Internet-Draft draft-ietf-rift-kv-registry-05 March 2023
Head & Przygienda Expires 14 September 2023 [Page]
Workgroup:
RIFT
Internet-Draft:
draft-ietf-rift-kv-registry-05
Published:
Intended Status:
Standards Track
Expires:
Authors:
J. Head, Ed.
Juniper Networks
T. Przygienda
Juniper Networks

RIFT Key/Value Structure and Registry

Abstract

The RIFT (Routing in Fat-Trees) protocol allows for key/value pairs to be advertised within Key-Value Topology Information Elements (KV-TIEs). The data contained within these KV-TIEs can be used for any imaginable purpose. This document defines the various Key-Types (i.e. Well-Known, OUI, and Experimental) and a method to structure corresponding values.

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 asdescribed 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/.

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 14 September 2023.

Table of Contents

1. Introduction

The Routing in Fat-Trees RIFT [RIFT] protocol allows for key/value pairs to be advertised within Key-Value Topology Information Elements (KV-TIEs). There are no restrictions placed on the type of data that is contained in KV-TIEs nor what the data is used for.

For example, it might be beneficial to advertise overlay protocol state from leaf nodes to the Top-of-Fabric (ToF) nodes. This would make it possible to view critical state of a fabric-wide service from a single ToF node rather than retrieving and reconciling the same state from multiple leaf nodes.

2. Key Structure

This section describes the generic Key structure and semantics, Figure 1 further illustrates these components.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Key-Type    |                Key Identifier                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Values (variable)                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 1: Generic Key-Value Structure

where:

2.1. Experimental Key-Type

This section reserves a value in the RIFT Key-Type Registry to indicate an Experimental Key-Type.

As shown in Figure 2, the Key-Type will be used to identify the Key-Type as Experimental. The Key Identifier will be used to identify the specific key and describe the structure of the contained values.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       1       |          Experimental Key Identifier          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                 Experimental Values (variable)                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 2: Experimental Key-Type

2.2. Well-Known Key-Type

This section reserves a value in the RIFT Key-Type Registry to indicate Well-Known Key-Types that all implementations SHOULD support.

As shown in Figure 3, the Key-Type will be used to identify the Key-Type as Well-Known. The Key Identifier will be used to identify the specific key and describe the structure of the contained values.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       2       |        Well-Known Key Identifier              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                 Well-Known Values (variable)                  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 3: Well-Known Key-Type

2.3. OUI Key-Type

This section reserves a value in the RIFT Key-Type Registry to indicate an OUI (vendor-specific) Key-Type that any implementation MAY support.

As shown in Figure 4, the Key-Type will be used to identify the Key-Type as OUI. The Key Identifier MUST use the implementing organization's reserved OUI space to indicate the key and value structure.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       3       |              OUI Key Identifier               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|               Vendor Specific Values (variable)               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 4: OUI Key-Type

3. Design Considerations

While no restrictions are placed on Key-Value data or what it is used for, it is RECOMMENDED that a serialized Thrift [THRIFT] model be used for simpler interoperability. [RIFT-AUTO-EVPN] is an example of this type of implementation.

Key-Value elements SHOULD NOT be used to carry topology information used by RIFT itself to perform distributed computations.

3.1. Tie-Breaking Considerations

In cases where KV-TIEs are flooded from north to south, policies SHOULD be implemented in order to avoid network-wide flooding.

For networks with more than one ToF node, it is RECOMMENDED that those ToF nodes contain identical KV-TIE information when being distributed from north to south. RIFT [RIFT] requires that only one KV-TIE is selected when identical keys are received from multiple northbound neighbors. If this is not considered then the tie-breaking rules may cause a node to select a suboptimal KV-TIE. Consider a case where failure conditions cause the ToF nodes to become split-brained. While the Key-Type and Key Identifier will be identical, the value(s) contained within may differ. The node(s) receiving these differing KV-TIEs will select the one from the ToF node with the highest System ID, potentially leading to unintended effects.

3.1.1. Southbound Key-Value TIE Tie-Breaking Key/Value Pair

This Key/Value pair contains information that allows for verification of proper tie-breaking for the Southbound Key store.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Well-Known  |         Southbound Tie-Break (Global)          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     (System ID,                                               |
|      Level),                                                  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Southbound Tie-Break (Global) Key/Value Pair

where:

  • System ID:
    A REQUIRED value indicating the node's unique System ID.
    Level:
    A RECOMMENDED value indicating the node's level.

4. IANA Considerations

Per [RFC8126], IANA is requested to create two new registries under the top-level "RIFT" category:

The following sections detail each registry's individual requirements and suggested values.

Experts reviewing requests for new values to either registry MUST consider the items in the Expert Review Guidance (Section 4.3) section.

4.1. RIFT Key-Types

This section requests that IANA create and help govern the following registry:

  • Registry Name:
    RIFT Key-Types
    Registration Procedures:
    Expert Review
    Description:
    Key-Type registry for the RIFT protocol.
    Reference:
    This document.

4.1.1. RIFT Key-Types Requested Entries

This section requests that IANA register the following suggested values to the "RIFT Key-Types" registry.

Table 1
Value Key-Type Description Status/Reference
0 Illegal Not allowed. This document
1 Experimental Indicates that the Key-Type is Experimental. This document.
2 Well-Known Indicates that the Key-Type is Well-Known. This document.
3 OUI Indicates that the Key-Type is OUI (vendor specific). This document.

4.2. RIFT Well-Known Key-Types

This section requests that IANA create and help govern the following registry:

  • Registry Name:
    RIFT Well-Known Key-Types
    Registration Procedures:
    Expert Review
    Description:
    Well-Known Key-Types registry for the RIFT protocol.
    Reference:
    This document.

4.2.1. RIFT Well-Known Key-Types Requested Entries

This section requests that IANA register the following suggested values to the "RIFT Well-Known Key-Types" Registry.

Table 2
Value Key-Identifier Description Status/Reference
0 Illegal Not allowed. This document.
1 MAC/IP Binding To be defined. To be defined.
2 FAM Security Roll-Over Key To be defined. To be defined.
127 Southbound Tie-Break Key Used for Southbound Keystore tie-breaking purposes. This document.

4.3. Expert Review Guidance

Experts reviewing requests for values from the "RIFT Key-Types" registry or the "RIFT Well-Known Key-Types" registry are responsible for the following:

  1. Determining the existence of a specification that clearly defines the purpose supporting the request and MUST contain all required fields for given registry.

    The document MUST also be permenent and publically available.

  2. Ensuring that any requests are made available to the RIFT working group for review should the work originate from outside of the RIFT Working Group.

  3. Ensuring that any work produce outside of the IETF does not conflict with any work that is already published or actively pursuing being published.

5. Security Considerations

This document introduces no new security concerns to RIFT or other specifications referenced in this document given that the Key-Value TIEs are already extensively secured by the RIFT [RIFT] protocol specification itself.

6. Acknowledgements

To be provided.

7. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC8126]
Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", , <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[RIFT]
Przygienda, T., Sharma, A., Thubert, P., Rijsman, B., and D. Afanasiev, "RIFT: Routing in Fat Trees", Work in Progress draft-ietf-rift-rift-15, , <https://www.ietf.org/archive/id/draft-ietf-rift-rift-15.pdf>.

8. Informative References

[RIFT-AUTO-EVPN]
Head, J., Przygienda, T., and W. Lin, "RIFT Auto-EVPN", Work in Progress, draft-ietf-rift-auto-evpn-03, , <https://www.ietf.org/archive/id/draft-ietf-rift-auto-evpn-03.html>.
[THRIFT]
Apache Software Foundation, "Thrift Language Implementation and Documentation", <https://github.com/apache/thrift/tree/0.15.0/doc>.

Appendix A. Thrift Models

This section contains the normative Thrift models required to support Auto-EVPN. Per the main RIFT [RIFT] specification, all signed values MUST be interpreted as unsigned values.

A.1. southbound_kv.thrift

include "common.thrift"

namespace py southbound_kv
namespace rs models

const i8            GlobalSystemIdentifierKV  = 127

/** simple type to test correct tie-breaking based on system ID */
struct SystemIdentifierKV {
    1:  required   common.SystemIDType         system_id,
    2:  optional   common.LevelType            level,
}

Figure 6: RIFT Common Schema for Auto-EVPN

Authors' Addresses

Jordan Head (editor)
Juniper Networks
1137 Innovation Way
Sunnyvale, CA
United States of America
Tony Przygienda
Juniper Networks
1137 Innovation Way
Sunnyvale, CA
United States of America