Alternatives for Multilevel TRILL (Transparent Interconnection of Lots of Links)
draft-ietf-trill-rbridge-multilevel-06

Document Type Active Internet-Draft (trill WG)
Last updated 2017-06-20 (latest revision 2017-06-16)
Replaces draft-perlman-trill-rbridge-multilevel
Stream IETF
Intended RFC status Informational
Formats plain text pdf html bibtex
Reviews
Stream WG state WG Consensus: Waiting for Write-Up
Document shepherd Susan Hares
Shepherd write-up Show (last changed 2016-08-28)
IESG IESG state In Last Call (ends 2017-06-28)
Consensus Boilerplate Yes
Telechat date On agenda of 2017-07-06 IESG telechat
Responsible AD Alia Atlas
Send notices to (None)
IANA IANA review state IANA OK - No Actions Needed
IANA action state None
TRILL Working Group                                        Radia Perlman
INTERNET-DRAFT                                                       EMC
Intended status: Informational                           Donald Eastlake
                                                            Mingui Zhang
                                                                  Huawei
                                                          Anoop Ghanwani
                                                                    Dell
                                                            Hongjun Zhai
                                                                     JIT
Expires: December 15, 2017                                 June 16, 2017

                   Alternatives for Multilevel TRILL
             (Transparent Interconnection of Lots of Links)
              <draft-ietf-trill-rbridge-multilevel-06.txt>

Abstract

   Although TRILL is based on IS-IS, which supports multilevel unicast
   routing, extending TRILL to multiple levels has challenges that are
   not addressed by the already-existing capabilities of IS-IS.  One
   issue is with the handling of multi-destination packet distribution
   trees. Other issues are with TRILL switch nicknames. How are such
   nicknames allocated across a multilevel TRILL network? Do nicknames
   need to be unique across an entire multilevel TRILL network or can
   they merely be unique within each multilevel area?

   This informational document enumerates and examines alternatives
   based on a number of factors including backward compatibility,
   simplicity, and scalability and makes recommendations in some cases.

Status of This Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.  Distribution of this document is
   unlimited.  Comments should be sent to the TRILL working group
   mailing list <trill@ietf.org>.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

R. Perlman, et al                                               [Page 1]
INTERNET-DRAFT                                          Multilevel TRILL

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
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R. Perlman, et al                                               [Page 2]
INTERNET-DRAFT                                          Multilevel TRILL

Table of Contents

      1. Introduction............................................4
      1.1 The Motivation for Multilevel..........................4
      1.2 Improvements Due to Multilevel.........................5
      1.2.1. The Routing Computation Load........................5
      1.2.2. LSDB Volatility Creating Too Much Control Traffic...5
      1.2.3. LSDB Volatility Causing To Much Time Unconverged....5
      1.2.4. The Size Of The LSDB................................6
      1.2.5 Nickname Limit.......................................6
      1.2.6 Multi-Destination Traffic............................7
      1.3 Unique and Aggregated Nicknames........................7
      1.4 More on Areas..........................................8
      1.5 Terminology and Acronyms...............................8

      2. Multilevel TRILL Issues................................10
      2.1 Non-zero Area Addresses...............................11
      2.2 Aggregated versus Unique Nicknames....................11
      2.2.1 More Details on Unique Nicknames....................12
      2.2.2 More Details on Aggregated Nicknames................13
      2.2.2.1 Border Learning Aggregated Nicknames..............14
      2.2.2.2 Swap Nickname Field Aggregated Nicknames..........16
      2.2.2.3 Comparison........................................17
      2.3 Building Multi-Area Trees.............................17
      2.4 The RPF Check for Trees...............................18
      2.5 Area Nickname Acquisition.............................18
      2.6 Link State Representation of Areas....................19

      3. Area Partition.........................................20

      4. Multi-Destination Scope................................21
      4.1 Unicast to Multi-destination Conversions..............21
      4.1.1 New Tree Encoding...................................22
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