IDR Working Group J. Tantsura
Internet-Draft Juniper Networks
Intended status: Standards Track Z. Wang
Expires: November 19, 2021 Q. Wu
Huawei
K. Talaulikar
Cisco Systems
May 18, 2021
Distribution of Traffic Engineering Extended Administrative Groups using
BGP-LS
draft-ietf-idr-eag-distribution-17
Abstract
Administrative groups are link attributes used for traffic
engineering. This document defines an extension to BGP-LS for
advertisement of extended administrative groups (EAGs).
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Advertising Extended Administrative Group in BGP-LS . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.1. Normative References . . . . . . . . . . . . . . . . . . 4
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Administrative groups (commonly referred to as "colors" or "link
colors") are link attributes that are advertised by link state
protocols like IS-IS [RFC1195], OSPFv2 [RFC2328] and OSPFv3
[RFC5340]. The BGP-LS advertisement of the originally defined (non-
extended) administrative groups is encoded using the Administrative
Group (color) TLV 1088 as defined in [RFC7752].
These administrative groups are defined as a fixed-length 32-bit
bitmask. As networks grew and more use-cases were introduced, the
32-bit length was found to be constraining and hence extended
administrative groups (EAG) were introduced in [RFC7308].
The EAG TLV (Section 2) is not a replacement for the Administrative
Group (color) TLV; as explained in [RFC7308] both values can coexist.
It is out of scope for this document to specify the behavior of the
BGP-LS consumer [RFC7752].
This document specifies an extension to BGP-LS for advertisement of
the extended administrative groups.
1.1. 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.
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2. Advertising Extended Administrative Group in BGP-LS
This document defines an extension that enables BGP-LS speakers to
signal the EAG of links in a network to a BGP-LS consumer of network
topology such as a centralized controller. The centralized
controller can leverage this information in traffic engineering
computations and other use-cases. When a BGP-LS speaker is
originating the topology learnt via link-state routing protocols like
OSPF or IS-IS, the EAG information of the links is sourced from the
underlying extensions as defined in [RFC7308].
The EAG of a link is encoded in a new Link Attribute TLV [RFC7752]
using the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extended Administrative Group (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Extended Administrative Group TLV Format
Where:
o Type: 1173
o Length: variable length which represents the total length of the
value field in octets. The length value MUST be a multiple of 4.
If the length is not a multiple of 4, the TLV MUST be considered
malformed.
o Value: one or more sets of 32-bit bitmasks that indicate the
administrative groups (colors) that are enabled on the link when
those specific bits are set.
3. IANA Considerations
This document requests assigning a code-point from the registry "BGP-
LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute
TLVs" based on table below. Early allocation for these code-points
have been done by IANA.
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+------------+-------------------------------+-------------------+
| Code Point | Description | IS-IS TLV/Sub-TLV |
+------------+-------------------------------+-------------------+
| 1173 | Extended Administrative Group | 22/14 |
+------------+-------------------------------+-------------------+
4. Security Considerations
The procedures and protocol extensions defined in this document do
not affect the BGP security model. See the "Security Considerations"
section of [RFC4271] for a discussion of BGP security. Also, refer
to [RFC4272] and [RFC6952] for analyses of security issues for BGP.
Security considerations for acquiring and distributing BGP-LS
information are discussed in [RFC7752]. The TLV introduced in this
document is used to propagate the EAG extensions defined in
[RFC7308]. It is assumed that the IGP instances originating this TLV
will support all the required security (as described in [RFC7308]) in
order to prevent any security issues when propagating the TLVs into
BGP-LS. The advertisement of the link attribute information defined
in this document presents no significant additional risk beyond that
associated with the existing link attribute information already
supported in [RFC7752].
5. Acknowledgments
The authors would like to thank Eric Osborne, Les Ginsberg, Tim
Chown, Ben Niven-Jenkins and Alvaro Retana for their reviews and
valuable comments.
6. References
6.1. Normative References
[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>.
[RFC7308] Osborne, E., "Extended Administrative Groups in MPLS
Traffic Engineering (MPLS-TE)", RFC 7308,
DOI 10.17487/RFC7308, July 2014,
<https://www.rfc-editor.org/info/rfc7308>.
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[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
S. Ray, "North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP", RFC 7752,
DOI 10.17487/RFC7752, March 2016,
<https://www.rfc-editor.org/info/rfc7752>.
[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>.
6.2. Informative References
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, DOI 10.17487/RFC1195,
December 1990, <https://www.rfc-editor.org/info/rfc1195>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<https://www.rfc-editor.org/info/rfc4271>.
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006,
<https://www.rfc-editor.org/info/rfc4272>.
[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>.
[RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of
BGP, LDP, PCEP, and MSDP Issues According to the Keying
and Authentication for Routing Protocols (KARP) Design
Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
<https://www.rfc-editor.org/info/rfc6952>.
Authors' Addresses
Jeff Tantsura
Juniper Networks
Email: jefftant.ietf@gmail.com
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Zitao Wang
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: wangzitao@huawei.com
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: bill.wu@huawei.com
Ketan Talaulikar
Cisco Systems
Email: ketant@cisco.com
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