SRIFT: Segment Routing in Fat Trees
draft-zzhang-rift-sr-03
RIFT Z. Zhang
Internet-Draft J. Tantsura
Intended status: Standards Track J. Head
Expires: 26 August 2021 Juniper Networks
D. Fedyk
Individual
22 February 2021
SRIFT: Segment Routing in Fat Trees
draft-zzhang-rift-sr-03
Abstract
This document specifies signaling procedures for Segment Routing in
RIFT. Each node's loopback address, Segment Routing Global Block
(SRGB) and Node Segment Identifier (Node-SID), which are typically
assigned by a configuration management system and distibuted by
routing protocols, are distributed southbound from the Top Of Fabric
(TOF) nodes via RIFT's Key-Value distribution mechanism, so that each
node can compute how to reach a segment represented by the active SID
in a packet. An SR controller signals SR policies to ingress nodes
so that they can send packets with a desired segment list to steer
traffic.
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.
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 26 August 2021.
Zhang, et al. Expires 26 August 2021 [Page 1]
Internet-Draft SRIFT February 2021
Copyright Notice
Copyright (c) 2021 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
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. SR in RIFT (SRIFT) . . . . . . . . . . . . . . . . . . . . . 4
3. Well-Known KV Registry Values . . . . . . . . . . . . . . . . 6
3.1. SRIFT Node Key-Type . . . . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Before we discuss the SR procedures for RIFT, let us first review how
SR works with OSPF [RFC8665] and IS-IS [RFC8667].
Each node is provisioned with a loopback address as well as SRGB and
Node-SID values. The loopback address and Node-SID are centrally
coordinated and are unique per-node within the SR network. These
values are then communicated to each node out-of-band and stored as
configuration information. Communication could be done via primitive
pen and paper or via modern signaling (Netconf/YANG) from a
configuration management system.
Zhang, et al. Expires 26 August 2021 [Page 2]
Internet-Draft SRIFT February 2021
SRGB information represents the label range of the "global" labels
that can be allocated on a particular node for SR. SRGB could have
more than one contiguous range of labeks allocated to it. It is
comprised of the first available label value and the total number of
available labels per range. While in modern networks it is common
for each node to have identical SRGB values so that a Node-SID will
Show full document text