Inter-Domain Routing S. Previdi, Ed.
Internet-Draft P. Psenak
Intended status: Standards Track C. Filsfils
Expires: January 27, 2018 Cisco Systems, Inc.
H. Gredler
RtBrick Inc.
M. Chen
Huawei Technologies
July 26, 2017
BGP Link-State extensions for Segment Routing
draft-ietf-idr-bgp-ls-segment-routing-ext-03
Abstract
Segment Routing (SR) allows for a flexible definition of end-to-end
paths within IGP topologies by encoding paths as sequences of
topological sub-paths, called "segments". These segments are
advertised by the link-state routing protocols (IS-IS, OSPF and
OSPFv3).
This draft defines extensions to the BGP Link-state address-family in
order to carry segment information via BGP.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 27, 2018.
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Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 5
2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5
2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 5
2.1.2. SR-Capabilities TLV . . . . . . . . . . . . . . . . . 6
2.1.3. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . 7
2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 7
2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 8
2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 9
2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 10
2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 10
2.2.3. L2 Bundle Member . . . . . . . . . . . . . . . . . . 11
2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 13
2.3.1. Prefix-SID TLV . . . . . . . . . . . . . . . . . . . 14
2.3.2. IGP Prefix Attributes TLV . . . . . . . . . . . . . . 15
2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 15
2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 16
2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 17
2.5. Equivalent OSPF/OSPFv3 Segment Routing TLVs/Sub-TLVs . . 18
3. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.1. Advertisement of a IS-IS Prefix SID TLV . . . . . . . . . 19
3.2. Advertisement of a OSPF/OSPFv3 Prefix-SID TLV . . . . . . 19
3.3. Advertisement of a range of prefix-to-SID mappings in
OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.4. Advertisement of a range of IS-IS SR bindings . . . . . . 20
4. Implementation Status . . . . . . . . . . . . . . . . . . . . 20
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
5.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 21
6. Manageability Considerations . . . . . . . . . . . . . . . . 22
6.1. Operational Considerations . . . . . . . . . . . . . . . 22
6.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 22
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7. Security Considerations . . . . . . . . . . . . . . . . . . . 22
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 23
10.1. Normative References . . . . . . . . . . . . . . . . . . 23
10.2. Informative References . . . . . . . . . . . . . . . . . 24
10.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction
Segment Routing (SR) allows for a flexible definition of end-to-end
paths by combining sub-paths called "segments". A segment can
represent any instruction, topological or service-based. A segment
can have a local semantic to an SR node or global within a domain.
Within IGP topologies an SR path is encoded as a sequence of
topological sub-paths, called "IGP segments". These segments are
advertised by the link-state routing protocols (IS-IS, OSPF and
OSPFv3).
Two types of IGP segments are defined, Prefix segments and Adjacency
segments. Prefix segments, by default, represent an ECMP-aware
shortest-path to a prefix, as per the state of the IGP topology.
Adjacency segments represent a hop over a specific adjacency between
two nodes in the IGP. A prefix segment is typically a multi-hop path
while an adjacency segment, in most of the cases, is a one-hop path.
[I-D.ietf-spring-segment-routing].
When Segment Routing is enabled in a IGP domain, segments are
advertised in the form of Segment Identifiers (SIDs). The IGP link-
state routing protocols have been extended to advertise SIDs and
other SR-related information. IGP extensions are described in: IS-IS
[I-D.ietf-isis-segment-routing-extensions], OSPFv2
[I-D.ietf-ospf-segment-routing-extensions] and OSPFv3
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]. Using these
extensions, Segment Routing can be enabled within an IGP domain.
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+------------+
| Consumer |
+------------+
^
|
v
+-------------------+
| BGP Speaker | +-----------+
| (Route-Reflector) | | Consumer |
+-------------------+ +-----------+
^ ^ ^ ^
| | | |
+---------------+ | +-------------------+ |
| | | |
v v v v
+-----------+ +-----------+ +-----------+
| BGP | | BGP | | BGP |
| Speaker | | Speaker | . . . | Speaker |
+-----------+ +-----------+ +-----------+
^ ^ ^
| | |
IGP IGP IGP
Figure 1: Link State info collection
Segment Routing (SR) allows advertisement of single or multi-hop
paths. The flooding scope for the IGP extensions for Segment routing
is IGP area-wide. Consequently, the contents of a Link State
Database (LSDB) or a Traffic Engineering Database (TED) has the scope
of an IGP area and therefore, by using the IGP alone it is not enough
to construct segments across multiple IGP Area or AS boundaries.
In order to address the need for applications that require
topological visibility across IGP areas, or even across Autonomous
Systems (AS), the BGP-LS address-family/sub-address-family have been
defined to allow BGP to carry Link-State information. The BGP
Network Layer Reachability Information (NLRI) encoding format for
BGP-LS and a new BGP Path Attribute called the BGP-LS attribute are
defined in [RFC7752]. The identifying key of each Link-State object,
namely a node, link, or prefix, is encoded in the NLRI and the
properties of the object are encoded in the BGP-LS attribute.
Figure Figure 1 describes a typical deployment scenario. In each IGP
area, one or more nodes are configured with BGP-LS. These BGP
speakers form an IBGP mesh by connecting to one or more route-
reflectors. This way, all BGP speakers (specifically the route-
reflectors) obtain Link-State information from all IGP areas (and
from other ASes from EBGP peers). An external component connects to
the route-reflector to obtain this information (perhaps moderated by
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a policy regarding what information is or isn't advertised to the
external component).
This document describes extensions to BGP-LS to advertise the SR
information. An external component (e.g., a controller) then can
collect SR information in the "northbound" direction across IGP areas
or ASes and construct the end-to-end path (with its associated SIDs)
that need to be applied to an incoming packet to achieve the desired
end-to-end forwarding.
2. BGP-LS Extensions for Segment Routing
This document defines IGP SR extensions BGP-LS TLVs and sub-TLVs.
Section 2.4 and Section 2.5 illustrates the equivalent TLVs and sub-
TLVs in IS-IS, OSPF and OSPFv3 protocols.
BGP-LS [RFC7752] defines the BGP-LS NLRI that can be a Node NLRI, a
Link NLRI or a Prefix NLRI. The corresponding BGP-LS attribute is a
Node Attribute, a Link Attribute or a Prefix Attribute. BGP-LS
[RFC7752] defines the TLVs that map link-state information to BGP-LS
NLRI and the BGP-LS attribute. This document adds additional BGP-LS
attribute TLVs in order to encode SR information.
2.1. Node Attributes TLVs
The following Node Attribute TLVs are defined:
+-----------------+----------+---------------+
| Description | Length | Section |
+-----------------+----------+---------------+
| SID/Label | variable | Section 2.1.1 |
| SR Capabilities | variable | Section 2.1.2 |
| SR Algorithm | variable | Section 2.1.3 |
| SR Local Block | variable | Section 2.1.4 |
| SRMS Preference | variable | Section 2.1.5 |
+-----------------+----------+---------------+
Table 1: Node Attribute TLVs
These TLVs can ONLY be added to the Node Attribute associated with
the Node NLRI that originates the corresponding SR TLV.
2.1.1. SID/Label Sub-TLV
The SID/Label TLV is used as sub-TLV by the SR-Capabilities
(Section 2.1.2) and SRLB (Section 2.1.4) TLVs and has following
format:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD, see Section 5.
Length: Variable, 3 or 4 bytes
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
represents a 32 bit SID.
The receiving router MUST ignore the SID/Label sub-TLV if the
length is other then 3 or 4.
2.1.2. SR-Capabilities TLV
The SR-Capabilities TLV is used in order to advertise the node's
Segment Routing Global Base (SRGB) as originated in:
o IS-IS, as defined by the SR-Capabilities TLV in
[I-D.ietf-isis-segment-routing-extensions].
o OSPF/OSPFv3, as defined by the SID/Label Range TLV in
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The SR Capabilities TLV has following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Range Size |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// SID/Label sub-TLV (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Type: TBD, see Section 5.
Length: Variable.
Flags: 1 octet of flags as defined in
[I-D.ietf-isis-segment-routing-extensions].
One or more entries, each of which have the following format:
Range Size: 3 octet value indicating the number of labels in
the range.
SID/Label sub-TLV (as defined in Section 2.1.1).
Multiple SRGB entries are encoded within the same SR Capabilities
TLV.
2.1.3. SR-Algorithm TLV
The SR-Algorithm TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Algorithm 1 | Algorithm... | Algorithm N | |
+- -+
| |
+ +
where:
Type: TBD, see Section 5.
Length: Variable.
Algorithm: 1 octet identifying the algorithm.
2.1.4. SR Local Block TLV
The SR Local Block (SRLB) TLV contains the range of labels the node
has reserved for local SIDs. Local SIDs are used, e.g., in IGP (IS-
IS, OSPF) for Adjacency-SIDs, and may also be allocated by other
components than IGP protocols. As an example, an application or a
controller may instruct a node to allocate a specific local SID.
Therefore, in order for such applications or controllers to know the
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range of local SIDs available, it is required that the node
advertises its SRLB.
The SRLB TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Range Size |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// SID/Label sub-TLV (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: TBD, see Section 5.
Length: Variable.
Flags: 1 octet of flags. None are defined at this stage.
One or more entries, each of which have the following format:
Range Size: 3 octet value indicating the number of labels in
the range.
SID/Label sub-TLV (as defined in Section 2.1.1).
Multiple SRLB entries are encoded within the same SRLB TLV.
2.1.5. SRMS Preference TLV
The Segment Routing Mapping Server (SRMS) Preference TLV is used in
order to associate a preference with SRMS advertisements from a
particular source.
The SRMS Preference TLV has following format:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference |
+-+-+-+-+-+-+-+-+
Type: TBD, see Section 5.
Length: 1.
Preference: 1 octet. Unsigned 8 bit SRMS preference.
The use of the SRMS Preference TLV is defined in
[I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
2.2. Link Attribute TLVs
The following Link Attribute TLVs are are defined:
+----------------------------------------+----------+---------------+
| Description | Length | Section |
+----------------------------------------+----------+---------------+
| Adjacency Segment Identifier (Adj-SID) | variable | Section 2.2.1 |
| TLV | | |
| LAN Adjacency Segment Identifier (Adj- | variable | Section 2.2.2 |
| SID) TLV | | |
| L2 Bundle Member TLV | variable | Section 2.2.3 |
+----------------------------------------+----------+---------------+
Table 2: Link Attribute TLVs
These TLVs can ONLY be added to the Link Attribute associated with
the link whose local node originates the corresponding TLV.
For a LAN, normally a node only announces its adjacency to the IS-IS
pseudo-node (or the equivalent OSPF Designated and Backup Designated
Routers)[I-D.ietf-isis-segment-routing-extensions]. The LAN
Adjecency Segment TLV allows a node to announce adjacencies to all
other nodes attached to the LAN in a single instance of the BGP-LS
Link NLRI. Without this TLV, the corresponding BGP-LS link NLRI
would need to be originated for each additional adjacency in order to
advertise the SR TLVs for these neighbor adjacencies.
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2.2.1. Adjacency SID TLV
The Adjacency SID (Adj-SID) TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Weight | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) |
+---------------------------------------------------------------+
where:
Type: TBD, see Section 5.
Length: Variable.
Flags. 1 octet field of following flags as defined in
[I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
Weight: Weight used for load-balancing purposes.
SID/Index/Label: Label or index value depending on the flags
setting as defined in [I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
2.2.2. LAN Adjacency SID TLV
The LAN Adjacency SID (LAN-Adj-SID-SID) TLV has the following format:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Weight | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OSPF Neighbor ID / IS-IS System-ID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) |
+---------------------------------------------------------------+
where:
Type: TBD, see Section 5.
Length: Variable.
Flags. 1 octet field of following flags as defined in
[I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
Weight: Weight used for load-balancing purposes.
SID/Index/Label: Label or index value depending on the flags
setting as defined in [I-D.ietf-isis-segment-routing-extensions],
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
2.2.3. L2 Bundle Member
The L2 Bundle Member Attribute TLV identifies an L2 Bundle Member
link which in turn is associated with a parent L3 link. The L3 link
is described by the Link NLRI defined in [RFC7752] and the L2 Bundle
Member Attribute TLV is associated with the Link NLRI. The TLV MAY
include sub-TLVs which describe attributes associated with the bundle
member. The identified bundle member represents a unidirectional
path from the originating router to the neighbor specified in the
parent L3 Link. Multiple L2 Bundle Member Attribute TLVs MAY be
associated with a Link NLRI.
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The L2 Bundle Member Attribute TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| L2 Bundle Member Descriptor |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Link attribute sub-TLVs(variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD, see Section 5.
Length: Variable.
L2 Bundle Member Descriptor: A Link Local Identifier as defined in
[RFC4202].
Link attributes for L2 Bundle Member Links are advertised as sub-TLVs
of the L2Bundle Member Attribute TLV. The sub-TLVs are identical to
existing BGP-LS TLVs as identified in the table below.
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+-----------+----------------------------+--------------------------+
| TLV Code | Description | Reference Document |
| Point | | |
+-----------+----------------------------+--------------------------+
| 1088 | Administrative group | [RFC7752] |
| | (color) | |
| 1089 | Maximum link bandwidth | [RFC7752] |
| 1090 | Max. reservable link | [RFC7752] |
| | bandwidth | |
| 1091 | Unreserved bandwidth | [RFC7752] |
| 1092 | TE default metric | [RFC7752] |
| 1093 | Link protection type | [RFC7752] |
| 1099 | Adjacency Segment | Section 2.2.1 |
| | Identifier (Adj-SID) TLV | |
| 1100 | LAN Adjacency Segment | Section 2.2.2 |
| | Identifier (Adj-SID) TLV | |
| 1104 | Unidirectional link delay | [I-D.ietf-idr-te-pm-bgp] |
| 1105 | Min/Max Unidirectional | [I-D.ietf-idr-te-pm-bgp] |
| | link delay | |
| 1106 | Min/Max Unidirectional | [I-D.ietf-idr-te-pm-bgp] |
| | link delay | |
| 1107 | Unidirectional packet loss | [I-D.ietf-idr-te-pm-bgp] |
| 1108 | Unidirectional residual | [I-D.ietf-idr-te-pm-bgp] |
| | bandwidth | |
| 1109 | Unidirectional available | [I-D.ietf-idr-te-pm-bgp] |
| | bandwidth | |
| 1110 | Unidirectional bandwidth | [I-D.ietf-idr-te-pm-bgp] |
| | utilization | |
+-----------+----------------------------+--------------------------+
Table 3: L2 Bundle Member Link Attribute TLVs
2.3. Prefix Attribute TLVs
The following Prefix Attribute TLVs and sub-TLVs are defined:
+-----------------------+----------+---------------+
| Description | Length | Section |
+-----------------------+----------+---------------+
| Prefix SID | variable | Section 2.3.1 |
| Range | variable | Section 2.3.4 |
| IGP Prefix Attributes | variable | Section 2.3.2 |
| Source Router-ID | variable | Section 2.3.3 |
+-----------------------+----------+---------------+
Table 4: Prefix Attribute TLVs
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2.3.1. Prefix-SID TLV
The Prefix-SID TLV can ONLY be added to the Prefix Attribute whose
local node in the corresponding Prefix NLRI is the node that
originates the corresponding SR TLV.
The Prefix-SID TLV is used in order to advertise a Prefix-SID as
originated in:
o IS-IS, as defined by the Prefix-SID TLV in
[I-D.ietf-isis-segment-routing-extensions].
o OSPF/OSPFv3, as defined by the Prefix-SID TLV in
[I-D.ietf-ospf-segment-routing-extensions] and
[I-D.ietf-ospf-ospfv3-segment-routing-extensions].
The Prefix-SID has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Index/Label (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD, see Section 5.
Length: Variable
Algorithm: 1 octet value identify the algorithm.
SID/Index/Label:
* IS-IS: Label or index value as defined in
[I-D.ietf-isis-segment-routing-extensions],
* OSPF: Label or index value as defined in
[I-D.ietf-ospf-segment-routing-extensions],
* OSPFv3: Label or index value as defined in
[I-D.ietf-ospf-ospfv3-segment-routing-extensions],
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The Prefix-SID TLV includes a Flags field. In the context of BGP-LS,
the Flags field format and the semantic of each individual flag MUST
be taken from the corresponding source protocol (i.e.: the protocol
of origin of the Prefix-SID being advertised in BGP-LS).
IS-IS Prefix-SID flags are defined in
[I-D.ietf-isis-segment-routing-extensions] section 2.1.
OSPF Prefix-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 5.
OSPFv3 Prefix-SID flags are defined in
[I-D.ietf-ospf-segment-routing-extensions] section 5.
2.3.2. IGP Prefix Attributes TLV
The IGP Prefix Attribute TLV carries IPv4/IPv6 prefix attribute flags
as defined in [RFC7684] and [RFC7794].
The IGP Prefix Attribute TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Flags (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD, see Section 5.
Length: variable.
Flags: a variable length flag field (according to the length
field). Flags are routing protocol specific (OSPF and IS-IS).
OSPF flags are defined in [RFC7684] and IS-IS flags are defined in
[RFC7794]. The receiver of the BGP-LS update, when inspecting the
IGP Prefix Attribute TLV, MUST check the Protocol-ID of the NLRI
and refer to the protocol specification in order to parse the
flags.
2.3.3. Source Router Identifier (Source Router-ID) TLV
The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the
originator as defined in [RFC7794]. While defined in the IS-IS
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protocol, the Source Router-ID TLV may be used to carry the OSPF
Router-ID of the prefix originator.
The Source Router-ID TLV has the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// IPv4/IPv6 Address (Router-ID) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Type: TBD, see Section 5.
Length: 4 or 16.
IPv4/IPv6 Address: 4 octet IPv4 address or 16 octet IPv6 address.
The semantic of the Source Router-ID TLV is defined in [RFC7794].
2.3.4. Range TLV
The Range TLV can ONLY be added to the Prefix Attribute whose local
node in the corresponding Prefix NLRI is the node that originates the
corresponding SR TLV.
When the range TLV is used in order to advertise a range of prefix-
to-SID mappings as defined in
[I-D.ietf-ospf-segment-routing-extensions],
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]and
[I-D.ietf-isis-segment-routing-extensions]. The Prefix-NLRI the
Range TLV is attached to MUST be advertised as a non-routing prefix
where no IGP metric TLV (TLV 1095) is attached.
The format of the Range TLV is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | RESERVED | Range Size |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// sub-TLVs //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Figure 2: Range TLV format
Type: TBD, see Section 5.
Length is 4.
Flags: as defined in [I-D.ietf-ospf-segment-routing-extensions],
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] and
[I-D.ietf-isis-segment-routing-extensions].
Range Size: 2 octets as defined in
[I-D.ietf-ospf-segment-routing-extensions].
Within the Range TLV, the Prefix-SID TLV (used as sub-TLV in this
context) MAY be present.
2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs
This section illustrate the IS-IS Segment Routing Extensions TLVs and
sub-TLVs mapped to the ones defined in this document.
The following table, illustrates for each BGP-LS TLV, its equivalence
in IS-IS.
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+----------------------------------------+----------+---------------+
| Description | Length | IS-IS TLV |
| | | /sub-TLV |
+----------------------------------------+----------+---------------+
| SR Capabilities | variable | 2 [1] |
| SR Algorithm | variable | 19 [2] |
| Adjacency Segment Identifier (Adj-SID) | variable | 31 [3] |
| TLV | | |
| LAN Adjacency Segment Identifier (LAN- | variable | 32 [4] |
| Adj-SID) TLV | | |
| Prefix SID | variable | 3 [5] |
| SID/Label TLV | variable | 1 [6] |
| IGP Prefix Attributes | variable | 4 [7] |
| Source Router ID | variable | 11/12 [8] |
| L2 Bundle Member TLV | variable | 25 [9] |
+----------------------------------------+----------+---------------+
Table 5: IS-IS Segment Routing Extensions TLVs/Sub-TLVs
2.5. Equivalent OSPF/OSPFv3 Segment Routing TLVs/Sub-TLVs
This section illustrate the OSPF and OSPFv3 Segment Routing
Extensions TLVs and sub-TLVs mapped to the ones defined in this
document.
The following table, illustrates for each BGP-LS TLV, its equivalence
in OSPF and OSPFv3.
+---------------------------------------+----------+----------------+
| Description | Length | OSPF TLV/sub- |
| | | TLV |
+---------------------------------------+----------+----------------+
| SR Capabilities | variable | 9 [10] |
| SR Algorithm | variable | 8 [11] |
| Adjacency Segment Identifier (Adj- | variable | 2 [12] |
| SID) TLV | | |
| LAN Adjacency Segment Identifier | variable | 3 [13] |
| (Adj-SID) TLV | | |
| Prefix SID | variable | 2 [14] |
| SID/Label TLV | variable | 1 [15] |
+---------------------------------------+----------+----------------+
Table 6: OSPF Segment Routing Extensions TLVs/Sub-TLVs
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+--------------------------------------+----------+-----------------+
| Description | Length | OSPFv3 TLV/sub- |
| | | TLV |
+--------------------------------------+----------+-----------------+
| SR Capabilities | variable | 9 [16] |
| SR Algorithm | variable | 8 [17] |
| Adjacency Segment Identifier (Adj- | variable | 5 [18] |
| SID) TLV | | |
| LAN Adjacency Segment Identifier | variable | 6 [19] |
| (Adj-SID) TLV | | |
| Prefix SID | variable | 4 [20] |
| SID/Label TLV | variable | 3 [21] |
+--------------------------------------+----------+-----------------+
Table 7: OSPFv3 Segment Routing Extensions TLVs/Sub-TLVs
3. Procedures
The following sections describe the different operations for the
propagation of SR TLVs into BGP-LS.
3.1. Advertisement of a IS-IS Prefix SID TLV
The advertisement of a IS-IS Prefix SID TLV has following rules:
The IS-IS Prefix-SID is encoded in the BGP-LS Prefix Attribute
Prefix-SID as defined in Section 2.3.1. The flags in the Prefix-
SID TLV have the semantic defined in
[I-D.ietf-isis-segment-routing-extensions] section 2.1.
3.2. Advertisement of a OSPF/OSPFv3 Prefix-SID TLV
The advertisement of a OSPF/OSPFv3 Prefix-SID TLV has following
rules:
The OSPF (or OSPFv3) Prefix-SID is encoded in the BGP-LS Prefix
Attribute Prefix-SID as defined in Section 2.3.1. The flags in
the Prefix-SID TLV have the semantic defined in
[I-D.ietf-ospf-segment-routing-extensions] section 5 or
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 5.
3.3. Advertisement of a range of prefix-to-SID mappings in OSPF
The advertisement of a range of prefix-to-SID mappings in OSPF has
following rules:
The OSPF/OSPFv3 Extended Prefix Range TLV is encoded in the BGP-LS
Prefix Attribute Range TLV as defined in Section 2.3.4. The flags
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of the Range TLV have the semantic mapped to the definition in
[I-D.ietf-ospf-segment-routing-extensions] section 4 or
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 4. The
Prefix-SID from the original OSPF Prefix SID sub-TLV is encoded
using the BGP-LS Prefix Attribute Prefix-SID as defined in
Section 2.3.1 with the flags set according to the definition in
[I-D.ietf-ospf-segment-routing-extensions] section 5 or
[I-D.ietf-ospf-ospfv3-segment-routing-extensions] section 5.
3.4. Advertisement of a range of IS-IS SR bindings
The advertisement of a range of IS-IS Mapping Server bindings
([I-D.ietf-isis-segment-routing-extensions]) is encoded using the
following TLV/sub-TLV structure:
Range TLV
Prefix-SID TLV (used as a sub-TLV in this context)
where:
o The Range TLV is defined in Section 2.3.4.
o The Prefix-SID TLV (used as sub-TLV in this context) is defined in
Section 2.3.1.
4. Implementation Status
Note to RFC Editor: Please remove this section prior to publication,
as well as the reference to RFC 7942.
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
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It is up to the individual working groups to use this information as
they see fit".
Several early implementations exist and will be reported in detail in
a forthcoming version of this document. For purposes of early
interoperability testing, when no FCFS code point was available,
implementations have made use of the values described in Table 8.
It will ease implementation interoperability and deployment if the
value could be preserved also due to the large amount of codepoints
this draft requires. However, when IANA-assigned values are
available, implementations will be updated to use them.
5. IANA Considerations
This document requests assigning code-points from the registry "BGP-
LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute
TLVs" based on table Table 8. The column "IS-IS TLV/Sub-TLV" defined
in the registry does not require any value and should be left empty.
5.1. TLV/Sub-TLV Code Points Summary
This section contains the global table of all TLVs/sub-TLVs defined
in this document.
+-------------+-------------------------------------+---------------+
| TLV Code | Description | Reference |
| Point | | |
+-------------+-------------------------------------+---------------+
| 1034 | SR Capabilities | Section 2.1.2 |
| 1035 | SR Algorithm | Section 2.1.3 |
| 1036 | SR Local Block | Section 2.1.4 |
| 1037 | SRMS Preference | Section 2.1.5 |
| 1099 | Adjacency Segment Identifier (Adj- | Section 2.2.1 |
| | SID) TLV | |
| 1100 | LAN Adjacency Segment Identifier | Section 2.2.2 |
| | (Adj-SID) TLV | |
| 1158 | Prefix SID | Section 2.3.1 |
| 1159 | Range | Section 2.3.4 |
| 1161 | SID/Label TLV | Section 2.1.1 |
| 1170 | IGP Prefix Attributes | Section 2.3.2 |
| 1171 | Source Router-ID | Section 2.3.3 |
| 1172 | L2 Bundle Member TLV | Section 2.2.3 |
+-------------+-------------------------------------+---------------+
Table 8: Summary Table of TLV/Sub-TLV Codepoints
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6. Manageability Considerations
This section is structured as recommended in [RFC5706].
6.1. Operational Considerations
6.1.1. Operations
Existing BGP and BGP-LS operational procedures apply. No additional
operation procedures are defined in this document.
7. Security Considerations
Procedures and protocol extensions defined in this document do not
affect the BGP security model. See the 'Security Considerations'
section of [RFC4271] for a discussion of BGP security. Also refer to
[RFC4272] and [RFC6952] for analysis of security issues for BGP.
8. Contributors
The following people have substantially contributed to the editing of
this document:
Les Ginsberg
Cisco Systems
Email: ginsberg@cisco.com
Acee Lindem
Cisco Systems
Email: acee@cisco.com
Saikat Ray
Individual
Email: raysaikat@gmail.com
Jeff Tantsura
Individual
Email: jefftant@gmail.com
9. Acknowledgements
The authors would like to thank Ketan Jivan Talaulikar for his review
of this document.
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10. References
10.1. Normative References
[I-D.ietf-idr-te-pm-bgp]
Previdi, S., Wu, Q., Gredler, H., Ray, S.,
jefftant@gmail.com, j., Filsfils, C., and L. Ginsberg,
"BGP-LS Advertisement of IGP Traffic Engineering
Performance Metric Extensions", draft-ietf-idr-te-pm-
bgp-06 (work in progress), June 2017.
[I-D.ietf-isis-segment-routing-extensions]
Previdi, S., Filsfils, C., Bashandy, A., Gredler, H.,
Litkowski, S., Decraene, B., and j. jefftant@gmail.com,
"IS-IS Extensions for Segment Routing", draft-ietf-isis-
segment-routing-extensions-13 (work in progress), June
2017.
[I-D.ietf-ospf-ospfv3-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3
Extensions for Segment Routing", draft-ietf-ospf-ospfv3-
segment-routing-extensions-09 (work in progress), March
2017.
[I-D.ietf-ospf-segment-routing-extensions]
Psenak, P., Previdi, S., Filsfils, C., Gredler, H.,
Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
Extensions for Segment Routing", draft-ietf-ospf-segment-
routing-extensions-18 (work in progress), July 2017.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions
in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005,
<http://www.rfc-editor.org/info/rfc4202>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>.
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[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>.
[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
S. Ray, "North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP", RFC 7752,
DOI 10.17487/RFC7752, March 2016,
<http://www.rfc-editor.org/info/rfc7752>.
[RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and
U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4
and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794,
March 2016, <http://www.rfc-editor.org/info/rfc7794>.
10.2. Informative References
[I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
and R. Shakir, "Segment Routing Architecture", draft-ietf-
spring-segment-routing-12 (work in progress), June 2017.
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006,
<http://www.rfc-editor.org/info/rfc4272>.
[RFC5706] Harrington, D., "Guidelines for Considering Operations and
Management of New Protocols and Protocol Extensions",
RFC 5706, DOI 10.17487/RFC5706, November 2009,
<http://www.rfc-editor.org/info/rfc5706>.
[RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of
BGP, LDP, PCEP, and MSDP Issues According to the Keying
and Authentication for Routing Protocols (KARP) Design
Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
<http://www.rfc-editor.org/info/rfc6952>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<http://www.rfc-editor.org/info/rfc7942>.
10.3. URIs
[1] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-3.1
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[2] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-3.2
[3] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-2.2.1
[4] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-2.2.2
[5] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-2.1
[6] http://tools.ietf.org/html/draft-ietf-isis-segment-routing-
extensions-05#section-2.3
[7] http://tools.ietf.org/html/RFC7794
[8] http://tools.ietf.org/html/RFC7794
[9] http://tools.ietf.org/html/draft-ietf-isis-l2bundles-05
[10] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-3.2
[11] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-3.1
[12] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-7.1
[13] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-7.2
[14] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-5
[15] http://tools.ietf.org/html/draft-ietf-ospf-segment-routing-
extensions-05#section-2.1
[16] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-3.2
[17] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-3.1
[18] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-7.1
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[19] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-7.2
[20] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-5
[21] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-
routing-extensions-05#section-2.1
Authors' Addresses
Stefano Previdi (editor)
Cisco Systems, Inc.
Via Del Serafico, 200
Rome 00142
Italy
Email: stefano@previdi.net
Peter Psenak
Cisco Systems, Inc.
Apollo Business Center
Mlynske nivy 43
Bratislava 821 09
Slovakia
Email: ppsenak@cisco.com
Clarence Filsfils
Cisco Systems, Inc.
Brussels
Belgium
Email: cfilsfil@cisco.com
Hannes Gredler
RtBrick Inc.
Email: hannes@rtbrick.com
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Mach(Guoyi) Chen
Huawei Technologies
Huawei Building, No. 156 Beiqing Rd.
Beijing 100095
China
Email: mach.chen@huawei.com
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