Internet-Draft MNA Entropy August 2024
Li & Drake Expires 1 March 2025 [Page]
Workgroup:
MPLS Working Group
Internet-Draft:
draft-li-mpls-mna-entropy-03
Published:
Intended Status:
Informational
Expires:
Authors:
T. Li
Juniper Networks
J. Drake

MPLS Network Action for Entropy

Abstract

Load balancing is a powerful tool for engineering traffic across a network and has been successfully used in MPLS as described in RFC 6790, "The Use of Entropy Labels in MPLS Forwarding". With the emergence of MPLS Network Actions (MNA), there is signficant benefit in being able to invoke the same load balancing capabilities within the more general MNA infrastructure.

This document describes a network action for entropy to be used in conjunction with "MPLS Network Action (MNA) Sub-Stack Solution".

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 1 March 2025.

Table of Contents

1. Introduction

Load balancing is a powerful tool for engineering traffic across a network. The use of entropy labels within MPLS was first described in [RFC6790] and [RFC6391] and has been deployed succesfully in multiple MPLS networks.

With the emergence of MPLS Network Actions [I-D.ietf-mpls-mna-requirements] [I-D.ietf-mpls-mna-fwk] [I-D.ietf-mpls-mna-hdr], there is a benefit to being able to describe entropy as a network action. Without this, a packet that required load balancing and network actions would need to deal with the overhead of having both MNA and an Entropy Label in the label stack. By defining an action for Entropy within the MNA infrastructure, overhead and complexity can be reduced. It is RECOMMENDED that MNA and the Entropy Label not be used in the same packet, but if they are, the Entropy Label and Entropy Value do not need to be the same as consistency for the flow suffices.

Given that [RFC6790] is widely deployed, it is expected that that will continue to be a common mechanism for encoding an Entropy Label. This document adds an alternative encoding that may be more efficient if other MNA actions are in use. The two encodings can co-exist in the same network.

1.1. Requirement 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. These words may also appear in this document in lower case as plain English words, absent their normative meanings.

2. The Entropy Action

This section describes the details of how the Entropy Action is encoded, per Section 5 of [I-D.ietf-mpls-mna-fwk].

3. Security Considerations

The forwarding plane is insecure. If an adversary can affect the forwarding plane, then they can inject data, remove data, corrupt data, or modify data. MNA additionally allows an adversary to make packets perform arbitrary network actions.

Link-level security mechanisms can help mitigate some on-link attacks, but does nothing to preclude hostile nodes.

4. IANA Considerations

This document requests that IANA allocate a codepoint (TBA1) from the "Multiprotocol Label Switching Architecture (MPLS)"/"MPLS Network Actions Parameters"/"Network Action Opcodes Registry" registry for the Entropy Action. The allocation should reference this document.

5. References

5.1. Normative References

[I-D.ietf-mpls-mna-fwk]
Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS Network Actions (MNA) Framework", Work in Progress, Internet-Draft, draft-ietf-mpls-mna-fwk-10, , <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-mna-fwk-10>.
[I-D.ietf-mpls-mna-hdr]
Rajamanickam, J., Gandhi, R., Zigler, R., Song, H., and K. Kompella, "MPLS Network Action (MNA) Sub-Stack Solution", Work in Progress, Internet-Draft, draft-ietf-mpls-mna-hdr-07, , <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-mna-hdr-07>.
[I-D.ietf-mpls-mna-requirements]
Bocci, M., Bryant, S., and J. Drake, "Requirements for Solutions that Support MPLS Network Actions (MNA)", Work in Progress, Internet-Draft, draft-ietf-mpls-mna-requirements-16, , <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-mna-requirements-16>.
[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>.
[RFC3032]
Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, DOI 10.17487/RFC3032, , <https://www.rfc-editor.org/info/rfc3032>.
[RFC6790]
Kompella, K., Drake, J., Amante, S., Henderickx, W., and L. Yong, "The Use of Entropy Labels in MPLS Forwarding", RFC 6790, DOI 10.17487/RFC6790, , <https://www.rfc-editor.org/info/rfc6790>.
[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>.

5.2. Informative References

[RFC6391]
Bryant, S., Ed., Filsfils, C., Drafz, U., Kompella, V., Regan, J., and S. Amante, "Flow-Aware Transport of Pseudowires over an MPLS Packet Switched Network", RFC 6391, DOI 10.17487/RFC6391, , <https://www.rfc-editor.org/info/rfc6391>.
[RFC8012]
Akiya, N., Swallow, G., Pignataro, C., Malis, A., and S. Aldrin, "Label Switched Path (LSP) and Pseudowire (PW) Ping/Trace over MPLS Networks Using Entropy Labels (ELs)", RFC 8012, DOI 10.17487/RFC8012, , <https://www.rfc-editor.org/info/rfc8012>.
[RFC8662]
Kini, S., Kompella, K., Sivabalan, S., Litkowski, S., Shakir, R., and J. Tantsura, "Entropy Label for Source Packet Routing in Networking (SPRING) Tunnels", RFC 8662, DOI 10.17487/RFC8662, , <https://www.rfc-editor.org/info/rfc8662>.

Authors' Addresses

Tony Li
Juniper Networks
John Drake