draft-ietf-ospf-segment-routing-extensions-07.txt   draft-ietf-ospf-segment-routing-extensions-08.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 22, 2016 Cisco Systems, Inc. Expires: October 29, 2016 Cisco Systems, Inc.
H. Gredler H. Gredler
Individual Individual
R. Shakir R. Shakir
Jive Communications, Inc. Jive Communications, Inc.
W. Henderickx W. Henderickx
Alcatel-Lucent Alcatel-Lucent
J. Tantsura J. Tantsura
Ericsson Individual
March 21, 2016 April 27, 2016
OSPF Extensions for Segment Routing OSPF Extensions for Segment Routing
draft-ietf-ospf-segment-routing-extensions-07 draft-ietf-ospf-segment-routing-extensions-08
Abstract Abstract
Segment Routing (SR) allows for a flexible definition of end-to-end Segment Routing (SR) allows a flexible definition of end-to-end paths
paths within IGP topologies by encoding paths as sequences of within IGP topologies by encoding paths as sequences of topological
topological sub-paths, called "segments". These segments are sub-paths, called "segments". These segments are advertised by the
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.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
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 22, 2016. This Internet-Draft will expire on October 29, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(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 39 skipping to change at page 2, line 39
4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 7 4. OSPF Extended Prefix Range TLV . . . . . . . . . . . . . . . 7
5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 9 5. Prefix SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 9
6. SID/Label Binding Sub-TLV . . . . . . . . . . . . . . . . . . 13 6. SID/Label Binding Sub-TLV . . . . . . . . . . . . . . . . . . 13
6.1. ERO Metric Sub-TLV . . . . . . . . . . . . . . . . . . . 14 6.1. ERO Metric Sub-TLV . . . . . . . . . . . . . . . . . . . 14
6.2. ERO Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . 15 6.2. ERO Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . 15
6.2.1. IPv4 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 15 6.2.1. IPv4 ERO Sub-TLV . . . . . . . . . . . . . . . . . . 15
6.2.2. Unnumbered Interface ID ERO Sub-TLV . . . . . . . . . 16 6.2.2. Unnumbered Interface ID ERO Sub-TLV . . . . . . . . . 16
6.2.3. IPv4 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 17 6.2.3. IPv4 Backup ERO Sub-TLV . . . . . . . . . . . . . . . 17
6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV . . . . . 18 6.2.4. Unnumbered Interface ID Backup ERO Sub-TLV . . . . . 18
7. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 19 7. Adjacency Segment Identifier (Adj-SID) . . . . . . . . . . . 19
7.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 19 7.1. Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 20
7.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 21 7.2. LAN Adj-SID Sub-TLV . . . . . . . . . . . . . . . . . . . 21
8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 22 8. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 23
8.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 22 8.1. Intra-area Segment routing in OSPFv2 . . . . . . . . . . 23
8.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 23 8.2. Inter-area Segment routing in OSPFv2 . . . . . . . . . . 23
8.3. SID for External Prefixes . . . . . . . . . . . . . . . . 24 8.3. SID for External Prefixes . . . . . . . . . . . . . . . . 25
8.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 24 8.4. Advertisement of Adj-SID . . . . . . . . . . . . . . . . 25
8.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 25 8.4.1. Advertisement of Adj-SID on Point-to-Point Links . . 25
8.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 25 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces . . . . 25
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
9.1. OSPF OSPF Router Information (RI) TLVs Registry . . . . . 25 9.1. OSPF OSPF Router Information (RI) TLVs Registry . . . . . 26
9.2. OSPF Extended Prefix LSA TLV Registry . . . . . . . . . . 25 9.2. OSPF Extended Prefix LSA TLV Registry . . . . . . . . . . 26
9.3. OSPF Extended Prefix LSA Sub-TLV Registry . . . . . . . . 25 9.3. OSPF Extended Prefix LSA Sub-TLV Registry . . . . . . . . 26
9.4. OSPF Extended Link LSA Sub-TLV Registry . . . . . . . . . 26 9.4. OSPF Extended Link LSA Sub-TLV Registry . . . . . . . . . 26
10. Security Considerations . . . . . . . . . . . . . . . . . . . 26 10. Implementation Status . . . . . . . . . . . . . . . . . . . . 27
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26 11. Security Considerations . . . . . . . . . . . . . . . . . . . 28
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 28
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28
13.1. Normative References . . . . . . . . . . . . . . . . . . 27 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 29
13.2. Informative References . . . . . . . . . . . . . . . . . 27 14.1. Normative References . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 14.2. Informative References . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
1. Introduction 1. Introduction
Segment Routing (SR) allows for a flexible definition of end-to-end Segment Routing (SR) allows a flexible definition of end-to-end paths
paths within IGP topologies by encoding paths as sequences of within IGP topologies by encoding paths as sequences of topological
topological sub-paths, called "segments". These segments are sub-paths, called "segments". These segments are advertised by the
advertised by the link-state routing protocols (IS-IS and OSPF). link-state routing protocols (IS-IS and OSPF). Prefix segments
Prefix segments represent an ecmp-aware shortest-path to a prefix (or represent an ECMP-aware shortest-path to a prefix (or a node), as per
a node), as per the state of the IGP topology. Adjacency segments the state of the IGP topology. Adjacency segments represent a hop
represent a hop over a specific adjacency between two nodes in the over a specific adjacency between two nodes in the IGP. A prefix
IGP. A prefix segment is typically a multi-hop path while an segment is typically a multi-hop path while an adjacency segment, in
adjacency segment, in most cases, is a one-hop path. SR's control- most cases, is a one-hop path. SR's control-plane can be applied to
plane can be applied to both IPv6 and MPLS data-planes, and does not both IPv6 and MPLS data-planes, and does not require any additional
require any additional signalling (other than IGP extensions). For signalling (other than IGP extensions). The IPv6 data plane is out
example, when used in MPLS networks, SR paths do not require any LDP of the scope of this specification - it is not applicable to OSPFv2
or RSVP-TE signalling. However, SR can interoperate in the presence which only supports the IPv4 address-family. For example, when used
of LSPs established with RSVP or LDP. in MPLS networks, SR paths do not require any LDP or RSVP-TE
signalling. However, SR can interoperate in the presence of LSPs
established with RSVP or LDP.
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 For the purpose of the advertisements of various SID values, new
Opaque LSAs [RFC5250] are defined in Opaque LSAs [RFC5250] are defined in [RFC7684]. These LSAs are
[I-D.ietf-ospf-prefix-link-attr]. These new LSAs are defined as
generic containers that can be used to advertise any additional generic containers that can be used to advertise any additional
attributes associated with a prefix or link. These new Opaque LSAs attributes associated with a prefix or link. These Opaque LSAs are
are complementary to the existing LSAs and are not aimed to replace complementary to the existing LSAs and are not aimed to replace any
any of the existing LSAs. 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 bytes 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 SID/Label Sub-TLV if the length
is other then 3 or 4. 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 [RFC4970]). 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 [RFC4970]). Opaque LSA (defined in [RFC7770]).
The SR-Algorithm Sub-TLV is optional. It MAY only be advertised once The SR-Algorithm Sub-TLV is optional. It MAY only be advertised once
in the Router Information Opaque LSA. If the SID/Label Range TLV, as in the Router Information Opaque LSA. If the SID/Label Range TLV, as
defined in Section 3.2, is advertised, then SR-Algorithm TLV MUST defined in Section 3.2, is advertised, then the SR-Algorithm TLV MUST
also be advertised. also be advertised.
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 that the router is currently using router to advertise the algorithms currently used by the router to
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
format: 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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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 Sub-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
the support of Algorithm 1 MUST NOT alter the forwarding support for Algorithm 1 MUST NOT alter the SPF paths computed
decision computed by Algorithm 1. by Algorithm 1.
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
the SR-Algorithm TLV propagation, 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 [RFC4970]). Opaque LSA (defined in [RFC7770]).
The SID/Label Range TLV MAY appear multiple times and has the The SID/Label Range TLV MAY appear multiple times and has the
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Range Size | Reserved | | Range Size | Reserved |
skipping to change at page 6, line 37 skipping to change at page 6, line 37
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 octets of the SID/label range
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 occurrence 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 same Opaque LSA. The originating router MUST ensure the order is the
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 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 Routing Global Block The receiving routers concatenate the ranges and build the Segment
(SRGB) is as follows: Routing Global Block (SRGB) as follows:
SRGB = [100, 199] SRGB = [100, 199]
[1000, 1099] [1000, 1099]
[500, 599] [500, 599]
The indexes span multiple ranges: The indexes span multiple ranges:
index=0 means label 100 index=0 means label 100
... ...
index 99 means label 199 index 99 means label 199
index 100 means label 1000 index 100 means label 1000
index 199 means label 1099 index 199 means label 1099
... ...
index 200 means label 500 index 200 means label 500
... ...
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 purposes of the (link, area, or autonomous system (AS)). For the purpose of SID/
SID/Label Range TLV propagation, area scope flooding is required. Label Range TLV advertisement, area scope flooding is required.
4. OSPF Extended Prefix Range TLV 4. OSPF Extended Prefix Range TLV
In some cases it is useful to advertise attributes for the range of In some cases it is useful to advertise attributes for a range of
prefixes. 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.
OSPF Extended Prefix Range TLV, which is a new top level TLV of the The OSPF Extended Prefix Range TLV, which is a new top level TLV of
Extended Prefix LSA described in [I-D.ietf-ospf-prefix-link-attr] is the Extended Prefix LSA described in [RFC7684] is defined for this
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
skipping to change at page 8, line 24 skipping to change at page 8, line 24
| Address Prefix (variable) | | Address Prefix (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) | | Sub-TLVs (variable) |
+- -+ +- -+
| | | |
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: 0 - IPv4 unicast
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: 1 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. ABR that is advertising the OSPF Extended Prefix area type. The ABR that is advertising the OSPF Extended
Range TLV between areas MUST set this bit. Prefix 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 advertisement An ABR always prefers intra-area Prefix Range advertisements
over inter-area one. 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 area. advertisements coming from non-backbone areas.
An ABR propagates inter-area Prefix Range advertisement from An ABR only propagates an inter-area Prefix Range
backbone area to connected non backbone areas only if such advertisement from the backbone area to connected non-
advertisement is considered to be the best one. backbone areas if the advertisement is considered to be the
best one.
Address Prefix: the prefix, encoded as an even multiple of 32-bit Address Prefix: The prefix, encoded as an even multiple of 32-bit
words, padded with zeroed bits as necessary. This encoding words, padded with zero bits as necessary. This encoding consumes
consumes ((PrefixLength + 31) / 32) 32-bit words. The Address ((PrefixLength + 31) / 32) 32-bit words. The Address Prefix
Prefix represents the first prefix in 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 [I-D.ietf-ospf-prefix-link-attr] and the OSPF Extended described in [RFC7684] and the OSPF Extended Prefix Range TLV
Prefix Range TLV described in Section 4. It MAY appear more than described in Section 4. It MAY appear more than once in the parent
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | MT-ID | Algorithm | | Flags | Reserved | MT-ID | Algorithm |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Index/Label (variable) | | SID/Index/Label (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBD, suggested value 2. Type: TBD, suggested value 2.
Length: variable Length: Variable
Flags: 1 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
+--+--+--+--+--+--+--+--+ +--+--+--+--+--+--+--+--+
| |NP|M |E |V |L | | | | |NP|M |E |V |L | | |
+--+--+--+--+--+--+--+--+ +--+--+--+--+--+--+--+--+
where: where:
NP-Flag: No-PHP flag. If set, then the penultimate hop MUST NP-Flag: No-PHP flag. If set, then the penultimate hop MUST
NOT pop the Prefix-SID before delivering the packet to the node NOT pop the Prefix-SID before delivering packets to the node
that advertised the Prefix-SID. that advertised the Prefix-SID.
M-Flag: Mapping Server Flag. If set, the SID is advertised M-Flag: Mapping Server Flag. If set, the SID was advertised by
from the Segment Routing Mapping Server functionality as a Segment Routing Mapping Server as described in
described in [I-D.filsfils-spring-segment-routing-ldp-interop]. [I-D.filsfils-spring-segment-routing-ldp-interop].
E-Flag: Explicit-Null Flag. If set, any upstream neighbor of E-Flag: Explicit-Null Flag. If set, any upstream neighbor of
the Prefix-SID originator MUST replace the Prefix-SID with a the Prefix-SID originator MUST replace the Prefix-SID with the
Prefix-SID having an Explicit-NULL value (0 for IPv4) before Explicit-NULL label (0 for IPv4) before forwarding the packet.
forwarding the packet.
V-Flag: Value/Index Flag. If set, then the Prefix-SID carries V-Flag: Value/Index Flag. If set, then the Prefix-SID carries
an absolute value. If not set, then the Prefix-SID carries an an absolute value. If not set, then the Prefix-SID carries an
index. index.
L-Flag: Local/Global Flag. If set, then the value/index L-Flag: Local/Global Flag. If set, then the value/index
carried by the Prefix-SID has local significance. If not set, carried by the Prefix-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
significance. significance.
Other bits: Reserved. These MUST be zero when sent and are Other bits: Reserved. These MUST be zero when sent and are
ignored when received. ignored when received.
MT-ID: Multi-Topology ID (as defined in [RFC4915]). MT-ID: Multi-Topology ID (as defined in [RFC4915]).
Algorithm: one octet identifying the algorithm the Prefix-SID is Algorithm: Single octet identifying the algorithm the Prefix-SID
associated with as defined in Section 3.1. is associated with as defined in Section 3.1.
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 the
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 E and P flags advertised by the next-hop router, if take into account the E and P flags advertised by the next-hop router
next-hop 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 on the Prefix-SIDs allocated to The NP-Flag (No-PHP) MUST be set for Prefix-SIDs allocated to inter-
inter-area prefixes that are originated by the ABR based on intra- area prefixes that are originated by the ABR based on intra-area or
area or inter-area reachability between areas. When the inter-area inter-area reachability between areas. When the inter-area prefix is
prefix is generated based on the prefix which is directly attached to generated based on a prefix which is directly attached to the ABR,
the ABR, NP-Flag SHOULD NOT be set the NP-Flag SHOULD NOT be set.
The NP-Flag (No-PHP) MUST be be set on the Prefix-SIDs allocated to The NP-Flag (No-PHP) MUST be be set for the Prefix-SIDs allocated to
redistributed prefixes, unless the redistributed prefix is directly redistributed prefixes, unless the redistributed prefix is directly
attached to 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
clear then the received E-flag is ignored. not set then the received E-flag is ignored.
If the NP-flag is set then: If the NP-flag is set then:
If the E-flag is not set then any upstream neighbor of the Prefix- If the E-flag is not set, then any upstream neighbor of the
SID originator MUST keep the Prefix-SID on top of the stack. This Prefix-SID originator MUST keep the Prefix-SID on top of the
is useful when the originator of the Prefix-SID must stitch the stack. This is useful when the originator of the Prefix-SID must
incoming packet into a continuing MPLS LSP to the final stitch the incoming packet into a continuing MPLS LSP to the final
destination. This could occur at an inter-area border router destination. This could occur at an Area Border Router (prefix
(prefix propagation from one area to another) or at an inter- propagation from one area to another) or at an AS Boundary Router
domain border router (prefix propagation from one domain to (prefix propagation from one domain to another).
another).
If the E-flag is set then any upstream neighbor of the Prefix-SID If the E-flag is set, then any upstream neighbor of the Prefix-SID
originator MUST replace the Prefix-SID with a Prefix-SID having an originator MUST replace the Prefix-SID with an Explicit-NULL
Explicit-NULL value. This is useful, e.g., when the originator of label. This is useful, e.g., when the originator of the Prefix-
the Prefix-SID is the final destination for the related prefix and SID is the final destination for the related prefix and the
the originator wishes to receive the packet with the original EXP originator wishes to receive the packet with the original EXP
bits. bits.
When M-Flag is set, NP-flag and E-flag MUST be ignored at reception. When the M-Flag is set, the NP-flag and the E-flag MUST be ignored at
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 may
safely be done in following cases: safely be done in following cases:
Prefix is of 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.
Prefix is of 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 the prefix reachability and is also
generating the Extended Prefix TLV with A-flag set for this prefix generating the Extended Prefix TLV with the A-flag set for this
as described in section 2.1 of [I-D.ietf-ospf-prefix-link-attr]. prefix as described in section 2.1 of [RFC7684].
Prefix is of 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 the prefix reachability and is also
generating the Extended Prefix TLV with A-flag set for this prefix generating the Extended Prefix TLV with the A-flag set for this
as described in section 2.1 of [I-D.ietf-ospf-prefix-link-attr]. prefix as 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 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
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 192.0.2.1, Prefix Length would be set to 32, Range Size would be to 192.0.2.1, Prefix Length would be set to 32, Range Size would be
set to 4 and the Index value in the Prefix-SID Sub-TLV would be set set to 4, and the Index value in the Prefix-SID Sub-TLV would be set
to 1. to 1.
Example 2: If the following prefixes need to be mapped into the Example 2: If the following prefixes need to be mapped into the
corresponding Prefix-SID indexes: corresponding Prefix-SID indexes:
10.1.1/24, Prefix-SID: Index 51 10.1.1/24, Prefix-SID: Index 51
10.1.2/24, Prefix-SID: Index 52 10.1.2/24, Prefix-SID: Index 52
10.1.3/24, Prefix-SID: Index 53 10.1.3/24, Prefix-SID: Index 53
10.1.4/24, Prefix-SID: Index 54 10.1.4/24, Prefix-SID: Index 54
10.1.5/24, Prefix-SID: Index 55 10.1.5/24, Prefix-SID: Index 55
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 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
skipping to change at page 13, line 29 skipping to change at page 13, line 29
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.
The SID/Label Binding Sub-TLV is a Sub-TLV of the OSPF Extended The SID/Label Binding Sub-TLV is a Sub-TLV of the OSPF Extended
Prefix TLV described in [I-D.ietf-ospf-prefix-link-attr] and the OSPF Prefix TLV described in [RFC7684] and the OSPF Extended Prefix Range
Extended Prefix Range TLV described in Section 4. Multiple SID/Label TLV described in Section 4. Multiple SID/Label Binding TLVs can be
Binding TLVs can be present in their parent TLV. The SID/Label present in their parent TLV. The SID/Label Binding Sub-TLV has
Binding Sub-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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | MT-ID | Weight | | Flags | Reserved | MT-ID | Weight |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-TLVs (variable) | | Sub-TLVs (variable) |
+- -+ +- -+
| | | |
where: where:
Type: TBD, suggested value 3 Type: TBD, suggested value 3
Length: variable Length: Variable
Flags: 1 octet field of 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
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|M| | |M| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
M-bit - When the bit is set the binding represents the M-bit - When the bit is set, the binding represents a mirroring
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].
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: Weight used for load-balancing purposes. The use of the
weight is defined in [I-D.ietf-spring-segment-routing]. 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 MUST only appear appear in the SID/Label Binding Sub-TLV and it SHOULD only appear
once. 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.
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
the condition SHOULD be logged for possible action by the 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
skipping to change at page 15, line 11 skipping to change at page 15, line 21
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ERO Metric Sub-TLV format ERO Metric Sub-TLV format
where: where:
Type: TBD, suggested value 8 Type: TBD, suggested value 8
Length: Always 4 Length: Always 4
Metric: A 4 octet metric representing the aggregate IGP or TE path Metric: A 4-octet metric representing the aggregate IGP or TE path
cost. cost.
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 must immediately follow the SID/Label Sub-TLV.
All Backup ERO Sub-TLVs must immediately follow the last ERO Sub-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
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | | Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address (4 octets) | | IPv4 Address (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv4 ERO Sub-TLV format IPv4 ERO Sub-TLV format
where: where:
Type: TBD, suggested value 4 Type: TBD, suggested value 4
Length: 8 bytes Length: 8 octets
Flags: 1 octet field of 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
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|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'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209].
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 not unique within a domain. All local to the router and therefore are not unique within a domain.
elements in an ERO path need to be unique within a domain and hence All elements in an ERO path need to be unique within a domain and
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface ID | | Interface ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Unnumbered Interface ID ERO Sub-TLV format Unnumbered Interface ID ERO Sub-TLV format
Type: TBD, suggested value 5 Type: TBD, suggested value 5
Length: 12 bytes Length: 12 octets
Flags: 1 octet field of 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
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|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'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209]
Router-ID: Router-ID of the next-hop. Router-ID: Router-ID of the next-hop.
Interface ID: is 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].
skipping to change at page 17, line 47 skipping to change at page 18, line 21
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address (4 octets) | | IPv4 Address (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv4 Backup ERO Sub-TLV format IPv4 Backup ERO Sub-TLV format
where: where:
Type: TBD, suggested value 6 Type: TBD, suggested value 6
Length: 8 bytes Length: 8 octets
Flags: 1 octet field of 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
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|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'. The terms 'loose' and 'strict' are
defined for RSVP subobjects in [RFC3209]
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
skipping to change at page 18, line 52 skipping to change at page 19, line 25
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface ID | | Interface ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Unnumbered Interface ID Backup ERO Sub-TLV format Unnumbered Interface ID Backup ERO Sub-TLV format
where: where:
Type: TBD, suggested value 7 Type: TBD, suggested value 7
Length: 12 bytes Length: 12 octets
Flags: 1 octet field of 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
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|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. Router-ID: Router-ID of the next-hop.
Interface ID: is 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
[I-D.ietf-ospf-prefix-link-attr]. It MAY appear multiple times in [RFC7684]. It MAY appear multiple times in the Extended Link TLV.
the Extended Link TLV. Examples where more than one Adj-SID may be Examples where more than one Adj-SID may be used per neighbor are
used per neighbor are described in section 4 of described in section 4 of
[I-D.filsfils-spring-segment-routing-use-cases]. The Adj-SID Sub-TLV [I-D.filsfils-spring-segment-routing-use-cases]. The Adj-SID Sub-TLV
has the following format: 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 | MT-ID | Weight | | Flags | Reserved | MT-ID | Weight |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) | | SID/Label/Index (variable) |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
where: where:
Type: TBD, suggested value 2. Type: TBD, suggested value 2.
Length: variable. Length: Variable.
Flags. 1 octet field of 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|S| | |B|V|L|G| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
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
significance. significance.
The S-Flag. Set Flag. When set, the S-Flag indicates that the The G-Flag: Group Flag. When set, the G-Flag indicates that
Adj-SID refers to a set of adjacencies (and therefore MAY be the Adj-SID refers to a group of adjacencies (and therefore MAY
assigned to other adjacencies as well). be assigned to other adjacencies as well).
Other bits: Reserved. These MUST be zero when sent and are Other bits: Reserved. These MUST be zero when sent and are
ignored when received. 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: Weight used for load-balancing purposes. The use of the
weight is defined in [I-D.ietf-spring-segment-routing]. weight is defined in [I-D.ietf-spring-segment-routing].
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.
An SR capable router MAY allocate an Adj-SID for each of its An SR capable router MAY allocate an Adj-SID for each of its
adjacencies and set the B-Flag when the adjacency is eligible for adjacencies and set the B-Flag when the adjacency is eligible for
protection by an FRR mechanism (IP or MPLS) as described in section protection by an FRR mechanism (IP or MPLS) as described in section
3.5 of [I-D.ietf-spring-segment-routing]. 3.5 of [I-D.ietf-spring-segment-routing].
7.2. LAN Adj-SID Sub-TLV 7.2. LAN Adj-SID Sub-TLV
LAN Adj-SID is an optional Sub-TLV of the Extended Link TLV defined LAN Adj-SID is an optional Sub-TLV of the Extended Link TLV defined
in [I-D.ietf-ospf-prefix-link-attr]. It MAY appear multiple times in in [RFC7684]. It MAY appear multiple times in the Extended-Link TLV.
the Extended-Link TLV. It is used to advertise a SID/Label for an It is used to advertise a SID/Label for an adjacency to a non-DR
adjacency to a non-DR node on a broadcast or NBMA network. router on a broadcast, NBMA, or hybrid [RFC6845] network.
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 | MT-ID | Weight | | Flags | Reserved | MT-ID | Weight |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor ID | | Neighbor ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) | | SID/Label/Index (variable) |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
where: where:
Type: TBD, suggested value 3. Type: TBD, suggested value 3.
Length: variable. Length: Variable.
Flags. 1 octet field of 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|S| | |B|V|L|G| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
B-Flag: Backup-flag: set if the LAN-Adj-SID refer to an B-Flag: Backup-flag. If set, the LAN-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 Prefix-SID The V-Flag: Value/Index Flag. If set, then the Prefix-SID
carries an absolute value. If not set, then the Prefix-SID carries an absolute value. If not set, then the Prefix-SID
carries an index. carries an 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 Prefix-SID has local significance. If not set, carried by the Prefix-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
significance. significance.
The S-Flag. Set Flag. When set, the S-Flag indicates that the The G-Flag: Group Flag. When set, the G-Flag indicates that
Adj-SID refers to a set of adjacencies (and therefore MAY be the LAN-Adj-SID refers to a group of adjacencies (and therefore
assigned to other adjacencies as well). MAY be assigned to other adjacencies as well).
Other bits: Reserved. These MUST be zero when sent and are Other bits: Reserved. These MUST be zero when sent and are
ignored when received. 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: Weight used for load-balancing purposes. The use of the
weight is defined in [I-D.ietf-spring-segment-routing]. weight is defined in [I-D.ietf-spring-segment-routing].
Neighbor ID: The Router ID of the neighbor for which the Adj-SID Neighbor ID: The Router ID of the neighbor for which the LAN-Adj-
is advertised. SID is advertised.
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.
8. Elements of Procedure 8. Elements of Procedure
8.1. Intra-area Segment routing in OSPFv2 8.1. Intra-area Segment routing in OSPFv2
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 network. destination exist in the OSPFv2 routing domain.
Prefix-SID can also be advertised by the SR Mapping Servers (as 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]). The
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.
SR Mapping Server MUST use OSPF Extended Prefix Range TLV when The SR Mapping Server MUST use 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. the 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, 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 is described in Section 4. OSPF Extended Prefix Range TLV are described in Section 4.
When propagating OSPF Extended Prefix Range TLV between areas, ABR When propagating an OSPF Extended Prefix Range TLV between areas,
MUST set the IA-Flag, that is used to prevent redundant flooding of ABRs MUST set the IA-Flag, that is used to prevent redundant flooding
the OSPF Extended Prefix Range TLV between areas as described in of the OSPF Extended Prefix Range TLV between areas as described in
Section 4. Section 4.
If the Prefix-SID that is advertised in Prefix SID Sub-TLV is also If the Prefix-SID that is advertised in a Prefix SID Sub-TLV is also
covered by the OSPF Extended Prefix Range TLV, the Prefix-SID covered by the OSPF Extended Prefix Range TLV, the Prefix-SID
advertised in Prefix SID Sub-TLV MUST be preferred. advertised in Prefix SID Sub-TLV MUST be preferred.
8.2. Inter-area Segment routing in OSPFv2 8.2. Inter-area Segment routing in OSPFv2
In order to support SR in a multi-area environment, OSPFv2 must In order to support SR in a multi-area environment, OSPFv2 must
propagate Prefix-SID information between areas. The following propagate Prefix-SID information between areas. The following
procedure is used in order to propagate Prefix SIDs between areas. procedure is used to propagate Prefix SIDs between areas.
When an OSPF ABR advertises a Type-3 Summary LSA from an intra-area When an OSPF ABR advertises a Type-3 Summary LSA from an intra-area
prefix to all its connected areas, it will also originate an Extended prefix to all its connected areas, it will also originate an Extended
Prefix Opaque LSA, as described in [I-D.ietf-ospf-prefix-link-attr]. Prefix Opaque LSA, as described in [RFC7684]. The flooding scope of
The flooding scope of the Extended Prefix Opaque LSA type will be set the Extended Prefix Opaque LSA type will be set to area-scope. The
to area-scope. The route-type in the OSPF Extended Prefix TLV is set route-type in the OSPF Extended Prefix TLV is set to inter-area. The
to inter-area. The Prefix-SID Sub-TLV will be included in this LSA Prefix-SID Sub-TLV will be included in this LSA and the Prefix-SID
and the Prefix-SID value will be set as follows: value will be set as follows:
The ABR will look at its best path to the prefix in the source The ABR will look at its best path to the prefix in the source
area and find the advertising router associated with the best path area and find the advertising router associated with the best path
to that prefix. to that prefix.
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 source area If no Prefix-SID was advertised for the prefix in the source area
by the router that contributes to the best path to the prefix, the by the router that contributes to the best path to the prefix, the
originating ABR will use the Prefix-SID advertised by any other 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. areas.
When an OSPF ABR advertises Type-3 Summary LSAs from an inter-area When an OSPF ABR advertises Type-3 Summary LSAs from an inter-area
route to all its connected areas it will also originate an Extended route to all its connected areas, it will also originate an Extended
Prefix Opaque LSA, as described in [I-D.ietf-ospf-prefix-link-attr]. Prefix Opaque LSA, as described in [RFC7684]. The flooding scope of
The flooding scope of the Extended Prefix Opaque LSA type will be set the Extended Prefix Opaque LSA type will be set to area-scope. The
to area-scope. The route-type in OSPF Extended Prefix TLV is set to route-type in OSPF Extended Prefix TLV is set to inter-area. The
inter-area. The Prefix-SID Sub-TLV will be included in this LSA and Prefix-SID Sub-TLV will be included in this LSA and the Prefix-SID
the Prefix-SID will be set as follows: will be set as follows:
The ABR will look at its best path to the prefix in the source The ABR will look at its best path to the prefix in the backbone
area and find the advertising router associated with the best path area and find the advertising router associated with the best path
to that prefix. to that prefix.
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 source area If no Prefix-SID was advertised for the prefix in the backbone
by the ABR that contributes to the best path to the prefix, the area by the ABR that contributes to the best path to the prefix,
originating ABR will use the Prefix-SID advertised by any other the originating ABR will use the Prefix-SID advertised by any
router when propagating the Prefix-SID for the prefix to other other router when propagating the Prefix-SID for the prefix to
areas. other areas.
8.3. SID for External Prefixes 8.3. SID 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 an Extended SR, generates Type-5 LSAs, it should also originate Extended Prefix
Prefix Opaque LSAs, as described in [I-D.ietf-ospf-prefix-link-attr]. Opaque LSAs, as described in [RFC7684]. The flooding scope of the
The flooding scope of the Extended Prefix Opaque LSA type is set to Extended Prefix Opaque LSA type is set to AS-scope. The route-type
AS-scope. The route-type in the OSPF Extended Prefix TLV is set to in the OSPF Extended Prefix TLV is set to external. The Prefix-SID
external. The Prefix-SID Sub-TLV is included in this LSA and the Sub-TLV is included in this LSA and the Prefix-SID value will be set
Prefix-SID value will be set to the SID that has been reserved for to the SID that has been reserved for that prefix.
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
also advertise the Prefix-SID for the prefix. The NSSA ABR also advertise the Prefix-SID for the prefix. The NSSA ABR
determines its best path to the prefix advertised in the translated determines its best path to the prefix advertised in the translated
Type-7 LSA and finds the advertising router associated with that Type-7 LSA and finds the advertising router associated with that
path. If the advertising router has advertised a Prefix-SID for the path. If the advertising router has advertised a Prefix-SID for the
prefix, then the NSSA ABR uses it when advertising the Prefix-SID for prefix, then the NSSA ABR uses it when advertising the Prefix-SID for
the Type-5 prefix. Otherwise, the Prefix-SID advertised by any other the Type-5 prefix. Otherwise, the Prefix-SID advertised by any other
router will be used. router will be used.
8.4. Advertisement of Adj-SID 8.4. Advertisement of Adj-SID
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. removed from the area.
8.4.2. Adjacency SID on Broadcast or NBMA Interfaces 8.4.2. Adjacency SID on Broadcast or NBMA Interfaces
Broadcast or NBMA networks in OSPF are represented by a star topology Broadcast, NBMA or or hybrid [RFC6845] networks in OSPF are
where the Designated Router (DR) is the central point to which all represented by a star topology where the Designated Router (DR) is
other routers on the broadcast or NBMA network connect. As a result, the central point to which all other routers on the broadcast, NBMA,
routers on the broadcast or NBMA network advertise only their or hybrid network connect. As a result, routers on the broadcast,
adjacency to the DR. Routers that do not act as DR do not form or NBMA, or hybrid network advertise only their adjacency to the DR.
advertise adjacencies with each other. They do, however, maintain Routers that do not act as DR do not form or advertise adjacencies
2-Way adjacency state with each other and are directly reachable. with each other. They do, however, maintain 2-Way adjacency state
with each 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 or NBMA
network MAY advertise the Adj-SID for its adjacency to the DR using network MAY advertise the Adj-SID for its adjacency to the DR using
Adj-SID Sub-TLV as described in Section 7.1. the Adj-SID Sub-TLV as described in Section 7.1.
SR capable routers MAY also advertise an Adj-SID for other neighbors SR capable routers MAY also advertise an LAN-Adj-SID for other
(e.g. BDR, DR-OTHER) on the broadcast or NBMA network using the LAN neighbors (e.g., BDR, DR-OTHER) on the broadcast, NBMA or hybrid
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
o 9 (IANA Preallocated) - SID/Label Range TLV o 9 (IANA Preallocated) - SID/Label Range TLV
skipping to change at page 26, line 25 skipping to change at page 27, line 4
o 8 - ERO Metric Sub-TLV o 8 - ERO Metric Sub-TLV
9.4. OSPF Extended Link LSA Sub-TLV Registry 9.4. OSPF Extended Link LSA Sub-TLV Registry
Following initial values are allocated: Following initial values are allocated:
o 1 - SID/Label Sub-TLV o 1 - SID/Label Sub-TLV
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. Security Considerations 10. Implementation Status
An implementation survey with seven questions related to the
implementer's support of OSPFv2 Segment Routing was sent to the OSPF
WG list and several known implementers. This section contains
responses from two implementers who completed the survey. No
external means were used to verify the accuracy of the information
submitted by the respondents. The respondents are considered experts
on the products they reported on. Additionally, responses were
omitted from implementers who indicated that they have not
implemented the function yet.
Responses from Nokia (former Alcatel-Lucent):
Link to a web page describing the implementation:
https://infoproducts.alcatel-lucent.com/cgi-bin/dbaccessfilename.cgi/
3HE10799AAAATQZZA01_V1_7450%20ESS%207750%20SR%20and%207950%20XRS%20Un
icast%20Routing%20Protocols%20Guide%20R14.0.R1.pdf
The implementation's level of maturity: Production.
Coverage: We have implemented all sections and have support for the
latest draft.
Licensing: Part of the software package that needs to be purchased.
Implementation experience: Great spec. We also performed inter-
operability testing with Cisco's OSPF Segment Routing implementation.
Contact information: wim.henderickx@nokia.com
Responses from Cisco Systems:
Link to a web page describing the implementation:
www.segment-routing.net/home/tutorial
The implementation's level of maturity: Production.
Coverage: All sections, except the section 6 (SID/Label Binding Sub-
TLV) have been implemented according to the latest draft.
Licensing: Part of a commercial software package.
Implementation experience: Many aspects of the draft are result of
the actual implementation experience, as the draft evolved from its
initial version to the current one. Interoperability testing with
Alcatel-Lucent was performed, which confirmed the draft's ability to
serve as a reference for the implementors.
Contact information: ppsenak@cisco.com
Responses from Juniper:
The implementation's name and/or a link to a web page describing the
implementation:
Feature name is OSPF SPRING
The implementation's level of maturity: To be released in 16.2
(second half of 2016)
Coverage: All sections implemented except Sections 4, and 6.
Licensing: JUNOS Licensing needed.
Implementation experience: NA
Contact information: shraddha@juniper.net
11. Security Considerations
Implementations must assure that malformed TLV and Sub-TLV Implementations must assure that malformed TLV and Sub-TLV
permutations do not result in errors which cause hard OSPF failures. permutations do not result in errors which cause hard OSPF failures.
11. Contributors 12. Contributors
The following people gave a substantial contribution to the content The following people gave a substantial contribution to the content
of this document: Acee Lindem, Ahmed Bashandy, Martin Horneffer, of this document: Acee Lindem, Ahmed Bashandy, Martin Horneffer,
Bruno Decraene, Stephane Litkowski, Igor Milojevic, Rob Shakir and Bruno Decraene, Stephane Litkowski, Igor Milojevic, Rob Shakir and
Saku Ytti. Saku Ytti.
12. Acknowledgements 13. Acknowledgements
We would like to thank Anton Smirnov for his contribution. We would like to thank Anton Smirnov for his contribution.
Many thanks to Yakov Rekhter, John Drake and Shraddha Hedge for their Many thanks to Yakov Rekhter, John Drake and Shraddha Hedge for their
contribution on earlier incarnations of the "Binding / MPLS Label contribution on earlier incarnations of the "Binding / MPLS Label
TLV" in [I-D.gredler-ospf-label-advertisement]. TLV" in [I-D.gredler-ospf-label-advertisement].
Thanks to Acee Lindem for the detail review of the draft, Thanks to Acee Lindem for the detail review of the draft,
corrections, as well as discussion about details of the encoding. corrections, as well as discussion about details of the encoding.
13. References 14. References
13.1. Normative References 14.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998, DOI 10.17487/RFC2328, April 1998,
<http://www.rfc-editor.org/info/rfc2328>. <http://www.rfc-editor.org/info/rfc2328>.
skipping to change at page 27, line 38 skipping to change at page 29, line 38
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, (TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003, DOI 10.17487/RFC3630, September 2003,
<http://www.rfc-editor.org/info/rfc3630>. <http://www.rfc-editor.org/info/rfc3630>.
[RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
RFC 4915, DOI 10.17487/RFC4915, June 2007, RFC 4915, DOI 10.17487/RFC4915, June 2007,
<http://www.rfc-editor.org/info/rfc4915>. <http://www.rfc-editor.org/info/rfc4915>.
[RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and
S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July
2007, <http://www.rfc-editor.org/info/rfc4970>.
[RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
OSPF Opaque LSA Option", RFC 5250, DOI 10.17487/RFC5250, OSPF Opaque LSA Option", RFC 5250, DOI 10.17487/RFC5250,
July 2008, <http://www.rfc-editor.org/info/rfc5250>. July 2008, <http://www.rfc-editor.org/info/rfc5250>.
13.2. Informative References [RFC6845] Sheth, N., Wang, L., and J. Zhang, "OSPF Hybrid Broadcast
and Point-to-Multipoint Interface Type", RFC 6845,
DOI 10.17487/RFC6845, January 2013,
<http://www.rfc-editor.org/info/rfc6845>.
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <http://www.rfc-editor.org/info/rfc7684>.
[RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and
S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 7770, DOI 10.17487/RFC7770,
February 2016, <http://www.rfc-editor.org/info/rfc7770>.
14.2. Informative References
[I-D.filsfils-spring-segment-routing-ldp-interop] [I-D.filsfils-spring-segment-routing-ldp-interop]
Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., Filsfils, C., Previdi, S., Bashandy, A., Decraene, B.,
Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R., Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R.,
Ytti, S., Henderickx, W., Tantsura, J., and E. Crabbe, Ytti, S., Henderickx, W., Tantsura, J., and E. Crabbe,
"Segment Routing interoperability with LDP", draft- "Segment Routing interoperability with LDP", draft-
filsfils-spring-segment-routing-ldp-interop-02 (work in filsfils-spring-segment-routing-ldp-interop-02 (work in
progress), September 2014. progress), September 2014.
[I-D.filsfils-spring-segment-routing-use-cases] [I-D.filsfils-spring-segment-routing-use-cases]
skipping to change at page 28, line 26 skipping to change at page 30, line 33
Ytti, S., Henderickx, W., Tantsura, J., Kini, S., and E. Ytti, S., Henderickx, W., Tantsura, J., Kini, S., and E.
Crabbe, "Segment Routing Use Cases", draft-filsfils- Crabbe, "Segment Routing Use Cases", draft-filsfils-
spring-segment-routing-use-cases-01 (work in progress), spring-segment-routing-use-cases-01 (work in progress),
October 2014. October 2014.
[I-D.gredler-ospf-label-advertisement] [I-D.gredler-ospf-label-advertisement]
Gredler, H., Amante, S., Scholl, T., and L. Jalil, Gredler, H., Amante, S., Scholl, T., and L. Jalil,
"Advertising MPLS labels in OSPF", draft-gredler-ospf- "Advertising MPLS labels in OSPF", draft-gredler-ospf-
label-advertisement-03 (work in progress), May 2013. label-advertisement-03 (work in progress), May 2013.
[I-D.ietf-ospf-prefix-link-attr]
Psenak, P., Gredler, H., rjs@rob.sh, r., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", draft-ietf-ospf-prefix-link-attr-13 (work
in progress), August 2015.
[I-D.ietf-spring-segment-routing] [I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., Filsfils, C., Previdi, S., Bashandy, A., Decraene, B.,
Litkowski, S., Horneffer, M., Shakir, R., Tantsura, J., Litkowski, S., Horneffer, M., Shakir, R., Tantsura, J.,
and E. Crabbe, "Segment Routing Architecture", draft-ietf- and E. Crabbe, "Segment Routing Architecture", draft-ietf-
spring-segment-routing-00 (work in progress), December spring-segment-routing-00 (work in progress), December
2014. 2014.
[I-D.minto-rsvp-lsp-egress-fast-protection] [I-D.minto-rsvp-lsp-egress-fast-protection]
Jeganathan, J., Gredler, H., and Y. Shen, "RSVP-TE LSP Jeganathan, J., Gredler, H., and Y. Shen, "RSVP-TE LSP
egress fast-protection", draft-minto-rsvp-lsp-egress-fast- egress fast-protection", draft-minto-rsvp-lsp-egress-fast-
skipping to change at page 30, line 13 skipping to change at page 32, line 13
Email: rrjs@rob.sh Email: rrjs@rob.sh
Wim Henderickx Wim Henderickx
Alcatel-Lucent Alcatel-Lucent
Copernicuslaan 50 Copernicuslaan 50
Antwerp 2018 Antwerp 2018
BE BE
Email: wim.henderickx@alcatel-lucent.com Email: wim.henderickx@alcatel-lucent.com
Jeff Tantsura Jeff Tantsura
Ericsson Individual
300 Holger Way
San Jose, CA 95134
US US
Email: Jeff.Tantsura@ericsson.com Email: Jeff.Tantsura@ericsson.com
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