Internet DRAFT - draft-ietf-lsr-igp-ureach-prefix-announce
draft-ietf-lsr-igp-ureach-prefix-announce
Networking Working Group P. Psenak, Ed.
Internet-Draft C. Filsfils
Intended status: Standards Track S. Litkowski
Expires: 24 April 2024 Cisco Systems
D. Voyer
Bell Canada
A. Dhamija
Rakuten
S. Hegde
Juniper Networks, Inc.
G. Van de Velde
Nokia
G. Mishra
Verizon Inc.
22 October 2023
IGP Unreachable Prefix Announcement
draft-ietf-lsr-igp-ureach-prefix-announce-01
Abstract
In the presence of summarization, there is a need to signal loss of
reachability to an individual prefix covered by the summary in order
to enable fast convergence away from paths to the node which owns the
prefix which is no longer reachable.
This document describes how to use the existing protocol mechanisms
in IS-IS and OSPF, together with the two new flags, to advertise such
prefix reachability loss.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119][RFC8174] when, and only when, they appear in all
capitals, as shown here.
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 https://datatracker.ietf.org/drafts/current/.
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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 24 April 2024.
Copyright Notice
Copyright (c) 2023 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 (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Supporting UPA in IS-IS . . . . . . . . . . . . . . . . . . . 3
2.1. Advertisement of UPA in IS-IS . . . . . . . . . . . . . . 4
2.2. Propagation of UPA in IS-IS . . . . . . . . . . . . . . . 5
3. Supporting UPA in OSPF . . . . . . . . . . . . . . . . . . . 5
3.1. Advertisement of UPA in OSPF . . . . . . . . . . . . . . 6
3.2. Propagation of UPA in OSPF . . . . . . . . . . . . . . . 6
4. Generation of the UPA . . . . . . . . . . . . . . . . . . . . 6
5. Signaling UPA . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Signaling UPA in IS-IS . . . . . . . . . . . . . . . . . 7
5.2. Signaling UPA in OSPF . . . . . . . . . . . . . . . . . . 7
5.2.1. Signaling UPA in OSPFv2 . . . . . . . . . . . . . . . 8
5.2.2. Signaling UPA in OSPFv3 . . . . . . . . . . . . . . . 8
5.3. Treatement of the U-Flag and UP-Flag . . . . . . . . . . 8
6. Deployment Considerations for UPA . . . . . . . . . . . . . . 9
7. Processing of the UPA . . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
8.1. IS-IS Prefix Attribute Flags Sub-TLV . . . . . . . . . . 10
8.2. OSPFv2 and OSPFv3 Prefix Extended TLV Flag Field . . . . 10
9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
11.1. Normative References . . . . . . . . . . . . . . . . . . 11
11.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
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1. Introduction
Link-state IGP protocols like IS-IS and OSPF are primarily used to
distribute routing information between routers belonging to a single
Autonomous System (AS) and to calculate the reachability for IPv4 or
IPv6 prefixes advertised by the individual nodes inside the AS. Each
node advertises the state of its local adjacencies, connected
prefixes, capabilities, etc. The collection of these states from all
the routers inside the area form a link-state database (LSDB) that
describes the topology of the area and holds additional state
information about the prefixes, router capabilities, etc.
The growth of networks running a link-state routing protocol results
in the addition of more state which leads to scalability and
convergence challenges. The organization of networks into levels/
areas and IGP domains helps limit the scope of link-state information
within certain boundaries. However, the state related to prefix
reachability often requires propagation across a multi-area/level
and/or multi-domain IGP network. Techniques such as summarization
have been used traditionally to address the scale challenges
associated with advertising prefix state outside of the local area/
domain. However, this results in suppression of the individual
prefix state that is useful for triggering fast-convergence
mechanisms outside of the IGPs - e.g., BGP PIC Edge [I-D.ietf-rtgwg-
bgp-pic].
This document defines two new flags in IS-IS and OSPF. These flags,
together with the existing protocol mechanisms, provide the support
for the necessary functionality. The functionality being described
is called Unreachable Prefix Announcement (UPA).
Similarly, when an egress router needs to be taken out for
maintenance, the traffic is drained from the node before taking it
down. This is typically achieved by setting OL-bit together with
using max-metric for all prefixes advertised by the node in IS-IS, or
by setting max-metric on all-links and prefixes advertised by the
node in OSPF. When prefixes from such node are summarized by the
ABR/ASBR, nodes outside of the area or domain are unaware of such
prefixes becoming unreachable. This document proposes protocol
extensions to carry information about such prefixes in a backward
compatible manner.
2. Supporting UPA in IS-IS
[RFC5305] defines the encoding for advertising IPv4 prefixes using 4
octets of metric information. Section 4 specifies:
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"If a prefix is advertised with a metric larger then MAX_PATH_METRIC
(0xFE000000, see paragraph 3.0), this prefix MUST NOT be considered
during the normal SPF computation. This allows advertisement of a
prefix for purposes other than building the normal IP routing table.
"
Similarly, [RFC5308] defines the encoding for advertising IPv6
prefixes using 4 octets of metric information. Section 2 states:
"...if a prefix is advertised with a metric larger than
MAX_V6_PATH_METRIC (0xFE000000), this prefix MUST NOT be considered
during the normal Shortest Path First (SPF) computation. This will
allow advertisement of a prefix for purposes other than building the
normal IPv6 routing table."
This functionality can be used to advertise a prefix (IPv4 or IPv6)
in a manner which indicates that reachability has been lost - and to
do so without requiring all nodes in the network to be upgraded to
support the functionality.
2.1. Advertisement of UPA in IS-IS
Existing nodes in a network that do not suport UPA will not use UPAs
during the route calculation, but will continue to flood them. This
allows flooding of such advertisements to occur without the need to
upgrade all nodes in a network.
Recognition of the advertisement as UPA is only required on routers
which have a use case for this information. Area Border Routers
(ABRs), which would be responsible for propagating UPA advertisements
into other areas would need to recognize such advertisements.
As per the definitions referenced in the preceding section, any
prefix advertisement with a metric value greater than 0xFE000000 can
be used for purposes other than normal routing calculations. Such an
advertisement can be interpreted by the receiver as a UPA.
Optionally, an implementation may use local configuration to limit
the set of metric values which will be interpreted as UPA. The only
restriction is that such values MUST be greater than 0xFE000000.
UPA in IS-IS is supported for all IS-IS Sub-TLVs Advertising Prefix
Reachability, e.g., SRv6 Locator [I-D.ietf-lsr-isis-srv6-extensions],
Extended IP reachability [RFC5305], MT IP Reach [RFC5120], IPv6 IP
Reach [RFC5308], MT IPv6 IP Reach [RFC5120], IPv4 Algorithm Prefix
Reachability TLV [I-D.ietf-lsr-ip-flexalgo], and IPv6 Algorithm
Prefix Reachability TLV [I-D.ietf-lsr-ip-flexalgo]
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2.2. Propagation of UPA in IS-IS
IS-IS allows propagation of IP prefixes in both directions between
level 1 and level 2. For reachable prefixes this is only done if the
prefix is reachable in source level - e.g., the prefix needs to be
reachable in level 1 to be propagated to level 2 and vice verse.
Such requirement of reachability MUST NOT be applied for UPAs, as
they are propagating unreachability.
IS-IS L1/L2 routers may wish to advertise received UPAs into other
areas (upwards and/or downwards). When propagating UPAs the original
metric value MUST be preserved. The cost to reach the originator of
the received UPA MUST NOT be considered when readvertising the UPA.
3. Supporting UPA in OSPF
[RFC2328] Appendix B defines the following architectural constant for
OSPF:
"LSInfinity The metric value indicating that the destination
described by an LSA is unreachable. Used in summary-LSAs and AS-
external-LSAs as an alternative to premature aging (see
Section 14.1). It is defined to be the 24-bit binary value of all
ones: 0xffffff."
[RFC5340] Appendix B states:
"Architectural constants for the OSPF protocol are defined in
Appendix B of OSPFV2."
indicating that these same constants are applicable to OSPFv3.
[RFC2328] section 14.1. also describes the usage of LSInfinity as a
way to indicate loss of prefix reachability:
"Premature aging can also be used when, for example, one of the
router's previously advertised external routes is no longer
reachable. In this circumstance, the router can flush its AS-
external-LSA from the routing domain via premature aging. This
procedure is preferable to the alternative, which is to originate a
new LSA for the destination specifying a metric of LSInfinity."
In addition, NU-bit is defined for OSPFv3 [RFC2328]. Prefixes having
the NU-bit set in their PrefixOptions field should be ignored by the
route calculation.
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UPA in OSPFv2 is supported for OSPFv2 Summary-LSA [RFC2328], AS-
external-LSAs [RFC2328], NSSA AS-external LSA.[RFC3101], and OSPFv2
Extended Prefix TLV [I-D.ietf-lsr-ip-flexalgo].
UPA in OSPFv3 is supported for Inter-Area-Prefix-LSA [RFC5340], AS-
External-LSA [RFC5340], NSSA-LSA [RFC5340], E-Inter-Area-Prefix-LSA
[RFC8362], E-AS-External-LSA [RFC8362], E-Type-7-LSA [RFC8362], and
SRv6 Locator LSA [I-D.ietf-lsr-ospfv3-srv6-extensions].
3.1. Advertisement of UPA in OSPF
Using the existing mechanism already defined in the standards, as
described in previous section, an advertisement of the inter-area or
external prefix inside OSPF or OSPFv3 LSA that has the age set to
value lower than MaxAge and metic set to LSInfinity can be
interpreted by the receiver as a UPA.
Existing nodes in a network which receive UPA advertisements will
propagate it following existing standard procedures defined by OSPF.
OSPF Area Border Routers (ABRs), which would be responsible for
propagating UPA advertisements into other areas would need to
recognize such advertisements.
3.2. Propagation of UPA in OSPF
Advertising prefix reachability between OSPF areas assumes prefix
reachability in a source area. Such requirement of reachability MUST
not be applied for UPAs, as they are propagating unreachability.
OSPF ABRs may wish to advertise received UPAs into other connected
areas. When doing so, the original LSInfinity metric value in UPA
MUST be preserved. The cost to reach the originator of the received
UPA MUST NOT be considered when readvertising the UPA to connected
areas.
4. Generation of the UPA
UPA MAY be generated by the ABR or ASBR that is performing the
summarization, when all of the following conditions are met:
- reachability of a prefix that was reachable earlier was lost
- a summary address which covers the prefix is being advertised by
the ABR/ASBR
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Implementations are free to limit the UPA generation to specific
prefixes, e.g. host prefixes, SRv6 locators, or similar. Such
filtering is optional and MAY be controlled via configuration.
5. Signaling UPA
In IS-IS a prefix can be advertised with metric higher than
0xFE000000, in OSPF with metric LSInfinity, or in OSPFv3 with NU-bit
set in PrefixOptions, for various reasons. Even though in all cases
the treatment of such metric, or NU-bit, is specified for IS-IS, OSPF
and OSPFv3, having an explicit way to signal that the prefix was
advertised in order to signal unreachability is required to
distinguish it from other cases where the prefix with such metric is
advertised.
5.1. Signaling UPA in IS-IS
Two new bits in the IPv4/IPv6 Extended Reachability Attribute Flags
[RFC7794] are defined:
U-Flag: - Unreachable Prefix Flag (Bit TBD). When set, it
indicates that the prefix is unreachable due to the unplanned
reason.
UP-Flag: - Unreachable Planned Prefix Flag (Bit TBD). When set,
it indicates that the prefix is unreachable due to the planned
reason, e.g., planned maintenance.
The prefix that is advertised with U-Flag or UP-Flag MUST have the
metric set to a value larger than 0xFE000000. If the prefix metric
is less than or equal 0xFE000000, both of these flags MUST be
ignored.
5.2. Signaling UPA in OSPF
A new Prefix Attributes Sub-TLV has been defined in
[I-D.chen-lsr-prefix-extended-flags] for advertising additional
prefix attribute flags in OSPFv2 and OSPFv3.
Two new bits in Prefix Attributes Sub-TLV are defined:
U-Flag: - Unreachable Prefix Flag (Bit TBD). When set, it
indicates that the prefix is unreachable due to the unplanned
reason.
UP-Flag: - Unreachable Planned Prefix Flag (Bit TBD). When set,
it indicates that the prefix is unreachable due to the planned
reason, e.g., planned maintenance.
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5.2.1. Signaling UPA in OSPFv2
In OSPFv2 the Prefix Attributes Sub-TLV is a Sub-TLV of the OSPFv2
Extended Prefix TLV [RFC7684].
The prefix that is advertised with U-Flag or UP-Flag MUST have the
metric set to a value LSInfinity. If the prefix metric is not equal
to LSInfinity, both of these flags MUST be ignored. For default
algorithm 0 prefixes with U-Flag or UP-Flag, it is therefore REQUIRED
to advertise the unreachable prefix in the base OSPFv2 LSA - e.g.,
OSPFv2 Summary-LSA [RFC2328], or AS-external-LSAs [RFC2328], or NSSA
AS-external LSA [RFC3101].
5.2.2. Signaling UPA in OSPFv3
In OSPFv3 the Prefix Attribute Flags Sub-TLV is defined as a Sub-TLV
of the following OSPFv3 TLVs as defined in [RFC8362]:
Intra-Area Prefix TLV
Inter-Area Prefix TLV
External Prefix TLV
The prefix that is advertised with U-Flag or UP-flag MUST have the
metric set to a value LSInfinity. For default algorithm 0 prefixes,
the LSInfinity MUST be set in the parent TLV. For IP Algorithm
Prefixes [I-D.ietf-lsr-ip-flexalgo], the LSInfinity MUST be set in
OSPFv3 IP Algorithm Prefix Reachability sub-TLV. If the prefix
metric is not equal to LSInfinity, both of these flags MUST be
ignored.
The prefix that is advertised with U-Flag or UP-Flag MUST have the
NU-bit set in the PrefixOptions of the parent TLV. If the NU-bit in
PrefixOptions of the parent TLV is not set, both of these flags MUST
be ignored.
5.3. Treatement of the U-Flag and UP-Flag
The setting of the U-Flag or the UP-Flag signals that the prefix is
unreachable. They constitute the UPA signals. Treatment of these
flags on the receiver is optional and the usage of them is outside of
scope of this document.
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6. Deployment Considerations for UPA
The intent of UPA is to provide an event driven signal of the
transition of a destination from reachable to unreachable. It is not
intended to advertise a persistent state. UPA advertisements should
therefore be withdrawn after a modest amount of time, that would
provides sufficient time for UPA to be flooded network-wide and acted
upon by receiving nodes, but limits the presence of UPA in the
network to a short time period. The time the UPA is kept in the
network SHOULD also reflect the intended use-case for which the UPA
was advertised.
As UPA advertisements in IS-IS are advertised in existing Link State
PDUs (LSPs) and the unit of flooding in IS-IS is an LSP, it is
recommended that, when possible, UPAs are advertised in LSPs
dedicated to this type of advertisement. This will minimize the
number of LSPs which need to be updated when UPAs are advertised and
withdrawn.
In OSPF and OSPFv3, each inter-area and external prefix is advertised
in it's own LSA, so the above optimisation does not apply to OSPF.
It is also recommended that implementations limit the number of UPA
advertisements which can be originated at a given time.
UPA is not meant to address an area/domain partition. When an area
partitions, while multiple ABRs advertise the same summary, each of
the ABRs can only reach portion of the summarized prefix. As a
result, depending on which ABR the traffic is using to enter a
partitioned area, the traffic could be dropped or be delivered to its
final destination. UPA does not make the problem of an area
partition any worse. In case of an area partition each of the ABRs
will generate UPAs for the destinations for which the reachability
was lost locally. As the UPA propagates to the nodes outside of a
partitioned area, it may result in such nodes picking an alternative
egress node for the traffic, if such alternate egress node exists.
If such alternate egress node resides outside of a partitioned area,
traffic will be restored. If such alternate egress node resides in a
partitioned area and is covered by the summary, the trafic will be
dropped if it enters a partitioned area via the ABR that can not
reach the alternate egress node - resulting in similar behavior as
without the UPA. Above is similarly applicable to a domain
partition.
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7. Processing of the UPA
Processing of the received UPAs is optional and SHOULD be controlled
by the configuration at the receiver. The receiver itself, based on
its configuration, decides what the UPA will be used for and what
applications, if any, will be notified when UPA is received.
8. IANA Considerations
8.1. IS-IS Prefix Attribute Flags Sub-TLV
This document adds two new bits in the "IS-IS Bit Values for Prefix
Attribute Flags Sub-TLV" registry:
Bit #: TBD
Description: U-Flag
Reference: This document (Section 5.1).
Bit #: TDB
Description: UP-Flag
Reference: This document (Section 5.1).
8.2. OSPFv2 and OSPFv3 Prefix Extended TLV Flag Field
This document adds two new bits in the "OSPFv2 Prefix Extended TLV
Flag Field" and "OSPFv3 Prefix Extended TLV Flag Field" registres:
Bit #: TBD
Description: U-Flag
Reference: This document (Section 5.2).
Bit #: TDB
Description: UP-Flag
Reference: This document (Section 5.2).
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9. Security Considerations
The use of UPAs introduces the possibility that an attacker could
inject a false, but apparently valid, UPA. However, the risk of this
occurring is no greater than the risk today of an attacker injecting
any other type of false advertisement .
The risks can be reduced by the use of existing security extensions
as described in [RFC5304] and [RFC5310] for IS-IS, in [RFC2328][ and
[RFC7474] for OSPFv2, and in [RFC5340] and [RFC4552] for OSPFv3.
10. Acknowledgements
The authors would like to thank Kamran Raza, Michael MacKenzie and
Luay Jalil for their contribution and support of the overall solution
proposed in this document.
11. References
11.1. Normative References
[I-D.chen-lsr-prefix-extended-flags]
Chen, R., Zhao, D., Psenak, P., and K. Talaulikar, "Prefix
Flag Extension for OSPFv2 and OSPFv3", Work in Progress,
Internet-Draft, draft-chen-lsr-prefix-extended-flags-01,
16 October 2023, <https://datatracker.ietf.org/doc/html/
draft-chen-lsr-prefix-extended-flags-01>.
[ISO10589] ISO, "Intermediate system to Intermediate system intra-
domain routeing information exchange protocol for use in
conjunction with the protocol for providing the
connectionless-mode Network Service (ISO 8473)", November
2002.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC3101] Murphy, P., "The OSPF Not-So-Stubby Area (NSSA) Option",
RFC 3101, DOI 10.17487/RFC3101, January 2003,
<https://www.rfc-editor.org/info/rfc3101>.
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[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality
for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
<https://www.rfc-editor.org/info/rfc4552>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008,
<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
Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <https://www.rfc-editor.org/info/rfc5305>.
[RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
DOI 10.17487/RFC5308, October 2008,
<https://www.rfc-editor.org/info/rfc5308>.
[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>.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<https://www.rfc-editor.org/info/rfc5340>.
[RFC7474] Bhatia, M., Hartman, S., Zhang, D., and A. Lindem, Ed.,
"Security Extension for OSPFv2 When Using Manual Key
Management", RFC 7474, DOI 10.17487/RFC7474, April 2015,
<https://www.rfc-editor.org/info/rfc7474>.
[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, <https://www.rfc-editor.org/info/rfc7684>.
[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, <https://www.rfc-editor.org/info/rfc7794>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
11.2. Informative References
[I-D.ietf-lsr-ip-flexalgo]
Britto, W., Hegde, S., Kaneriya, P., Shetty, R., Bonica,
R., and P. Psenak, "IGP Flexible Algorithms (Flex-
Algorithm) In IP Networks", Work in Progress, Internet-
Draft, draft-ietf-lsr-ip-flexalgo-17, 24 July 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-ip-
flexalgo-17>.
[I-D.ietf-lsr-isis-srv6-extensions]
Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and
Z. Hu, "IS-IS Extensions to Support Segment Routing over
IPv6 Dataplane", Work in Progress, Internet-Draft, draft-
ietf-lsr-isis-srv6-extensions-19, 14 November 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-
isis-srv6-extensions-19>.
[I-D.ietf-lsr-ospfv3-srv6-extensions]
Li, Z., Hu, Z., Talaulikar, K., and P. Psenak, "OSPFv3
Extensions for SRv6", Work in Progress, Internet-Draft,
draft-ietf-lsr-ospfv3-srv6-extensions-15, 21 June 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-
ospfv3-srv6-extensions-15>.
Authors' Addresses
Peter Psenak (editor)
Cisco Systems
Pribinova Street 10
Bratislava 81109
Slovakia
Email: ppsenak@cisco.com
Clarence Filsfils
Cisco Systems
Brussels
Belgium
Psenak, et al. Expires 24 April 2024 [Page 13]
Internet-Draft IGP Unreachable Prefix Announcement October 2023
Email: cfilsfil@cisco.com
Stephane Litkowski
Cisco Systems
La Rigourdiere
Cesson Sevigne
France
Email: slitkows@cisco.com
Daniel Voyer
Bell Canada
Email: daniel.voyer@bell.ca
Amit Dhamija
Rakuten
Email: amit.dhamija@rakuten.com
Shraddha Hegde
Juniper Networks, Inc.
Embassy Business Park
Bangalore, KA
560093
India
Email: shraddha@juniper.net
Gunter Van de Velde
Nokia
Antwerp
Belgium
Email: gunter.van_de_velde@nokia.com
Gyan Mishra
Verizon Inc.
Email: gyan.s.mishra@verizon.com
Psenak, et al. Expires 24 April 2024 [Page 14]
