IGP Flexible Algorithm
draft-ietf-lsr-flex-algo-05
Network Working Group P. Psenak, Ed.
Internet-Draft Cisco Systems
Intended status: Standards Track S. Hegde
Expires: May 7, 2020 Juniper Networks, Inc.
C. Filsfils
K. Talaulikar
Cisco Systems, Inc.
A. Gulko
Thomson Reuters
November 4, 2019
IGP Flexible Algorithm
draft-ietf-lsr-flex-algo-05.txt
Abstract
IGP protocols traditionally compute best paths over the network based
on the IGP metric assigned to the links. Many network deployments
use RSVP-TE based or Segment Routing based Traffic Engineering to
enforce traffic over a path that is computed using different metrics
or constraints than the shortest IGP path. This document proposes a
solution that allows IGPs themselves to compute constraint based
paths over the network. This document also specifies a way of using
Segment Routing (SR) Prefix-SIDs and SRv6 locators to steer packets
along the constraint-based paths.
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 May 7, 2020.
Psenak, et al. Expires May 7, 2020 [Page 1]
Internet-Draft IGP Flexible Algorithm November 2019
Copyright Notice
Copyright (c) 2019 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 . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements notation . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Flexible Algorithm . . . . . . . . . . . . . . . . . . . . . 5
5. Flexible Algorithm Definition Advertisement . . . . . . . . . 5
5.1. ISIS Flexible Algorithm Definition Sub-TLV . . . . . . . 6
5.2. OSPF Flexible Algorithm Definition TLV . . . . . . . . . 7
5.3. Common Handling of Flexible Algorithm Definition TLV . . 8
6. Sub-TLVs of ISIS FAD Sub-TLV . . . . . . . . . . . . . . . . 9
6.1. ISIS Flexible Algorithm Exclude Admin Group Sub-TLV . . . 9
6.2. ISIS Flexible Algorithm Include-Any Admin Group Sub-TLV . 10
6.3. ISIS Flexible Algorithm Include-All Admin Group Sub-TLV . 11
6.4. ISIS Flexible Algorithm Definition Flags Sub-TLV . . . . 11
7. Sub-TLVs of OSPF FAD TLV . . . . . . . . . . . . . . . . . . 12
7.1. OSPF Flexible Algorithm Exclude Admin Group Sub-TLV . . . 12
7.2. OSPF Flexible Algorithm Include-Any Admin Group Sub-TLV . 13
7.3. OSPF Flexible Algorithm Include-All Admin Group Sub-TLV . 13
7.4. OSPF Flexible Algorithm Definition Flags Sub-TLV . . . . 13
8. ISIS Flex-Algorithm Prefix Metric Sub-TLV . . . . . . . . . . 14
9. OSPF Flex-Algorithm Prefix Metric Sub-TLV . . . . . . . . . . 15
10. Advertisement of Node Participation in a Flex-Algorithm . . . 16
10.1. Advertisement of Node Participation for Segment Routing 17
10.2. Advertisement of Node Participation for Other
Applications . . . . . . . . . . . . . . . . . . . . . . 17
11. Advertisement of Link Attributes for Flex-Algorithm . . . . . 17
12. Calculation of Flexible Algorithm Paths . . . . . . . . . . . 18
12.1. Multi-area and Multi-domain Considerations . . . . . . . 19
13. Flex-Algorithm and Forwarding Plane . . . . . . . . . . . . . 20
Show full document text