Preferred Path Routing (PPR) in IS-IS
draft-chunduri-lsr-isis-preferred-path-routing-06
LSR Working Group U. Chunduri
Internet-Draft R. Li
Intended status: Standards Track Futurewei
Expires: April 1, 2021 R. White
Juniper Networks
J. Tantsura
Apstra Inc.
L. Contreras
Telefonica
Y. Qu
Futurewei
September 28, 2020
Preferred Path Routing (PPR) in IS-IS
draft-chunduri-lsr-isis-preferred-path-routing-06
Abstract
This document specifies Preferred Path Routing (PPR), an extensible
method of providing path based dynamic routing for a number of packet
types including IPv4, IPv6 and MPLS. PPR uses a simple encapsulation
to add the path identity to the packet. PPR can also be used to
mitigate the MTU and data plane processing issues that may result
from Segment Routing (SR) packet overhead; and also supports further
extensions along the paths.
Requirements Language
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 RFC2119 [RFC2119],
RFC8174 [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
Chunduri, et al. Expires April 1, 2021 [Page 1]
Internet-Draft Preferred Path Routing (PPR) in IS-IS September 2020
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 April 1, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Preferred Path Routing (PPR) . . . . . . . . . . . . . . . . 4
2.1. PPR-ID and Data Plane Extensibility . . . . . . . . . . . 4
2.2. PPR Path Description . . . . . . . . . . . . . . . . . . 4
2.3. ECMP Considerations . . . . . . . . . . . . . . . . . . . 5
2.4. Scalability and PPR Graphs . . . . . . . . . . . . . . . 5
3. PPR Related TLVs . . . . . . . . . . . . . . . . . . . . . . 5
3.1. PPR-Prefix Sub-TLV . . . . . . . . . . . . . . . . . . . 8
3.2. PPR-ID Sub-TLV . . . . . . . . . . . . . . . . . . . . . 8
3.3. PPR-PDE Sub-TLV . . . . . . . . . . . . . . . . . . . . . 10
3.4. PPR-Attributes Sub-TLV . . . . . . . . . . . . . . . . . 13
4. PPR Processing Procedure Example . . . . . . . . . . . . . . 13
4.1. PPR TLV Processing . . . . . . . . . . . . . . . . . . . 15
4.2. Path Fragments . . . . . . . . . . . . . . . . . . . . . 16
5. PPR Data Plane aspects . . . . . . . . . . . . . . . . . . . 16
5.1. SR-MPLS with PPR . . . . . . . . . . . . . . . . . . . . 16
5.2. PPR Native IP Data Planes . . . . . . . . . . . . . . . . 17
5.3. SRv6 with PPR . . . . . . . . . . . . . . . . . . . . . . 17
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
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