IS-IS Multi Topology Deployment Considerations
draft-chunduri-lsr-isis-mt-deployment-cons-04
LSR Working Group U. Chunduri
Internet-Draft Futurewei USA
Intended status: Informational J. Tantsura
Expires: May 28, 2021 Apstra, Inc.
S. Hegde
Juniper Networks
November 24, 2020
IS-IS Multi Topology Deployment Considerations
draft-chunduri-lsr-isis-mt-deployment-cons-04
Abstract
This document analyzes IS-IS Multi Topology (MT) applicability in
various IS-IS deployments. This document explores the nuances around
the terminology and usage of various IS-IS address families,
topologies with different considerations, for choosing the right
combination for a specific deployment scenario.
This document also discusses various ways one can deploy IPv6 only
IS-IS topology.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 28, 2021.
Chunduri, et al. Expires May 28, 2021 [Page 1]
Internet-DraftIS-IS Multi Topology Deployment ConsiderationNovember 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Need for MT in IS-IS networks . . . . . . . . . . . . . . . . 3
3. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Topologies and Address Families . . . . . . . . . . . . . . . 4
4.1. Single Topology Mode and Multiple Address Families . . . 4
4.2. Multiple Topology Mode and Multiple Address Families . . 5
4.2.1. Transition Mode . . . . . . . . . . . . . . . . . . . 6
4.3. IPv6 Only Topology . . . . . . . . . . . . . . . . . . . 6
5. IS-IS MT and LFA . . . . . . . . . . . . . . . . . . . . . . 7
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. Security Considerations . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Normative References . . . . . . . . . . . . . . . . . . 7
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
IS-IS originally developed for OSI [ISO.10589.1992] and extensions
have been made available to support IPv4 [RFC1195]. A method for
exchanging IPv6 routing information using the IS-IS routing protocol
is specified in [RFC5308]. How to run a set of independent IP
topologies with topology specific adjacencies, within a single IS-IS
domain has been defined in IS-IS MT [RFC5120].
There are number of networks, including mobile backhaul networks
seeking to use IPv6 only solutions. It is possible to conceive,
various parts of the backhaul networks use IPv4 and appropriate
migration strategy needed before eventually moving towards IPv6 only
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