| Internet-Draft | BGP-LS Extensions for IS-IS FR | July 2022 |
| Head & Przygienda | Expires 6 January 2023 | [Page] |
This document defines new BGP-LS (BGP Link-State) TLVs in order to carry IS-IS Flood Reflection information.¶
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BGP Link-State RFC7752 [RFC7752] defines mechanisms to advertise information about the underlying IGP in BGP NLRI to an external entity (e.g. a controller). New BGP-LS TLVs are required in order to faciliate IS-IS Flood Reflection [IS-IS-FR] extensions.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].¶
Controllers may need to compute traffic engineered paths across Flood Reflection clusters. This requires that they be aware of Flood Reflection specific details, such as Cluster ID, C-bit (which indicates Flood Reflector or Flood Reflector Client), or any sub-TLVs.¶
This document defines the following BGP-LS TLV code point value in accordance with RFC7752 rules:¶
| TLV Code Point | Description | IS-IS TLV |
|---|---|---|
| TBD1 | Flood Reflection TLV | TBD1 (161) [IS-IS-FR] |
TLV formats are described in detail in subsequent subsections.¶
This TLV advertises Flood Reflection details. The semantics of any fields within the TLV/sub-TLVs is described in [IS-IS-FR].¶
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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |C| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flood Reflection Cluster ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-TLVs ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+¶
where:¶
This section requests the following (suggested) values from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" registry for the following TLVs:¶
| TLV Code Point | Description | IS-IS TLV/Sub-TLV | Reference |
|---|---|---|---|
| TBD1 (161) | IS-IS Flood Reflection | 161 | This document. |
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 BGP security issues. Security considerations for acquiring and distributing BGP-LS information are discussed in [RFC7752].¶
The TLVs introduced in this document are used to propagate IS-IS Flood Reflection TLVs defined in [IS-IS-FR]. These TLVs represent IS-IS Flood Reflection state and are therefore assumed to support any/all of the required security and authentication mechanisms as described in [IS-IS-FR] to prevent any security issues when propagating the TLVs into BGP-LS.¶