L R. chen
Internet-Draft Sh. Peng
Intended status: Standards Track ZTE Corporation
Expires: March 14, 2022 P. Psenak
Cisco Systems
September 10, 2021
Updates to Algorithm Related Adjacency SID Advertisement in RF9085
draft-chen-idr-bgp-ls-algo-related-adjacency-sid-00
Abstract
This draft updates [RFC9085] to defines extensions to the Border
Gateway Protocol-Link State (BGP-LS) address family in order to carry
algorithm Related Adjacency SID.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on March 14, 2022.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
3. BGP-LS Extensions for link Attribute . . . . . . . . . . . . 2
3.1. Adjacency SID per Algorithm TLV . . . . . . . . . . . . . 3
3.2. LAN Adjacency SID per Algorithm TLV . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
6. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
[I-D.ietf-lsr-algorithm-related-adjacency-sid] defines the algorithm
identifier can be included as part of an Adjacency-SID advertisement
for SR-MPLS.
[RFC9085]defines extensions to the Border Gateway Protocol-Link State
(BGP-LS) address family in order to carry SR information via BGP, and
an algorithm identifier is included as part of the Prefix-SID TLV
advertisement. This draft updates [RFC9085] and defines extensions
to the Border Gateway Protocol-Link State (BGP-LS) address family in
order to carry algorithm Related Adjacency SID.
2. 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.
3. BGP-LS Extensions for link Attribute
The following link attribute TLVs are defined:
+======+===========================================+
| Type | Description |
+======+===========================================+
| TBD1 | Adjacency SID per Algorithm |
+------+-------------------------------------------+
| TBD2 | LAN Adjacency SID per Algorithm |
+------+-------------------------------------------+
Figure 1: Link Attribute TLVs
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3.1. Adjacency SID per Algorithm TLV
The Adjacency SID per Algorithm TLV is used in order to advertise
information related to an algorithm Related Adjacency SID. This
information is derived from the Adjacency Segment Identifier (Adj-
SID) per Algorithm Sub-TLV of ISIS/OSPFv2/OSPFv3(Section 4 of
[I-D.ietf-lsr-algorithm-related-adjacency-sid]).
The Adjacency SID per Algorithm TLV has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Weight | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) //
+---------------------------------------------------------------+
Figure 2: Adjacency SID per Algorithm TLV
where:
Type: TBD1 (Suggested value to be assigned by IANA)
Length: variable.
Flags: 1-octet value that should be set as:
o IS-IS Adj-SID per Algorithm flags as defined in Section 4.1.1 of
[I-D.ietf-lsr-algorithm-related-adjacency-sid]).
o OSPFv2 Adj-SID per Algorithm Sub-TLV as defined in Section 4.2.1
of [I-D.ietf-lsr-algorithm-related-adjacency-sid]).
o OSPFv3 Adj-SID per Algorithm Sub-TLV as defined in Section 4.3.1
of [I-D.ietf-lsr-algorithm-related-adjacency-sid]).
Weight: 1 octet carrying the weight used for load-balancing purposes.
The use of weight is described in Section 3.4 of [RFC8402].
Algorithm: Refer to ISIS/OSPFv2/OSPFv3 Adj-SID per
Algorithm([I-D.ietf-lsr-algorithm-related-adjacency-sid]).
Reserved: 1-octet that MUST be set to 0 and ignored on receipt.
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SID/Label/Index:Refer to ISIS/OSPFv2/OSPFv3 Adj-SID per
Algorithm([I-D.ietf-lsr-algorithm-related-adjacency-sid]).
3.2. LAN Adjacency SID per Algorithm TLV
This information is derived from LAN-Adj-SID per Algorithm Sub-TLV of
ISIS/OSPFv2/OSPFv3(Section 4 of
[I-D.ietf-lsr-algorithm-related-adjacency-sid]).
The LAN Adjacency SID per Algorithm TLV has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Weight | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OSPF Neighbor ID / IS-IS System ID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID/Label/Index (variable) //
+---------------------------------------------------------------+
Figure 3:LAN Adjacency SID per Algorithm TLV
where:
Type: TBD2 (Suggested value to be assigned by IANA)
Length: variable.
Flags: 1-octet value that should be set as:
o IS-IS LAN-Adj-SID per Algorithm flags as defined in Section 4.1.2
of [I-D.ietf-lsr-algorithm-related-adjacency-sid]).
o OSPFv2 LAN-Adj-SID per Algorithm Sub-TLV as defined in
Section 4.2.2 of [I-D.ietf-lsr-algorithm-related-adjacency-sid]).
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o OSPFv3 LAN-Adj-SID per Algorithm Sub-TLV as defined in
Section 4.3.2 of [I-D.ietf-lsr-algorithm-related-adjacency-sid]).
Weight: 1 octet carrying the weight used for load-balancing purposes.
The use of weight is described in Section 3.4 of [RFC8402].
Algorithm: Refer to ISIS/OSPFv2/OSPFv3 LAN-Adj-SID per
Algorithm([I-D.ietf-lsr-algorithm-related-adjacency-sid]).
Reserved: 1-octet that MUST be set to 0 and ignored on receipt.
Neighbor ID/IS-IS System ID: Refer to ISIS/OSPFv2/OSPFv3 LAN-Adj-SID
per Algorithm([I-D.ietf-lsr-algorithm-related-adjacency-sid]).
SID/Label/Index:Refer to ISIS/OSPFv2/OSPFv3 LAN-Adj-SID per
Algorithm([I-D.ietf-lsr-algorithm-related-adjacency-sid]).
4. IANA Considerations
This document makes the following Link Attribute TLVs registry under
the "Border Gateway Protocol-Link State (BGP-LS) Parameter".
+======+===========================================+
| Type | Description |
+======+===========================================+
| TBD1 | Adjacency SID per Algorithm |
+------+-------------------------------------------+
| TBD2 | LAN Adjacency SID per Algorithm |
+------+-------------------------------------------+
Table 1: The new Link Attribute TLVs
5. Acknowledgements
TBD
6. Normative References
[I-D.ietf-lsr-algorithm-related-adjacency-sid]
Peng, S., Chen, R., Talaulikar, K., and P. Psenak,
"Algorithm Related IGP-Adjacency SID Advertisement",
draft-ietf-lsr-algorithm-related-adjacency-sid-00 (work in
progress), June 2021.
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[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>.
[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>.
[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>.
[RFC9085] Previdi, S., Talaulikar, K., Ed., Filsfils, C., Gredler,
H., and M. Chen, "Border Gateway Protocol - Link State
(BGP-LS) Extensions for Segment Routing", RFC 9085,
DOI 10.17487/RFC9085, August 2021,
<https://www.rfc-editor.org/info/rfc9085>.
Authors' Addresses
Ran Chen
ZTE Corporation
No.50 Software Avenue,Yuhuatai District
Nanjing, Jiangsu Province 210012
China
Email: chen.ran@zte.com.cn
Shaofu
ZTE Corporation
No.50 Software Avenue,Yuhuatai District
Nanjing, Jiangsu Province 210012
China
Email: peng.shaofu@zte.com.cn
Peter Psenak
Cisco Systems
Email: ppsenak@cisco.com
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