertises the cost of an ERO path. It is
used to compare the cost of a given source/destination path. A used to compare the cost of a given source/destination path. ERO
router SHOULD advertise the ERO Metric Sub-TLV in an advertised ERO Metric Sub-TLV is an option sub-TLV. The cost of the ERO Metric Sub-
TLV. The cost of the ERO Metric Sub-TLV SHOULD be set to the TLV SHOULD be set to the cumulative IGP or TE path cost of the
cumulative IGP or TE path cost of the advertised ERO. Since advertised ERO. Since manipulation of the Metric field may attract
manipulation of the Metric field may attract or repel traffic to and or repel traffic to and from the advertised segment, it MAY be
from the advertised segment, it MAY be manually overridden. manually overridden.
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Metric (4 octets) | | Metric (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ERO Metric Sub-TLV format ERO Metric Sub-TLV format
skipping to change at page 18, line 33 skipping to change at page 18, line 35
6.2. ERO Sub-TLVs 6.2. ERO Sub-TLVs
All ERO information represents an ordered set which describes the All ERO information represents an ordered set which describes the
segments of a path. The first ERO Sub-TLV describes the first segments of a path. The first ERO Sub-TLV describes the first
segment of a path. Similiarly, the last ERO Sub-TLV describes the segment of a path. Similiarly, the last ERO Sub-TLV describes the
segment closest to the egress point. If a router extends or stitches segment closest to the egress point. If a router extends or stitches
a path, it MUST prepend the new segment's path information to the ERO a path, it MUST prepend the new segment's path information to the ERO
list. This applies equally to advertised backup EROs. list. This applies equally to advertised backup EROs.
All ERO Sub-TLVs must immediately follow the SID/Label Sub-TLV. All ERO sub-TLVs are sub-TLVs of the SID/Label Binding TLV.
All Backup ERO Sub-TLVs must immediately follow the last ERO Sub-TLV.
6.2.1. IPv4 ERO Sub-TLV 6.2.1. IPv4 ERO Sub-TLV
The IPv4 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV. The IPv4 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV.
The IPv4 ERO Sub-TLV describes a path segment using IPv4 Address The IPv4 ERO Sub-TLV describes a path segment using IPv4 Address
style encoding. Its semantics have been borrowed from [RFC3209]. style encoding. Its semantics have been borrowed from [RFC3209].
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 37 skipping to change at page 19, line 37
|L| | |L| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
L-bit - If the L-bit is set, then the segment path is L-bit - If the L-bit is set, then the segment path is
designated as 'loose'. Otherwise, the segment path is designated as 'loose'. Otherwise, the segment path is
designated as 'strict'. The terms 'loose' and 'strict' are designated as 'strict'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209]. defined for RSVP subobjects in [RFC3209].
Other bits: Reserved. These MUST be zero when sent and are
ignored when received.
IPv4 Address - The address of the explicit route hop. IPv4 Address - The address of the explicit route hop.
6.2.2. Unnumbered Interface ID ERO Sub-TLV 6.2.2. Unnumbered Interface ID ERO Sub-TLV
The Unnumbered Interface ID ERO Sub-TLV is a Sub-TLV of the SID/Label The Unnumbered Interface ID ERO Sub-TLV is a Sub-TLV of the SID/Label
Binding Sub-TLV. Binding Sub-TLV.
The appearance and semantics of the 'Unnumbered Interface ID' have The appearance and semantics of the 'Unnumbered Interface ID' have
been borrowed from [RFC3477]. been borrowed from [RFC3477].
The Unnumbered Interface-ID ERO Sub-TLV describes a path segment that The Unnumbered Interface-ID ERO Sub-TLV describes a path segment that
includes an unnumbered interface. Unnumbered interfaces are includes an unnumbered interface. Unnumbered interfaces are
referenced using the interface index. Interface indices are assigned referenced using the interface index. Interface indices are assigned
local to the router and therefore are not unique within a domain. local to the router and therefore are not unique within a domain.
All elements in an ERO path need to be unique within a domain and All elements in an ERO path need to be unique within a domain and
hence need to be disambiguated using a domain unique Router-ID. hence need to be disambiguated using a domain-unique Router-ID.
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router ID | | Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 20, line 39 skipping to change at page 20, line 42
|L| | |L| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
L-bit - If the L-bit is set, then the segment path is L-bit - If the L-bit is set, then the segment path is
designated as 'loose'. Otherwise, the segment path is designated as 'loose'. Otherwise, the segment path is
designated as 'strict'. The terms 'loose' and 'strict' are designated as 'strict'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209] defined for RSVP subobjects in [RFC3209]
Router-ID: Router-ID of the next-hop. Other bits: Reserved. These MUST be zero when sent and are
ignored when received.
Router ID: Router ID of the next-hop.
Interface ID: The identifier assigned to the link by the router Interface ID: The identifier assigned to the link by the router
specified by the Router-ID. specified by the Router ID.
6.2.3. IPv4 Backup ERO Sub-TLV 6.2.3. IPv4 Backup ERO Sub-TLV
IPv4 Prefix Backup ERO Sub-TLV is a Sub-TLV of the SID/Label Binding IPv4 Prefix Backup ERO Sub-TLV is a Sub-TLV of the SID/Label Binding
Sub-TLV. Sub-TLV.
The IPv4 Backup ERO Sub-TLV describes a path segment using IPv4 The IPv4 Backup ERO Sub-TLV describes a path segment using IPv4
Address style of encoding. Its semantics have been borrowed from Address style of encoding. Its semantics have been borrowed from
[RFC3209]. [RFC3209].
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|L| | |L| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
L-bit - If the L-bit is set, then the segment path is L-bit - If the L-bit is set, then the segment path is
designated as 'loose'. Otherwise, the segment path is designated as 'loose'. Otherwise, the segment path is
designated as 'strict'. The terms 'loose' and 'strict' are designated as 'strict'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209] defined for RSVP subobjects in [RFC3209]
Other bits: Reserved. These MUST be zero when sent and are
ignored when received.
IPv4 Address - The address of the explicit route hop. IPv4 Address - The address of the explicit route hop.
6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV 6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV
The Unnumbered Interface ID Backup ERO Sub-TLV is a Sub-TLV of the The Unnumbered Interface ID Backup ERO Sub-TLV is a Sub-TLV of the
SID/Label Binding Sub-TLV. SID/Label Binding Sub-TLV.
The appearance and semantics of the 'Unnumbered Interface ID' have The appearance and semantics of the 'Unnumbered Interface ID' have
been borrowed from [RFC3477]. been borrowed from [RFC3477].
The Unnumbered Interface-ID Backup ERO Sub-TLV describes a path The Unnumbered Interface-ID Backup ERO Sub-TLV describes a path
segment that includes an unnumbered interface. Unnumbered interfaces segment that includes an unnumbered interface. Unnumbered interfaces
are referenced using the interface index. Interface indices are are referenced using the interface index. Interface indices are
assigned local to the router and are therefore not unique within a assigned local to the router and are therefore not unique within a
domain. All elements in an ERO path need to be unique within a domain. All elements in an ERO path need to be unique within a
domain and hence need to be disambiguated with specification of the domain and hence need to be disambiguated with specification of the
domain unique Router-ID. domain-unique Router-ID.
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Router ID | | Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|L| | |L| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
L-bit - If the L-bit is set, then the segment path is L-bit - If the L-bit is set, then the segment path is
designated as 'loose'. Otherwise, the segment path is designated as 'loose'. Otherwise, the segment path is
designated as 'strict'. designated as 'strict'.
Router-ID: Router-ID of the next-hop. Other bits: Reserved. These MUST be zero when sent and are
ignored when received.
Router ID: Router ID of the next-hop.
Interface ID: The identifier assigned to the link by the router Interface ID: The identifier assigned to the link by the router
specified by the Router-ID. specified by the Router ID.
7. Adjacency Segment Identifier (Adj-SID) 7. Adjacency Segment Identifier (Adj-SID)
An Adjacency Segment Identifier (Adj-SID) represents a router An Adjacency Segment Identifier (Adj-SID) represents a router
adjacency in Segment Routing. adjacency in Segment Routing.
7.1. Adj-SID Sub-TLV 7.1. Adj-SID Sub-TLV
Adj-SID is an optional Sub-TLV of the Extended Link TLV defined in Adj-SID is an optional Sub-TLV of the Extended Link TLV defined in
[RFC7684]. It MAY appear multiple times in the Extended Link TLV. [RFC7684]. It MAY appear multiple times in the Extended Link TLV.
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Flags: Single octet field containing the following flags: Flags: Single octet field containing the following flags:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|B|V|L|G|P| | |B|V|L|G|P| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
B-Flag: Backup Flag. If set, the Adj-SID refers to an B-Flag: Backup Flag. If set, the Adj-SID refers to an
adjacency that is eligible for protection (e.g.: using IPFRR or adjacency that is eligible for protection (e.g., using IPFRR or
MPLS-FRR) as described in section 3.5 of MPLS-FRR) as described in section 3.5 of
[I-D.ietf-spring-segment-routing]. [I-D.ietf-spring-segment-routing].
The V-Flag: Value/Index Flag. If set, then the Adj-SID carries The V-Flag: Value/Index Flag. If set, then the Adj-SID carries
an absolute value. If not set, then the Adj-SID carries an an absolute value. If not set, then the Adj-SID carries an
index. index.
The L-Flag: Local/Global Flag. If set, then the value/index The L-Flag: Local/Global Flag. If set, then the value/index
carried by the Adj-SID has local significance. If not set, carried by the Adj-SID has local significance. If not set,
then the value/index carried by this Sub-TLV has global then the value/index carried by this Sub-TLV has global
skipping to change at page 26, line 41 skipping to change at page 27, line 5
An OSPFv2 router that supports segment routing MAY advertise Prefix- An OSPFv2 router that supports segment routing MAY advertise Prefix-
SIDs for any prefix to which it is advertising reachability (e.g., a SIDs for any prefix to which it is advertising reachability (e.g., a
loopback IP address as described in Section 5). loopback IP address as described in Section 5).
If multiple routers advertise a Prefix-SID for the same prefix, then If multiple routers advertise a Prefix-SID for the same prefix, then
the Prefix-SID MUST be the same. This is required in order to allow the Prefix-SID MUST be the same. This is required in order to allow
traffic load-balancing when multiple equal cost paths to the traffic load-balancing when multiple equal cost paths to the
destination exist in the OSPFv2 routing domain. destination exist in the OSPFv2 routing domain.
Prefix-SID can also be advertised by the SR Mapping Servers (as A Prefix-SID can also be advertised by the SR Mapping Servers (as
described in [I-D.filsfils-spring-segment-routing-ldp-interop]). The described in [I-D.filsfils-spring-segment-routing-ldp-interop]). A
Mapping Server advertises Prefix-SIDs for remote prefixes that exist Mapping Server advertises Prefix-SIDs for remote prefixes that exist
in the OSPFv2 routing domain. Multiple Mapping Servers can advertise in the OSPFv2 routing domain. Multiple Mapping Servers can advertise
Prefix-SIDs for the same prefix, in which case the same Prefix-SID Prefix-SIDs for the same prefix, in which case the same Prefix-SID
MUST be advertised by all of them. The flooding scope of the OSPF MUST be advertised by all of them. The flooding scope of the OSPF
Extended Prefix Opaque LSA that is generated by the SR Mapping Server Extended Prefix Opaque LSA that is generated by the SR Mapping Server
could be either area scoped or AS scoped and is determined based on could be either area scoped or AS scoped and is determined based on
the configuration of the SR Mapping Server. the configuration of the SR Mapping Server.
The SR Mapping Server MUST use OSPF Extended Prefix Range TLV when An SR Mapping Server MUST use the OSPF Extended Prefix Range TLV when
advertising SIDs for prefixes. Prefixes of different route-types can advertising SIDs for prefixes. Prefixes of different route-types can
be combined in a single OSPF Extended Prefix Range TLV advertised by be combined in a single OSPF Extended Prefix Range TLV advertised by
the SR Mapping Server. an SR Mapping Server.
Area-scoped OSPF Extended Prefix Range TLV are propagated between Area-scoped OSPF Extended Prefix Range TLV are propagated between
areas. Similar to propagation of prefixes between areas, an ABR only areas. Similar to propagation of prefixes between areas, an ABR only
propagates the OSPF Extended Prefix Range TLV that it considers to be propagates the OSPF Extended Prefix Range TLV that it considers to be
the best from the set it received. The rules used to pick the best the best from the set it received. The rules used to pick the best
OSPF Extended Prefix Range TLV are described in Section 4. OSPF Extended Prefix Range TLV are described in Section 4.
When propagating an OSPF Extended Prefix Range TLV between areas, When propagating an OSPF Extended Prefix Range TLV between areas,
ABRs MUST set the IA-Flag, that is used to prevent redundant flooding ABRs MUST set the IA-Flag, that is used to prevent redundant flooding
of the OSPF Extended Prefix Range TLV between areas as described in of the OSPF Extended Prefix Range TLV between areas as described in
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The ABR will then determine if such router advertised a Prefix-SID The ABR will then determine if such router advertised a Prefix-SID
for the prefix and use it when advertising the Prefix-SID to other for the prefix and use it when advertising the Prefix-SID to other
connected areas. connected areas.
If no Prefix-SID was advertised for the prefix in the backbone If no Prefix-SID was advertised for the prefix in the backbone
area by the ABR that contributes to the best path to the prefix, area by the ABR that contributes to the best path to the prefix,
the originating ABR will use the Prefix-SID advertised by any the originating ABR will use the Prefix-SID advertised by any
other router when propagating the Prefix-SID for the prefix to other router when propagating the Prefix-SID for the prefix to
other areas. other areas.
8.3. SID for External Prefixes 8.3. Segment Routing for External Prefixes
Type-5 LSAs are flooded domain wide. When an ASBR, which supports Type-5 LSAs are flooded domain wide. When an ASBR, which supports
SR, generates Type-5 LSAs, it should also originate Extended Prefix SR, generates Type-5 LSAs, it should also originate Extended Prefix
Opaque LSAs, as described in [RFC7684]. The flooding scope of the Opaque LSAs, as described in [RFC7684]. The flooding scope of the
Extended Prefix Opaque LSA type is set to AS-scope. The route-type Extended Prefix Opaque LSA type is set to AS-scope. The route-type
in the OSPF Extended Prefix TLV is set to external. The Prefix-SID in the OSPF Extended Prefix TLV is set to external. The Prefix-SID
Sub-TLV is included in this LSA and the Prefix-SID value will be set Sub-TLV is included in this LSA and the Prefix-SID value will be set
to the SID that has been reserved for that prefix. to the SID that has been reserved for that prefix.
When an NSSA ABR translates Type-7 LSAs into Type-5 LSAs, it should When an NSSA ABR translates Type-7 LSAs into Type-5 LSAs, it should
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The Adjacency Segment Routing Identifier (Adj-SID) is advertised The Adjacency Segment Routing Identifier (Adj-SID) is advertised
using the Adj-SID Sub-TLV as described in Section 7. using the Adj-SID Sub-TLV as described in Section 7.
8.4.1. Advertisement of Adj-SID on Point-to-Point Links 8.4.1. Advertisement of Adj-SID on Point-to-Point Links
An Adj-SID MAY be advertised for any adjacency on a P2P link that is An Adj-SID MAY be advertised for any adjacency on a P2P link that is
in neighbor state 2-Way or higher. If the adjacency on a P2P link in neighbor state 2-Way or higher. If the adjacency on a P2P link
transitions from the FULL state, then the Adj-SID for that adjacency transitions from the FULL state, then the Adj-SID for that adjacency
MAY be removed from the area. If the adjacency transitions to a MAY be removed from the area. If the adjacency transitions to a
state lower then 2-Way, then the Adj-SID advertisement MUST be state lower then 2-Way, then the Adj-SID advertisement MUST be
removed from the area. withdrawn from the area.
8.4.2. Adjacency SID on Broadcast or NBMA Interfaces 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces
Broadcast, NBMA or or hybrid [RFC6845] networks in OSPF are Broadcast, NBMA, or hybrid [RFC6845] networks in OSPF are represented
represented by a star topology where the Designated Router (DR) is by a star topology where the Designated Router (DR) is the central
the central point to which all other routers on the broadcast, NBMA, point to which all other routers on the broadcast, NBMA, or hybrid
or hybrid network connect. As a result, routers on the broadcast, network connect. As a result, routers on the broadcast, NBMA, or
NBMA, or hybrid network advertise only their adjacency to the DR. hybrid network advertise only their adjacency to the DR. Routers
Routers that do not act as DR do not form or advertise adjacencies that do not act as DR do not form or advertise adjacencies with each
with each other. They do, however, maintain 2-Way adjacency state other. They do, however, maintain 2-Way adjacency state with each
with each other and are directly reachable. other and are directly reachable.
When Segment Routing is used, each router on the broadcast or NBMA When Segment Routing is used, each router on the broadcast, NBMSA, or
network MAY advertise the Adj-SID for its adjacency to the DR using hybrid network MAY advertise the Adj-SID for its adjacency to the DR
the Adj-SID Sub-TLV as described in Section 7.1. using the Adj-SID Sub-TLV as described in Section 7.1.
SR capable routers MAY also advertise an LAN-Adj-SID for other SR capable routers MAY also advertise a LAN-Adj-SID for other
neighbors (e.g., BDR, DR-OTHER) on the broadcast, NBMA or hybrid neighbors (e.g., BDR, DR-OTHER) on the broadcast, NBMA, or hybrid
network using the LAN-ADJ-SID Sub-TLV as described in Section 7.2. network using the LAN-ADJ-SID Sub-TLV as described in Section 7.2.
9. IANA Considerations 9. IANA Considerations
This specification updates several existing OSPF registries. This specification updates several existing OSPF registries.
9.1. OSPF OSPF Router Information (RI) TLVs Registry 9.1. OSPF OSPF Router Information (RI) TLVs Registry
o 8 (IANA Preallocated) - SR-Algorithm TLV o 8 (IANA Preallocated) - SR-Algorithm TLV
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o 2 - Adj-SID Sub-TLV o 2 - Adj-SID Sub-TLV
o 3 - LAN Adj-SID/Label Sub-TLV o 3 - LAN Adj-SID/Label Sub-TLV
10. Implementation Status 10. Implementation Status
An implementation survey with seven questions related to the An implementation survey with seven questions related to the
implementer's support of OSPFv2 Segment Routing was sent to the OSPF implementer's support of OSPFv2 Segment Routing was sent to the OSPF
WG list and several known implementers. This section contains WG list and several known implementers. This section contains
responses from two implementers who completed the survey. No responses from three implementers who completed the survey. No
external means were used to verify the accuracy of the information external means were used to verify the accuracy of the information
submitted by the respondents. The respondents are considered experts submitted by the respondents. The respondents are considered experts
on the products they reported on. Additionally, responses were on the products they reported on. Additionally, responses were
omitted from implementers who indicated that they have not omitted from implementers who indicated that they have not
implemented the function yet. implemented the function yet.
Responses from Nokia (former Alcatel-Lucent): Responses from Nokia (former Alcatel-Lucent):
Link to a web page describing the implementation: Link to a web page describing the implementation:
https://infoproducts.alcatel-lucent.com/cgi-bin/dbaccessfilename.cgi/ https://infoproducts.alcatel-lucent.com/cgi-bin/dbaccessfilename.cgi/
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