draft-ietf-lsr-isis-srv6-extensions-11.txt   draft-ietf-lsr-isis-srv6-extensions-12.txt 
Networking Working Group P. Psenak, Ed. Networking Working Group P. Psenak, Ed.
Internet-Draft C. Filsfils Internet-Draft C. Filsfils
Intended status: Standards Track Cisco Systems Updates: 7370 (if approved) Cisco Systems
Expires: April 11, 2021 A. Bashandy Intended status: Standards Track A. Bashandy
Individual Expires: October 10, 2021 Individual
B. Decraene B. Decraene
Orange Orange
Z. Hu Z. Hu
Huawei Technologies Huawei Technologies
October 8, 2020 April 8, 2021
IS-IS Extension to Support Segment Routing over IPv6 Dataplane IS-IS Extension to Support Segment Routing over IPv6 Dataplane
draft-ietf-lsr-isis-srv6-extensions-11 draft-ietf-lsr-isis-srv6-extensions-12
Abstract Abstract
Segment Routing (SR) allows for a flexible definition of end-to-end The Segment Routing (SR) allows for a flexible definition of end-to-
paths by encoding paths as sequences of topological sub-paths, called end paths by encoding paths as sequences of topological sub-paths,
"segments". Segment routing architecture can be implemented over an called "segments". Segment routing architecture can be implemented
MPLS data plane as well as an IPv6 data plane. This draft describes over an MPLS data plane as well as an IPv6 data plane. This document
the IS-IS extensions required to support Segment Routing over an IPv6 describes the IS-IS extensions required to support Segment Routing
data plane. over an IPv6 data plane.
This documents updates [RFC7370] by modifying an existing registry.
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", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
Status of This Memo Status of This Memo
skipping to change at page 1, line 48 skipping to change at page 2, line 4
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 10, 2021.
This Internet-Draft will expire on April 11, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . . . . 4 2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . . . . 3
3. Advertising Supported Algorithms . . . . . . . . . . . . . . 4 3. Advertising Supported Algorithms . . . . . . . . . . . . . . 4
4. Advertising Maximum SRv6 SID Depths . . . . . . . . . . . . . 5 4. Advertising Maximum SRv6 SID Depths . . . . . . . . . . . . . 4
4.1. Maximum Segments Left MSD Type . . . . . . . . . . . . . 5 4.1. Maximum Segments Left MSD Type . . . . . . . . . . . . . 5
4.2. Maximum End Pop MSD Type . . . . . . . . . . . . . . . . 5 4.2. Maximum End Pop MSD Type . . . . . . . . . . . . . . . . 5
4.3. Maximum H.Encaps MSD Type . . . . . . . . . . . . . . . . 5 4.3. Maximum H.Encaps MSD Type . . . . . . . . . . . . . . . . 5
4.4. Maximum End D MSD Type . . . . . . . . . . . . . . . . . 6 4.4. Maximum End D MSD Type . . . . . . . . . . . . . . . . . 5
5. SRv6 SIDs and Reachability . . . . . . . . . . . . . . . . . 6 5. SRv6 SIDs and Reachability . . . . . . . . . . . . . . . . . 6
6. Advertising Anycast Property . . . . . . . . . . . . . . . . 7 6. Advertising Anycast Property . . . . . . . . . . . . . . . . 7
7. Advertising Locators and End SIDs . . . . . . . . . . . . . . 8 7. Advertising Locators and End SIDs . . . . . . . . . . . . . . 8
7.1. SRv6 Locator TLV Format . . . . . . . . . . . . . . . . . 8 7.1. SRv6 Locator TLV Format . . . . . . . . . . . . . . . . . 8
7.2. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . . . 10 7.2. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . . . 10
8. Advertising SRv6 Adjacency SIDs . . . . . . . . . . . . . . . 11 8. Advertising SRv6 Adjacency SIDs . . . . . . . . . . . . . . . 11
8.1. SRv6 End.X SID sub-TLV . . . . . . . . . . . . . . . . . 12 8.1. SRv6 End.X SID sub-TLV . . . . . . . . . . . . . . . . . 12
8.2. SRv6 LAN End.X SID sub-TLV . . . . . . . . . . . . . . . 13 8.2. SRv6 LAN End.X SID sub-TLV . . . . . . . . . . . . . . . 13
9. SRv6 SID Structure Sub-Sub-TLV . . . . . . . . . . . . . . . 15 9. SRv6 SID Structure Sub-Sub-TLV . . . . . . . . . . . . . . . 15
10. Advertising Endpoint Behaviors . . . . . . . . . . . . . . . 16 10. Advertising Endpoint Behaviors . . . . . . . . . . . . . . . 16
11. Implementation Status . . . . . . . . . . . . . . . . . . . . 16 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
11.1. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . 17 11.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 16
11.2. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 17 11.1.1. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . 17
11.3. Juniper . . . . . . . . . . . . . . . . . . . . . . . . 17 11.1.2. Revised sub-TLV table . . . . . . . . . . . . . . . 17
11.4. Arrcus . . . . . . . . . . . . . . . . . . . . . . . . . 17 11.2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . 18
11.5. Interoperability Testing. . . . . . . . . . . . . . . . 18 11.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs . . . . . 18
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 11.4. MSD Types . . . . . . . . . . . . . . . . . . . . . . . 19
12.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 18 11.5. Sub-Sub-TLVs for SID Sub-TLVs . . . . . . . . . . . . . 19
12.1.1. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . 18 11.6. Prefix Attribute Flags Sub-TLV . . . . . . . . . . . . . 20
12.1.2. Revised sub-TLV table . . . . . . . . . . . . . . . 18 12. Security Considerations . . . . . . . . . . . . . . . . . . . 20
12.2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . 19 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 20
12.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs . . . . . 19 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
12.4. MSD Types . . . . . . . . . . . . . . . . . . . . . . . 20 14.1. Normative References . . . . . . . . . . . . . . . . . . 21
12.5. Sub-Sub-TLVs for SID Sub-TLVs . . . . . . . . . . . . . 20 14.2. Informative References . . . . . . . . . . . . . . . . . 24
12.6. Prefix Attribute Flags Sub-TLV . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
13. Security Considerations . . . . . . . . . . . . . . . . . . . 21
14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 22
15.1. Normative References . . . . . . . . . . . . . . . . . . 22
15.2. Informative References . . . . . . . . . . . . . . . . . 24
15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25
1. Introduction 1. Introduction
With Segment Routing (SR) [RFC8402], a node steers a packet through With Segment Routing (SR) [RFC8402], a node steers a packet through
an ordered list of instructions, called segments. an ordered list of instructions, called segments.
Segments are identified through Segment Identifiers (SIDs). Segments are identified through Segment Identifiers (SIDs).
Segment Routing can be directly instantiated on the IPv6 data plane Segment Routing can be directly instantiated on the IPv6 data plane
through the use of the Segment Routing Header defined in [RFC8754]. through the use of the Segment Routing Header defined in [RFC8754].
SRv6 refers to this SR instantiation on the IPv6 dataplane. SRv6 refers to this SR instantiation on the IPv6 dataplane.
The network programming paradigm The network programming paradigm [RFC8986] is central to SRv6. It
[I-D.ietf-spring-srv6-network-programming] is central to SRv6. It
describes how any behavior can be bound to a SID and how any network describes how any behavior can be bound to a SID and how any network
program can be expressed as a combination of SIDs. program can be expressed as a combination of SIDs.
This document specifies IS-IS extensions that allow the IS-IS This document specifies IS-IS extensions that allow the IS-IS
protocol to encode some of these SIDs and their behaviors. protocol to encode some of these SIDs and their behaviors.
Familiarity with the network programming paradigm Familiarity with the network programming paradigm [RFC8986] is
[I-D.ietf-spring-srv6-network-programming] is necessary to understand necessary to understand the extensions specified in this document.
the extensions specified in this document.
This document defines one new top level IS-IS TLV and several new IS- The new SRv6 Locator top level TLV announces SRv6 locators - a form
IS sub-TLVs. of summary address for the set of topology/algorithm specific SIDs
instantiated at the node.
The SRv6 Capabilities sub-TLV announces the ability to support SRv6. The SRv6 Capabilities sub-TLV announces the ability to support SRv6.
Several new sub-TLVs are defined to advertise various SRv6 Maximum Several new sub-TLVs are defined to advertise various SRv6 Maximum
SID Depths. SID Depths.
The new SRv6 Locator top level TLV announces SRv6 locators - a form
of summary address for the set of topology/algorithm specific SIDs
instantiated at the node.
The SRv6 End SID sub-TLV, the SRv6 End.X SID sub-TLV, and the SRv6 The SRv6 End SID sub-TLV, the SRv6 End.X SID sub-TLV, and the SRv6
LAN End.X SID sub-TLV are used to advertise which SIDs are LAN End.X SID sub-TLV are used to advertise which SIDs are
instantiated at a node and what Endpoint behavior is bound to each instantiated at a node and what Endpoint behavior is bound to each
instantiated SID. instantiated SID.
This documents updates [RFC7370] by modifying an existing registry
Section 11.1.2.
2. SRv6 Capabilities sub-TLV 2. SRv6 Capabilities sub-TLV
A node indicates that it supports the SR Segment Endpoint Node A node indicates that it supports the SR Segment Endpoint Node
functionality as specified in [RFC8754] by advertising a new SRv6 functionality as specified in [RFC8754] by advertising a new SRv6
Capabilities sub-TLV of the router capabilities TLV [RFC7981]. Capabilities sub-TLV of the router capabilities TLV [RFC7981].
The SRv6 Capabilities sub-TLV may contain optional sub-sub-TLVs. No The SRv6 Capabilities sub-TLV may contain optional sub-sub-TLVs. No
sub-sub-TLVs are currently defined. sub-sub-TLVs are currently defined.
The SRv6 Capabilities sub-TLV has the following format: The SRv6 Capabilities sub-TLV has the following format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Flags | | Type | Length | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| optional sub-sub-TLVs... | optional sub-sub-TLVs...
Type: 25 Type: 25
Length: 2 + length of sub-sub-TLVs Length: 2 + length of sub-sub-TLVs
skipping to change at page 4, line 40 skipping to change at page 4, line 32
0 1 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |O| | | |O| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
O-flag: If set, the router supports use of the O-bit O-flag: If set, the router supports use of the O-bit
in the Segment Routing Header(SRH) as defined in in the Segment Routing Header (SRH) as defined in
[I-D.ietf-6man-spring-srv6-oam]. [I-D.ietf-6man-spring-srv6-oam].
3. Advertising Supported Algorithms 3. Advertising Supported Algorithms
SRv6 capable router indicates supported algorithm(s) by advertising An SRv6 capable router indicates supported algorithm(s) by
the SR Algorithm TLV as defined in [RFC8667]. advertising the SR Algorithm sub-TLV as defined in [RFC8667].
4. Advertising Maximum SRv6 SID Depths 4. Advertising Maximum SRv6 SID Depths
[RFC8491] defines the means to advertise node/link specific values [RFC8491] defines the means to advertise node/link specific values
for Maximum SID Depths (MSD) of various types. Node MSDs are for Maximum SID Depths (MSD) of various types. Node MSDs are
advertised in a sub-TLV of the Router Capabilities TLV [RFC7981]. advertised in a sub-TLV of the Router Capabilities TLV [RFC7981].
Link MSDs are advertised in a sub-TLV of TLVs 22, 23, 141, 222, and Link MSDs are advertised in a sub-TLV of TLVs 22, 23, 141, 222, and
223. 223.
This document defines the relevant SRv6 MSDs and requests MSD type This document defines the relevant SRv6 MSDs and requests MSD type
assignments in the MSD Types registry created by [RFC8491]. assignments in the MSD Types registry created by [RFC8491].
4.1. Maximum Segments Left MSD Type 4.1. Maximum Segments Left MSD Type
The Maximum Segments Left MSD Type specifies the maximum value of the The Maximum Segments Left MSD Type specifies the maximum value of the
"SL" field [RFC8754] in the SRH of a received packet before applying "Segments Left" field [RFC8754] in the SRH of a received packet
the Endpoint behavior associated with a SID. before applying the Endpoint behavior associated with a SID.
SRH Max SL Type: 41 SRH Max Segments Left Type: 41
If no value is advertised the supported value is assumed to be 0. If no value is advertised the supported value is 0.
4.2. Maximum End Pop MSD Type 4.2. Maximum End Pop MSD Type
The Maximum End Pop MSD Type specifies the maximum number of SIDs in The Maximum End Pop MSD Type signals the maximum number of SIDs in
the SRH to which the router can apply "PSP" or USP" behavior, as the SRH to which the router can apply "Penultimate Segment Pop of the
defined in [I-D.ietf-spring-srv6-network-programming] flavors. SRH" or "Ultimate Segment Pop of the SRH" behavior, as defined in
[RFC8986] flavors.
SRH Max End Pop Type: 42 SRH Max End Pop Type: 42
If the advertised value is zero or no value is advertised If the advertised value is zero or no value is advertised
then it is assumed that the router cannot apply PSP or USP flavors. then the router cannot apply PSP or USP flavors.
4.3. Maximum H.Encaps MSD Type 4.3. Maximum H.Encaps MSD Type
The Maximum H.Encaps MSD Type specifies the maximum number of SIDs The Maximum H.Encaps MSD Type signals the maximum number of SIDs that
that can be included as part of the "H.Encaps" behavior as defined in can be added as part of the "H.Encaps" behavior as defined in
[I-D.ietf-spring-srv6-network-programming]. [RFC8986].
SRH Max H.encaps Type: 44 SRH Max H.encaps Type: 44
If the advertised value is zero or no value is advertised If the advertised value is zero or no value is advertised then the
then the router can apply H.Encaps only by encapsulating headend can apply an SR Policy that only contains one segment, without
the incoming packet in another IPv6 header without SRH inserting any SRH header.
the same way IPinIP encapsulation is performed.
If the advertised value is non-zero then the router supports both A non-zero SRH Max H.encaps MSD indicates that the headend can insert
IPinIP and SRH encapsulation subject to the SID limitation an SRH up to the advertised value.
specified by the advertised value.
4.4. Maximum End D MSD Type 4.4. Maximum End D MSD Type
The Maximum End D MSD Type specifies the maximum number of SIDs in an The Maximum End D MSD Type specifies the maximum number of SIDs
SRH when performing decapsulation associated with "End.Dx" behaviors present in an SRH when performing decapsulation. These includes, but
(e.g., "End.DX6" and "End.DT6") as defined in not limited to, End.DX6, End.DT4, End.DT46, End with USD, End.X with
[I-D.ietf-spring-srv6-network-programming]. USD as defined in [RFC8986]).
SRH Max End D Type: 45 SRH Max End D Type: 45
If the advertised value is zero or no value is advertised If the advertised value is zero or no value is advertised
then it is assumed that the router cannot apply then the router cannot apply any behavior that results in
"End.DX6" or "End.DT6" behaviors if the outer IPv6 header decapsulation and forwarding of the inner packet if the
contains an SRH. other IPv6 header contains an SRH.
5. SRv6 SIDs and Reachability 5. SRv6 SIDs and Reachability
As discussed in [I-D.ietf-spring-srv6-network-programming], an SRv6 As discussed in [RFC8986], an SRv6 Segment Identifier (SID) is 128
Segment Identifier (SID) is 128 bits and consists of Locator, bits and consists of Locator, Function and Argument parts.
Function and Argument parts.
A node is provisioned with topology/algorithm specific locators for A node is provisioned with topology/algorithm specific locators for
each of the topology/algorithm pairs supported by that node. Each each of the topology/algorithm pairs supported by that node. Each
locator is a covering prefix for all SIDs provisioned on that node locator is a covering prefix for all SIDs provisioned on that node
which have the matching topology/algorithm. which have the matching topology/algorithm.
Locators MUST be advertised in the SRv6 Locator TLV (see Locators MUST be advertised in the SRv6 Locator TLV (see
Section 7.1). Forwarding entries for the locators advertised in the Section 7.1). Forwarding entries for the locators advertised in the
SRv6 Locator TLV MUST be installed in the forwarding plane of SRv6 Locator TLV MUST be installed in the forwarding plane of
receiving SRv6 capable routers when the associated topology/algorithm receiving SRv6 capable routers when the associated topology/algorithm
is supported by the receiving node. is supported by the receiving node. The processing of the prefix
advertised in the SRv6 Locator TLV, the calculation of its
Locators are routable and MAY also be advertised in Prefix reachability and the installation in the forwarding plane follows the
Reachability TLVs (236 or 237). process defined for the Prefix Reachability TLV 236 [RFC5308], or TLV
237 [RFC5120].
Locators associated with Flexible Algorithms [I-D.ietf-lsr-flex-algo]
SHOULD NOT be advertised in Prefix Reachability TLVs (236 or 237).
Locators associated with algorithm 0 and 1 (for all supported Locators associated with algorithm 0 and 1 (for all supported
topologies) SHOULD be advertised in a Prefix Reachability TLV (236 or topologies) SHOULD be advertised in a Prefix Reachability TLV (236 or
237) so that legacy routers (i.e., routers which do NOT support SRv6) 237) so that legacy routers (i.e., routers which do NOT support SRv6)
will install a forwarding entry for algorithm 0 and 1 SRv6 traffic. will install a forwarding entry for algorithm 0 and 1 SRv6 traffic.
In cases where a locator advertisement is received in both a Prefix In cases where a locator advertisement is received in both a Prefix
Reachability TLV and an SRv6 Locator TLV, the Prefix Reachability Reachability TLV and an SRv6 Locator TLV - (e.g. prefix, prefix-
advertisement MUST be preferred when installing entries in the length, MTID all being equal and Algorithm being 0 in Locator TLV),
forwarding plane. This is to prevent inconsistent forwarding entries the Prefix Reachability advertisement MUST be preferred when
between SRv6 capable and SRv6 incapable routers. installing entries in the forwarding plane. This is to prevent
inconsistent forwarding entries between SRv6 capable and SRv6
incapable routers. Such preference of Prefix Reachability
advertisement does not have any impact on the rest of the data
advertised in the SRv6 Locator TLV.
Locators associated with Flexible Algorithms (see Section 4 of
[I-D.ietf-lsr-flex-algo]) SHOULD NOT be advertised in Prefix
Reachability TLVs (236 or 237). Advertising the Flexible Algorithm
locator in regular Prefix Reachability TLV (236 or 237) would make
the forwarding for it to follow algo 0 path.
SRv6 SIDs are advertised as sub-TLVs in the SRv6 Locator TLV except SRv6 SIDs are advertised as sub-TLVs in the SRv6 Locator TLV except
for SRv6 End.X SIDs/LAN End.X SIDs which are associated with a for SRv6 SIDs which are associated with a specific Neighbor/Link and
specific Neighbor/Link and are therefore advertised as sub-TLVs in are therefore advertised as sub-TLVs in TLVs 22, 23, 222, 223, and
TLVs 22, 23, 222, 223, and 141. 141.
SRv6 SIDs are not directly routable and MUST NOT be installed in the SRv6 SIDs received from other nodes are not directly routable and
forwarding plane. Reachability to SRv6 SIDs depends upon the MUST NOT be installed in the forwarding plane. Reachability to SRv6
existence of a covering locator. SIDs depends upon the existence of a covering locator.
Adherence to the rules defined in this section will assure that SRv6 Adherence to the rules defined in this section will assure that SRv6
SIDs associated with a supported topology/algorithm pair will be SIDs associated with a supported topology/algorithm pair will be
forwarded correctly, while SRv6 SIDs associated with an unsupported forwarded correctly, while SRv6 SIDs associated with an unsupported
topology/algorithm pair will be dropped. NOTE: The drop behavior topology/algorithm pair will be dropped. NOTE: The drop behavior
depends on the absence of a default/summary route covering a given depends on the absence of a default/summary route covering a given
locator. locator.
In order for forwarding to work correctly, the locator associated In order for forwarding to work correctly, the locator associated
with SRv6 SID advertisements MUST be the longest match prefix with SRv6 SID advertisements must be the longest match prefix
installed in the forwarding plane for those SIDs. There are a number installed in the forwarding plane for those SIDs. In order to ensure
of ways in which this requirement could be compromised. In order to correct forwarding, network operators should take steps to make sure
ensure correct forwarding, network operators should take steps to that this requirement is not compromised. For example, the following
make sure that this requirement is not compromised. situations should be avoided:
o Another locator associated with a different topology/algorithm is o Another locator associated with a different topology/algorithm is
the longest match the longest match
o A prefix advertisement (i.e., from TLV 236 or 237) is the longest o Another prefix advertisement (i.e., from TLV 236 or 237) is the
match longest match
6. Advertising Anycast Property 6. Advertising Anycast Property
Both prefixes and SRv6 Locators may be configured as anycast and as Both prefixes and SRv6 Locators may be configured as anycast and as
such the same value can be advertised by multiple routers. It is such the same value can be advertised by multiple routers. It is
useful for other routers to know that the advertisement is for an useful for other routers to know that the advertisement is for an
anycast identifier. anycast identifier.
A new flag in "Bit Values for Prefix Attribute Flags Sub-TLV" A new flag in Prefix Attribute Flags Sub-TLV [RFC7794] is defined to
registry [RFC7794] is defined to advertise the anycast property: advertise the anycast property:
Bit #: 4 Bit #: 4
Name: Anycast Flag (A-flag) Name: Anycast Flag (A-flag)
When the prefix/SRv6 locator is configured as anycast, the A-flag When the prefix/SRv6 locator is configured as anycast, the A-flag
SHOULD be set. Otherwise, this flag MUST be clear. SHOULD be set. Otherwise, this flag MUST be clear.
The A-flag MUST be preserved when leaked between levels. The A-flag MUST be preserved when the advertisement is leaked between
levels.
The A-flag and the N-flag MUST NOT both be set.
If both N-flag and A-flag are set in the prefix/SRv6 Locator The A-flag and the N-flag MUST NOT both be set. If both N-flag and
advertisement, the receiving routers MUST ignore the N-flag. A-flag are set in the prefix/SRv6 Locator advertisement, the
receiving routers MUST ignore the N-flag.
The same prefix/SRv6 Locator can be advertised by multiple routers. The same prefix/SRv6 Locator can be advertised by multiple routers.
If at least one of them sets the A-Flag in its advertisement, the If at least one of them sets the A-Flag in its advertisement, the
prefix/SRv6 Locator SHOULD be considered as anycast. prefix/SRv6 Locator SHOULD be considered as anycast.
A prefix/SRv6 Locator that is advertised by a single node and without A prefix/SRv6 Locator that is advertised by a single node and without
an A-Flag SHOULD be interpreted as a node specific locator. an A-Flag is considered node specific.
All the nodes advertising the same anycast locator MUST instantiate All the nodes advertising the same anycast locator MUST instantiate
the exact same set of SIDs under such anycast locator. Failure to do the exact same set of SIDs under such anycast locator. Failure to do
so may result in traffic being black-holed or mis-routed. so may result in traffic being black-holed or mis-routed.
The Prefix Attribute Flags Sub-TLV can be carried in the SRv6 Locator The Prefix Attribute Flags Sub-TLV can be carried in the SRv6 Locator
TLV as well as the Prefix Reachability TLVs. When a router TLV as well as the Prefix Reachability TLVs. When a router
originates both the Prefix Reachability TLV and the SRv6 Locator TLV originates both the Prefix Reachability TLV and the SRv6 Locator TLV
for a given prefix, and the router is originating the Prefix for a given prefix, and the router is originating the Prefix
Attribute Flags Sub-TLV in one of the TLVs, the router SHOULD Attribute Flags Sub-TLV in one of the TLVs, the router SHOULD
advertise identical versions of the Prefix Attribute Flags Sub-TLV in advertise the same flags in the Prefix Attribute Flags Sub-TLV in
both TLVs. both TLVs. However, unlike TLVs 236 [RFC5308] and 237 [RFC5120] the
X-flag in the Prefix Attributes Flags sub-TLV is valid when sent in
the SRv6 Locator TLV. The state of the X-flag in the Prefix
Attributes Flags sub-TLV when included in the Locator TLV MUST match
the setting of the embedded "X-bit" in any advertisement of the same
prefix in TLVs 236 [RFC5308] and 237 [RFC5120]. In case of any
inconsistency between the Prefix Attribute Flags advertised in the
Locator TLV and in the Prefix Reachability TLV, the ones advertised
in Prefix Reachability TLV MUST be preferred.
7. Advertising Locators and End SIDs 7. Advertising Locators and End SIDs
The SRv6 Locator TLV is introduced to advertise SRv6 Locators and End The SRv6 Locator TLV is introduced to advertise SRv6 Locators and End
SIDs associated with each locator. SIDs associated with each locator.
This new TLV shares the sub-TLV space defined for TLVs 135, 235, 236 This new TLV shares the sub-TLV space defined for TLVs 135, 235, 236
and 237. and 237.
7.1. SRv6 Locator TLV Format 7.1. SRv6 Locator TLV Format
The SRv6 Locator TLV has the following format: The SRv6 Locator 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 |R|R|R|R| MTID | | Type | Length |R|R|R|R| MT ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 27
Type: 27
Length: variable. Length: variable.
R bits: reserved for future use. They MUST be R bits: reserved for future use. They MUST be
set to zero on transmission and MUST be ignored on receipt. set to zero on transmission and MUST be ignored on receipt.
MTID: Multitopology Identifier as defined in [RFC5120]. MT ID: Multitopology Identifier as defined in [RFC5120].
Note that the value 0 is legal. Note that the value 0 is legal.
Followed by one or more locator entries of the form: Followed by one or more locator entries of the form:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Metric | | Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Algorithm | | Flags | Algorithm |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Loc Size | Locator (variable)... | Loc Size | Locator (variable)...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-tlv-len | Sub-TLVs (variable) . . . | | Sub-TLV-len | Sub-TLVs (variable) . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Metric: 4 octets. As described in [RFC5305]. Metric: 4 octets. As described in [RFC5305].
Flags: 1 octet. The following flags are defined Flags: 1 octet. The following flags are defined
0 0
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|D| Reserved | |D| Reserved |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
D bit: When the Locator is leaked from level-2 to level-1, the D D bit: Same as described in section 4.1. of [RFC5305].
bit MUST be set. Otherwise, this bit MUST be clear. Locators
with the D bit set MUST NOT be leaked from level-1 to level-2.
This is to prevent looping.
The remaining bits are reserved for future use. They MUST be The remaining bits are reserved for future use. They MUST be
set to zero on transmission and MUST be ignored on receipt. set to zero on transmission and MUST be ignored on receipt.
Algorithm: 1 octet. Associated algorithm. Algorithm values Algorithm: 1 octet. As defined in [RFC8665].
are defined in the IGP Algorithm Type registry.
Loc-Size: 1 octet. Number of bits in the SRv6 Locator field. Loc-Size: 1 octet. Number of bits in the SRv6 Locator field.
(1 - 128) MUST be from the range (1 - 128). The TLV MUST be ignored if
the Loc-Size is outside of this range.
Locator: 1-16 octets. This field encodes the advertised SRv6 Locator: 1-16 octets. This field encodes the advertised SRv6
Locator. The Locator is encoded in the minimal number of Locator. The Locator is encoded in the minimal number of
octets for the given number of bits. Trailing bits MUST be set octets for the given number of bits. Trailing bits MUST be set
to zero and ignored when received. to zero and ignored when received.
Sub-TLV-length: 1 octet. Number of octets used by sub-TLVs Sub-TLV-length: 1 octet. Number of octets used by sub-TLVs
Optional sub-TLVs. Optional sub-TLVs: Sub-TLVs 1, 2, 4, 5, 11, 12 are allowed.
Any other Sub-TLVs MUST be ignored.
7.2. SRv6 End SID sub-TLV 7.2. SRv6 End SID sub-TLV
The SRv6 End SID sub-TLV is introduced to advertise SRv6 Segment The SRv6 End SID sub-TLV is introduced to advertise SRv6 Segment
Identifiers (SID) with Endpoint behaviors which do not require a Identifiers (SID) with Endpoint behaviors which do not require a
particular neighbor in order to be correctly applied particular neighbor in order to be correctly applied. SRv6 SIDs
[I-D.ietf-spring-srv6-network-programming]. SRv6 SIDs associated associated with a neighbor are advertised using the sub-TLVs defined
with a neighbor are advertised using the sub-TLVs defined in in Section 8.
Section 8.
Supported behavior values together with parent TLVs in which they
area advertised are specified in Section 10 of this document. Please
note that not all behaviors defined in [RFC8986] are defined in this
document, e.g. END.T is not.
This new sub-TLV is advertised in the SRv6 Locator TLV defined in the This new sub-TLV is advertised in the SRv6 Locator TLV defined in the
previous section. SRv6 End SIDs inherit the topology/algorithm from previous section. SRv6 End SIDs inherit the topology/algorithm from
the parent locator. the parent locator.
The SRv6 End SID sub-TLV has the following format: The SRv6 End SID sub-TLV has the following format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 10, line 39 skipping to change at page 10, line 47
| Flags | Endpoint Behavior | | Flags | Endpoint Behavior |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (128 bits) . . . | | SID (128 bits) . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Sub-sub-tlv-len| sub-sub-TLVs (variable) . . . | |Sub-sub-TLV-len| Sub-sub-TLVs (variable) . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 5. Type: 5.
Length: variable. Length: variable.
Flags: 1 octet. No flags are currently defined. Flags: 1 octet. No flags are currently defined.
Endpoint Behavior: 2 octets, as defined in [I-D.ietf-spring-srv6- Endpoint Behavior: 2 octets, as defined in [RFC8986]. Supported
network-programming]. Legal behavior values for this sub-TLV are behavior values for this sub-TLV are defined in Section 10 of this
defined in Section 10 of this document. document. Unsupported or unrecognized behavior values are ignored
by the receiver.
SID: 16 octets. This field encodes the advertised SRv6 SID. SID: 16 octets. This field encodes the advertised SRv6 SID.
Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub-
TLVs. TLVs.
Optional sub-sub-TLVs. Optional Sub-sub-TLVs.
The SRv6 End SID MUST be a subnet of the associated Locator. SRv6 The SRv6 End SID MUST be a subnet of the associated Locator. SRv6
End SIDs which are NOT a subnet of the associated locator MUST be End SIDs which are not a subnet of the associated locator MUST be
ignored. ignored.
Multiple SRv6 End SIDs MAY be associated with the same locator. In Multiple SRv6 End SIDs MAY be associated with the same locator. In
cases where the number of SRv6 End SID sub-TLVs exceeds the capacity cases where the number of SRv6 End SID sub-TLVs exceeds the capacity
of a single TLV, multiple Locator TLVs for the same locator MAY be of a single TLV, multiple Locator TLVs for the same locator MAY be
advertised. For a given MTID/Locator the algorithm MUST be the same advertised. For a given MTID/Locator the algorithm MUST be the same
in all TLVs. If this restriction is not met all TLVs for that MTID/ in all TLVs. If this restriction is not met all TLVs for that MTID/
Locator MUST be ignored. Locator MUST be ignored.
8. Advertising SRv6 Adjacency SIDs 8. Advertising SRv6 Adjacency SIDs
Certain SRv6 Endpoint behaviors Certain SRv6 Endpoint behaviors [RFC8986] are associated with a
[I-D.ietf-spring-srv6-network-programming] are associated with a
particular adjacency. particular adjacency.
This document defines two new sub-TLVs of TLV 22, 23, 222, 223, and This document defines two new sub-TLVs of TLV 22, 23, 222, 223, and
141 - namely "SRv6 End.X SID" and "SRv6 LAN End.X SID". 141 - namely "SRv6 End.X SID sub-TLVs" and "SRv6 LAN End.X SID sub-
TLVs".
IS-IS Neighbor advertisements are topology specific - but not IS-IS Neighbor advertisements are topology specific - but not
algorithm specific. End.X SIDs therefore inherit the topology from algorithm specific. SIDs advertised in SRv6 End.X SID and SRv6 LAN
the associated neighbor advertisement, but the algorithm is specified End.X SID sub-TLVs therefore inherit the topology from the associated
in the individual SID. neighbor advertisement, but the algorithm is specified in the
individual SID.
All End.X SIDs MUST be a subnet of a Locator with matching topology
and algorithm which is advertised by the same node in an SRv6 Locator
TLV. End.X SIDs which do not meet this requirement MUST be ignored.
All End.X and LAN End.X SIDs MUST be subsumed by the subnet of a All SIDs advertised in SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs
Locator with the matching algorithm which is advertised by the same MUST be a subnet of a Locator with matching topology and algorithm
node in an SRv6 Locator TLV. End.X SIDs which do not meet this which is advertised by the same node in an SRv6 Locator TLV. SIDs
requirement MUST be ignored. This ensures that the node advertising that do not meet this requirement MUST be ignored. This ensures that
the End.X or LAN End.X SID is also advertising its corresponding the node advertising these SIDs is also advertising its corresponding
Locator with the algorithm that will be used for computing paths Locator with the algorithm that will be used for computing paths
destined to the SID. destined to the SID.
8.1. SRv6 End.X SID sub-TLV 8.1. SRv6 End.X SID sub-TLV
This sub-TLV is used to advertise an SRv6 SID associated with a point This sub-TLV is used to advertise an SRv6 SID associated with a point
to point adjacency. Multiple SRv6 End.X SID sub-TLVs MAY be to point adjacency. Multiple SRv6 End.X SID sub-TLVs MAY be
associated with the same adjacency. associated with the same adjacency.
The SRv6 End.X SID sub-TLV has the following format: The SRv6 End.X SID sub-TLV has the following format:
skipping to change at page 12, line 46 skipping to change at page 12, line 48
Flags: 1 octet. Flags: 1 octet.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|B|S|P|Reserved | |B|S|P|Reserved |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where: where:
B-Flag: Backup flag. If set, the End.X SID is eligible for B-Flag: Backup flag. If set, the SID is eligible for
protection (e.g., using IPFRR) as described in [RFC8355]. protection (e.g., using IPFRR) as described in [RFC8355].
S-Flag. Set flag. When set, the S-Flag indicates that the S-Flag. Set flag. When set, the S-Flag indicates that the SID
End.X SID refers to a set of adjacencies (and therefore MAY be refers to a set of adjacencies (and therefore MAY be assigned
assigned to other adjacencies as well). to other adjacencies as well).
P-Flag. Persistent flag. When set, the P-Flag indicates that P-Flag. Persistent flag. When set, the P-Flag indicates that
the End.X SID is persistently allocated, i.e., the End.X SID the SID is persistently allocated, i.e., the SID value remains
value remains consistent across router restart and/or interface consistent across router restart and/or interface flap.
flap.
Reserved bits: MUST be zero when originated and ignored when Reserved bits: MUST be zero when originated and ignored when
received. received.
Algorithm: 1 octet. Associated algorithm. Algorithm values are Algorithm: 1 octet. As defined in [RFC8665].
defined in the IGP Algorithm Type registry.
Weight: 1 octet. The value represents the weight of the End.X SID Weight: 1 octet. The value represents the weight of the SID for
for the purpose of load balancing. The use of the weight is the purpose of load balancing. The use of the weight is defined
defined in [RFC8402]. in [RFC8402].
Endpoint Behavior: 2 octets. As defined in [I-D.ietf-spring-srv6- Endpoint Behavior: 2 octets. As defined in [RFC8986]. Supported
network-programming] Legal behavior values for this sub-TLV are behavior values for this sub-TLV are defined in Section 10 of this
defined in Section 10. document. Unsupported or unrecognized behavior values are ignored
by the receiver.
SID: 16 octets. This field encodes the advertised SRv6 SID. SID: 16 octets. This field encodes the advertised SRv6 SID.
Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub-
TLVs. TLVs.
Note that multiple TLVs for the same neighbor may be required in Note that multiple TLVs for the same neighbor may be required in
order to advertise all of the SRv6 End.X SIDs associated with that order to advertise all of the SRv6 SIDs associated with that
neighbor. neighbor.
8.2. SRv6 LAN End.X SID sub-TLV 8.2. SRv6 LAN End.X SID sub-TLV
This sub-TLV is used to advertise an SRv6 SID associated with a LAN This sub-TLV is used to advertise an SRv6 SID associated with a LAN
adjacency. Since the parent TLV is advertising an adjacency to the adjacency. Since the parent TLV is advertising an adjacency to the
Designated Intermediate System(DIS) for the LAN, it is necessary to Designated Intermediate System (DIS) for the LAN, it is necessary to
include the System ID of the physical neighbor on the LAN with which include the System ID of the physical neighbor on the LAN with which
the SRv6 SID is associated. Given that a large number of neighbors the SRv6 SID is associated. Given that a large number of neighbors
may exist on a given LAN a large number of SRv6 LAN END.X SID sub- may exist on a given LAN a large number of SRv6 LAN END.X SID sub-
TLVs may be associated with the same LAN. Note that multiple TLVs TLVs may be associated with the same LAN. Note that multiple TLVs
for the same DIS neighbor may be required in order to advertise all for the same DIS neighbor may be required in order to advertise all
of the SRv6 End.X SIDs associated with that neighbor. of the SRv6 SIDs associated with that neighbor.
The SRv6 LAN End.X SID sub-TLV has the following format: The SRv6 LAN End.X SID sub-TLV has the following format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | | Type | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Neighbor System-ID (ID length octets) | | Neighbor System-ID (ID length octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 14, line 24 skipping to change at page 14, line 24
| Endpoint Behavior | | Endpoint Behavior |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (128 bits) . . . | | SID (128 bits) . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (cont . . .) | | SID (cont . . .) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Sub-sub-tlv-len| sub-sub-TLVs (variable) . . . | |Sub-sub-TLV-len| sub-sub-TLVs (variable) . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: 44 Type: 44
Length: variable. Length: variable.
Neighbor System-ID: IS-IS System-ID of length "ID Length" as Neighbor System-ID: IS-IS System-ID of length "ID Length" as
defined in [ISO10589]. defined in [ISO10589].
Flags: 1 octet. Flags: 1 octet.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|B|S|P|Reserved | |B|S|P|Reserved |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
where B,S, and P flags are as described in Section 8.1. where B,S, and P flags are as described in Section 8.1.
Reserved bits MUST be zero when originated and MUST be ignored Reserved bits MUST be zero when originated and MUST be ignored
when received. when received.
Algorithm: 1 octet. Associated algorithm. Algorithm values are Algorithm: 1 octet. As defined in [RFC8665].
defined in the IGP Algorithm Type registry.
Weight: 1 octet. The value represents the weight of the End.X SID Weight: 1 octet. The value represents the weight of the SID for
for the purpose of load balancing. The use of the weight is the purpose of load balancing. The use of the weight is defined
defined in [RFC8402]. in [RFC8402].
Endpoint Behavior: 2 octets. As defined in [I-D.ietf-spring-srv6- Endpoint Behavior: 2 octets. As defined in [RFC8986]. Supported
network-programming] Legal behavior values for this sub-TLV are behavior values for this sub-TLV are defined in Section 10 of this
defined in Section 10. document. Unsupported or unrecognized behavior values are ignored
by the receiver.
SID: 16 octets. This field encodes the advertised SRv6 SID. SID: 16 octets. This field encodes the advertised SRv6 SID.
Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub-
TLVs. TLVs.
9. SRv6 SID Structure Sub-Sub-TLV 9. SRv6 SID Structure Sub-Sub-TLV
SRv6 SID Structure Sub-Sub-TLV is an optional Sub-Sub-TLV of: SRv6 SID Structure Sub-Sub-TLV is an optional Sub-Sub-TLV of:
SRv6 End SID Sub-TLV (Section 7.2) SRv6 End SID Sub-TLV (Section 7.2)
SRv6 End.X SID Sub-TLV (Section 8.1) SRv6 End.X SID Sub-TLV (Section 8.1)
SRv6 LAN End.X SID Sub-TLV (Section 8.2) SRv6 LAN End.X SID Sub-TLV (Section 8.2)
SRv6 SID Structure Sub-Sub-TLV is used to advertise the length of SRv6 SID Structure Sub-Sub-TLV is used to advertise the as defined in
each individual part of the SRv6 SID as defined in [RFC8986]. It has the following format:
[I-D.ietf-spring-srv6-network-programming]. It 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LB Length | LN Length | Fun. Length | Arg. Length | | LB Length | LN Length | Fun. Length | Arg. Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
skipping to change at page 16, line 12 skipping to change at page 16, line 6
Fun. Length: 1 octet. SRv6 SID Function length in bits. Fun. Length: 1 octet. SRv6 SID Function length in bits.
Arg. Length: 1 octet. SRv6 SID Arguments length in bits. Arg. Length: 1 octet. SRv6 SID Arguments length in bits.
ISIS SRv6 SID Structure Sub-Sub-TLV MUST NOT appear more than once in ISIS SRv6 SID Structure Sub-Sub-TLV MUST NOT appear more than once in
its parent Sub-TLV. If it appears more than once in its parent Sub- its parent Sub-TLV. If it appears more than once in its parent Sub-
TLV, the parent Sub-TLV MUST be ignored by the receiver. TLV, the parent Sub-TLV MUST be ignored by the receiver.
The sum of all four sizes advertised in ISIS SRv6 SID Structure Sub- The sum of all four sizes advertised in ISIS SRv6 SID Structure Sub-
Sub-TLV must be lower or equal to 128 bits. If the sum of all four Sub-TLV MUST be lower or equal to 128 bits. If the sum of all four
sizes advertised in the ISIS SRv6 SID Structure Sub-Sub-TLV is larger sizes advertised in the ISIS SRv6 SID Structure Sub-Sub-TLV is larger
than 128 bits, the parent Sub-TLV MUST be ignored by the receiver. than 128 bits, the parent Sub-TLV MUST be ignored by the receiver.
The SRv6 SID Structure Sub-Sub-TLV indicates the structure of the SID
associated with it. It's usage is outside of the scope of this
document.
10. Advertising Endpoint Behaviors 10. Advertising Endpoint Behaviors
Endpoint behaviors are defined in Endpoint behaviors are defined in [RFC8986]. The codepoints for the
[I-D.ietf-spring-srv6-network-programming]. The codepoints for the
Endpoint behaviors are defined in the "SRv6 Endpoint Behaviors" Endpoint behaviors are defined in the "SRv6 Endpoint Behaviors"
registry defined in [I-D.ietf-spring-srv6-network-programming]. This registry defined in [RFC8986]. If this behavior is advertised it
section lists the Endpoint behaviors which MAY be advertised by ISIS,
together with their codepoints. If this behavior is advertised it
MUST only be advertised in the TLV[s] as indicated by "Y" in the MUST only be advertised in the TLV[s] as indicated by "Y" in the
table below, and MUST NOT be advertised in the TLV[s] as indicated by table below, and MUST NOT be advertised in the TLV[s] as indicated by
"N" in the table below. "N" in the table below.
Endpoint |Endpoint | End | End.X | Lan End.X | Endpoint |Endpoint | End | End.X | Lan End.X |
Behavior |Behavior Codepoint| SID | SID | SID | Behavior |Behavior Codepoint| SID | SID | SID |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End (PSP, USP, USD)| 1-4, 28-31 | Y | N | N | End (PSP, USP, USD)| 1-4, 28-31 | Y | N | N |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.X (PSP, USP, USD)| 5-8, 32-35 | N | Y | Y | End.X (PSP, USP, USD)| 5-8, 32-35 | N | Y | Y |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.DX6 | 16 | N | Y | Y | End.DX6 | 16 | N | Y | Y |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.DX4 | 17 | N | Y | Y | End.DX4 | 17 | N | Y | Y |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.DT6 | 18 | Y | N | N | End.DT6 | 18 | Y | N | N |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.DT4 | 19 | Y | N | N | End.DT4 | 19 | Y | N | N |
----------------------|------------------|-----|-------|-----------| ----------------------|------------------|-----|-------|-----------|
End.DT64 | 20 | Y | N | N | End.DT46 | 20 | Y | N | N |
11. Implementation Status
RFC Ed.: Please remove this section prior to publication.
This section describes the implementation status of the ISIS SRv6
extensions.
11.1. Cisco
Cisco's ISIS SRv6 implementation supports following functionalities:
Types of SID supported: End, End.X, LAN End.X, END.OP
Intra/Inter area/level support: Yes
Anycast SID support: Yes, including A-flag (Section 6)
SID Structure Sub-Sub-TLV: Yes
11.2. Huawei
Huawei's ISIS SRv6 implementation supports following functionalities:
Types of SID supported: End, End.X, LAN End.X
Intra/Inter area/level support: Yes
Anycast SID support: Yes, no A-flag support (Section 6)
SID Structure Sub-Sub-TLV: Yes
11.3. Juniper
Juniper's ISIS SRv6 implementation supports following
functionalities:
Types of SID supported: End, End.X, LAN End.X
Intra/Inter area/level support: Yes
Anycast SID support: Yes, no A-flag support (Section 6)
SID Structure Sub-Sub-TLV: No
11.4. Arrcus
Arrcus's ISIS SRv6 implementation supports following functionalities:
Types of SID supported: End, End.X, LAN End.X
Intra/Inter area/level support: Yes
Anycast SID support: No (Section 6)
SID Structure Sub-Sub-TLV: Yes
11.5. Interoperability Testing.
EANTC interoperability testing has been performed in April 2019.
Results can be found at EANTC site [1].
12. IANA Considerations 11. IANA Considerations
This document requests allocation for the following TLVs, sub-TLVs, This document requests allocation for the following TLVs, sub-TLVs,
and sub-sub-TLVs as well updating the ISIS TLV registry and defining and sub-sub-TLVs as well updating the ISIS TLV registry and defining
a new registry. a new registry.
12.1. SRv6 Locator TLV 11.1. SRv6 Locator TLV
This document makes the following registrations in the the IS-IS TLV This document makes the following registrations in the the IS-IS TLV
Codepoints registry: Codepoints registry.
Type: 27
Description: SRv6 Locator TLV. Type Description IIH LSP SNP Purge
---- --------------------- --- --- --- -----
27 SRv6 Locator TLV n y n n
Reference: This document (Section 7.1). 11.1.1. SRv6 End SID sub-TLV
A Locator TLV shares sub-TLV space with existing "Sub-TLVs for TLVs The SRv6 Locator TLV shares sub-TLV space with TLVs 135, 235, 236 and
135, 235, 236 and 237 registry". The name of this registry needs to 237. This document updates the "Sub-TLVs for TLVs 135, 235, 236, and
be changed to "Sub-TLVs for TLVs 27, 135, 235, 236 and 237 registry". 237 (Extended IP reachability, MT IP. Reach, IPv6 IP. Reach, and MT
IPv6 IP. Reach TLVs)" registry defined in [RFC7370]. IANA is
requested to update the name of the "Sub-TLVs for TLVs 135, 235, 236,
and 237 (Extended IP reachability, MT IP. Reach, IPv6 IP. Reach,
and MT IPv6 IP. Reach TLVs)" registry to "Sub-TLVs for TLVs 27, 135,
235, 236, and 237 (SRv6 Locator, Extended IP reachability, MT IP.
Reach, IPv6 IP. Reach, and MT IPv6 IP. Reach TLVs)".
12.1.1. SRv6 End SID sub-TLV IANA is asked to add this document as a reference to (renamed) "Sub-
TLVs for TLVs 27, 135, 235, 236, and 237 (SRv6 Locator, Extended IP
reachability, MT IP. Reach, IPv6 IP. Reach, and MT IPv6 IP. Reach
TLVs)" registry.
This document makes the following registrations in the (renamed) This document makes the following registrations in the (renamed)
"Sub-TLVs for TLVs 27, 135, 235, 236 and 237 registry": "Sub-TLVs for TLVs 27, 135, 235, 236, and 237 (SRv6 Locator, Extended
IP reachability, MT IP. Reach, IPv6 IP. Reach, and MT IPv6 IP.
Reach TLVs)" registry:
Type: 5 Type: 5
Description: SRv6 End SID sub-TLV. Description: SRv6 End SID sub-TLV.
Reference: This document (Section 7.2). Reference: This document (Section 7.2).
12.1.2. Revised sub-TLV table 11.1.2. Revised sub-TLV table
The revised table of sub-TLVs for the (renamed) "Sub-TLVs for TLVs The revised table of sub-TLVs for the (renamed) "Sub-TLVs for TLVs
27, 135, 235, 236 and 237 registry" is shown below: 27, 135, 235, 236, and 237 (SRv6 Locator, Extended IP reachability,
MT IP. Reach, IPv6 IP. Reach, and MT IPv6 IP. Reach TLVs)"
registry is shown below:
Type 27 135 235 236 237 Type 27 135 235 236 237
1 y y y y y 1 y y y y y
2 y y y y y 2 y y y y y
3 n y y y y 3 n y y y y
4 y y y y y 4 y y y y y
5 y n n n n 5 y n n n n
6 n y y y y 6 n y y y y
11 y y y y y 11 y y y y y
12 y y y y y 12 y y y y y
32 n y y y y 32 n y y y y
12.2. SRv6 Capabilities sub-TLV 11.2. SRv6 Capabilities sub-TLV
This document makes the following registrations in the "Sub- TLVs for This document makes the following registrations in the "Sub-TLVs for
TLV 242 registry": TLV 242 (IS-IS Router CAPABILITY TLV)":
Type: 25 Type: 25
Description: SRv6 Capabilities sub-TLV. Description: SRv6 Capabilities sub-TLV.
Reference: This document (Section 2). Reference: This document (Section 2).
This document requests the creation of a new IANA managed registry This document requests the creation of a new IANA managed registry,
for sub-sub-TLVs of the SRv6 Capability sub-TLV. The registration under "IS-IS TLV Codepoints" registry - sub-sub-TLVs of the SRv6
procedure is "Expert Review" as defined in [RFC8126]. Suggested Capability sub-TLV. The registration procedure is "Expert Review" as
registry name is "sub-sub-TLVs for SRv6 Capability sub-TLV". No sub- defined in [RFC8126]. Guidance for the Designated Experts is
sub-TLVs are defined by this document except for the reserved value. provided in [RFC7370]. Suggested registry name is "sub-sub-TLVs for
SRv6 Capability sub-TLV". No sub-sub-TLVs are defined by this
document except for the reserved value.
0: Reserved 0: Reserved
1-255: Unassigned 1-255: Unassigned
12.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs 11.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs
This document makes the following registrations in the "sub- TLVs for This document makes the following registrations in the "Sub-TLVs for
TLV 22, 23, 25, 141, 222 and 223 registry": TLVs 22, 23, 25, 141, 222, and 223 (Extended IS reachability, IS
Neighbor Attribute, L2 Bundle Member Attributes, inter-AS
reachability information, MT-ISN, and MT IS Neighbor Attribute TLVs)"
registry:
Type: 43 Type: 43
Description: SRv6 End.X SID sub-TLV. Description: SRv6 End.X SID sub-TLV.
Reference: This document (Section 8.1). Reference: This document (Section 8.1).
Type: 44 Type: 44
Description: SRv6 LAN End.X SID sub-TLV. Description: SRv6 LAN End.X SID sub-TLV.
Reference: This document (Section 8.2). Reference: This document (Section 8.2).
Type 22 23 25 141 222 223 Type 22 23 25 141 222 223
43 y y y y y y 43 y y y y y y
44 y y y y y y 44 y y y y y y
12.4. MSD Types 11.4. MSD Types
This document makes the following registrations in the IGP MSD Types This document makes the following registrations in the IGP MSD-Types
registry: registry:
Type Description Value Name Reference
------------------ ------------------
41 SRH Max SL 41 SRH Max SL Section 4.1
42 SRH Max End Pop 42 SRH Max End Pop Section 4.2
44 SRH Max H.encaps 44 SRH Max H.encaps Section 4.3
45 SRH Max End D 45 SRH Max End D Section 4.4
12.5. Sub-Sub-TLVs for SID Sub-TLVs 11.5. Sub-Sub-TLVs for SID Sub-TLVs
This document requests a new IANA registry be created under the IS-IS This document requests a new IANA registry be created under the IS-IS
TLV Codepoints Registry to control the assignment of sub-TLV types TLV Codepoints Registry to control the assignment of sub-TLV types
for the SID Sub-TLVs specified in this document - Section 7.2, for the SID Sub-TLVs specified in this document - Section 7.2,
Section 8.1, Section 8.2. The suggested name of the new registry is Section 8.1, Section 8.2. The suggested name of the new registry is
"Sub-Sub-TLVs for SID Sub-TLVs". The registration procedure is "sub-sub-TLVs for SRv6 End SID (5) (sub-TLV of TLVs 27, 135, 235, 236
"Expert Review" as defined in [RFC8126]. The following assignments and 237) and SRv6 End.X SID (43)/SRv6 LAN End.X SID (44) (sub-TLVs of
are made by this document: TLVs 27, 135, 235, 236 and 237)". The registration procedure is
"Expert Review" as defined in [RFC8126]. Guidance for the Designated
Experts is provided in [RFC7370]The following assignments are made by
this document:
0: Reserved Type Description Encoding
Reference
---------------------------------------------------------
0 Reserved
1 SRv6 SID Structure Sub-Sub-TLV Section 9
2-255 Unassigned
1: SRv6 SID Structure Sub-Sub-TLV (Section 9). Type 5 43 44
12.6. Prefix Attribute Flags Sub-TLV 1 y y y
11.6. Prefix Attribute Flags Sub-TLV
This document adds a new bit in the "Bit Values for Prefix Attribute This document adds a new bit in the "Bit Values for Prefix Attribute
Flags Sub-TLV" registry: Flags Sub-TLV" registry:
Bit #: 4 Bit #: 4
Description: A bit Description: Anycast Flag (A-flag)
Reference: This document (Section 6). Reference: This document (Section 6).
13. Security Considerations 12. Security Considerations
Security concerns for IS-IS are addressed in [ISO10589], [RFC5304], Security concerns for IS-IS are addressed in [ISO10589], [RFC5304],
and [RFC5310]. and [RFC5310]. While IS-IS is deployed under a single administrative
domain, there can be deployments where potential attackers have
access to one or more networks in the IS-IS routing domain. In these
deployments, the stronger authentication mechanisms defined in the
aforementioned documents SHOULD be used.
14. Contributors This document describes the IS-IS extensions required to support
Segment Routing over an IPv6 data plane. The security considerations
for Segment Routing are discussed in [RFC8402]. [RFC8986] defines
the SRv6 Network Programming concept and specifies the main Segment
Routing behaviors to enable the creation of interoperable overlays;
the security considerations from that document apply too.
The advertisement of an incorrect MSD value may have negative
consequences, see [RFC8491] for additional considerations.
13. Contributors
The following people gave a substantial contribution to the content The following people gave a substantial contribution to the content
of this document and should be considered as co-authors: of this document and should be considered as co-authors:
Stefano Previdi Stefano Previdi
Huawei Technologies Huawei Technologies
Email: stefano@previdi.net Email: stefano@previdi.net
Paul Wells Paul Wells
Cisco Systems Cisco Systems
skipping to change at page 22, line 44 skipping to change at page 21, line 44
Robert Hanzl Robert Hanzl
Cisco Systems Cisco Systems
Millenium Plaza Building, V Celnici 10, Prague 1, Millenium Plaza Building, V Celnici 10, Prague 1,
Prague, Czech Republic Prague, Czech Republic
Email rhanzl@cisco.com Email rhanzl@cisco.com
Ketan Talaulikar Ketan Talaulikar
Cisco Systems, Inc. Cisco Systems, Inc.
Email: ketant@cisco.com Email: ketant@cisco.com
15. References 14. References
15.1. Normative References 14.1. Normative References
[I-D.ietf-6man-spring-srv6-oam] [I-D.ietf-6man-spring-srv6-oam]
Ali, Z., Filsfils, C., Matsushima, S., Voyer, D., and M. Ali, Z., Filsfils, C., Matsushima, S., Voyer, D., and M.
Chen, "Operations, Administration, and Maintenance (OAM) Chen, "Operations, Administration, and Maintenance (OAM)
in Segment Routing Networks with IPv6 Data plane (SRv6)", in Segment Routing Networks with IPv6 Data plane (SRv6)",
draft-ietf-6man-spring-srv6-oam-07 (work in progress), draft-ietf-6man-spring-srv6-oam-08 (work in progress),
July 2020. October 2020.
[I-D.ietf-spring-srv6-network-programming] [I-D.ietf-lsr-flex-algo]
Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
Matsushima, S., and Z. Li, "SRv6 Network Programming", A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex-
draft-ietf-spring-srv6-network-programming-24 (work in algo-13 (work in progress), October 2020.
progress), October 2020.
[ISO10589] [ISO10589]
Standardization", I. ". O. F., "Intermediate system to International Organization for Standardization,
Intermediate system intra-domain routeing information "Intermediate system to Intermediate system intra-domain
exchange protocol for use in conjunction with the protocol routeing information exchange protocol for use in
for providing the connectionless-mode Network Service (ISO conjunction with the protocol for providing the
8473), ISO/IEC 10589:2002, Second Edition.", Nov 2002. connectionless-mode Network Service (ISO 8473)", Nov 2002.
[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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120, Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008, DOI 10.17487/RFC5120, February 2008,
<https://www.rfc-editor.org/info/rfc5120>. <https://www.rfc-editor.org/info/rfc5120>.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
Authentication", RFC 5304, DOI 10.17487/RFC5304, October
2008, <https://www.rfc-editor.org/info/rfc5304>.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <https://www.rfc-editor.org/info/rfc5305>. 2008, <https://www.rfc-editor.org/info/rfc5305>.
[RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., [RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
and M. Fanto, "IS-IS Generic Cryptographic DOI 10.17487/RFC5308, October 2008,
Authentication", RFC 5310, DOI 10.17487/RFC5310, February <https://www.rfc-editor.org/info/rfc5308>.
2009, <https://www.rfc-editor.org/info/rfc5310>.
[RFC7370] Ginsberg, L., "Updates to the IS-IS TLV Codepoints [RFC7370] Ginsberg, L., "Updates to the IS-IS TLV Codepoints
Registry", RFC 7370, DOI 10.17487/RFC7370, September 2014, Registry", RFC 7370, DOI 10.17487/RFC7370, September 2014,
<https://www.rfc-editor.org/info/rfc7370>. <https://www.rfc-editor.org/info/rfc7370>.
[RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and [RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and
U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4 U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4
and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794, and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794,
March 2016, <https://www.rfc-editor.org/info/rfc7794>. March 2016, <https://www.rfc-editor.org/info/rfc7794>.
skipping to change at page 24, line 24 skipping to change at page 23, line 19
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
[RFC8491] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg, [RFC8491] Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg,
"Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491, "Signaling Maximum SID Depth (MSD) Using IS-IS", RFC 8491,
DOI 10.17487/RFC8491, November 2018, DOI 10.17487/RFC8491, November 2018,
<https://www.rfc-editor.org/info/rfc8491>. <https://www.rfc-editor.org/info/rfc8491>.
[RFC8665] Psenak, P., Ed., Previdi, S., Ed., Filsfils, C., Gredler,
H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF
Extensions for Segment Routing", RFC 8665,
DOI 10.17487/RFC8665, December 2019,
<https://www.rfc-editor.org/info/rfc8665>.
[RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C.,
Bashandy, A., Gredler, H., and B. Decraene, "IS-IS Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
Extensions for Segment Routing", RFC 8667, Extensions for Segment Routing", RFC 8667,
DOI 10.17487/RFC8667, December 2019, DOI 10.17487/RFC8667, December 2019,
<https://www.rfc-editor.org/info/rfc8667>. <https://www.rfc-editor.org/info/rfc8667>.
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>. <https://www.rfc-editor.org/info/rfc8754>.
15.2. Informative References [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
[I-D.ietf-lsr-flex-algo] 14.2. Informative References
Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
algo-12 (work in progress), October 2020. Authentication", RFC 5304, DOI 10.17487/RFC5304, October
2008, <https://www.rfc-editor.org/info/rfc5304>.
[RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
and M. Fanto, "IS-IS Generic Cryptographic
Authentication", RFC 5310, DOI 10.17487/RFC5310, February
2009, <https://www.rfc-editor.org/info/rfc5310>.
[RFC8355] Filsfils, C., Ed., Previdi, S., Ed., Decraene, B., and R. [RFC8355] Filsfils, C., Ed., Previdi, S., Ed., Decraene, B., and R.
Shakir, "Resiliency Use Cases in Source Packet Routing in Shakir, "Resiliency Use Cases in Source Packet Routing in
Networking (SPRING) Networks", RFC 8355, Networking (SPRING) Networks", RFC 8355,
DOI 10.17487/RFC8355, March 2018, DOI 10.17487/RFC8355, March 2018,
<https://www.rfc-editor.org/info/rfc8355>. <https://www.rfc-editor.org/info/rfc8355>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
15.3. URIs
[1] http://www.eantc.de/fileadmin/eantc/downloads/events/2017-
2020/MPLS2019/Segment_Routing_IPv6__SRv6_.pdf
Authors' Addresses Authors' Addresses
Peter Psenak (editor) Peter Psenak (editor)
Cisco Systems Cisco Systems
Pribinova Street 10 Pribinova Street 10
Bratislava 81109 Bratislava 81109
Slovakia Slovakia
Email: ppsenak@cisco.com Email: ppsenak@cisco.com
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